# FAN5333ASX

**onsemi** · LED Drivers · SOT-23-5

FAN5333ASX from onsemi, in a SOT-23-5. 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 | SW | passive | Switching node connected to the internal N-channel switch; the datasheet gives an SW to GND absolute maximum range of −0.3 V to 35 V. |
| 2 | GND | power_in | Analog and power ground; the datasheet recommends a PCB ground plane connected to this pin as an EMI shield. |
| 3 | FB | input | Feedback pin that connects to the external current-set resistor divider; for the FAN5333A (this MPN) the feedback voltage is 110 mV typical (99 mV to 121 mV), and FB to GND is limited to −0.3 V to VIN + 0.3 V. |
| 4 | SHDN | input | Shutdown control where logic HIGH enables and logic LOW disables the device, with a device-on threshold of 1.5 V and device-off threshold of 0.5 V; SHDN to GND is limited to −0.3 V to VIN + 0.3 V. |
| 5 | VIN | power_in | Input voltage pin with a recommended operating range of 1.8 V to 5.5 V and an absolute maximum VIN to GND of 6.0 V. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | onsemi |
| Package | SOT-23-5 |
| Category | LED Drivers |
| Pins | 5 |

## Electrical characteristics

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

| Parameter | Symbol | Min | Typ | Max | Unit | Conditions | Page |
|---|---|---|---|---|---|---|---|
| Feedback Voltage (FAN5333A, 110 mV variant) | VFB | 99 | 110 | 121 | mV |  | 3 |
| Switch Current Limit | ILIM | 1.1 | 1.5 |  | A | VIN = 3.2 V | 3 |
| Switching Frequency | fSW | 1.2 | 1.5 | 1.8 | MHz |  | 3 |
| Maximum Duty Cycle | DMAX | 87 | 93 |  | % |  | 3 |
| Shutdown Threshold, Device ON | VSHDN | 1.5 |  |  | V | Device ON | 3 |
| Shutdown Threshold, Device OFF | VSHDN |  |  | 0.5 | V | Device OFF | 3 |
| OFF Mode Current | IOFF |  | 0.1 | 3 | µA | VSHDN = 0 V | 3 |
| Shutdown Pin Bias Current | ISHDN |  | 1 | 300 | nA | VSHDN = 0 V or VSHDN = 5.5 V | 3 |
| Feedback Pin Bias Current | IFB |  | 1 | 300 | nA |  | 3 |
| Load Current Capability | ILOAD |  | 65 |  | mA | VOUT ≤ 20 V, VIN = 3.2 V | 3 |
| Switch On-resistance | RDS(ON) |  | 0.6 |  |  | VIN = 5 V | 3 |
| Switch On-resistance | RDS(ON) |  | 0.7 |  |  | VIN = 3.6 V | 3 |
| Quiescent Current | IQ |  | 0.6 |  | mA | VSHDN = 3.6 V, No Switching | 3 |
| Feedback Voltage Line Regulation |  |  | 0.3 |  | % | 2.7 V < VIN < 5.5 V, VOUT ≤ 20 V | 3 |
| Switch Leakage Current |  |  | 1 |  | µA | No Switching, VIN = 5.5 V | 3 |
| OVP (over-voltage protection threshold above nominal) |  |  | 15 |  | % |  | 3 |
| Thermal Shutdown Temperature |  |  | 150 |  | °C |  | 3 |
| Input Voltage | VIN | 1.8 |  | 5.5 | V |  | 3 |
| Output Voltage | VOUT |  |  | 30 | V |  | 3 |
| Operating Ambient Temperature | TA | -40 | 25 | 85 | °C |  | 3 |
| Output Capacitance (rated at required output) | COUT | 0.47 |  |  | µF | For maximum load current | 3 |
| VIN to GND | VIN |  |  | 6 | V |  | 3 |
| FB, SHDN to GND |  | -0.3 |  |  | V | Maximum printed as VIN + 0.3 V | 3 |
| SW to GND |  | -0.3 |  | 35 | V |  | 3 |
| Lead Soldering Temperature |  |  |  | 300 | °C | 10 seconds | 3 |
| Junction Temperature | TJ |  |  | 150 | °C |  | 3 |
| Storage Temperature | TSTG | -55 |  | 150 | °C |  | 3 |
| Thermal Resistance (junction to ambient) | RθJA |  | 210 |  | °C/W |  | 3 |
| Electrostatic Discharge Protection, HBM | ESD |  | 2 |  | kV | HBM, EIA/JESD22-A114B | 3 |
| Electrostatic Discharge Protection, CDM | ESD |  | 1 |  | kV | CDM, EIA/JESD22-C101-A | 3 |

## CAD (KiCad official)

- Symbol: `FAN5333ASX`
- Footprint: `Package_TO_SOT_SMD:SOT-23-5`
- 3D model: SOT-23-5 (KiCad packages3D, STEP)
- 3D model files: `fan5333asx-etched.step` / `fan5333asx-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `fan5333asx.step` / `fan5333asx.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [onsemi datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8589977327133224961) (10 pp, sha256 `48c0d98df2bf045f`, retrieved 2026-10-20, 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/fan5333asx-datasheet.pdf)