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NIXIE Driver ICs
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| Device |
Technology |
Inputs
Active on |
Output for Input>9 |
| A |
B |
C |
D |
E |
F |
| 7441A |
TTL |
TRUE |
0 |
1 |
2 |
3 |
4 |
5 |
| 74141 |
TTL |
TRUE |
none |
none |
none |
none |
none |
none |
| Fairchild 9315 |
TTL |
TRUE |
2, 8 |
3, 9 |
none |
none |
6 |
7 |
| Fairchild 9960 |
CµL (RTL) |
FALSE |
2, 8 |
3, 9 |
4, 8 |
5, 9 |
6, 8 |
7, 9 |
| HP 1820-0092 |
? |
FALSE |
none |
none |
none |
none |
none |
none |
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Following is a list of NIXIE decoder/driver integrated circuits and comparison of some their characteristics.
7441A & 74141
The standard TTL NIXIE decoder/drivers.
The 7441A was the first released sometime in the late 1960s.
It wasn't long before it was replaced by the 74141 which is pin-compatible but provides blanking capability via input values greater than 9.
Fairchild 9315
The 9315 is from Fairchild's early 9300-series TTL series.
Fairchild 9960
The 9960 is something of an odd device.
It is part of a small series of ICs Fairchild produced in the 1960s called Counter Micrologic.
The electronic design puts it in the RTL class and it operates with a 3.6V supply, but the 9960 can also be found directly driven by TTL devices and 5V supply.
The inputs sink 1.3mA @ +3.6V for logical 1 and open-circuit is logical 0.
The 9960 may also be identified or referred to as type 960, or may be found stamped with, for example: "F 996079".
HP 1820-0092
A proprietary device manufactured by Hewlett-Packard in the late 1960s.
These were used in conjunction with special HP decade-counter ICs (1820-0093 and 1820-0119) to achieve zero-blanking in their digital counters of the late-1960s, such as the HP 5216A.
It is not clear what technology this device is, it operates at 5V in systems with TTL ICs, but the inputs sink 1.5-1.7mA @ +5V for logical 1 and open-circuit is logical 0, suggesting RTL.
My experience with these devices shows them to be failure-prone.
I would guess that a lot of HP equipment using them has been discarded due to failure of these ICs and the difficulty of replacing them.
In my opinion, these ICs are best reserved for replacement in equipment that requires them, rather than scavenging them for use in new construction.
Pinouts
- IC packages as viewed from above.
- Dx = binary data input
- Cx = output to cathode for numeral x, goes to ground when active.
Source of Data:
- 7441A: National TTL data book 1976
- 74141: TI TTL data book
- 9315: Fairchild TTL data book 1978
- 9960: Fairchild catalog 1966, observation of device
- 1820-0092: observation of device