# FS432M

**FOSAN** · Voltage Reference · SOT-23

FS432M from FOSAN, in a SOT-23. 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 | REF | input | Reference input pin (R) that sets the output voltage via the R1/R2 divider, with VREF of 1.240 V typ and absolute max reference input current of 3 mA. |
| 2 | CATHODE | passive | Cathode (K) of the shunt regulator, rated for up to 20 V cathode-to-anode voltage and 100 mA cathode current. |
| 3 | ANODE | power_in | Anode (A) of the shunt regulator, normally connected to ground as the lowest-potential reference. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | FOSAN |
| Package | SOT-23 |
| Category | Power Management (PMIC) |
| Pins | 3 |

## Electrical characteristics

Limits as printed in the datasheet (page.json `metadata.characteristics` carries them as data).

| Parameter | Symbol | Min | Typ | Max | Unit | Conditions | Page |
|---|---|---|---|---|---|---|---|
| Cathode to Anode Voltage | VKA |  |  | 20 | V |  | 1 |
| Cathode Current Range | IK |  |  | 100 | mA |  | 1 |
| Reference Input Current Range | IREF |  |  | 3 | mA |  | 1 |
| Power dissipation | PD |  |  | 200 | mW |  | 1 |
| Thermal Resistance Junction-Ambient | RΘJA |  | 625 |  | ℃/W |  | 1 |
| Solder Temperature/time | Td |  |  | 260 | ℃/S | 10 s | 1 |
| Operating Ambient Temperature | Top | 0 |  | 70 | ℃ |  | 1 |
| Junction and Storage Temperature | TJ,Tstg | -40 |  | 125 | ℃ |  | 1 |
| Reference Input Voltage (0.5% grade) | VREF | 1.234 | 1.24 | 1.247 | V | VKA=VREF IKA=10mA Ta=25℃; 0.5% grade | 2 |
| Reference Input Voltage (1% grade) | VREF | 1.228 | 1.24 | 1.252 | V | VKA=VREF IKA=10mA Ta=25℃; 1% grade | 2 |
| Deviation of reference Input Voltage Over temperature | ΔVREF/ΔT |  | 10 | 25 | mV | VKA=VREF IKA=10mA 0 ~ 70℃ | 2 |
| Ratio of Change in Reference Input Voltage to Change in Cathode Voltage | ΔVREF/ΔVKA |  | -1 | -2.7 | mV/V | IKA=10mA ΔVKA=18V~VREF | 2 |
| Reference Input Current | IREF |  | 0.25 | 0.5 | µA | IKA=10mA R1=10kΩ,R2=∞ | 2 |
| Deviation of Reference Input Current Over Full Temperature Range | ΔIREF/ΔT |  | 0.05 | 0.3 | µA | IKA=10mA R1=10kΩ,R2=∞ TA=0~70℃ | 2 |
| Minimum Cathode Current for Regulation | IKA(MIN) |  | 60 | 80 | mA | VKA=VREF | 2 |
| Off-state Cathode Current | IKA(OFF) |  | 0.04 | 0.5 | µA | VKA=18V VREF=0V | 2 |
| Dynamic Impedance | ZKA |  | 0.2 | 0.4 | Ω | VKA=VREF IKA=1 ~ 100mA f≤1kHz | 2 |

## CAD (KiCad official)

- Symbol: `FS432M`
- Footprint: `Package_TO_SOT_SMD:SOT-23`
- 3D model: SOT-23 (KiCad packages3D, STEP)
- 3D model files: `fs432m-etched.step` / `fs432m-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `fs432m.step` / `fs432m.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [FOSAN datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8757315884539232256) (3 pp, sha256 `b15dc1ebb377ef62`, retrieved 2026-10-18, tier: lcsc)
- **Datasheet language:** Chinese. Pin names, descriptions, and specs on this page were extracted and translated to English by ds2sf; the linked PDF is the manufacturer original.
- **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/fs432m-datasheet.pdf)