Unknown Circuits - die pictures - Page 1
Forum section: electronics / projects

author: Noopy
author_rank: Super Contributor
timestamp: March 10, 2024, 04:24:47 am
content: Let´s start a new topic for unknown circuits.UICs - Unknown Integrated Circuits?This component contains the letters WE, the character sequence F61489 and the numbers 2384. 2384 could be a date code, which would then refer to the year 1984. WE probably stands for Western Electric. This is also supported by the integrated circuit. F61489 could be the designation of the component.The die has several testpads. There are large contacts on the edges, which were probably mainly used to tune the circuit. There are also many small contact areas within the circuit that are only suitable for special tests. A clear division into two parts is recognisable in the structures. The right part is smaller but contains very similar areas. The image is available in full resolution:https://www.richis-lab.de/images/TBD/01x03XL.jpg(24MB)The only labelling can be found on the left edge. BKA, JRB and TM could be the initials of the developers. M7062D appears to be an internal project designation.Some test structures have been integrated in the bottom left-hand corner and at the bottom edge, which make it possible to check the alignment of the masks against each other.There are resistance strips on each side, whose resistance values can be set with a few testpoints and fuses.The upper section contains structures that are typical for switched capacitor filters. The functionality of such filters is described in more detail with the U1001 (https://www.richis-lab.de/phone01.htm). The repeating structures of several opamps can be clearly recognised. These opamps are connected with different capacitances, which are represented by individual rectangles.The filters indicate that this is indeed a Western Electric component. Western Electric was very active in the telecommunications industry. It therefore seems very likely that, like the U1001, it is a transmit and receive filter for digital transmission links.The control logic is integrated in the lower section of the module.https://www.richis-lab.de/TBD01.htm

author: RoGeorge
author_rank: Super Contributor
timestamp: March 10, 2024, 06:06:48 am
content: First!

author: Noopy
author_rank: Super Contributor
timestamp: May 30, 2024, 03:08:11 am
content: This component comes from an internal collection of Philips or NXP. There is no datasheet for the designation TDA8445. 8618 is probably a date code.There are some remnants of bondwires in the package. It is probably not the first die to be inserted into this package.On the left-hand side, three identical and one very similar circuit section are arranged one above the other. Four output stages can be seen at the bottom edge.This picture is also available in a higher resolution:https://www.richis-lab.de/images/tbd/02x03XL.jpg(51MB)At the top edge of the die there is the character string R0185C1. But that string cannot be assigned.Here you can see one of the repeating blocks. It is immediately recognisable that this is a bipolar process. Two layers of metal were used. In the centre is a large block of small transistors connected in parallel. The strips in the right-hand area represent I2L logic, as described in more detail in the CA3161 (https://www.richis-lab.de/logic22.htm).There is no information on the type designation TDA8445. However, Philips sold a TDA8446. It is a video signal switcher that can be used to process different video standards. It is not only the name that suggests a similarity. The three identical circuit blocks of the TDA8445 could be the RGB inputs, while the fourth, similar block could be the Y input. At the bottom edge there are three identical and one slightly different output stage. This would match the outputs of the TDA8446. However, the TDA8445 is missing two pins compared to the TDA8446.https://www.richis-lab.de/TBD02.htm

author: amyk
author_rank: Super Contributor
timestamp: May 30, 2024, 04:04:43 am
content: Some Chinese websites I could find claim that TDA8445 is a TV "field output" (vertical) IC.

author: Noopy
author_rank: Super Contributor
timestamp: May 30, 2024, 05:11:27 am
content: Quote from: amyk on May 30, 2024, 04:04:43 amI have found this site but I assume that's a mistake. These "field output integrated circuits" are power devices.

author: RoGeorge
author_rank: Super Contributor
timestamp: May 30, 2024, 06:20:51 am
content: Quote from: Noopy on May 30, 2024, 03:08:11 amCould that be just a malfunction in the bonding machine? Asking because I assume it won't be easy to remove a die without damaging the packaging, or is it? Then, how would the bonding machine know to avoid the bond leftovers on the pads? Or maybe it was made with a manually bonding machine?I know nothing about chips manufacturing, is package-reusing a common practice for IC prototypes?

author: Noopy
author_rank: Super Contributor
timestamp: May 30, 2024, 06:33:56 am
content: I think we can be sure that this is an prototype. With that in mind I assume it was bonded by hand.I assumed there was a die in the package before this one because a bad bond process probably would have left some residues on the die but we don't see anything on the bondpads.You can remove a die from such a package. Of course that's just something for development purposes but as I said I assume that is a prototype device.

author: magic
author_rank: Super Contributor
timestamp: May 30, 2024, 09:10:12 am
content: The outputs are totem poles driven by the digital circuitry, so this is not an amplifier. Surprisingly, it looks like the logic drives high and low side separately, so shoot-through prevention needs to be included in the logic.Pinout so far:17, 18, 1, 2: analog(?) inputs, the circuitry here should be easy to figure out3, 4: outputs5: GND6, 7: outputs8: VCC9: seems to act as output enable, maybe a logic supply too...15: looks like a logic supply

author: magic
author_rank: Super Contributor
timestamp: May 30, 2024, 03:55:20 pm
content: Actually, this looks like some DAC or DDS kind of thing. The "analog inputs" on pins 17, 18, 1, 2 really are (low power) outputs, each driven by an ordinary class AB NPN/PNP emitter follower pair and level-shifted 0.7V down by a diode and a cascoded constant current sink. These outputs are controlled by simple RC4558-style opamps with capacitive feedforward around the PNP differential stage and a cascoded second stage. The circuitry seems oriented towards speed rather than precision.Noninverting inputs are biased by the potential on pin 13, while pin 14 controls an open collector NPN which temporarily pulls pin 13 to ground. Pin 15 supplies the opamps, not logicand pin 16 might be some sort of output stage shutdown. Inverting inputs are connected to on-die feedback resistors and variable current sources controlled by the logic - that's what the arrays of transistors hidden under upper layer metal appear to be. There are also provisions for the logic to disable any opamp and drive its output into either positive or negative saturation.Pins 12, 11, 10 go into the logic or some analog-looking circuitry in the middle of the logic, under pad 13. Pin 9 does appear to be logic power supply, pin 8 is power supply for the digital outputs on pins 7, 6, 4, 3 and nothing else, apparently. Pin 5 is ground.Do we have anymasochistI2L expert here able to explain what this control circuit is doing?

author: Noopy
author_rank: Super Contributor
timestamp: May 30, 2024, 06:00:17 pm
content: Thank you magic! Very interesting!I found no Philips part with a functionality similar to what we see here. But of course I didn´t check every Philips part.Perhaps it was just a prototype which never went into series production.Quote from: magic on May 30, 2024, 03:55:20 pmNo, that´s not my business.

author: magic
author_rank: Super Contributor
timestamp: May 30, 2024, 10:30:33 pm
content: It really is a triple channel DAC.Next to each transimpedance amp there is an array of 31 NPNs: emitters grounded, bases driven in parallel, collectors connected in groups of 16, 8, 4, 2, 1. For each group there are three NPNs controlled by the logic which route the group's current either to the TIA directly, or to the TIA through an inverting Wilson mirror (3 PNPs between the TIA and the array), or to a dummy emitter follower where nothing happens. Pretty sure we have seen this kind of DAC architecture before.By the way, I2L logic outputs are open collector so they shouldn't be able to drive the NPN current steering switches. It seems that in this chip the logic is "grounded" through a diode-connected Darlington pair, shifting its potential two diode drops above real ground. What appears to be inverter gates driving the switches, actually are ordinary emitter followers working in forward mode and feeding current from logic virtual ground into the bases of the switches.The apparent fourth channel is another story. The TIA is a dummy - it simply outputs the same quiescent DC voltage as other amps, there is no signal current going into it. It looks like pin 17 is a reference voltage for the other outputs. There is no Wilson mirror on this channel, in its place there is a fifth opamp which drives the bases of all current sink arrays in such way to produce a particular output current from the fourth DAC. The fourth DAC is also modified, it is single-ended only and has groups of 4, 10, 4, 2, 1By controlling this DAC, the logic forces the opamp to set different levels of current per one cell of the array. Hence gain of the main DACs can be varied.I found only three inputs to the chip. They go to the analog section near pad 13, which is simply a bunch of comparators. Comparator outputs go to the logic, so these are digital inputs. I doubt that they are fast enough to feed complete raw data to all DACs in real time. I think it's some special purpose chip, which receives simple commands and generates more complex output. I suppose it could be all sorts of weird things, from an OSD generator to a fully integrated simple video game.I didn't find any obvious oscillator or other clock source

author: Noopy
author_rank: Super Contributor
timestamp: May 31, 2024, 03:13:27 am
content: Quote from: magic on May 30, 2024, 10:30:33 pmSo these are 5Bit-DACs. Now it´s clear what the transistor arays are used for. Yes, this architeture sounds quite common.Quote from: magic on May 30, 2024, 10:30:33 pmYou are right. That is really strange.

author: magic
author_rank: Super Contributor
timestamp: June 02, 2024, 09:53:14 pm
content: It's a 6-bit DAC because there is a sign bit tooThe sign bit flips all current sinks of the given DAC channel between the noninverting or the inverting path. This is unexpected, because it means that for negative outputs the signal passes through a PNP Wilson current mirror. I don't know how fast it is, but lateral PNPs are somewhat infamous for being slow so maybe it's not a very fast DAC and maybe not for video. But for what? I don't know...I looked at the logic of the DACs and it's not too complex. The image below shows one bit. Starting from the left, we have three ordinary noninverting emitter followers which drive the three current steering switches (inverting, noninverting, null). Next is a pair of common emitter transistors with direct mutual feedback - a flip-flop. Right side disables the null output, left side disables the inverting and noninverting outputs. The FF is controlled by a two-transistor, single-ended to differential buffer: the right transistor drives one side of the FF, the left transistor is a slave inverter which drives the other side. POR is power-on-reset, which asynchronously forces all bits of all DACs to null when the digital power supply is too low. LATCH disables the buffer and causes the FF to hold its current state - this allows all DACs to share one data bus because their latch lines are separate. The final transistor is data input from the bus to the buffer.We have five such bit drivers per DAC. The sixth, almost identical circuit reads the sign bit from the bus and disables all inverting or noninverting switches accordingly. The remaining two bits control the TIA (enabled, saturated positive, saturated negative). They have their own, independent latch signal which is shared by all DACs and each DAC takes these two bits from a different positions on the bus, so the TIAs are controlled independently with one bus word.The fourth DAC (gain control) is connected to the same bus and has its own latch line, which is shared with a small circuit that drives the digital pins. Upper four bits go to DAC4, lower four bits go to the pins.The bus is driven by eight similar circuit blocks arranged in a column right next to the DAC logic. There are links between consecutive blocks and I think it may be an 8-bit shift register. We have so far covered about 75% of all the logic, so the reminder can't be too complex. I'm starting to think that the chip is nothing more than a DAC with a simple serial input interface like SPI or similar...

author: Noopy
author_rank: Super Contributor
timestamp: June 03, 2024, 03:10:04 am
content: Good job! Thank you!Philips had the TDA8444 with six DACs controlled by I2C. In the datasheet they are talking about a I2L-compatible process."Each DAC can be programmed separately by a 6-bit word to 64 values, but VMAX determines the maximum output voltage for all DACs."Sounds like the TDA8444 is quite similar.

author: magic
author_rank: Super Contributor
timestamp: June 03, 2024, 06:24:24 am
content: Interesting. Part numbers are not too far apart and I just noticed that TDA8445 has an open collector transistor under logic control, connected to one of the I/O pins. I²C is old enough, so maybe that's what it is. I will see if I ever get bored enough again to decode this interface logicThe DACs are a little different, though. Bipolar not unipolar, output amplitude is variable digitally in a few preset steps, and an analog input controls the DC bias instead. The TIA outputs don't seem capable of reaching close to ground.Hmm, do you have some I²C controller which could scan this chip for any addresses it might acknowledge?

author: Noopy
author_rank: Super Contributor
timestamp: June 03, 2024, 05:30:12 pm
content: The TDA8444 and TDA8445 are related but not the same.I'm trying to avoid software wherever it is possible, a I²C controller is already software.

author: Noopy
author_rank: Super Contributor
timestamp: December 21, 2024, 04:47:59 am
content: The 4” wafer shown here comes from the former "Institut für Regelungstechnik" (IfR), Storkower Straße, Berlin. Only the designation MP609 is known.The wafer contains two test structures. One is approximately square and is shown once on the right and left. The other test structure is elongated and runs through the wafer from bottom to top.The approximately square test structure shows the imaging performance of the manufacturing process.This image is also available in a higher resolution:https://www.richis-lab.de/images/wafer/07x02XL.jpg(72MB)In the middle of the test structure, the various masks depict geometries. These can be used to evaluate the alignment and, above all, the resolution.The elongated test structure consists of three areas with the designations MT33 K, MT33 M and MT33 E. Various elements can be electrically measured in these areas.This image is also available in a higher resolution:https://www.richis-lab.de/images/wafer/07x04XL.jpg(18MB)The testpads were apparently contacted three times. The test needles have left clear marks. In each test area, there is a small silicon art next to the name, reminiscent of an animal's head.The circuit shown on this wafer is 3,0mm x 2,4mm in size. The circuit is not overly complex, but its function is not immediately obvious.This image is also available in a higher resolution:https://www.richis-lab.de/images/wafer/07x06XL.jpg(38MB)The designation MP609 is shown in the milling line. Below this is the character string U1502. One could conclude that the circuit, like the U1500PC050 (https://www.richis-lab.de/phone03.htm), is based on the U1500 standard cell design system. However, the structures on the bondpads of the MP609 do not match the structures that can be found on U1500 variants.https://www.richis-lab.de/wafer08.htm

author: shakalnokturn
author_rank: Super Contributor
timestamp: December 22, 2024, 03:04:33 am
content: Quote from: Noopy on June 03, 2024, 03:10:04 amThe TDA8442 is close too with 4 independent DAC's.The TDA8445 with its common DAC makes me think it may have been intended for RGB control of high end CRT monitors.I'd be curious to know if Sony may have inherited a CXA / CXD labeled device from this development or if it was sold under a less common than TDAxxxx part numbering by Phillips. (If not abandoned...)

author: Noopy
author_rank: Super Contributor
timestamp: December 22, 2024, 04:01:32 am
content: Interesting thouthts!We have a big audience here. Perhaps sometime someone can tell us...

author: Noopy
author_rank: Super Contributor
timestamp: January 06, 2025, 04:10:11 am
content: Another unidentified Philips lab part.From two pins two bondwires lead to the die.The die is still reasonably clear. The circuit is based on bipolar transistors and uses two metal layers.This image is also available in higher resolution:https://www.richis-lab.de/images/tbd/03x03XL.jpg(8MB)Some test structures are shown in the bottom right-hand corner. The designation R158C2 does not allow any conclusions to be drawn as to which circuit is involved.If you take a closer look at the circuit, you can guess some of the functions. The two bondpads in the bottom left-hand corner (pins 2 and 3) represent a differential input. The first block (yellow) contains a differential amplifier. The bias current setting appears to be located at the lower edge (red). The signal of the differential amplifier is further processed in the lower right area (orange). The structure of the circuit suggests that it is a type of comparator.The signal is fed further differentially into the area in the middle (purple). The bias potential is also passed on. The complete circuit is supplied via pins 4 and 8, whereby the lower circuit section uses its own bondwires to these pins. In the left-hand area four wires lead upwards (blue) from the middle section of the circuit. From there, the signal runs again via two lines to the last circuit section (green). There appears to be a feedback loop there. The signal is finally output via pins 6 and 7. The last part of the circuit can be influenced in some way via pin 5.To summarize, the part processes a differential signal and outputs it differentially. An additional input allows the output signal to be deactivated or perhaps modulated.https://www.richis-lab.de/TBD03.htm

author: Noopy
author_rank: Super Contributor
timestamp: January 06, 2025, 06:55:54 pm
content: Quote from: Noopy on December 21, 2024, 04:47:59 amI was told this could be a periphery IC for the 80286 system.The GDR developed a copy of the 80286 system which included round about 10 ICs. The 80286 itself was developed in the "Funkwerk Erfurt" (MME) and was called MP610.

author: Noopy
author_rank: Super Contributor
timestamp: January 07, 2025, 04:20:37 am
content: Quote from: Noopy on January 06, 2025, 04:10:11 amIt could be the SAB6456, a frequency divider that processes frequencies up to 1GHz. The divider factor can be switched between 64 and 256. The pin assignment matches the documented component. The middle circuit section on the die could contain the dividers. The four lines leading from this middle section would match the function of the SAB6456. They could carry the signal divided by 64 and the signal divided by 256. The control signal of pin 5 seems to deactivate a last divider block. The two signals are then combined in the top circuit section and finally output.https://www.richis-lab.de/TBD03.htm#SAB6456

author: Noopy
author_rank: Super Contributor
timestamp: January 24, 2025, 07:56:32 pm
content: And another unidentified Philips lab part soldered on a PCB.The lid of the package is attached with a tape.The package contains a relatively small die.It appears to be a test circuit. This is supported by the fact that very little of the available silicon area is used and many of the bondpads have no function. The character sequences QU2AGC1 and OQT063C1 are shown next to the Philips lettering. The first character string can also be found on the circuit board and could therefore be the name of the circuit.The outer bondpads on the upper edge clearly represent the power supply. In addition to these two the circuit is contacted via seven further bondwires. The three bondwires that lead to the inner area of the die are particularly interesting. There are no bondpads there.This image is also available in higher resolution:https://www.richis-lab.de/images/tbd/04x04XL.jpg24MBThe integrated circuit is quite clear. There appear to be two signals coming in from the left, each of which is routed via a relatively large coupling capacitor. This could be a differential input. Here you can see that unusually thin lines lead from the inner three bondwires into the circuit. It is very likely that these lines were constructed using an FIB.An FIB (Focused Ion Beam) is a tool that generates a beam of accelerated ions. Various elements are used to generate these ions, including gallium and some noble gases. Where the ions hit, they remove material. By introducing different process gases into the reaction chamber, it is possible to ensure that material is removed selectively. In contrast, other process gases allow certain layers to grow exactly where the ion beam strikes. All in all, this provides a tool that allows integrated circuits to be extensively modified down to the smallest detail. Small testpads can also be created. These are usually testpads for test needles. In this case, the testpads were apparently large and robust enough to apply bondwires to.The lines subsequently constructed with the FIB are approximately 1µm wide. There appear to be deposits in the immediate vicinity. The point where the retrofitted line contacts the original circuit is clearly visible, even if the details of the contact itself are not resolved.In this line, the contact can be recognized by a taper. In this area, the metal layer has also been cut at three positions. A resistor has been configured that consists of several partially bridged elements. A remnant of the metal layer appears to have remained at the middle interruption.A wider, diffuse stripe was already visible in the previous image. Here, this stripe can be seen once again. A second stripe crosses outside the circuit. It remains unclear how these stripes were created.https://www.richis-lab.de/TBD04.htm