PI4MSD5V9548ALEX from Diodes Incorporated, in a TSSOP-24. 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	A0	input	Address input 0. Combined with A1/A2 to form the lower three bits of the 7-bit I2C slave address (fixed prefix 1110). Tie to VCC or GND.
2	A1	input	Address input 1. Hardware-selectable slave address bit; tie to VCC or GND.
3	RESET	input	Active-LOW reset input. Asserting LOW for at least tw(rst)L resets the internal register and I2C state machine, deselecting all channels. Must be pulled up to VCC through a resistor.
4	SD0	bidirectional	Serial data line for downstream channel 0. Switched to/from the upstream SDA when channel 0 is enabled in the control register.
5	SC0	bidirectional	Serial clock line for downstream channel 0. Switched to/from the upstream SCL when channel 0 is enabled.
6	SD1	bidirectional	Serial data line for downstream channel 1.
7	SC1	bidirectional	Serial clock line for downstream channel 1.
8	SD2	bidirectional	Serial data line for downstream channel 2.
9	SC2	bidirectional	Serial clock line for downstream channel 2.
10	SD3	bidirectional	Serial data line for downstream channel 3.
11	SC3	bidirectional	Serial clock line for downstream channel 3.
12	GND	power_in	Device supply ground reference.
13	SD4	bidirectional	Serial data line for downstream channel 4.
14	SC4	bidirectional	Serial clock line for downstream channel 4.
15	SD5	bidirectional	Serial data line for downstream channel 5.
16	SC5	bidirectional	Serial clock line for downstream channel 5.
17	SD6	bidirectional	Serial data line for downstream channel 6.
18	SC6	bidirectional	Serial clock line for downstream channel 6.
19	SD7	bidirectional	Serial data line for downstream channel 7.
20	SC7	bidirectional	Serial clock line for downstream channel 7.
21	A2	input	Address input 2. Hardware-selectable slave address bit; tie to VCC or GND.
22	SCL	bidirectional	Upstream I2C serial clock line. Requires external pull-up to VPU1 (typically the master's bus voltage).
23	SDA	bidirectional	Upstream I2C serial data line. Requires external pull-up to VPU1.
24	VCC	power_in	Positive supply voltage, 1.65 V to 5.5 V. Also sets the maximum voltage passed by the switch pass gates (Vpass), providing simple voltage-level translation between the upstream and downstream buses.

Key specifications

Parameter	Value
Manufacturer	Diodes Incorporated
Package	TSSOP-24
Category	Logic
Pins	24

Ordering variants

Same part, different packaging or reel option.

PI4MSD5V9548ALEX
PI4MSD5V9548ALEXZD

CAD (KiCad official)

Symbol: PI4MSD5V9548ALEX
Footprint: Package_SO:TSSOP-24_4.4x7.8mm_P0.65mm
3D model: TSSOP-24 (KiCad packages3D, STEP)

Provenance

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

Datasheet: Diodes Incorporated datasheet (14 pp, sha256 c09e71838e2ca2e4, 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