PCA9535PWR from Texas Instruments, 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	INT	output	Open-drain, active-low interrupt output. Asserts when any input state differs from its corresponding Input Port register value; requires an external pullup to VCC.
2	A1	input	I2C address input bit 1. Tie directly to VCC or GND to program the fixed I2C slave address (up to eight devices per bus).
3	A2	input	I2C address input bit 2. Tie directly to VCC or GND to program the fixed I2C slave address.
4	P00	bidirectional	Port 0 bit 0 general-purpose I/O. Push-pull structure, 5-V tolerant; configurable as input or output via the I2C Configuration register. Sink up to 25 mA / source up to 10 mA per pin.
5	P01	bidirectional	Port 0 bit 1 general-purpose I/O. Push-pull, 5-V tolerant; direction and polarity set via I2C registers.
6	P02	bidirectional	Port 0 bit 2 general-purpose I/O. Push-pull, 5-V tolerant; direction and polarity set via I2C registers.
7	P03	bidirectional	Port 0 bit 3 general-purpose I/O. Push-pull, 5-V tolerant; direction and polarity set via I2C registers.
8	P04	bidirectional	Port 0 bit 4 general-purpose I/O. Push-pull, 5-V tolerant; direction and polarity set via I2C registers.
9	P05	bidirectional	Port 0 bit 5 general-purpose I/O. Push-pull, 5-V tolerant; direction and polarity set via I2C registers.
10	P06	bidirectional	Port 0 bit 6 general-purpose I/O. Push-pull, 5-V tolerant; direction and polarity set via I2C registers.
11	P07	bidirectional	Port 0 bit 7 general-purpose I/O. Push-pull, 5-V tolerant; octal current limited to 100 mA total for P00-P07.
12	GND	power_in	Ground reference. Continuous current through GND rated to -250 mA.
13	P10	bidirectional	Port 1 bit 0 general-purpose I/O. Push-pull, 5-V tolerant; direction and polarity set via I2C registers.
14	P11	bidirectional	Port 1 bit 1 general-purpose I/O. Push-pull, 5-V tolerant; direction and polarity set via I2C registers.
15	P12	bidirectional	Port 1 bit 2 general-purpose I/O. Push-pull, 5-V tolerant; direction and polarity set via I2C registers.
16	P13	bidirectional	Port 1 bit 3 general-purpose I/O. Push-pull, 5-V tolerant; direction and polarity set via I2C registers.
17	P14	bidirectional	Port 1 bit 4 general-purpose I/O. Push-pull, 5-V tolerant; direction and polarity set via I2C registers.
18	P15	bidirectional	Port 1 bit 5 general-purpose I/O. Push-pull, 5-V tolerant; direction and polarity set via I2C registers.
19	P16	bidirectional	Port 1 bit 6 general-purpose I/O. Push-pull, 5-V tolerant; direction and polarity set via I2C registers.
20	P17	bidirectional	Port 1 bit 7 general-purpose I/O. Push-pull, 5-V tolerant; octal current limited to 100 mA total for P10-P17.
21	A0	input	I2C address input bit 0. Tie directly to VCC or GND to program the fixed I2C slave address.
22	SCL	input	I2C serial clock input. Requires an external pullup resistor to VCC; supports Standard and Fast mode up to 400 kHz.
23	SDA	bidirectional	I2C serial data line, open-drain. Requires an external pullup resistor to VCC.
24	VCC	power_in	Supply voltage input, 2.3 V to 5.5 V. Continuous current through VCC rated to 160 mA; bypass locally to GND.

Key specifications

Parameter	Value
Manufacturer	Texas Instruments
Package	TSSOP-24
Category	Comm/UART
Pins	24

Ordering variants

Same part, different packaging or reel option.

PCA9535PWR
PCA9535PWRDB
PCA9535PWRDBR
PCA9535PWRDBQ
PCA9535PWRDBQR
PCA9535PWRDGV
PCA9535PWRDGVR
PCA9535PWRDW
PCA9535PWRDWR
PCA9535PWRRGE
PCA9535PWRRGER
PCA9535PWRRTW
PCA9535PWRRTWR

CAD (KiCad official)

Symbol: PCA9535PWR
Footprint: Package_SO:TSSOP-24_4.4x7.8mm_P0.65mm
3D model: TSSOP-24 (KiCad packages3D, STEP)

3D model downloads

Two STEP files. Same geometry, different body top:

File	Size	Use it when
`pca9535pwr.step`	315 KB	You want the bare part, or you mark your own boards.
`pca9535pwr-etched.step`	3.1 MB	You want the part with `PCA9535PWR` already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 764 faces against 387 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: Texas Instruments datasheet (51 pp, sha256 83403a8bf8ce02e6, retrieved 2026-08-17, tier: manufacturer)
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