Espressif ESP8266 WiFi-serial interface : weekend die-shot

Since August of 2014 internet is literally blown by WiFi-serial modules on new ESP8266 chip which are currently being sold for less than 4$. Chinese company Espressif managed to cram entire WiFi, TCP/IP and HTTP stack into on-chip memory, without external DRAM. Analog front-end requires minimal external components, all filters are internal. All this allowed them to offer extremely aggressive price. Chip has marking ESP8089, which is their more advanced 40nm product. Apparently, they only differ in bonding and ROM content.

Die size 2050x2169 µm, half of which is occupied by transceiver and PA, 25% - on-chip memory (rough size estimations are ~300KiB), and the rest is Xtensa LX106 CPU core and other digital logic.





Chinese engineers did an outstanding job here on finally making WiFi IoT devices cost effective. Let's hope Espressif will eventually open more internal chip information for amateurs and end users.

Analog Devices AD558 - MIL-Spec 8-bit I²L DAC : weekend die-shot

Analog Devices AD558 is an 8-bit I²L DAC in ceramic package (MIL spec).

It is still an open question how this chip got into ex-USSR/Russia - anonymous reader left no comments on that (this smells like cold war...). It is not a secret that Russia had no extensive civilian IC assortment in manufacturing, hence all military IC's must have been designed and manufactured from scratch (i.e. all R&D, prototypes and masks must be paid by government). In such conditions providing all variety of domestic ICs is economically impossible, at least without government expenses comparable to whole world's expenses on IC R&D. So "temporary", "case-by-case" permit to use imported (both legitimately and not-so-legitimately) western ICs in military equipment "until domestic products are ready" is still here after 24 years despite numerous attempts to end this practice.

Die size 2713x2141 µm, 6µm manufacturing technology, trimming laser was leaving ~8µm diameter spots.


Oh, these rounded resistors are just beautiful... Autorouters in 2014, do you see this?
Note how amount of laser trimming on R-ladder is different for different bits.



PS. Could anyone share position of western engineers on plastic-vs-ceramic package for military/space-grade IC's? It appears modern plastic packages offer more benefits (like better G-shock/vibration reliability and obviously cost) without sacrificing anything (temperature range and moisture are less of a concern now, radiation was never a concern for a package).

74HC4094 - 8-bit shift register : weekend die-shot

74HC4094 is an 8-bit serial-in/parallel-out shift register.

Atmel AT90USB162 : weekend die-shot

Atmel AT90USB162 is an 8-bit microcontroller with hardware USB, 16KiB flash and 512B of SRAM/EEPROM.

Ti CC1100 (formerly Chipcon) : weekend die-shot

Ti CC1100 is a radio transceiver for 300-348 MHz, 400-464 MHz and 800-928 MHz ranges.



Apparently there are 30 initials of the people, involved in the design of this chip mentioned at the lower right corner. Although this chip was designed after Ti acquisition of Chipcon (that happened in January 2006), it is still marked as Chipcon.

Fairchild NC7SZ57 - universal 2-input gate : weekend die-shot

Fairchild NC7SZ57 (and 58) - are universal 2-input shmitt gates, which let us implement various 2-input logic functions by wiring pins in different ways.

Die size 416x362 µm, which is the smallest among microchips we've seen.

Comparing to 1-gate NAND2 Ti SN74AHC1G00 - die area here is 1/3 smaller because area below pads is not wasted and used for IO transistors and wiring. It is unclear though how they achieved decent yields (as things there might get damaged during wire bonding) - we can only tell that insulation before last metal is much thicker than usual.

Drop us a message if you have experience or knowledge on getting high-yield logic under pads - this is something we would be interested to have in our own product.

NXP PCA9570 - 4-bit IO expander : weekend die-shot

NXP PCA9570 is an I²C 4-bit IO expander, although there are 4 unused pads on the die: probably 8-bit version uses the same die. 800nm technology.

Die size 589x600 µm.



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