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Contents

README

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TCA9539RTWR

Texas Instruments · I/O Expanders · WQFN-24-EP(4x4)

TCA9539RTWR from Texas Instruments, in a WQFN-24-EP(4x4). Pinout and pin descriptions extracted from the manufacturer datasheet (extract_pins, cross-checked by a second model); symbol, footprint, and 3D from KiCad-official CAD.

Pinout

Pin Name Type Function
1 P00 bidirectional P-port input-output. Push-pull design structure. At power on, P00 is configured as an input.
2 P01 bidirectional P-port input-output. Push-pull design structure. At power on, P01 is configured as an input.
3 P02 bidirectional P-port input-output. Push-pull design structure. At power on, P02 is configured as an input.
4 P03 bidirectional P-port input-output. Push-pull design structure. At power on, P03 is configured as an input.
5 P04 bidirectional P-port input-output. Push-pull design structure. At power on, P04 is configured as an input.
6 P05 bidirectional P-port input-output. Push-pull design structure. At power on, P05 is configured as an input.
7 P06 bidirectional P-port input-output. Push-pull design structure. At power on, P06 is configured as an input.
8 P07 bidirectional P-port input-output. Push-pull design structure. At power on, P07 is configured as an input.
9 GND power_in Ground.
10 P10 bidirectional P-port input-output. Push-pull design structure. At power on, P10 is configured as an input.
11 P11 bidirectional P-port input-output. Push-pull design structure. At power on, P11 is configured as an input.
12 P12 bidirectional P-port input-output. Push-pull design structure. At power on, P12 is configured as an input.
13 P13 bidirectional P-port input-output. Push-pull design structure. At power on, P13 is configured as an input.
14 P14 bidirectional P-port input-output. Push-pull design structure. At power on, P14 is configured as an input.
15 P15 bidirectional P-port input-output. Push-pull design structure. At power on, P15 is configured as an input.
16 P16 bidirectional P-port input-output. Push-pull design structure. At power on, P16 is configured as an input.
17 P17 bidirectional P-port input-output. Push-pull design structure. At power on, P17 is configured as an input.
18 A0 input Address input. Connect directly to VCC or ground.
19 SCL input Serial clock bus. Connect to VCC through a pull-up resistor.
20 SDA bidirectional Serial data bus. Connect to VCC through a pull-up resistor.
21 VCC power_out Supply voltage.
22 INT output Interrupt open-drain output. Connect to VCC through a pull-up resistor.
23 A1 input Address input. Connect directly to VCC or ground.
24 RESET input Active-low reset input. Connect to VCC through a pull-up resistor if no active connection is used.
25 EP passive Exposed pad (from the footprint; not named in the datasheet pin table).

Key specifications

Parameter Value
Manufacturer Texas Instruments
Package WQFN-24-EP(4x4)
Category Interface
Pins 25

CAD (KiCad official)

  • Symbol: TCA9539RTWR
  • Footprint: Package_DFN_QFN:QFN-24-1EP_4x4mm_P0.5mm_EP2.7x2.7mm
  • 3D model: WQFN-24-EP(4x4) (KiCad packages3D, STEP)
  • 3D model files: tca9539rtwr-etched.step / tca9539rtwr-etched.glb carry the MPN laser-etched on the die in a toggleable Adom.LaserEtch group (Fusion-ready); tca9539rtwr.step / tca9539rtwr.glb are the bare package body.

Provenance

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

  • Datasheet: Texas Instruments datasheet (49 pp, sha256 fec29f61c247a467, retrieved 2026-09-24, tier: lcsc)
  • Extractor: parts-factory 2.0.0 / extract_pins 0.2, primary claude-haiku-4-5-20251001 (text), consensus claude-sonnet-4-6 (agreed), guards: pin_guards 0.1: passed. Pins are checked against the footprint pad set and their cited datasheet pages before publish.
  • CAD: KiCad official libraries (CC-BY-SA 4.0).

Datasheet PDF