ATL431BQDBZR from Texas Instruments, in a SOT-23. 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	CATHODE	passive	Shunt current/voltage input (cathode of the internal shunt reference). Sinks the regulated shunt current; Vcathode is programmed by external divider tied to REF. Absolute max VKA = 40 V, IKA continuous -100 to 150 mA.
2	REF	input	Reference/threshold input, sensed relative to the common anode. Internal bandgap regulates so VREF ~= 2.5 V (2487-2512 mV for B-grade). Reference input current typ 30 nA (max 150 nA); absolute max I(ref) -0.05 to 10 mA.
3	ANODE	passive	Common pin, normally connected to ground. All voltages in the datasheet are referenced to ANODE.

Key specifications

Parameter	Value
Manufacturer	Texas Instruments
Package	SOT-23
Category	PMIC
Pins	3

Ordering variants

ATL431BQDBZR
ATL431BQDBZRDBZT

CAD (KiCad official)

Symbol: ATL431BQDBZR
Footprint: Package_TO_SOT_SMD:SOT-23
3D model: SOT-23 (KiCad packages3D, STEP)

3D model downloads

Two STEP files. Same geometry, different body top:

File	Size	Use it when
`atl431bqdbzr.step`	59 KB	You want the bare part, or you mark your own boards.
`atl431bqdbzr-etched.step`	1.9 MB	You want the part with `ATL431BQDBZR` already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 481 faces against 69 in the bare model. It survives export, section views, and rendering in any CAD tool, and it drops straight into KiCad or Fusion with no extra setup.

Provenance

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

Datasheet: Texas Instruments datasheet (31 pp, sha256 ef107d8a8d5c2bab, retrieved 2026-08-17, tier: manufacturer)
Datasheet language: Chinese. Pin names, descriptions, and specs on this page were extracted and translated to English by ds2sf; the linked PDF is the manufacturer original.
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