# BL8531CC3TR33

**BL Shanghai Belling** · DC-DC Converters · SOT-89-3

BL8531CC3TR33 from BL Shanghai Belling, in a SOT-89-3. 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 | GND | power_in | Ground pin of the converter. |
| 2 | OUT | power_in | Output feedback pin that also supplies the internal circuitry; absolute maximum -0.3V to 12V. |
| 3 | LX | passive | Switching pin connected to the inductor and Schottky diode; absolute maximum -0.3V to 6.5V and 0.7A output current. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | BL Shanghai Belling |
| Package | SOT-89-3 |
| 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 |
|---|---|---|---|---|---|---|---|
| Output Voltage (3.3V variant) | Vout | 3.234 | 3.3 | 3.366 | V |  | 3 |
| Input Current | Iin |  | 12 | 15 | uA | Iout=0mA, Vin=Vout*0.6 | 3 |
| Start-up voltage | Vstart |  | 0.8 | 0.9 | V | Iout=1mA, Vin: 0→2V | 3 |
| Hold-on voltage | Vhold |  | 0.6 | 0.7 | V | Iout=1mA, Vin: 2→0V | 3 |
| Quiescent current drawn from power source | IDD |  | 4 | 7 | uA | Without external components, Vout=Vout×1.05 | 3 |
| LX leakage current | ILXleak |  | 0.5 | 5 | uA | Vout=Vlx=6.5V | 3 |
| CE H threshold voltage (rising) | VCEH | 0.8 |  |  | V | VCE: 0→2V | 3 |
| CE H threshold voltage (falling) | VCEL |  |  | 0.3 | V | VCE: 2→0V | 3 |
| Oscillator duty cycle | Maxdty | 70 | 75 | 80 | % | On (Vlx "L") side | 3 |
| Oscillator frequency | Fosc |  | 400 |  | kHz | LX on "L" side, Vout=Vout*0.96 | 3 |
| Switch ON resistance | Rswon |  | 0.5 |  | Ω |  | 3 |
| Efficiency | η |  | 85 |  | % |  | 3 |
| Input Voltage Range (recommended) |  | 0.8 |  |  | V | Recommended: Vout | 3 |
| Inductor | L | 10 | 27 | 100 | μH |  | 3 |
| Input Capacitor | Cin | 0 |  |  | μF |  | 3 |
| Output Capacitor | Cout | 47 | 100 | 220 | μF |  | 3 |
| Ambient Temperature (recommended) | Ta | -40 |  | 85 | °C |  | 3 |
| Output voltage range |  | -0.3 |  | 12 | V |  | 2 |
| LX Voltage |  | -0.3 |  | 6.5 | V |  | 2 |
| CE Pin Voltage |  | -0.3 |  |  | V |  | 2 |
| Lx Pin Output Current |  |  |  | 0.7 | A |  | 2 |
| Operating Junction Temperature | Tj |  |  | 125 | °C |  | 2 |
| Ambient Temperature (absolute maximum) | Ta | -40 |  | 85 | °C |  | 2 |
| Storage Temperature | Ts | -40 |  | 150 | °C |  | 2 |
| Lead Temperature |  |  |  | 260 | °C | 10 s | 2 |
| Power Dissipation (SOT-89-3) | PD |  |  | 500 | mW | SOT-89-3 package | 2 |

## CAD (KiCad official)

- Symbol: `BL8531CC3TR33`
- Footprint: `Package_TO_SOT_SMD:SOT-89-3`
- 3D model: SOT-89-3 (KiCad packages3D, STEP)
- 3D model files: `bl8531cc3tr33-etched.step` / `bl8531cc3tr33-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `bl8531cc3tr33.step` / `bl8531cc3tr33.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [BL Shanghai Belling datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8586182260936069120) (10 pp, sha256 `101c5e9f3cdd194d`, retrieved 2026-10-17, 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/bl8531cc3tr33-datasheet.pdf)