SSP1922 from Shanghai Siproin Microelectronics, in a QFN-32-EP(5x5). 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	XIN	input	High-speed oscillator driver input (2-8 MHz ceramic/crystal). Tie to GND if unused.
2	XOUT	output	High-speed oscillator driver output. Leave floating if unused.
3	VIO	power_in	I/O supply voltage, 2.5 V to 3.6 V. Must equal Vcc for correct operation.
4	GND	power_in	Ground reference. Connect to a solid ground plane.
5	FIRE_UP	output	Fire pulse generator output 1 (upstream). Drives ultrasonic transducer with up to 48 mA, Rdson ~4 Ω.
6	FIRE_DOWN	output	Fire pulse generator output 2 (downstream). Drives ultrasonic transducer with up to 48 mA, Rdson ~4 Ω.
7	FIRE_IN	input	'Sing-around' signal input terminal for continuous ultrasonic measurement. Tie to GND if unused.
8	INTN	output	Interrupt flag output, LOW active. 4 mA drive. Cleared by rising edge of the first SCK.
9	SSN	input	SPI slave select input, LOW active. Required for 4-wire SPI operation.
10	SCK	input	SPI serial clock input. Up to 20 MHz at Vio = 3.3 V (15 MHz at Vio = 2.5 V).
11	SI	input	SPI serial data input (MOSI). MSB-first byte transfers.
12	SO	output	SPI serial data output (MISO). Drives low when SPI bus is free (non-tristate).
13	RSTN	input	Reset input, LOW active. After power-on reset wait ≥500 µs before starting the analog section.
14	VCC	power_in	Core supply voltage, 2.5 V to 3.6 V. Must equal Vio.
15	CLK32OUT	output	32 kHz clock generator output. Leave n.c. if not used.
16	CLK32IN	input	32 kHz clock generator input (crystal / external clock). Tie to GND if unused.
17	SENSET	input	Sense input for temperature measurement (Schmitt trigger). Tie to GND if unused.
18	LOADT	output	Load output for temperature measurement (24 mA drive). Leave n.c. if unused.
19	PT4	output	Port 4 temperature measurement (RTD drive, >96 mA open drain).
20	PT3	output	Port 3 temperature measurement (RTD drive, >96 mA open drain).
21	GND	power_in	Ground reference. Connect to a solid ground plane.
22	VIO	power_in	I/O supply voltage, 2.5 V to 3.6 V (second Vio pin, must equal Vcc).
23	PT2	output	Port 2 temperature measurement (RTD drive, >96 mA open drain).
24	PT1	output	Port 1 temperature measurement (RTD drive, >96 mA open drain).
25	EN_STOP2	input	Enable pin for STOP input 2, HIGH active. Tie to Vio if unused / always enabled.
26	EN_STOP1	input	Enable pin for STOP input 1, HIGH active. Tie to Vio if unused / always enabled.
27	STOP2	input	TDC stop input 2 (analog frontend via ~200 Ω switch). Tie to GND if unused.
28	GND	power_in	Ground reference. Connect to a solid ground plane.
29	VCC	power_in	Core supply voltage (second Vcc pin), 2.5 V to 3.6 V.
30	STOP1	input	TDC stop input 1 (analog frontend via ~200 Ω switch). Tie to GND if unused.
31	START	input	TDC start input. Tie to GND if unused.
32	EN_START	input	Enable pin for START input, HIGH active. Tie to Vio if unused / always enabled.

Key specifications

Parameter	Value
Manufacturer	Shanghai Siproin Microelectronics
Package	QFN-32-EP(5x5)
Category	Sensor
Pins	32

Ordering variants

Same part, different packaging or reel option.

SSP1922
SSP1922P

CAD (KiCad official)

Symbol: SSP1922
Footprint: Package_DFN_QFN:QFN-32-1EP_5x5mm_P0.5mm_EP3.3x3.3mm
3D model: QFN-32-EP(5x5) (KiCad packages3D, STEP)

3D model downloads

Two STEP files. Same geometry, different body top:

File	Size	Use it when
`ssp1922.step`	346 KB	You want the bare part, or you mark your own boards.
`ssp1922-etched.step`	2.1 MB	You want the part with `SSP1922` already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 529 faces against 206 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: Shanghai Siproin Microelectronics datasheet (47 pp, sha256 e322d1593761f7b8, 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