XD231 from XINLUDA, in a DIP-8. 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	IOUT	output	Current Output. Switched current source output (typ. 135 µA with RS = 14 kΩ). Delivers a precise current pulse (i = 1.90 V / RS) into the RL/CL network at pin 6 during each timer period.
2	IREF	output	Reference Current pin. Held at regulated 1.90 VDC by the internal band-gap reference; an external resistor RS to ground sets the reference current i = 1.90 V / RS (usable 10-500 µA). Can serve as a voltage reference for other components if negligible current is drawn.
3	FOUT	output	Frequency Output. Open-collector logic output (requires external pull-up to VLOGIC). Sinks up to 5 mA with VSAT ≈ 0.15 V; short-circuit-proof up to 40 V. Drives up to 3 TTL loads.
4	GND	power_in	Ground / device common. All voltages are referenced to this pin.
5	RC	input	R-C timing (filter) input. Connects to the external RtCt timing network that sets the one-shot period t = 1.1 × Rt × Ct. Timer comparator trips at 2/3 × VCC (0.667 × VS typ.).
6	THRESH	input	Threshold input (Vx). Inverting input of the input comparator; tied to the RL/CL integrating node. Compared against the signal at pin 7 to trigger the one-shot timer.
7	COMPIN	input	Comparator Input (V1). Non-inverting input of the precision input comparator (typ. bias -90 nA, common-mode range -0.2 V to VCC-2 V). Applied signal voltage that programs the output frequency.
8	VS	power_in	Positive supply voltage (VS / VCC). Operating range 4 V to 40 V (abs. max 40 V). Bypass to GND with a 1 µF low-ESR (X7R) capacitor placed close to the pin.

Key specifications

Parameter	Value
Manufacturer	XINLUDA
Package	DIP-8
Category	Data Acquisition
Pins	8

Ordering variants

Same part, different packaging or reel option.

XD231

CAD (KiCad official)

Symbol: XD231
Footprint: Package_DIP:DIP-8_W7.62mm
3D model: DIP-8 (KiCad packages3D, STEP)

Provenance

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

Datasheet: XINLUDA datasheet (20 pp, sha256 bb745b5e85acba0a, 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