Contents

README

markdown

BL8503-40PRM

BL Shanghai Belling · Voltage Regulators - Linear, Low Drop Out (LDO) Regulators · SOT-23-3L

BL8503-40PRM from BL Shanghai Belling, in a SOT-23-3L. Pinout and pin descriptions extracted from the manufacturer datasheet by ds2sf; symbol, footprint, and 3D from KiCad-official CAD.

Pinout

Pin Name Type Function
1 Vss power_in Ground reference (0V). Common return for input and output. Connect to system ground with a low-impedance path.
2 Vout power_out Regulated output voltage (4.0V nominal, ±2%) for the -40 option. Delivers up to 250mA. Requires a 1µF output capacitor (tantalum recommended) for loop stability.
3 Vin power_in Supply voltage input, 1.5V to 10V absolute max (recommended max 8V). Requires a 1µF input capacitor (tantalum recommended). For Vout=4.0V, Vin must exceed Vout + dropout (~4.4V @ 250mA).

Key specifications

Parameter Value
Manufacturer BL Shanghai Belling
Package SOT-23-3L
Category PMIC
Pins 3

Ordering variants

  • BL8503-40PRM
  • BL8503-40PRMPSM
  • BL8503-40PRMPSA
  • BL8503-40PRMPSB
  • BL8503-40PRMPT

CAD (KiCad official)

  • Symbol: BL8503-40PRM
  • Footprint: Package_TO_SOT_SMD:SOT-23-3
  • 3D model: SOT-23-3L (KiCad packages3D, STEP)

Provenance

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

  • Datasheet: BL Shanghai Belling datasheet (None pp, sha256 8f6684221c2cf4c4, retrieved 2026-08-17, tier: lcsc)
  • Extractor: ds2sf (Claude). Every pin and dimension is cited to a datasheet page; it refuses to fabricate.
  • CAD: KiCad official libraries (CC-BY-SA 4.0).

Datasheet PDF

Symbol & Footprint

Schematic Symbol

Open full view ↗

PCB Footprint

Open full view ↗