HT331VRTZ from HTCSEMI, in a SOT-23-5. 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	+IN	input	Non-inverting comparator input. Common-mode range GND+0.2 V to VCC-0.2 V. Input offset +/-5 mV max, internal hysteresis ~5 mV typ, input resistance >100 GOhm.
2	GND	power_in	Ground / negative supply reference for the comparator.
3	-IN	input	Inverting comparator input. Common-mode range GND+0.2 V to VCC-0.2 V. Datasheet pin-description table mislabels this as '+VIN inverting input'; the pin-configuration diagram (SOT23-5 top view) clearly shows pin 3 as -IN.
4	OUTPUT	output	Comparator digital output, rail-to-rail CMOS/TTL-compatible Class-AB push-pull. VOH >= VCC-0.3 V, VOL <= GND+0.3 V. Short-circuit current to VDD ~25 mA. Rise ~35 ns, fall ~28 ns, propagation delay ~140 ns at 100 mV overdrive.
5	VCC	power_in	Positive supply. Operating range 2.7-5.5 V (absolute max 5.5 V). Quiescent current ~200 uA. PSRR ~63 dB.

Key specifications

Parameter	Value
Manufacturer	HTCSEMI
Package	SOT-23-5
Category	Op-amp/Cmp
Pins	5

Ordering variants

Same part, different packaging or reel option.

HT331VRTZ
HT331VRTZRMZ
HT331VRTZRZ

CAD (KiCad official)

Symbol: HT331VRTZ
Footprint: Package_TO_SOT_SMD:SOT-23-5
3D model: SOT-23-5 (KiCad packages3D, STEP)

3D model downloads

Two STEP files. Same geometry, different body top:

File	Size	Use it when
`ht331vrtz.step`	85 KB	You want the bare part, or you mark your own boards.
`ht331vrtz-etched.step`	1.5 MB	You want the part with `HT331VRTZ` already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 389 faces against 102 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: HTCSEMI datasheet (7 pp, sha256 a9fab51f2b1754c2, 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