LM331AN

Texas Instruments · V/F And F/V Converters · PDIP-8

LM331AN from Texas Instruments, in a PDIP-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	IOUT	output	Current output of the switched current source, which supplies i = 1.90 V/RS to the timing network and is specified at 116 to 156 µA for LM331AN at RS = 14 kΩ with pin 1 at 0 V (136 µA typical).
2	IREF	input	Reference current input where the internal band-gap regulates the pin voltage to about 1.9 V (1.7 to 2.08 V for LM331) and the set resistor RS defines the current, with an operating range of 10 to 500 µA.
3	FOUT	output	Frequency output that is an open-collector output requiring a pullup resistor, with a saturation voltage of 0.5 V maximum at 5 mA and an OFF leakage of 1 µA maximum.
4	GND	power_in	Ground reference for the device; all voltages are measured with respect to GND = 0 V.
5	RC	input	R-C filter input connected to the external RtCt timing network, where the timer threshold is 0.63 to 0.7 × VS (0.667 × VS typical) and the reset saturation voltage is 0.5 V maximum at 5 mA.
6	THRESH	input	Threshold input to the input comparator, which compares it against COMPIN (pin 7), with a common-mode range of −0.2 V to VCC − 2 V and offset voltage of ±10 mV maximum for LM331 (±14 mV over temperature).
7	COMPIN	input	Comparator input for the signal voltage VIN, which the input comparator compares against THRESH (pin 6), with a bias current of −300 nA maximum and an offset current of ±100 nA maximum.
8	VS	power_in	Supply voltage, specified over 4 V to 40 V with an absolute maximum of 40 V.

Key specifications

Parameter	Value
Manufacturer	Texas Instruments
Package	PDIP-8
Category	Data Acquisition
Pins	8

CAD (KiCad official)

Symbol: LM331AN
Footprint: Package_DIP:DIP-8_W7.62mm
3D model: PDIP-8 (KiCad packages3D, STEP)
3D model files: lm331an-etched.step / lm331an-etched.glb carry the MPN laser-etched on the die in a toggleable Adom.LaserEtch group (Fusion-ready); lm331an.step / lm331an.glb are the bare package body.

Provenance

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

Datasheet: Texas Instruments datasheet (24 pp, sha256 a5847f55707c2947, retrieved 2026-10-08, tier: lcsc)
Extractor: parts-factory 2.0.0 / extract_pins 0.3, primary claude-haiku-5-5 (text), consensus claude-sonnet-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

# LM331AN

**Texas Instruments** · V/F And F/V Converters · PDIP-8

LM331AN from Texas Instruments, in a PDIP-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 | IOUT | output | Current output of the switched current source, which supplies i = 1.90 V/RS to the timing network and is specified at 116 to 156 µA for LM331AN at RS = 14 kΩ with pin 1 at 0 V (136 µA typical). |
| 2 | IREF | input | Reference current input where the internal band-gap regulates the pin voltage to about 1.9 V (1.7 to 2.08 V for LM331) and the set resistor RS defines the current, with an operating range of 10 to 500 µA. |
| 3 | FOUT | output | Frequency output that is an open-collector output requiring a pullup resistor, with a saturation voltage of 0.5 V maximum at 5 mA and an OFF leakage of 1 µA maximum. |
| 4 | GND | power_in | Ground reference for the device; all voltages are measured with respect to GND = 0 V. |
| 5 | RC | input | R-C filter input connected to the external RtCt timing network, where the timer threshold is 0.63 to 0.7 × VS (0.667 × VS typical) and the reset saturation voltage is 0.5 V maximum at 5 mA. |
| 6 | THRESH | input | Threshold input to the input comparator, which compares it against COMPIN (pin 7), with a common-mode range of −0.2 V to VCC − 2 V and offset voltage of ±10 mV maximum for LM331 (±14 mV over temperature). |
| 7 | COMPIN | input | Comparator input for the signal voltage VIN, which the input comparator compares against THRESH (pin 6), with a bias current of −300 nA maximum and an offset current of ±100 nA maximum. |
| 8 | VS | power_in | Supply voltage, specified over 4 V to 40 V with an absolute maximum of 40 V. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Texas Instruments |
| Package | PDIP-8 |
| Category | Data Acquisition |
| Pins | 8 |

## CAD (KiCad official)

- Symbol: `LM331AN`
- Footprint: `Package_DIP:DIP-8_W7.62mm`
- 3D model: PDIP-8 (KiCad packages3D, STEP)
- 3D model files: `lm331an-etched.step` / `lm331an-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `lm331an.step` / `lm331an.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/cn/lit/gpn/lm231) (24 pp, sha256 `a5847f55707c2947`, retrieved 2026-10-08, tier: lcsc)
- **Extractor:** parts-factory `2.0.0` / `extract_pins 0.3`, primary `claude-haiku-5-5` (text), consensus `claude-sonnet-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/lm331an-datasheet.pdf)