LM2903 Pinout
LM2903 Dual Comparator · Dual voltage comparator, single-supply, open-collector outputs — the automotive-grade twin of the LM393.
| Pin | Name | Type | Function |
|---|---|---|---|
| 1 | OUT1 | Output | Comparator 1 output (open-collector) |
| 2 | IN1− | Input | Comparator 1 inverting input |
| 3 | IN1+ | Input | Comparator 1 non-inverting input |
| 4 | GND · V− | GND | Ground / negative supply |
| 5 | IN2+ | Input | Comparator 2 non-inverting input |
| 6 | IN2− | Input | Comparator 2 inverting input |
| 7 | OUT2 | Output | Comparator 2 output (open-collector) |
| 8 | VCC · V+ | Power | Positive supply (2–36V) |
How to read the LM2903 pinout
- 01
Find pin 1
One end of the chip has a half-circle notch or a dot; with the notch facing up, the top-left pin is pin 1.
- 02
Count counter-clockwise
Count counter-clockwise from pin 1: go down the left side first, then up the right side from the bottom.
- 03
Check the table below
Look up each pin's function by number in the table below; power/ground are color-coded, and alternate-function signals are in parentheses.
Frequently asked questions
Is the LM2903 the same as the LM393?
Effectively yes — same pinout, same open-collector dual-comparator function. The LM2903 is specified over the automotive temperature range; the LM393 is the general/industrial part.
Why does the output need a pull-up resistor?
The outputs are open-collector and can only pull low. Add a pull-up (typically 1–10kΩ) from each used output to your logic supply, or the high state floats.
Pinout data comes from TI LM2903 datasheet (standard DIP-8 numbering). Refer to the actual device datasheet as authoritative for the pinout.