hybridfree/eevblog-posts huggingface dataset:
TP4056 lithium charger module - modification to add load sharing - Page 1
Forum section: electronics / projects

author: Peabody
author_rank: Super Contributor
timestamp: June 30, 2022, 10:51:24 pm
content: I posted about this on the Arduino forum, and wanted to post it here for hobbyists to use if needed. This is a modification of the standard TP4056 charger module - the one with battery protection built in - to add the three components that make up a load sharing circuit - a logic level P-channel mosfet, a schottky diode, and a resistor. The OUT+ and B+ terminals of the module are shorted together, but if we cut that trace, and reverse the functions of those terminals, we can add the three parts directly to the module. The module and the schematic showing the modification are shown in the pictures below.In addition to the three parts, you will also need a little adapter board for mounting the SOT-23 package of the mosfet so it can be connected into the circuit. These are called "SOT-23 to DIP" adapters, or possibly "SOT-23 to SIP". Or if you still have any NDP6020P mosfets in a TO-220 package, you won't need the adapter. Unfortunately, the NDP6020P has been discontinued, and I don't know of another suitable logic level P-channel mosfet in a through-hole package.The terminal holes on the board are not big enough to hold the multiple wires connected to them, but the pads are pretty big, and you can solder to the pads on the bottom of the board.Keep in mind the following:1. The charging current is set at 1A by default. Your battery has to be able to tolerate that, or you can change the 1.2K R3 resistor to a higher value as set forth in the datasheet.2. Your mains 5V supply must be able to deliver both the 1A charging current plus the load current at the same time.3. This circuit does not work with solar panels. It depends on the mains voltage being either 5V or 0V, but not in between.4. Downstream of this circuit you will need a regulator of some kind - either a 3.3V LDO or buck converter, or a 5V boost converter. You should also have a manual on/off switch before the regulator so you can prevent the regulator from wasting power when the device is not in use, but still be able to charge the battery if needed when the device is switched off.5. If your battery is already protected, you can avoid double protection by bridging the B- and OUT- terminals, and removing R5 (or cutting its trace). The module comes in a version with no protection built in, but it may be physically more difficult to do the modification on that version since it only has B+ and B- output terminals.6. No, the mosfet orientation is not incorrect. The drain goes to the battery, and the source to the load. That's so the body diode will block high voltage from coming back into the battery.It is still a mystery to me why the module makers of the Far East don't offer a TP4056 module with load sharing built in.
TP4056 + switch mode power supply = bad? - Page 1
Forum section: electronics / projects

author: okw
author_rank: Frequent Contributor
timestamp: December 03, 2021, 06:14:55 pm
content: My kitchen scale (which I love) eats 9V batteries, so I wanted to upgrade it to be rechargeable. I added one of those flat 3.7V li-ion and a TP4055 charger module (https://www.aliexpress.com/item/33039542964.html). Set the boost to 9V (no time to reverse engineer and hook directly into some 3v/5v rail). Everything works good, battery life is awesome. Charging via USB works good (almost hits the spec of 1A). However, when I connected a 6V switch mode PS (http://www.vanson.com.hk/product/smp-27wme/) via the IN+/IN-, I immediately heard crackling sounds, it smelled burned and TP4056 became extremely hot. I disconnected immediately. It's impossible to touch still, after 45 min. Scale powers up, so the boost part of the circuit is undamaged. The power supply shows 6V and has 1.5mV ripple under no load.Strange thing is, the power supply of a a commercial scale at work went missing, so we bought this particular PS as a replacement. The guy replacing it being a chef (=less technical inclined), was unaware of polarity and just hooked it up. That fried a few components on the PCB pretty badly. I'm not sure if he had it hooked up as + or - center pin. At the time, I just assumed he had it hooked up reversed (since it fried the PCB). I replaced all visibly damaged components and tried it again. It exhibited exactly the same behaviour as my private kitchen scale (though scales and circuits are completely different). At this point, I'm suspecting the power supply is the common culprit.Could it have something to do with both the power supply and TP4056 being switch mode, and can go into oscillation?

author: magic
author_rank: Super Contributor
timestamp: December 03, 2021, 07:10:38 pm
content: Any USB charger is switch mode too and TP4056 actually is not.It's a simple linear regulator and one potential problem with running it from 6V is that it dissipates over 2W with 1A current.There is supposed to be some sort of overtemperature protection in it, but something could be wrong with that.

author: okw
author_rank: Frequent Contributor
timestamp: December 03, 2021, 07:21:58 pm
content: Oh, of courseDissipation...From the TP4056 datasheet it seems I can replace a resistor to lower the charge current (I have no use for 1A). Along with using a 5V supply, that would take care of it. I didn't have USB panel sockets so I need to use a regular plug charger (I mounted a 5.5x2.1mm socket under it).Thanks! I'll try it and see if it helps.
TP5400 vs TP5410 LiPo power bank chip - Page 1
Forum section: electronics / projects

author: thinkfat
author_rank: Unknown
timestamp: March 06, 2019, 08:42:45 pm
content: Hi,I'm currently developing a battery shield for a small micro controller board. I found the TP5410 used in many of the LiPo charger/booster boards you can get via ebay and it seems like a good solution. But as this chip is currently unavailable (I try sourcing from LCSC) I looked for an alternative and found the TP5400, which seems to be a functionally identical IC at first glance, save a few differences in external components.Is anyone around here familiar enough with these ICs to explain what the difference is between the two? The datasheet is in Mandarin of course and even with valiant help of Google translate it's difficult to tell what discerns these two.The TP5400 seems to be an older, potentially obsolete chip, though from looking at the internal structure according to the data sheet there isn't any fundamental difference with the TP5410.TIAMatthias

author: thinkfat
author_rank: Unknown
timestamp: March 18, 2019, 10:29:10 am
content: So, I ended up using the TP5400 after a supply query for the TP5410 with LCSC was turned down and the chip marked as "not available". It seems like all the application notes from the TP5410 data sheet apply to the TP5400 as well and you can simply use the TP5400 as a replacement, if you adjust the external components slightly.Anyway, I'm happy with the result and the battery shield is working fine.BR,Matthias
TPA3112 Class D Amplifier Chip - Low Output - Page 1
Forum section: electronics / projects

author: David_AVD
author_rank: Super Contributor
timestamp: April 19, 2016, 04:28:15 am
content: Has anyone used the TPA3112 class D amplifier chips in a design ?I've designed one into a board, but can only get < 5W out of it despite it being spec'd as 25W into 8 Ohms @ 24V.If I drive the input harder you can hear it distorting with no apparent increase in output level.

author: Zero999
author_rank: Super Contributor
timestamp: April 19, 2016, 10:03:51 am
content: Schematic, circuit layout?

author: peter.mitchell
author_rank: Super Contributor
timestamp: April 19, 2016, 10:29:01 am
content: whats your gain set to?also, if you're using ferrite beads for the output, make sure they have a low DCR, some can have quite high DCR.correct size bootstrap caps?correct pvcc decoupling?is plimit set or grounded?

author: David_AVD
author_rank: Super Contributor
timestamp: April 19, 2016, 10:43:03 am
content: Schematic is per the typical application in the datasheet using same values.I am using ferrite beads - from memory they are also per the datasheet.The plimit pin is pulled to Gvcc (correct name?) via 100K I think, again as per the app note (unless I misunderstood how it works).All decoupling caps are there (1n + 100n + 100u per "side"), gain pins are grounded.

author: moffy
author_rank: Super Contributor
timestamp: April 20, 2016, 12:14:25 am
content: "If I drive the input harder you can hear it distorting with no apparent increase in output level."That sounds like you don't have enough gain selected for the TPA3112 and are therefore overdriving the input.

author: David_AVD
author_rank: Super Contributor
timestamp: April 20, 2016, 01:06:44 am
content: Yeah, I had that thought nagging at me earlier today, but haven't had a chance to lift those pins to change the gain.Thanks for the reply. I'll let you know what I find.

author: David_AVD
author_rank: Super Contributor
timestamp: April 26, 2016, 02:49:40 am
content: Problem solved. Turned out to be a combination of assumptions and measurement errors.Chip works as advertised.
TPA3255 PCB Layout Advice - Page 1
Forum section: electronics / projects

author: kgray9
author_rank: Newbie
timestamp: February 13, 2022, 03:57:48 pm
content: Hi all!I am designing a 1200W@4Ω audio amplifier based on 2x TPA3255. I have completed the schematic and PCB, but am looking for advice on my layout and so on, before I order all the parts and PCBs. I have kind of been doing thislooking for help, and have now posted on 4 () forums!Any advice would begreatlyappreciated.Attached are the PCB layout, schematic and 3D.

author: NiHaoMike
author_rank: Super Contributor
timestamp: February 13, 2022, 09:53:38 pm
content: Forget about using single transistor stages for the preamp, they're not going to perform as well as good opamps. To get the best performance, you'll want a fully differential signal path, probably the easiest is to use differential output DACs with built in PGAs.When there are multiple TPA3255 on the same supply, use the oscillator synchronization to prevent unwanted interactions between them.

author: kgray9
author_rank: Newbie
timestamp: February 14, 2022, 12:56:53 am
content: Thanks @NiHaoMike !Sorry, I'm kind of new to audio, so I have some questions.What is a "PGA"?If I use a DAC, doesn't that mean the input audio signal would need to be digital? I would rather it analog.What is a good op-amp for a pre-amplifier?What is a "fully differential signal path"?

author: NiHaoMike
author_rank: Super Contributor
timestamp: February 14, 2022, 01:40:26 am
content: Quote from: kgray9 on February 14, 2022, 12:56:53 amProgrammable Gain Amplifier, basically a solid state volume control. Some DACs have that built in, but it can also be obtained as a standalone part such as the PGA4311.QuoteIt would be digital, but it really takes a good signal path to bring out what the TPA3255 can do. You can look at differential input connectors as an alternative. In that case, you'll want a "fully differential amplifier" for compatibility with single ended sources as well as better CMRR.Try OPA1612 for high end audio opamps. That's if you need them, that is - the PGA or DAC might do all the preamp functionality you need.QuoteThe signal stays differential all the way from the source (DAC if digital, pickup for a turntable or other analog) to the speakers, helping to maintain a high SNR.

author: kgray9
author_rank: Newbie
timestamp: February 15, 2022, 11:23:00 pm
content: Thanks @NiHaoMike!I am using the TDA7418 which has this in the data sheet:"• Loudness– Second order frequency response– Programmable center frequency(400 Hz / 800 Hz / 2400 Hz)– 15dB with 1dB steps– Selectable low and high frequency boost– Selectable flat-mode (constant attenuation)• Volume– +15dB to -79dB with 1dB step resolution– Soft-step control with programmable blend times"Is that good enough? Or would I also need a preamp? That audio op-amp is awesome!I've also heard that the PCB layout has a lot to do with audio quality. Do you have any suggestions for my layout? Is the layout in the photo attached, better (for single TPA3225)?Ignore the arrows and circles on the photo.Thanks!
TPD12S016PW HDMI ESD & RPi Compute Module - Page 1
Forum section: electronics / projects

author: SgtSiff
author_rank: Contributor
timestamp: February 05, 2019, 08:52:58 pm
content: Is anybody able to give feedback on the following schematic please?I'm trying to design an open source CM3 prototyping board that has hand solder friendly components, so I'm hoping to replace the BGA ESD5384 with a TSSOP TPD12S016:I have pulled LS_OE and CT_HPD high via 10K resistors, I believe this should disable any power saving and ensure the i2c lines are pulled up appropriately.As far as I can tell, HDMI_HPD on the CM3 is active low, so I have used a mosfet inverter for this (in line with the original schematic).My main concern is the CEC line, I'm not sure what to do with it and I'm not sure what the function of Q3 is in the original schematic:Datasheet for the aforementioned ESD IC:http://www.ti.com/lit/ds/symlink/tpd12s016.pdfhttp://www.ti.com/lit/an/slla324/slla324.pdfThanks!
TPL5100 Timer on INT - Page 1
Forum section: electronics / projects

author: ripper121
author_rank: Contributor
timestamp: May 04, 2016, 01:30:27 pm
content: Hello,i want to use the TPL5100 as 512 Second Timer (so every 512 Seconds the timer should wakeup my µC).I want to connect only the MOS_DRV to my µC INT Pin, if the INT pin goes LOW my µC will Wakeup, do the Work and sleep again until the next Interrupt.But if the INT pin is LOW the µC cant go sleep, so the INT Pin should go HIGH again after a short periode.I have only this pin left, so i don't send a DONE to the TPL5100.Connections:D2=HIGHD1=HIGHD0=LOWPGOOD=HIGHTCAL= Not ConnectedDONE= Not ConnectedMOS_DRV = Connected to INT on my µCIs this possible? (i haven't found it in the Datasheet maybe you find it)http://www.ti.com/lit/ds/symlink/tpl5100.pdf

author: ripper121
author_rank: Contributor
timestamp: May 13, 2016, 06:51:20 am
content: This works for me, a 1024 Second Timer.If the time has expired the TPL5100 sets the Mos_Drv for 50ms to LOW that enough for my µC to Interrupt and wakeup.The TPL5100 needs only 30nA (2.5V) so very low energy devices are possible
TPL5110 power timer - Page 1
Forum section: electronics / projects

author: LukeW
author_rank: Frequent Contributor
timestamp: August 28, 2018, 10:17:47 am
content: OK, tell me if I'm going crazy here or reading the datasheet wrong.When power is applied, the output rail does not start up.(I would like it to start up initially with no button press, after a short delay for TPL5110 calibration.)When the button is pressed, the output rail does start up, and then waits a minute (as expected) and turns off (and it never turns back on). No "done" signal is asserted from the downstream MCU at this time. It's not coded at all at the moment.I would expect the TPL5110 to wait a certain time and fail to receive a done signal, and then reset - so it would go to sleep again for a while, then wake up again and turn the output rail on. But it never turns back on, and it does not turn on initially without a button press.When the done signal is asserted (high) from the MCU, I would expect the output to turn off immediately (the drive output from the TPL5110 goes high, so the high-side P-Ch turns off) and then we wait for the sleep period, and then the load turns back on.A brief short from Vdd (3.3V) to pin 4 on the TPL5110 when the load is turned on should have made the load turn off but it didn't, so that's weird.Any thoughts? See pic attached.

author: SiliconWizard
author_rank: Super Contributor
timestamp: August 29, 2018, 02:46:56 pm
content: I've taken a quick look at the DS so I may be missing something, but doesn't it behave as though it were in "one shot mode"?As the EN pin is connected to the power supply, it shouldn't be in this mode, but since it seems to be (again as far as I've gotten it, may be mistaken), I'd suggest checking the soldering of this pin.
[Solved] TPM-200A-CO Carbon Monoxide sensor module datasheet? - Page 1
Forum section: electronics / projects

author: davorin
author_rank: Unknown
timestamp: March 29, 2023, 09:18:46 am
content: Good morning (o;Just received a CO Zigbee sensor in the hope it would work with ConBee II, but of course it doesn't (o;Has anyone came across a datasheet for this TPM-200A-CO carbon monoxide sensor module?All I see is the same HEX pattern coming out from a pin @ 9600 bits/sec, which is:2C 00 00 03 E8 17thanks in advancerichard

author: davorin
author_rank: Unknown
timestamp: March 29, 2023, 09:55:41 am
content: Seems according to an Aliexpress product I've found it is quite simple...Code:B1: 0x2CB2: PPM-HighbyteB3: PPM-LowbyteB4: 0x03B5: 0xE8B6: uint_8(B1 + B2 + B3 + B4 + B5)Which gives the simple checksum 0x17 for the sequence 0x2C 0x00 0x00 0x03 0xE8.Wondering now how I could simulate carbon monoxide without burning down the house, as it always returns 0 ppm (o;
TPS2113A vs TPS2115A - Page 1
Forum section: electronics / projects

author: petersanch
author_rank: Regular Contributor
timestamp: October 13, 2020, 03:51:31 am
content: Anybody know what's the difference between TSP2113A and TPS2115A? The comparison on the TI website and the datasheets look like pretty much identical. Is one recommended over the other?Cheers

author: NiHaoMike
author_rank: Super Contributor
timestamp: October 13, 2020, 03:57:44 am
content: You have to open the datasheets and carefully compare them to find the difference. It's probably something small like the polarity of a control line or one of the detailed specifications.

author: petersanch
author_rank: Regular Contributor
timestamp: October 13, 2020, 04:05:02 am
content: With taking a closer look. The TPS2113A has VSNS pin "An internal power FET connects OUT to IN1 if the VSNS voltage is greater than 0.8 V". TPS2115A has a different mode for that pin.Maybe that helps someone in the future
TPS2116 replacement, Powermux jellybean? - Page 1
Forum section: electronics / projects

author: Hawaka
author_rank: Regular Contributor
timestamp: April 07, 2022, 05:29:58 pm
content: Hi,I was planning to use the TPS2116 in one of my project, but due to extreme lead time I want to replace it. My circuit is powered by an AC adapter or, if not present, by a battery. Power rail is +5V/2A max.I looked around and I could find some replacements, but nothing that comes close to the price of the TPS2116 or as simple. Also leadtime is often a problem.Is there an industry standard powermux around? Easily available would be my prio 1, then price.
tps26633 Turn ON - Page 1
Forum section: electronics / projects

author: rakeshm55
author_rank: Regular Contributor
timestamp: August 22, 2019, 04:17:34 pm
content: Hi,I am planning to use TPS2663x efuse in one of my circuit. (28V ) input supply.Device can be kept in shutdown position by pulling down SHDN pin of efuse.I would like to hold the pin in shut down mode using a push button controller like LTC2955.Is there any circuit that i can trigger using EN pin of LTC2955?? By default LTC2955 + "circuit"" will hold eFuse in SHDN mode.On pressing push button SHDN is left floating so that efuse turns ONIs there any jelly bean depletion type FET that can be triggered by Vgs 1.3V max??
TPS40210/11 Boost Driver circuit not working whatsoever. - Page 1
Forum section: electronics / projects

author: SittingBear
author_rank: Contributor
timestamp: August 27, 2014, 02:10:13 pm
content: Hello EEVBlog community,I’ve been attempting to prototype the boost driver with no luck so far. My initial build was on a breadboard, but then after that didn’t work I went over to etching a PCB. I have tested each connection and ensured proper continuity as shown in the schematic. My schematic is a replica of the one found on page 34 of the TPS40210/11 datasheet. I changed a few minor values to fit the closest common commercial value.The schematic can be foundhere. Page 34 of the TPS40210/11 datasheet ishere.The issue I get is that nothing seems to happen at all and the GDRV voltage, when probed with an oscilloscope, remains fixed at VCC. Which is odd, because measuring resistance returns OL or ‘open-circuit’. I believe it’s either an issue with the MOSFETs I chose, or with my handling in the driver (i.e. ESD damage).

author: mux
author_rank: Regular Contributor
timestamp: August 27, 2014, 02:22:34 pm
content: Are you trying to make a constant voltage or a constant current supply? Because the schematic on page 34 of the datasheet is specifically for a constant current supply. Without sufficient load on the output, it will not function and stay off.What is your input and output voltage?

author: SittingBear
author_rank: Contributor
timestamp: August 27, 2014, 03:14:18 pm
content: Quote from: mux on August 27, 2014, 02:22:34 pm12V in and roughly 23-24 volts out for the LEDs. It's constant current to ensure each LED is at the same brightness.I believe I found the mistake. I must have done something, because C8 and R5 decide the switching frequency. C8 was supposed to be 100pF, but it is 10uF which is way too large. After de-soldering and reattaching the proper capacitor the circuit seems to work decently! Now to fine tune it.
TPS40211 feedback resistor - can someone tell explain this to me? - Page 1
Forum section: electronics / projects

author: shadewind
author_rank: Frequent Contributor
timestamp: July 06, 2011, 10:18:10 am
content: I've already asked this in another thread but it was sort of off topic so I'm giving it its own thread.I want to build a HB LED driver using the Texas Instruments TPS40211:http://focus.ti.com/lit/ds/symlink/tps40211.pdfIf you look at page 34, Figure 36, there is an application circuit for this. R6 is the current sense resistor and C5, C6 and R4 is the compensation network. R23 is for loop injection when fiddling with the optimal compensation. But what is R13? I'm assuming it has something to do with the compensation but how can I determine its value and what exactly is the function of it? I would be very grateful for answers on this one.

author: Mechatrommer
author_rank: Super Contributor
timestamp: July 06, 2011, 11:14:15 am
content: Quote from: shadewind on July 06, 2011, 10:18:10 amthe value is 30.1K Ohm in page 35. i'm "assuming" the function is to separate high voltage/current from feedback/compensation network. and also r6 and r23 (and probably including the r13) will form current/voltage sense/divider, not r6 alone.

author: shadewind
author_rank: Frequent Contributor
timestamp: July 06, 2011, 11:52:38 am
content: Quote from: Mechatrommer on July 06, 2011, 11:14:15 amYes, that is the value for this particular design. But the fact that it's 30.1k 1% and not 33k 5% suggests that it's value isn't really chosen to be just "really big". Also, it's not a divider. R6 is a current shunt resistor for sensing the current through the LED string. If we removed the compensation network I don't see any reason why it would be included since the input impedance of the inverting EA input is large that 30.1k is nothing in comparison.

author: qno
author_rank: Frequent Contributor
timestamp: July 06, 2011, 09:35:03 pm
content: Looks to me like a current measurement resistor.10 ohm will give you 10 mV for every mA.

author: shadewind
author_rank: Frequent Contributor
timestamp: July 06, 2011, 10:41:03 pm
content: That's not the resistor I mean. I mean the 30.1k, 1% resistor. It doesn't seem to be needed when using a voltage divider for voltage feedback.

author: Mechatrommer
author_rank: Super Contributor
timestamp: July 07, 2011, 04:10:25 am
content: did you consider my assumption as voltage separator? ie to avoid voltage in sensing/respond side to affect voltage in the feedback side?and have you tried removing it and see how the circuit behave?

author: shadewind
author_rank: Frequent Contributor
timestamp: July 07, 2011, 01:07:57 pm
content: After a bit of research, it seems to me that R13 is simply part of Rin as in an inverting amplifier op-amp configuration and the compensation network would be Rf. Thus, the total amount of gain would be Zf/R13 (if we ignore R23).
TPS4H160-Q1 (Version A) Smart High Side Switch - Fail - Page 1
Forum section: electronics / projects

author: jwhitmore
author_rank: Regular Contributor
timestamp: July 11, 2017, 06:40:37 pm
content: I want to turn on a few loads in a 12V vehicle. I was thinking of using a P Channel FET somebody on the forum mentioned Smart High Side Switches. I had a look and yes they roll a few features which make them wroth a look. So for no intelligent reason I had a look at the Texas TPS4H160-Q1 (Version A). I just picked it out of the blue and ordered up a simple test PCB. So I've had a chance to play with it and in spite of the promises of the Data Sheet it's a fail. Without a good load to hand I just grabbed a 50W headlight bulb, which I had handy. I decided that it wasn't an extreme load but it would be just over 4Amps.So the long and the sort is that the device could only switch just over 2Amps to the bulb. The data sheets states that the current limit is 8Amps. (Unless you use the external current limiting circuit. I've connected that to ground so only using the internal 8Amp current limiting circuits.) Perhaps the device is overheating, but if so it's almost instantaneous. Now that is a Surface Mount package so perhaps I should have a look for a package to which I can put a heat shrink.

author: Benta
author_rank: Super Contributor
timestamp: July 11, 2017, 06:58:11 pm
content: You're reading the datasheet like the devil reads the bible. "Recommended operating conditions" say 2.5 A max. The 8 A you quote are only for device self survival.The 'fail' is not on the device side.

author: Niklas
author_rank: Frequent Contributor
timestamp: July 11, 2017, 11:57:40 pm
content: Light bulbs can draw huge amounts (>30A) of inrush current before they warm up. A common trick for the first generation of high side switches, to not trip the overcurrent protection, was to preheat the bulb with a low duty cycle pwm.
TPS54232 buck regulator - Page 1
Forum section: electronics / projects

author: LukeW
author_rank: Frequent Contributor
timestamp: August 03, 2016, 12:53:07 pm
content: Your basic, typical regulator stage with Vo=5V, Io=2A max, Vi=24V. Vo is actually set slightly high on purpose, at about 5.25V.I was just looking for a quick bit of peer review on this, a sanity check to ensure that nothing silly is missing.

author: Kean
author_rank: Unknown
timestamp: August 03, 2016, 02:15:47 pm
content: Looks basically fine to me.You might want to increase R22/R23 values and decrease the ratio though. Those values are lower than typically recommended (waste of 2mA?), and with that ratio you'll be enabling the regulator from something like 9V which seems low if you're expecting a stable 24V supply.

author: tszaboo
author_rank: Super Contributor
timestamp: August 03, 2016, 02:42:51 pm
content: Fuse or two, ESD protection, reverse input protection (everyone loves the popcorn capacitors). Any of these might be unnecessary. I would put some extra lower value ceramics on the output (100n), just for good measure. You can never have enough capacitors.

author: Niklas
author_rank: Frequent Contributor
timestamp: August 03, 2016, 03:18:29 pm
content: LC-filter between +24V and the two input capacitors to attenuate conducted emissions. Could be possible to reuse footprints for L2 and C19.As NANDBlog mentioned, add some input protection. You don't need much wiring, just a couple of inches, to create turn on transients that will exceed 30 V as stated in absolute maximum ratings. We have a board that is supplied with 28V, with 2x100nF at the input, that peaks at about 50V with a linear PSU and 2x20cm 0.25mm^2 wires.http://cds.linear.com/docs/en/application-note/an88f.pdf
TPS54302 prevent powering the circuit from regulator's output - Page 1
Forum section: electronics / projects

author: evansg
author_rank: Contributor
timestamp: September 05, 2020, 10:44:57 am
content: I use the TPS54302 a synchronous step down converter in a couple of my circuits and I'm wondering how I can prevent the following scenario:If you accidentally provide voltage to the output (lets say 12V), the circuit is powered (with these 12V) as the voltage runs through the coil and the regulator.The regulator is not damaged until the current reaches its maximum (in this case 3Amps). After that regulator dies with the "magic smoke".Is there any way or an easy circuitry to prevent a user to accidentally power the circuit from the regulator output? I use the same DC sockets (2.1mm) for input and outputand unfortunately this cannot change easily.

author: sdouble
author_rank: Frequent Contributor
timestamp: September 06, 2020, 04:50:17 am
content: I usually solve this kind of issues in putting 2 little stickers above or below the barrel connector : one writes "input" and the other one "output"

author: magic
author_rank: Super Contributor
timestamp: September 06, 2020, 06:42:16 am
content: You mean, somebody connects power to the output and load to the input and a parasitic diode in the regulator blows it up?Bypass the regulator with a reverse Schottky diode, but user's load will then see 11.7V instead of 8V.Add a diode in series with the input and screw efficiency.Figure out some "ideal diode" protection circuit which will work even in absence of 12V power.Input and output connectors shouldn't be same sex even if they are same size.

author: evansg
author_rank: Contributor
timestamp: September 06, 2020, 03:30:11 pm
content: Not exactly.User accidentally plugs the 12V DC jack to this regulator's output and whole circuit works bypassing the main DC input. I need to find a way to stop this.

author: Peabody
author_rank: Super Contributor
timestamp: September 06, 2020, 04:34:34 pm
content: Are you saying your 8V circuit actually tolerates being powered at 12V? I should get you to design my circuits.

author: Someone
author_rank: Super Contributor
timestamp: September 07, 2020, 05:46:36 am
content: Quote from: evansg on September 06, 2020, 03:30:11 pmThis has been solved in other systems with a "crowbar" circuit, but to provide sufficient protection while still working as a power output can get large/expensive/complex.

author: Hiemal
author_rank: Regular Contributor
timestamp: September 07, 2020, 01:24:40 pm
content: Would something like this work?http://tinyurl.com/yxt5wbzhsimulator version
TPS54360 synchronization - Page 1
Forum section: electronics / projects

author: void_error
author_rank: Frequent Contributor
timestamp: August 25, 2016, 09:02:15 pm
content: This chip was chosen for one of my projects mostly because of availability and space constraints and it's going to be synchronized to an external clock provided by the microcontroller it's going to power which means that it has to start up without a sync signal present.Thedatasheetgives two examples for external sync so there's two ways it can be done.Since I'm going to have two regulators based on this IC on the same board and I want to have both of them sync'd I thought it might be a good idea to provide one of them with an inverted signal, because, well, is that better for the bulk filter cap after the rectifier?In case I stick to out of phase sync signals how should I approach this? Use 3-state buffers?

author: void_error
author_rank: Frequent Contributor
timestamp: August 26, 2016, 10:02:51 am
content: Forget about this, even though most of the circuit takes less space compared to the LTC3824 I wanted to use initially there still wouldn't be enough board space left for the sync circuitry.Swapped the TPS54360 out for a LT3680 which has a dedicated sync pin. Still sticking with the differential sync to the two regulators, got a +5V and a +12V rail.The challenge will still be to clock the sync pin only if there's a sync signal present.

author: prasimix
author_rank: Unknown
timestamp: August 26, 2016, 03:35:58 pm
content: If I understood you correctly you have two SMPS regulators. Do you want to sync them with external sync signal or just want to promote one of them to master and sync the other (slave) with inverted sync signal?

author: void_error
author_rank: Frequent Contributor
timestamp: August 27, 2016, 02:09:43 pm
content: I want to sync both to an external signal coming from a microcontroller on another board which is going to be powered by this board through a local regulator, also sync'd.One of the two LT3680s will receive an inverted sync signal.
TPS62740 Switching Converter - Efficiency graphs - Page 1
Forum section: electronics / projects

author: Nikos A.
author_rank: Regular Contributor
timestamp: January 30, 2020, 09:30:04 am
content: Hi everyone, I am looking the datasheet of the TPS62740 Switching Converter. On page 15, figures 9 - 13 show the efficiency vsoutput currentfor several Vin options. The graphs are for CTRL=GND meaning that the load is disabled (page 3 - Pin Functions table). Where does theoutput currentgo if the load is disabled? I suppose that the graphs should be generated with the load enabled instead disabled...http://www.ti.com/lit/ds/symlink/tps62740.pdfThanks in advance

author: Jay_Diddy_B
author_rank: Super Contributor
timestamp: January 30, 2020, 11:53:37 am
content: Quote from: Nikos A. on January 30, 2020, 09:30:04 amHi,There is a load switch inside the TPS62740 that is independent of the main output:So it is possible to measure the efficiency of the main output with the load switch off.In fact the load switch, when on, increases the quiescent current by 12.5uA. This will impact the light load efficiency.Regards,Jay_Diddy_B

author: Nikos A.
author_rank: Regular Contributor
timestamp: January 30, 2020, 01:16:42 pm
content: Thanks Jay_Diddy_B, now it's clear to me!!Nick
TPS63000 Buck/boost issue  - Page 1
Forum section: electronics / projects

author: angust_uk
author_rank: Regular Contributor
timestamp: June 11, 2020, 01:23:24 pm
content: Hi allI have an odd issue with a design using a TI TPS63000 buck/boost controller; it is set up to give an output voltage of 3.6V.When applying power (4.1V limited to 100mA in this case) with the enable pin low all is well, but when I enable the device with a 3.3V 'enable' signal the bench supply goes into CC mode as this part is trying to pull >100mA.I'm a bit stumped as I've used the fixed voltage variant of this part in the past with no problems, and in this example have isolated all circuitry that is powered by this device.The waveform is pretty ugly; the VBAT net is in yellow (i.e. the device's input, set to 4.1V and limited to 100mA from my bench supply), and the output is in blue. Note that for this test I tied the device's enable pin to the VINA and PS/SYNC pins as per the datasheet's example.Have I missed something obvious?!(By the way, the schematic shows the TPS63001, but the correct part (TPS63000) is indeed fitted)

author: FenTiger
author_rank: Regular Contributor
timestamp: June 11, 2020, 01:55:53 pm
content: Is it struggling to charge C51 and come out of soft start?What happens if you charge C51 and then turn it on?

author: angust_uk
author_rank: Regular Contributor
timestamp: June 11, 2020, 02:06:07 pm
content: Quote from: FenTiger on June 11, 2020, 01:55:53 pmI think you might be on to something! I just charged up C51 to around 3.5V then enabled power and it does indeed to start up correctly (although I am only seeing 3.3V on the 3.6V rail which is odd EDIT: no it's not. I'm an idiot and can't calculate my feedback resistor values correctly). Thanks!As there is no simple way of controlling the soft-start, how would you get around this issue? Ideally I'm trying to find at least a temporary solution so I don't have to respin the board!

author: angust_uk
author_rank: Regular Contributor
timestamp: June 11, 2020, 02:17:22 pm
content: FenTiger, I owe you a beer. Thanks! I swapped out the (probably overly large) output cap with 10uF just for testing, and I now get a nice stable supply. Phew!

author: FenTiger
author_rank: Regular Contributor
timestamp: June 11, 2020, 03:55:50 pm
content: I'd have suggested turning up your 100mA input current limit a bit, and then perhaps reducing it once the supply is up, if this is just for initial bringup testing. I'm guessing you'll have more than 100mA available in production.The data sheet says the soft start begins at 400mA output current, so perhaps 500mA input limit?
TPS65070: Powering up TPS65070 - Page 1
Forum section: electronics / projects

author: madhu.wesly01
author_rank: Regular Contributor
timestamp: July 24, 2018, 06:17:22 am
content: Hello,If anyone worked on this or knew this, pls. clarify how to start up the TPS65070 to achieve the following things:Note: I don`t use a possibility of turning TPS65070 on and off using a button.My application is such that should not require an ON-key but shall power-up automatically once supply voltage is applied.The device must do the following things:1. Turn ON from USB/AC when there are USB/AC supply and LiPo Battery charging.2. Turn ON from Li-Ion battery when there is no USB/AC supply.3. Should Work until battery will be discharged (VBAT < VUVLO) when there is no USB/AC supply.4. Should automatically turn ON the system(Load) when AC/USB again get plugged while charging the battery on one hand.How should be the PB_IN# and POWER_ON hardware and software configuration??Query:I want to use Case C in the TI document provided(http://www.ti.com/lit/an/slva512/slva512.pdf). But here in the Case C, it is not mentioned about the scenario where if there is battery also connected and getting charged as long as there is AC or USB which is providing supply to load, then soon after the AC or USB disconnected Will the battery come into the picture and provide supply to the Load without the need of pulling the PB_IN# to LOW?Could you please explain the Case C by considering that Battery is also connected to PMIC battery terminals??Thanks in advance.
TPS65130 regulator feedforward capacitor? - Page 1
Forum section: electronics / projects

author: hal9001
author_rank: Regular Contributor
timestamp: July 15, 2025, 08:04:46 am
content: How important are the feedforward capacitors for TPS65130?QuoteR1 and R3 are 1meg, c9=6.8pf, c10=7.5pf.Can I make both c9 and c106.8pfas I have them in my parts already? Why are they different?

author: Paradroid
author_rank: Contributor
timestamp: July 15, 2025, 09:34:29 am
content: The datasheet clearly says "recommendation" to speed up the control loop. If you have a stable, hardly changing load, you can probably skip on a parallel cap, but I'd expect that step response is greatly improved with a cap in the feedback loop. Since neither the component, nor board real estate are that much of an investment, I'd just design it in and make a decision about populating the component after measuring how it behaves in worst-case with and without the cap.

author: hal9001
author_rank: Regular Contributor
timestamp: July 17, 2025, 03:20:04 am
content: Quote from: Paradroid on July 15, 2025, 09:34:29 amCheers. Do you know why the positive and negative rails need different cap values if the regulator runs the same frequency for both? Do you think its safe to use 6.8pf for both?

author: Paradroid
author_rank: Contributor
timestamp: July 17, 2025, 06:38:26 am
content: TBH, I never designed with this part. My own LCD voltage conversion circuits are more discrete, but also way more cost efficient. You don't need much current, and for the gate voltages, a simple Z-Diode+cap regulator is sufficient. And you can cheat a bit if you're making a higher voltage for back light anyway; a double diode and cap for an almost-voltage-doubler plus yet another Zener for a low-current higher semi-regulated voltage, all for just a few cents. I don't understand why anyone would spend more than a dollar on the TPS65130.So no, I could only speculate about your question. However, TI has their own forum with a "power management" sub-forum, and TI engineers are active there:https://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum

author: PGPG
author_rank: Frequent Contributor
timestamp: July 17, 2025, 07:17:14 am
content: Quote from: hal9001 on July 17, 2025, 03:20:04 amWhy do you think they should be identical if they don't work in the same conditions.If you step-up from 5 to 15 you have at L 5V/10V, but if you change 5 into -15 you have at L 5V/15V. This means at least different duty factors what certainly have the influence on feedback loop characteristics.I have never used this part and didn't read the datasheet but.1. If you can use 0pF or 7.5pF than using 6.8pF seems being OK.2. Don't the values calculated are minimum values? Isn't it possible to short these resistors for AC by using even 100nF capacitors. You should be able find it from datasheet. If so you will be ably to use some other capacitor you already have.
TPS65987D - Anybody else using this chip? - Page 1
Forum section: electronics / projects

author: tron9000
author_rank: Frequent Contributor
timestamp: July 16, 2021, 11:54:37 am
content: Hi Guys and gals, Its been a while since I last posted.I have a problem involving theTPS65987Dand not sending data from any of its I2C ports upon a successful event.I've been followingTIs application notein order to set the current limit into aBQ257x3 Bi-directional Buck-Boost Charger.(x = 0, 1 or 2 they are all near as damn it identical)Now I have managed to find a configuration of the I2C ports where I am Using I2C2 as a slave from the host controller and use I2C1 as a master to the Charger. I have been able to configure the PD controller to send data from it to the charger upon POR event. I checked this by reading the registers of the battery charger using the battery management studio GUI that TI supplied, and they were mostly correct, some where set to 0 and some had reserved field that set themselves, but there was a level of confidence that the data was being sent.The problems start when I want to send I2C data to the charger upon triggered events. I set up a sink contract(5V, 3A) and trigger event and programmed the EEPROM for the PD controller. Reset the power on the device and the initialisation config is loaded to the charger as before but when I connect a source to my device, the PD controller acknowledges the contract successfully (which I confirmed from the PD controller GUI interface), but the data is not being sent to the charger.Now I've scoured the TI forums for a someone with the same problem that has a fix, and there are people with similar problems, but no fix. Someone MUST have a fix. even if its something stupid as not defining a parameter or setting a flag in the PD config tool.Has anyone else experienced this with this PD controller? Do they have a solution?On a tangent, what are peoples opinions of TI as a company now? I used to think they were good, but now am loosing confidence, not related to the above issue mind you, but their quality in support and documentation.
TPS7A4701 and TPS7A3301 +/- Linear Regulator Module - Page 1
Forum section: electronics / projects

author: drtaylor
author_rank: Regular Contributor
timestamp: February 19, 2025, 09:40:20 pm
content: Has anyone bought and used the dual regulator module from AliExpress supplier DykbRadio? It is a dual regulator capable of 1A if properly cooled. From what I have measured so far, the two regulators are isolated from each other, each having a GND and Input and GND and output pins. I want to turn this into a primitive variable regulator with two panel mounted pots. I suspect the PCB design is pretty much data sheet example for the two regulators, but to add an external pot that acts even partly linearly, I will need to trace the circuit out. There are two unplaced resistors R5 and R6 that probably adjust the output voltage, as well as a trimpot on both regulators. So before I begin the laborious task of reverse engineering the design, I was hoping someone already has. I have not been able to find any data sheet, schematic, or user instructions for this module, but of course I have the data sheets from TI for their typical application circuits.
TPS7A8300ARGR ANY-OUT operation output voltage setting issue - Page 1
Forum section: electronics / projects

author: madhu.wesly01
author_rank: Regular Contributor
timestamp: October 08, 2018, 05:42:42 am
content: Hi,I am using the following(find the web-link below) LDO in my application. The LDO allows two ways to set output voltage: 1. using External resistors and 2. ANY-OUT programming pins(6 pins). I have implemented ANY-OUT operation on my PCB, no external resistor divider circuit.ANY-OUT programming is set by equation: Vout = V(NR/SS) + (the accumulated sum of the respective voltages assigned to each active(connecting to GND) pin).By leaving all program pins open, floating, or Grounding, the output is thereby programmed to the minimum possible output voltage equal to V FB.The problem is: I am getting the minimum voltage only i.e the accumulated sum of the respective voltages assigned to each active(connecting to GND) pin. The V NR/SS which should be equivalent to 0.8V is not getting added to the final output voltage??? It is showing 0V at NR/SS pin.Please let me know if anyone have any pointers on this??http://www.ti.com/lit/ds/symlink/tps7a83a.pdf?HQS=TI-null-null-mousermode-df-pf-null-wwe&DCM=yes&ref_url=https%3A%2F%2Fwww.mouser.com%2FThanks & regards,Wesly.
TPS7A88: TPS7A88 PowerGood(PG) signal functionality - Page 1
Forum section: electronics / projects

author: madhu.wesly01
author_rank: Regular Contributor
timestamp: July 01, 2018, 05:43:51 pm
content: Hi,I am little doubtful on PG(Power Good pin) functionality lets say in the mentioned Linear Regulator(TPS7A88). Let me please get clarity on this:How will it be defined?? How will it decide if the output is good or bad??Will it be defined with constant output voltage when we fix(in Schematics) the output voltage we require?? Or the output is dynamic in relation with Input??Thanks in advance.

author: KrudyZ
author_rank: Frequent Contributor
timestamp: July 01, 2018, 05:52:37 pm
content: Did you try looking in the data sheet?Chapter 7.3.8 titled Power-Good Function would be a good place to start...
TPS92200 Led driver failed - Page 1
Forum section: electronics / projects

author: Muffins
author_rank: Regular Contributor
timestamp: August 16, 2024, 09:00:47 am
content: Hi guys,I'm busy making a circuit with some high power leds powered by a 20v drill battery. I'm using aTPS92200, I got a little PCB made up, attached power to it and it blew up with a decent sized jet of flame.I did apply power to it without connecting the leds so I thought that might have been a problem but in the datasheet it says it has 'no load' protection. Maybe I just need a second set of eyes on this, any ideas on why this failed? I've attached some images of the schematic and PCB layout.Also, it seems to have failed around the ground pin. Could this be an inrush current problem? Power was applied via a slide switch.Looking at the datasheet, it seems I didn't put a the feedback resistor in the circuit as I was following a diagram without one in it. But since there was no load connected it would have been pulled to ground.Update:I tried a second PCB since I had two assembled. This time I had the LEDs attached and it didn't explode but the leds didn't turn on either. Then I connected it to some leds and resistors on a breadboard and they came on but the dimmer did not do anything when the pot was turned. I'm guessing this is has something to do with the driver not being able to achieve it's set current value due to the high resistance. Then after turning it off and on a couple times the driver popped again. Considering using a completely different device now.

author: jmelson
author_rank: Super Contributor
timestamp: August 16, 2024, 03:10:10 pm
content: The oddity is this IC has a low-side transistor. I don't see the need for that in a buck LED driver. If the low-side transistor and high-side one ever turn on at the same time, then an explosion is guaranteed. I have used the LM3405 with good results.Jon

author: Muffins
author_rank: Regular Contributor
timestamp: August 16, 2024, 09:08:50 pm
content: Think I might want a bit more current then that. Looking at one of these right nowhttps://www.diodes.com/part/view/AL8843#tab-overviewAm I right in thinking that if the supply voltage is 20v, and that is within the output range of the IC, if 3 LEDs with forward voltage drops of 6v are connected on the output it should be fine? The total voltage drop of the LEDs just needs to be less than the maximum output voltage of the chip?