July 24, 2017

Ti TLC5540I 8bit 40MSPS semiflash ADC : weekend die-shot

Ti TLC5540I is a CMOS semi-flash 8bit 40MSPS ADC. Die is much smaller than simple 8bit flash ADC.

Die size 1699x1801 µm, 1µm minimum half-pitch.

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July 23, 2017
July 8, 2017

Fairchild BCV27 - npn darlington BJT : weekend die-shot

Fairchild BCV27 - is a tiny SOT-23 Darlington npn BJT with hFE of 20'000.
Die size 612x611 µm.

July 3, 2017

Ti NE555 - real vs fake : weekend die-shot

It is easy to understand reasons to fake 80$ "audiophile-grade" opamp. But why would someone fake one of the cheapest microchips in the world?

With volumes high enough that's still decent money for a small company. It could also be an economic warfare: each fake chip sold means 7 cents less in US GDP and Ti sales.

Genuine Ti NE555D. This one is directly from distributor. You can see several mentions of Texas Instruments on the die.
I really like designs with pads in the middle of the die, it looks so elegant and efficient (when it's not reducing yield).
Die size 1034x762 µm.

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June 30, 2017

BTR004K - heart of Batteriser/Batteroo : weekend die-shot

There was quite some hate heard in engineering communities regarding Batteriser : product claiming to extract "up to" 800% more power from the battery. It's a thin sleeve with 1 active component - BTR004 chip. This is a boost DCDC chip with external capacitors and inductors.

Chip itself is not all that dumb - it's a custom job (see BTR004K marking at the top left corner), with very low quiescent current and apparently able to drive large range of loads.

More than half of the chip area is occupied by 4 MOSFETs. Most likely they are connecting SW1/SW2 pins to ground/output - so we have SW1->ground, SW1->VO1, SW2->ground, SW2->VO2 MOSFETs. Looks like synchronous 2-phase boost converter.

While Batteiser/Batteroo as a product itself is almost never useful (with rare exceptions of badly designed electronic goods consuming low current with unusually high cut-off voltage and/or absolutely no or very bad voltage regulation), chip itself could have been useful as a standalone product, especially if higher output voltages were available. Technologically it's quite advanced product spoiled by marketing and product placement.

Die size 1267x749 µm.

Thanks for the chips to DextersLab2013 (blog, YouTube), guys at EEVBlog forum and of course David Jones for rising this issue in the first place.
June 29, 2017

ST 2STD1665 - power NPN BJT : weekend die-shot

ST 2STD1665 have quite outstanding hFE of 320 (for a non-darlington 65V power BJT). That makes it very useful for switching applications where you wish to drive it with low voltage (e.g. pin of microcontroller with 1.8V VCC) where N-MOSFET would require external circuitry.

You can see extensive net to stitch thin, high-resistance base with metal. Emitter resistance could have been slightly lower with different pad placement (closer to center and on the diagonal) but apparently it's not a major performance-limiting factor.

And... it's just beautiful!

Die size 1740x1727 µm.

April 30, 2017

1107PV2 - 20MHz 8bit Soviet flash ADC : weekend die-shot

1107PV2 is another Soviet flash ADC - 8-bit with 20MHz conversion rate.

Closer look at comparators: