Chip of the day!!!......... - Page 1
Forum section: electronics / general

author: Smokey
author_rank: Super Contributor
timestamp: July 09, 2023, 09:04:16 am
content: Find an interesting/useful part?Think other people will also think it's interesting and/or useful?Post it here.Chip of the day!

author: Smokey
author_rank: Super Contributor
timestamp: July 09, 2023, 09:05:09 am
content: LM7705 Low-Noise Negative Bias Generatorhttps://www.ti.com/lit/ds/symlink/lm7705.pdf3V-5.25V Input-0.23V Out at about 20mAGood for those "RRIO" opamps if you actually need actual RRIOOnly $0.86 in 1s at Digikeyhttps://www.digikey.com/en/products/detail/texas-instruments/LM7705MMX-NOPB/2020262

author: Warhawk
author_rank: Frequent Contributor
timestamp: July 09, 2023, 10:07:49 am
content: I like OPA991 family (or the 992 upgrade). Quite a universal opamp.

author: Warhawk
author_rank: Frequent Contributor
timestamp: July 09, 2023, 10:09:21 am
content: Quote from: Smokey on July 09, 2023, 09:05:09 amI like this one LM27762

author: Smokey
author_rank: Super Contributor
timestamp: July 09, 2023, 09:10:02 pm
content: Quote from: Warhawk on July 09, 2023, 10:09:21 amNice. That must be a new part. it's not in webbench yet.One thing to watch out for is the positive output is just LDO down regulated from the input voltage, and the negative output is inverted from the input voltage and then LDO regulated. So you can't have +/-5V from a 3.3V input (even though it sort of looks that way from the banner specs).If you actually need +/-5V from something like 3.3V input, this would work:TPS65133https://www.digikey.com/en/products/detail/texas-instruments/TPS65133DPDR/https://www.ti.com/lit/ds/symlink/tps65133.pdfQTY UNIT PRICE1 $2.56

author: Benta
author_rank: Super Contributor
timestamp: July 09, 2023, 11:32:00 pm
content: I have several favourites, but the latest is the TI LM2660 (and LM2662). Not new, but to me they are.+/-5 V from a single USB +5 V input with just two caps.I love it!

author: floobydust
author_rank: Super Contributor
timestamp: July 10, 2023, 01:12:11 am
content: Quote from: Smokey on July 09, 2023, 09:05:09 amUm all that work for -0.23V? I am confused... The ICL7660 came out in 1980 and gave more, like -5V.

author: Smokey
author_rank: Super Contributor
timestamp: July 10, 2023, 07:48:32 am
content: Quote from: floobydust on July 10, 2023, 01:12:11 amThere is a good answer to this one. Say you are using a single supply opamp like the TL900x series:https://www.ti.com/lit/ds/symlink/tlv9002.pdfIt has a supply range up to 5.5V. If you are already running it from a +5V rail and all you need to actually output 0V, then you only have at most -0.5V that the negative rail can be. Since you only need about -20mV for the supposedly RRIO to be able to drive to 0V, the -0.23V of the LM7705 is more than enough to keep the opamp in the recommended operation range and drive 0V out.

author: tautech
author_rank: Super Contributor
timestamp: July 10, 2023, 08:38:40 am
content: Magic little SOT23-6 dual complementary MOSFETS....pick your poison.Typically pins 2 and 5 are Gate inputs which makes them a challenge to route but certainly not impossible, even with home etching.Used them for power device gate drivers for years and some will warn you about shoot through but never had this issue.I use them at logic levels as both a driver and level shifter for which they have been brilliant, even gate driving 200A IGBT's.Gate charge is typically very low so with care driving them from 4000 IC's is simple.Just one randomly selected:https://www.farnell.com/datasheets/2300062.pdfYMMV

author: Someone
author_rank: Super Contributor
timestamp: July 10, 2023, 08:47:52 am
content: Quote from: Warhawk on July 09, 2023, 10:07:49 amTI are iterating on "universal opamp" with others like OPAx828, or chopper OPAx189 lots of progress with analog capabilities still growing.

author: SiliconWizard
author_rank: Super Contributor
timestamp: July 10, 2023, 09:39:30 pm
content: Quote from: Smokey on July 10, 2023, 07:48:32 amYes, but it's not just about being enough for the job - it can achieve a significantly lower output ripple than the venerable ICL7660. Hence why it's marketed as "low noise".

author: nctnico
author_rank: Super Contributor
timestamp: July 10, 2023, 10:22:53 pm
content: Currently I'm quite pleasantly surprised by the abilities of the ESP32-S3 chip. Only downside I've seen so far is the crappy ADC but other than that the software ecosystem is nice, well documented and the chip is very capable.

author: VK3DRB
author_rank: Super Contributor
timestamp: July 13, 2023, 07:28:59 am
content: Quote from: nctnico on July 10, 2023, 10:22:53 pmYou are right, the ESP32's in general are great other than the ADC. Super low cost and unlike other MCU suppliers (Microchip, TI and STM), I could get ESP32-C3's during COVID - and that is the reason I used them in two projects, albeit at risk. Also used an ESP32-S3-WROOM. You can calibrate the ADC's but still they are mediocre at best. No good for accurate analogue measurements, but I did use it on one project for a non-critical battery fuel gauge (could not get fuel gauge chips during COVID) and it was OK.Espressif's BLE documentation is a dog's breakfast. Their hardware datasheets has ambiguity in them and is missing some detail that would be found in, say, TI and Analog Devices datasheets. The ecosystem is satisfactory but not great. Mind you I recently found a glaring pin-out error in Texas Instruments two year-old chip that no-one at TI had even picked up. The pinout list showed input pin for CAN bus data incorrectly described as a chip enable pinTI's documentation QA is in trouble if such an error can exist for two years before they know about it. Overall Espressif does a reasonable job with their English documentation, considering it is a Chinese company.No complaints though, because ESP32's got me out of a bind during COVID. Super low cost, which is good for high volume cost-sensitive projects. Plus I learnt to use a new MCU.

author: Warhawk
author_rank: Frequent Contributor
timestamp: July 13, 2023, 11:27:34 am
content: Quote from: VK3DRB on July 13, 2023, 07:28:59 amWhich TI chip? I get it fixed.

author: Simon
author_rank: Unknown
timestamp: July 13, 2023, 12:33:38 pm
content: Quote from: Smokey on July 09, 2023, 09:04:16 amNo thanks, I want them to be available tomorrow

author: Warhawk
author_rank: Frequent Contributor
timestamp: July 13, 2023, 02:15:09 pm
content: Quote from: Simon on July 13, 2023, 12:33:38 pm

author: Simon
author_rank: Unknown
timestamp: July 13, 2023, 06:08:28 pm
content: I don't think documentation feedback will help with supply.

author: VK3DRB
author_rank: Super Contributor
timestamp: July 15, 2023, 08:02:50 am
content: Quote from: Warhawk on July 13, 2023, 11:27:34 amThe ISOW1044BDFMR. I did report it about 3 weeks ago, and to TI's credit they fixed it immediately and re-released the document. Pin 3 was listed as a chip enable when it was in fact a transmit data line.I find it incredible no-one else has ever used this chip, of if they have, they are too busy or self-centred to report the error. Mind you, if I reported every bug in Altium, I'd never get any work done.

author: Smokey
author_rank: Super Contributor
timestamp: July 15, 2023, 08:47:59 pm
content: Quote from: Someone on July 10, 2023, 08:47:52 amWow. Those are some impressive specs.. but at $6.30 in 1s... Not quite universal prices...https://www.digikey.com/en/products/detail/texas-instruments/OPA4189IDR/15857137

author: Smokey
author_rank: Super Contributor
timestamp: July 15, 2023, 10:44:59 pm
content: Quote from: VK3DRB on July 15, 2023, 08:02:50 amDatasheet from TI shows revision date of Dec 2021. Pinout for Pin3 shows it correctly as TXD. (Enable shows as Pin8).https://www.ti.com/lit/ds/symlink/isow1044.pdfTI document control almost certainly is ISO9001, which makes revising a document but not bumping the revision essentially impossible.

author: tooki
author_rank: Super Contributor
timestamp: July 16, 2023, 04:03:32 pm
content: Quote from: VK3DRB on July 15, 2023, 08:02:50 amI was pleasantly surprised at TI’s responsiveness to datasheet errors. I once found an error in the website description of some weird version of the 5534 op-amp (perhaps a mil-spec version or somethinf), where it was described as a quad op-amp (it’s a single). They fixed it right away.

author: tooki
author_rank: Super Contributor
timestamp: July 16, 2023, 04:10:29 pm
content: The UTI (universal transducer interface) from Smartec.https://smartec-sensors.eu/cms/pages/products/uti-interface.phpIt can measure capacitance down to a 2pF range (14-bit resolution) over long cables, more or less regardless of cable capacitance. I used it (in the 0-300pF range) to measure the level of liquid xenon in a cryostat through 3m of coax cable (at 100pF/m). Measurements reproducible down to 0.02pF with averaging.It can also do resistance, e.g. for PT1000’s.Downside is that it’s hard to find. None of the major distributors carry it any more, so you have to find a small local distributor.

author: griffinadams
author_rank: Newbie
timestamp: July 17, 2023, 03:02:51 pm
content: Quote from: tooki on July 16, 2023, 04:10:29 pmNice. Quite a useful part, unfortunate name...Along the same lines, TI has the TDC7200 for ultrasonic timing measurements.https://www.ti.com/product/TDC7200

author: tooki
author_rank: Super Contributor
timestamp: July 25, 2023, 03:58:51 pm
content: Quote from: griffinadams on July 17, 2023, 03:02:51 pmAin't that the truth!Quote from: griffinadams on July 17, 2023, 03:02:51 pmNeat!

author: Smokey
author_rank: Super Contributor
timestamp: August 31, 2023, 03:49:58 am
content: Chip of the day = TMP1075https://www.ti.com/lit/ds/symlink/tmp1075.pdfhttps://www.digikey.com/en/products/detail/texas-instruments/TMP1075NDRLR/15222310$0.64 in 1s, $0.25 in 4000s.-40°C ~ 125°C Range, I2C Interface, Tiny SOT-563 package, Thermal Alert Output. Measure thermal load or ambient temp with a cutout.

author: Someone
author_rank: Super Contributor
timestamp: August 31, 2023, 04:11:21 am
content: Quote from: Smokey on August 31, 2023, 03:49:58 am... NIST traceable tested!

author: Circlotron
author_rank: Super Contributor
timestamp: August 31, 2023, 04:40:04 am
content: Quote from: Smokey on July 15, 2023, 08:47:59 pmTHD + noise 0.00006%

author: dietert1
author_rank: Super Contributor
timestamp: August 31, 2023, 05:59:28 am
content: Meanwhile they provide PowerPAD packages for opamps to reduce self-heating. Amazing how improvements in analog technology still continue.

author: Smokey
author_rank: Super Contributor
timestamp: September 29, 2023, 03:29:12 am
content: I'm not sure if this is officially a chip of the day considering I haven't personally use it yet... butSQJQ184ER-T1_GE3https://www.digikey.com/en/products/detail/vishay-siliconix/SQJQ184ER-T1-GE3/16181886https://www.vishay.com/docs/71298/sqjq184er.pdfQTY UNIT PRICE EXT PRICE1 $3.53000 $3.5310 $2.96500 $29.65100 $2.39890 $239.89500 $2.13232 $1,066.161,000 $1.82579 $1,825.79N-Channel MOSFET, 80V, 1.4mOhm Rds-on, 430A Id25, 600W 8-PowerSMDThat is a serious little FET!

author: Smokey
author_rank: Super Contributor
timestamp: November 08, 2023, 07:51:13 am
content: This one could be super useful.....TPL5110QDDCRQ1It's a timer/power gating high side switch chip. So for example if you want to only power up your system every x seconds, do something, then power down to save batteries. Timer intervals from 100ms to 7200s and 35nA quiescent current draw for this chip. Could be super useful if your system doesn't have a deep sleep mode or otherwise lots of quiescent current.https://www.digikey.com/en/products/detail/texas-instruments/TPL5110QDDCRQ1/6816812https://www.ti.com/lit/ds/symlink/tpl5110-q1.pdfQTY UNIT PRICE EXT PRICE1 $0.88000 $0.88100 $0.61560 $61.561,000 $0.40148 $401.48

author: Smokey
author_rank: Super Contributor
timestamp: October 11, 2025, 02:51:39 am
content: App note of the day...https://www.ti.com/lit/an/snvaa85/snvaa85.pdf"How to Implement a Simple Constant Current Regulation Scheme to a PCM Based Buck"Sort of a cool hack to add CC to a buck regulator with PCM.