74141: BCD to Nixie Driver (7-mA, 60-Volt Outputs)

This device is intended to convert the TTL level 1-2-4-8 BCD outputs of a BCD counter to levels that will drive a Nixie or other neon 1-of-10 indicator.

The cathodes of the Nixie tube are connected to the outputs as indicated. The Nixie tube anode is connected to a suitable high-voltage supply, typically +175 volts DC, through a current-limiting resistor, typically 15K. (Consult readout data sheet for more information.)

One, and only one, output is pulled low per selected input code. Codes 10 through 15 (1010 through 1111) are considered invalid and may be used to blank the outputs, leaving all outputs high.

For non-Nixie applications, the outputs will withstand up to 60 volts and can sink up to 7 milliamperes in the low condition. The output saturation voltage is high—2.5 volts for a 7-milliampere load.

Note that the supply voltage remains at +5V. Be extremely careful when testing this device. A short from pins 2 to 3, however brief, will destroy the IC.

Pinout
Pin # Pin Assignment
1 Output 8
2 Output 9
3 Input 1
4 Input 8
5 Power (+5V)
6 Input 2
7 Input 4
8 Output 2
9 Output 3
10 Output 7
11 Output 6
12 Ground
13 Output 4
14 Output 5
15 Output 1
16 Output 0

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