M1820B from Mysentech, in a TO-92S. 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	GND	power_in	Ground reference (0 V) for the chip. Connect to the system ground plane.
2	DQ	bidirectional	1-Wire single-bus data I/O. Open-drain/tri-state pin: requires an external pull-up resistor (typ 4.7 kΩ, 1-10 kΩ; use 1 kΩ for long cables or multi-drop). VIL ≤ 0.3·VDD, VIH ≥ 0.7·VDD; VOL ≤ 0.4 V at IOL = −3 mA. Bus idle state is high; a hold-low > 480 µs resets all devices on the bus.
3	VDD	power_in	Positive supply, 1.8-5.5 V (typ 3.3 V; absolute max 6 V). IDD ≈ 0.1 µA idle (single-shot mode), 450 µA peak during conversion, 4.8 µA average at 1 measurement/s. For long cables or multi-drop networks keep VDD ≥ 3.3 V.

Key specifications

Parameter	Value
Manufacturer	Mysentech
Package	TO-92S
Category	Sensor
Pins	3

CAD (KiCad official)

Symbol: M1820B
Footprint: Package_TO_SOT_THT:TO-92_Inline
3D model: TO-92S (KiCad packages3D, STEP)

3D model downloads

Two STEP files. Same geometry, different body top:

File	Size	Use it when
`m1820b.step`	27 KB	You want the bare part, or you mark your own boards.
`m1820b-etched.step`	1.2 MB	You want the part with `M1820B` already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 297 faces against 19 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: Mysentech datasheet (28 pp, sha256 aeda39d8ec9e0fa0, retrieved 2026-08-17, tier: lcsc)
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