Gregory's ServerAn interesting military chip, built by UTMC in 1991. It's a transceiver for the MIL-STD-1553 serial data bus, a standard bus that is used extensively used in military aircraft and other systems. 1/18
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The chip's die is pretty complicated, considering that it just converts voltages and doesn't deal with the bus protocol at all. Here's a block diagram from the datasheet. 3/18 The chip is built with bipolar transistors (NPN and PNP), not the CMOS circuits used in most modern chips. Here are four NPN transistors with the collector (rectangle), base (smaller rectangle), and emitter (small square) on each rectangular transistor. 4/18 |
The 1553 bus transmits data at 1 megahertz using 27-volt pulses on two wires. The chip receives bus data and converts it to digital (TTL) levels. The chip also transmits data on the bus, generating high-current pulses. 2/18