What is an HP1858-0054 transistor array?

[Tony Duell]

> Search for RCA CA3080, 3081, 3082 and also look at 3046.  RCA did a large 
> number of transistor arrays (and MOS transistor arrays).


I'm pretty sure I've  checked it against all of those, and none make any 
sense. Also, it's a 16 pin DIL pacakge, many of the transistor arrays 
I've looked at are 14 pin DIL (or 10 / 12 lead metal cans)

Here's what I've discovered so far : 

Pins 2 and 4 are grounded on the PCB, and are probably the emitters of 2 
transsitors

Pin 3 is linked to pin 6, then pulled up by a 464R ressitor. This goes to 
the input of a '14 schmitt trigger. I guess pins 3 and 6 are collectors 
of transistors in the chip

Pin 16 is not connected

Pins 7,8, 9 aren't connected either. They appear to be the 3 connections 
of another transistor in the chip, with pin 89 as the base



> 
> The common layouts were 8 common transisters with emitter(grounded) base 
> and collectors brought to pins, 8 common collector (VCC) with emitter and 

Certainly not either of those.

> base brought to pins.  Others include differential amps, darlington arrays
> and some combination arrays.  You have noticed there are a large number 
> of parasitic diodes as a side effect of forming the devices on one die.

Yes, and they sure make sorting out the internal configuration 
non-trivial :-)

> 
> FYI here is a sample of some of the devices: 
> 
> The common collector and common emitter devices were handy for LED
> segment and digit drivers but were not limited to those uses.  
> Ca3081, ca3082 are examples of this.

FWIW, the display anode driver (segment driver) chip in the HP67 
calculator is one of these. It's about the only non-custom chip you'll 
find in an LED-display HP handheld calculator.

-tony