main
History Download
Ray Publish 0.1.0 bf148e7 7d ago

A1121ELHLX-T

Allegro MicroSystems, LLC · Hall Sensor · SOT-23

A1121ELHLX-T from Allegro MicroSystems, LLC, 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 VCC power_in Connects power supply to chip; operating range 3 to 24 V (absolute maximum 26.5 V forward, -30 V reverse), with a 0.1 µF bypass capacitor to GND recommended.
2 VOUT output Open-drain output from circuit that turns on (logic low) in a south-pole field above BOP for the A1121, sinking up to 25 mA continuous with a 26 V maximum off voltage.
3 GND power_in Ground connection for the device.

Key specifications

Parameter Value
Manufacturer Allegro MicroSystems, LLC
Package SOT-23
Category Sensors
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
Forward Supply Voltage (absolute max) VCC 26.5 V 3
Reverse Supply Voltage VRCC -30 V 3
Output Off Voltage VOUT 26 V 3
Continuous Output Current IOUT 25 mA 3
Reverse Output Current IROUT -50 mA 3
Operating Ambient Temperature, Range E TA -40 85 °C Range E 3
Maximum Junction Temperature TJ(max) 165 °C 3
Storage Temperature Tstg -65 170 °C 3
Forward Supply Voltage (operating) VCC 3 24 V Operating, TJ < 165°C 4
Output Leakage Current IOUTOFF 10 µA VOUT = 24 V, B < BRP 4
Output Saturation Voltage VOUT(SAT) 185 500 mV IOUT = 20 mA, B > BOP 4
Output Current Limit IOM 30 60 mA B > BOP 4
Power-On Time tPO 25 µs VCC > 3.0 V, B < BRP(min), 10 G, B > BOP(max) + 10 G 4
Chopping Frequency fC 800 kHz 4
Output Rise Time tr 0.2 2 µs RL = 820 Ω, CS = 20 pF 4
Output Fall Time tf 0.1 2 µs RL = 820 Ω, CS = 20 pF 4
Supply Current (On) ICC(ON) 4 mA VCC = 12 V, B > BOP 4
Supply Current (Off) ICC(OFF) 4 mA VCC = 12 V, B < BRP 4
Reverse Supply Current IRCC -5 mA VRCC = -30 V 4
Supply Zener Clamp Voltage VZ 28 V ICC = 5 mA; TA = 25°C 4
Zener Impedance IZ 50 Ω ICC = 5 mA; TA = 25°C 4
Operate Point BOP 50 95 135 G A1121 5
Release Point BRP 40 70 110 G A1121 5
Hysteresis BHYS 10 25 42 G A1121, BOP, BRP 5
Package Thermal Resistance, LH 1-layer PCB RθJA 228 °C/W Package LH, 1-layer PCB with copper limited to solder pads 6
Package Thermal Resistance, LH 2-layer PCB RθJA 110 °C/W Package LH, 2-layer PCB with 0.463 in.2 of copper area each side connected by thermal vias 6

Materials and finish

As the datasheet states them (page.json metadata.appearance; the 3D model's colours follow it).

Part Material Colour / plating Datasheet says Page
contacts tin SIP for through-hole mounting. Each package type is lead (Pb) free (suffix, -T), with a 100% matte-tin-plated leadframe. 1

CAD (KiCad official)

  • Symbol: A1121ELHLX-T
  • Footprint: Package_TO_SOT_SMD:SOT-23
  • 3D model: SOT-23 (KiCad packages3D, STEP)
  • 3D model files: a1121elhlx-t-etched.step / a1121elhlx-t-etched.glb carry the MPN laser-etched on the die in a toggleable Adom.LaserEtch group (Fusion-ready); a1121elhlx-t.step / a1121elhlx-t.glb are the bare package body.

Provenance

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

  • Datasheet: Allegro MicroSystems, LLC datasheet (18 pp, sha256 708f85ed25b42178, retrieved 2026-10-26, tier: lcsc)
  • Extractor: parts-factory 2.0.0 / extract_pins 0.3, primary claude-sonnet-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