# LM311DR-CN

**ChipNobo** · Comparators · SOP-8

LM311DR-CN from ChipNobo, in a SOP-8. Pinout and pin descriptions extracted from the manufacturer datasheet (extract_pins, cross-checked by a second model); symbol, footprint, and 3D from KiCad-official CAD.

## Pinout

| Pin | Name | Type | Function |
|---|---|---|---|
| 1 | EMIT OUT | output | Emitter output of the open-emitter output transistor; voltage from emitter output to VCC- is limited to 30 V maximum. |
| 2 | IN+ | input | Non-inverting comparator input; input voltage is limited to ±15 V and differential input voltage to ±30 V. |
| 3 | IN- | input | Inverting comparator input; input voltage is limited to ±15 V and differential input voltage to ±30 V. |
| 4 | VCC- | power_in | Negative supply (ground in single-supply operation); dual supply is ±1.75 V to ±15 V recommended, ±18 V absolute maximum. |
| 5 | BALANCE | input | Offset balance input used for input offset adjustment. |
| 6 | BAL/STRB | input | Balance/strobe input; if the strobe is low the output is off regardless of differential input, and it must be current driven at -3 mA to -5 mA, never shorted to ground. |
| 7 | COL OUT | output | Open-collector output that can switch up to 40 V at 50 mA and can be wire-OR connected; voltage from collector output to VCC- is 40 V maximum. |
| 8 | VCC+ | power_in | Positive supply; single supply is 3.5 V to 30 V recommended, 36 V absolute maximum. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | ChipNobo |
| Package | SOP-8 |
| Category | Amplifiers/Comparators |
| Pins | 8 |

## CAD (KiCad official)

- Symbol: `LM311DR-CN`
- Footprint: `Package_SO:SOIC-8_3.9x4.9mm_P1.27mm`
- 3D model: SOP-8 (KiCad packages3D, STEP)
- 3D model files: `lm311dr-cn-etched.step` / `lm311dr-cn-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `lm311dr-cn.step` / `lm311dr-cn.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [ChipNobo datasheet](docs/lm311dr-cn-datasheet.pdf) (6 pp, sha256 `19797b9635eb3523`, retrieved 2026-10-09, tier: lcsc)
- **Extractor:** parts-factory `2.0.0` / `extract_pins 0.3`, primary `claude-sonnet-5-5` (text+vision), consensus `claude-opus-5-5` (agreed), guards: pin_guards 0.1: passed. Pins are checked against the footprint pad set and their cited datasheet pages before publish.
- **CAD:** KiCad official libraries (CC-BY-SA 4.0).

[Datasheet PDF](docs/lm311dr-cn-datasheet.pdf)