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Contents

README

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TCA9555RTWR

UMW · I/O Expanders · VQFN-24-EP(4x4)

TCA9555RTWR from UMW, in a VQFN-24-EP(4x4). 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 P00 bidirectional Port 0 bit 0 quasi-bidirectional I/O. Totem-pole output capable of driving LEDs. Configured as input at power-on. Low-level drive up to 10 mA (VOL=0.7V).
2 P01 bidirectional Port 0 bit 1 quasi-bidirectional I/O. Input at power-on.
3 P02 bidirectional Port 0 bit 2 quasi-bidirectional I/O. Input at power-on.
4 P03 bidirectional Port 0 bit 3 quasi-bidirectional I/O. Input at power-on.
5 P04 bidirectional Port 0 bit 4 quasi-bidirectional I/O. Input at power-on.
6 P05 bidirectional Port 0 bit 5 quasi-bidirectional I/O. Input at power-on.
7 P06 bidirectional Port 0 bit 6 quasi-bidirectional I/O. Input at power-on.
8 P07 bidirectional Port 0 bit 7 quasi-bidirectional I/O. Input at power-on.
9 GND power_in Ground reference. Continuous current through GND rated up to -250 mA.
10 P10 bidirectional Port 1 bit 0 quasi-bidirectional I/O. Input at power-on.
11 P11 bidirectional Port 1 bit 1 quasi-bidirectional I/O. Input at power-on.
12 P12 bidirectional Port 1 bit 2 quasi-bidirectional I/O. Input at power-on.
13 P13 bidirectional Port 1 bit 3 quasi-bidirectional I/O. Input at power-on.
14 P14 bidirectional Port 1 bit 4 quasi-bidirectional I/O. Input at power-on.
15 P15 bidirectional Port 1 bit 5 quasi-bidirectional I/O. Input at power-on.
16 P16 bidirectional Port 1 bit 6 quasi-bidirectional I/O. Input at power-on.
17 P17 bidirectional Port 1 bit 7 quasi-bidirectional I/O. Input at power-on.
18 A0 input I2C slave address input bit 0. Tie directly to VCC or GND to set the 7-bit slave address.
19 SCL input I2C serial clock input. Connect to VCC through a pull-up resistor. VIH >= 0.7*VCC.
20 SDA bidirectional I2C serial data bus, open-drain. Connect to VCC through a pull-up resistor. Low-level sink 3 mA at VOL=0.4V.
21 VCC power_in Supply voltage, 1.6V to 5.5V (typ 3.3V). Continuous current through VCC rated up to 160 mA. Standby current 0.5 uA typ.
22 INT output Active-low, open-drain interrupt output. Asserted when any input port pin changes state. Connect to VCC through a pull-up resistor. Sinks 3 mA at VOL=0.4V.
23 A1 input I2C slave address input bit 1. Tie directly to VCC or GND.
24 A2 input I2C slave address input bit 2 (TCA9555 variant; the same pin is RST on TCA9539). Tie directly to VCC or GND.
25 EP passive Exposed thermal pad on package underside. Recommended to solder to a ground copper plane for thermal dissipation.

Key specifications

Parameter Value
Manufacturer UMW
Package VQFN-24-EP(4x4)
Category Interface
Pins 25

Ordering variants

Same part, different packaging or reel option.

  • TCA9555RTWR
  • TCA9555RTWRPWR
  • TCA9555RTWRDBR

CAD (KiCad official)

  • Symbol: TCA9555RTWR
  • Footprint: Package_DFN_QFN:QFN-24-1EP_4x4mm_P0.5mm_EP2.7x2.7mm
  • 3D model: VQFN-24-EP(4x4) (KiCad packages3D, STEP)
  • 3D model files: tca9555rtwr-etched.step / tca9555rtwr-etched.glb carry the MPN laser-etched on the die in a toggleable Adom.LaserEtch group (Fusion-ready); tca9555rtwr.step / tca9555rtwr.glb are the bare package body.

Provenance

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

  • Datasheet: UMW datasheet (20 pp, sha256 11ecf82339e41b05, 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