Who we are

ZeptoBars is a Russian based R&D company focused on microelectronics and high-tech.

We are working on our commercial, slightly unusual microelectronic product and on the weekends having fun dissolving microchips in boiling acid. We are also trying to reinvent dye lasers utilizing the most recent advances in micro- and optoelectronics.

April 12, 2014

Phillips PCF8574 - 8-bit I2C port expander : weekend die-shot

Phillips PCF8574 is 8-bit I2C port expander, 3µm manufacturing technology.

April 8, 2014

Fake audiophile opamps: OPA627 (AD744?!)

Walking around ebay I noticed insanely cheap OPA627's. It's rather old, popular and high-quality opamps, often used in audiophile gear. Manufacturer (Texas Instruments / Burr Brown) sells them 16-80$ each (depending on package & options) while on ebay it's cost was 2.7$, shipping included.

Obviously, something fishy was going on. I ordered one, and for comparison - older one in metal can package, apparently desoldered from some equipment. Let's see if there is any difference.


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March 29, 2014

SiTime SiT8008 - MEMS oscillator : weekend die-shot

SiTime SiT8008 is a programmable MEMS oscillator reaching quartz precision but with higher reliability and lower g-sensitivity. Also SiTime is one of companies who received investments from Rosnano - Russian high-tech investment fund.

Photo of MEMS die puzzled us for quite some time. Is it some sort of integrated SAW/STW resonator?

The trick is that to reach maximum Q-factor (up to ~186'000 according to patents) MEMS resonator must operate in vacuum. So they package resonator _inside_ the die in hydrogen atmosphere, then anneal it in vacuum so that hydrogen escapes through silicon. So we see here only a cap with contacts to "buried" MEMS resonator. We were unable to reach the resonator itself without x-ray camera or ion mill.

MEMS die size - 457x454 µm.

Thankfully relevant patents were specified right on the die : US6936491 US7514283 US7075160 US7750758 :)



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March 22, 2014

TI TL431 adjustable shunt regulator : weekend die-shot

TI TL431 in an adjustable shunt regulator often used in linear supplies with external power transistor.
Die size 1011x1013 µm.


March 18, 2014

TI LM393 - dual comparator : weekend die-shot

TI LM393 - dual comparator, one of old workhorses of electronics.
Die size 704x748 µm.


March 16, 2014

Ti TS5A3159 - 1Ω analog switch : weekend die-shot

Ti TS5A3159 is an 1.65-5V 2:1 analog switch with ~1Ω matched channel resistance and "break-before-make" feature.
Die size 1017x631 µm, 1µm technology.


February 17, 2014

FTDI FT232RL: real vs fake

For quite some time when you buy FTDI FT232RL chips from shady suppliers you have a good chance of getting mysteriously buggy chip which only works with drivers 2.08.14 or earlier. We've got a pair of such FTDI FT232RL chips - one genuine and one fake and decided to check if there is an internal difference between them. On the following photo - left one is genuine, right one is fake. One can notice difference in marking - on genuine chip it's laser engraved while on buggy it is printed (although this is not a universal distinguishing factor for other chips).

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