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74HC32 Quad OR Gate

Four 2-input OR gates, in the same pin arrangement as the 74HC00 and 74HC08.

1.Pinout diagram

Pins 1-7

74HC32

Pins 8-14

Pin detail

Hover a pin for its mappings and gotchas. Click to keep it here.

Fig. 1. 74HC32 Quad OR Gate, PDIP-14. Hover or tap a signal to light up every pin that carries it.

OR combines two active-high signals, which in practice most often means merging two interrupt or alarm sources.
Same pin arrangement as the 74HC00, 74HC08 and 74HC86. Only the part marking distinguishes them.
For active-low signals you usually want an AND instead, or just wire open-drain outputs together and save the chip.
HC inputs need a level near their own rail. Driving a 5 V part from 3.3 V logic wants the HCT version.

What has to go around the chip before it will run.

Fig. 2. Minimum circuit, drawn from Table 1. Crossing wires are not connected.

Table 1. External parts, and why each one is there.
Part	Between	Why
Wire link	1B (2) to GND	One input low makes the gate a buffer for the other, the OR equivalent of tying an AND input high.
Wire link	4A (12) to GND	Unused inputs go to a rail. Floating CMOS inputs oscillate and draw supply current.
Wire link	4B (13) to GND	The other input of the same unused gate.
100 nF	VCC (14) to GND	Supply decoupling at the pin.

On an OR gate an unused input must go low, not high: tie it high and the output is stuck at 1 forever. The opposite of the rule for an AND gate.

Every pin, alias and mapping. This is the table that prints.

Table 2. Pin assignments.

Complete pin reference for 74HC32 Quad OR Gate
Pin	Name	Also called	Functions	Notes
1	1A	-	Gate 1 input A
2	1B	-	Gate 1 input B
3	1Y	-	Gate 1 output (OR)
4	2A	-	Gate 2 input A
5	2B	-	Gate 2 input B
6	2Y	-	Gate 2 output (OR)
7	GND	-	Ground
8	3Y	-	Gate 3 output (OR)	Output comes first on this side.
9	3A	-	Gate 3 input A
10	3B	-	Gate 3 input B
11	4Y	-	Gate 4 output (OR)
12	4A	-	Gate 4 input A
13	4B	-	Gate 4 input B
14	VCC2-6 V	-	Positive supply	100 nF at the pin.

Found a wrong pin? The whole board is one file, data/boards/sn74hc32.json.