# LM2903

**Texas Instruments** · Comparator · SOIC-8

The LM2903 is a dual differential comparator with open-collector outputs, able to run from a single 2 V to 36 V supply or a split supply. The open-collector outputs wire-OR and interface to different logic rails through a pull-up. It is the wider-temperature-range sibling of the LM393, common in threshold detection and level sensing.

## Pinout

| Pin | Name | Type | Function |
|---|---|---|---|
| 1 | 1OUT | output | Output pin of comparator 1. Open-collector output; requires an external pull-up resistor to VCC. Compatible with TTL, MOS, and CMOS logic. Low-level output voltage typically 110 mV (400 mV max) at ISINK ≤ 4 mA. |
| 2 | 1IN- | input | Inverting (negative) input of comparator 1. Common-mode input range extends from V- (ground) up to (V+) - 2.0V. Input bias current typically -3.5 nA (-25 nA max). |
| 3 | 1IN+ | input | Non-inverting (positive) input of comparator 1. Common-mode input range extends from V- (ground) up to (V+) - 2.0V. Input bias current typically -3.5 nA (-25 nA max). |
| 4 | GND | power_in | Ground (V-). Negative supply / reference for both comparators. Connect to system ground for single-supply operation. |
| 5 | 2IN+ | input | Non-inverting (positive) input of comparator 2. Common-mode input range extends from V- (ground) up to (V+) - 2.0V. Input bias current typically -3.5 nA (-25 nA max). |
| 6 | 2IN- | input | Inverting (negative) input of comparator 2. Common-mode input range extends from V- (ground) up to (V+) - 2.0V. Input bias current typically -3.5 nA (-25 nA max). |
| 7 | 2OUT | output | Output pin of comparator 2. Open-collector output; requires an external pull-up resistor to VCC. Compatible with TTL, MOS, and CMOS logic. Low-level output voltage typically 110 mV (400 mV max) at ISINK ≤ 4 mA. |
| 8 | VCC | power_in | Positive supply (V+). Operating range 2V to 30V (LM2903), absolute maximum 36V. Quiescent current typically 400 µA (600 µA max) at VS = 5V, no load. |

## Key specifications

| Parameter | Value |
|---|---|
| Type | Dual differential comparator |
| Output | Open-collector |
| Supply voltage | 2 V to 36 V single, or +-1 V to +-18 V |
| Input offset voltage | 2 mV typ |
| Response time | 1.5 us typ |
| Operating temperature | -40 C to 125 C |

## Ordering variants

Same part, different packaging or reel option.

- `LM2903D`
- `LM2903DGK`
- `LM2903P`
- `LM2903PS`
- `LM2903PW`

## CAD (KiCad official)

- Symbol: `lm2903.kicad_sym`
- Footprint: `lm2903.kicad_mod`
- 3D model: SOIC-8 body from KiCad `Package_SO/SOIC-8_3.9x4.9mm_P1.27mm`.
- 3D model files: `lm2903-etched.step` / `lm2903-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `lm2903.step` / `lm2903.glb` are the bare package body.

## Provenance

Data extracted from the manufacturer datasheet, not a distributor listing:

- **Datasheet:** [Texas Instruments datasheet](https://www.ti.com/lit/ds/symlink/lm2903.pdf) (56 pp, sha256 `24c6b3c03dd65dfd`, retrieved 2026-08-17, tier: manufacturer)
- **Extractor:** `ds2sf` (Claude). Every pin and dimension is cited to a datasheet page; it refuses to fabricate.
- **CAD:** KiCad official libraries (CC-BY-SA 4.0).

[Datasheet PDF](docs/lm2903-datasheet.pdf)