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Contents

README

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CD74AC257M

Texas Instruments · Signal Switches, Multiplexers, Decoders · SOIC-16

CD74AC257M from Texas Instruments, in a SOIC-16. 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 S input Select input; routes channel I0 to output when low, channel I1 to output when high.
2 1I0 input Channel 1 input 0; data input selected to 1Y output when select pin is low.
3 1I1 input Channel 1 input 1; data input selected to 1Y output when select pin is high.
4 1Y tri_state Channel 1 output; tri-state multiplexed output driven by selected input and controlled by output enable.
5 2I0 input Channel 2 input 0; data input selected to 2Y output when select pin is low.
6 2I1 input Channel 2 input 1; data input selected to 2Y output when select pin is high.
7 2Y tri_state Channel 2 output; tri-state multiplexed output driven by selected input and controlled by output enable.
8 GND power_in Ground; reference voltage for all signal and power pins.
9 3Y tri_state Channel 3 output; tri-state multiplexed output driven by selected input and controlled by output enable.
10 3I1 input Channel 3 input 1; data input selected to 3Y output when select pin is high.
11 3I0 input Channel 3 input 0; data input selected to 3Y output when select pin is low.
12 4Y tri_state Channel 4 output; tri-state multiplexed output driven by selected input and controlled by output enable.
13 4I1 input Channel 4 input 1; data input selected to 4Y output when select pin is high.
14 4I0 input Channel 4 input 0; data input selected to 4Y output when select pin is low.
15 OE input Output enable, active low; when high forces all outputs to high impedance state regardless of inputs.
16 VCC power_in Positive power supply; 1.5V to 5.5V operating range for AC type, temperature range -55°C to 125°C.

Key specifications

Parameter Value
Manufacturer Texas Instruments
Package SOIC-16
Category Logic
Pins 16

CAD (KiCad official)

  • Symbol: CD74AC257M
  • Footprint: Package_SO:SOIC-16_3.9x9.9mm_P1.27mm
  • 3D model: SOIC-16 (KiCad packages3D, STEP)
  • 3D model files: cd74ac257m-etched.step / cd74ac257m-etched.glb carry the MPN laser-etched on the die in a toggleable Adom.LaserEtch group (Fusion-ready); cd74ac257m.step / cd74ac257m.glb are the bare package body.

Provenance

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

  • Datasheet: Texas Instruments datasheet (29 pp, sha256 f4d61e0b521229dd, retrieved 2026-09-27, tier: lcsc)
  • Datasheet language: Chinese. Pin names, descriptions, and specs on this page were extracted and translated to English by ds2sf; the linked PDF is the manufacturer original.
  • 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