# BL1084-CY

**BL Shanghai Belling** · Voltage Regulators - Linear, Low Drop Out (LDO) Regulators · TO-252-2

BL1084-CY from BL Shanghai Belling, in a TO-252-2. 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 | Adj | passive | Adjust pin, which sets the output voltage through two external resistors; adjust pin current is 45 µA typical and 120 µA maximum over 2.85V≤Vin≤4.25V and 10mA≤Iout≤5A. |
| 2 | Vout | power_out | Regulated output, with an adjustable output range of 1.25V to 10V set by the external resistors; the minimum load current is 10mA. |
| 3 | Vin | power_in | Input supply, with a maximum input voltage of 15V and a dropout of 1.4V typical (1.6V maximum) at 5A load current. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | BL Shanghai Belling |
| Package | TO-252-2 |
| 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 |
|---|---|---|---|---|---|---|---|
| Reference Voltage | Vref | 1.225 | 1.25 | 1.275 | V | 10mA≤Iout≤5A, 1.5V≤Vin-Vout≤5V | 3 |
| Line Regulation (BL1084-ADJ) | ΔVout |  | 10 | 40 | mV | Iout=10mA, 2.85V≤Vin≤10V | 3 |
| Load Regulation (BL1084-ADJ) | ΔVout |  | 16 | 50 | mV | Vin-Vout=1.6V, 10mA≤Iout≤5A | 3 |
| Dropout Voltage | Vin-Vout |  | 1.4 | 1.6 | V | ΔVout, ΔVref =1%, Iout=5A | 4 |
| Current Limit | Ilimit |  | 7 |  | A | Vin-Vout=3V, Tj=25℃ | 4 |
| Minimum Load Current (BL1084-ADJ) |  |  | 3 | 10 | mA |  | 4 |
| Quiescent Current | Iq |  | 5 | 10 | mA | Vin=10V | 4 |
| Adjust Pin Current | IAdj |  | 45 | 120 | uA | 2.85V≤Vin≤4.25V, 10mA≤Iout≤5A | 4 |
| Ripple Rejection |  |  | 60 | 65 | dB | F=120Hz, Cout=25uF(tan), Iout=5A, Vin-Vout=3V | 4 |
| Adjust Pin Current Change | Ichange |  | 0.4 | 10 | µA | 10mA≤Iout≤5A, 1.5V≤Vin-Vout≤6V | 4 |
| Temperature Stability |  |  | 0.5 |  | % | Iout=10mA, Vin-Vout=1.5V | 4 |
| Max Input Voltage |  |  |  | 15 | V |  | 2 |
| Operating Junction Temperature (Tj) | Tj |  |  | 150 | C |  | 2 |
| Ambient Temperature (Ta) | Ta | -40 |  |  | C | Printed as -40C -85C; upper value printed as -85C, not transcribed (see review_required) | 2 |
| Storage Temperature (Ts) | Ts | -40 |  |  | C | Printed as -40C -150C; upper value not transcribed (see review_required) | 2 |
| Lead Temperature |  |  |  | 260 | C | 10S | 2 |
| Input Voltage Range (recommended) |  |  |  | 15 | V |  | 2 |
| Operating Junction Temperature (Tj, recommended) | Tj | -20 |  |  | C | Printed as -20C -125C; upper value not transcribed (see review_required) | 2 |
| Thermal Resistance Junction to Case (TO-252) | JC |  | 12.5 |  | ℃ / W |  | 4 |
| Package Thermal Resistance (TO-252) |  |  | 6 |  | ℃ / W |  | 2 |
| Over Temperature Protection |  |  | 150 |  | ℃ |  | 4 |

## CAD (KiCad official)

- Symbol: `BL1084-CY`
- Footprint: `Package_TO_SOT_SMD:TO-252-2`
- 3D model: TO-252-2 (KiCad packages3D, STEP)
- 3D model files: `bl1084-cy-etched.step` / `bl1084-cy-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `bl1084-cy.step` / `bl1084-cy.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/8586203987883773952) (13 pp, sha256 `bb5efe271c8036b3`, retrieved 2026-10-18, 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/bl1084-cy-datasheet.pdf)