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Contents

README

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SN74HC257DR

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

SN74HC257DR from Texas Instruments, in a SOIC-16. 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 A/B input Common address-select input for all four channels; low selects A data inputs, high selects B data inputs.
2 1A input Data input A for channel 1; selected when A/B is low and G is low.
3 1B input Data input B for channel 1; selected when A/B is high and G is low.
4 1Y tri_state Non-inverting 3-state output for channel 1; enters high-impedance state when G is high; ±6 mA drive at 5 V.
5 2A input Data input A for channel 2; selected when A/B is low and G is low.
6 2B input Data input B for channel 2; selected when A/B is high and G is low.
7 2Y tri_state Non-inverting 3-state output for channel 2; enters high-impedance state when G is high; ±6 mA drive at 5 V.
8 GND power_in Ground supply reference; continuous current rating ±70 mA.
9 3Y tri_state Non-inverting 3-state output for channel 3; enters high-impedance state when G is high; ±6 mA drive at 5 V.
10 3B input Data input B for channel 3; selected when A/B is high and G is low.
11 3A input Data input A for channel 3; selected when A/B is low and G is low.
12 4Y tri_state Non-inverting 3-state output for channel 4; enters high-impedance state when G is high; ±6 mA drive at 5 V.
13 4B input Data input B for channel 4; selected when A/B is high and G is low.
14 4A input Data input A for channel 4; selected when A/B is low and G is low.
15 ~{G} input Active-low output-enable (strobe) input common to all channels; high level forces all four Y outputs into the high-impedance state.
16 VCC power_in Positive supply voltage; recommended operating range 2 V to 6 V; continuous current rating ±70 mA.

Key specifications

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

CAD (KiCad official)

  • Symbol: SN74HC257DR
  • Footprint: Package_SO:SOIC-16_3.9x9.9mm_P1.27mm
  • 3D model: SOIC-16 (KiCad packages3D, STEP)
  • 3D model files: sn74hc257dr-etched.step / sn74hc257dr-etched.glb carry the MPN laser-etched on the die in a toggleable Adom.LaserEtch group (Fusion-ready); sn74hc257dr.step / sn74hc257dr.glb are the bare package body.

Provenance

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

  • Datasheet: Texas Instruments datasheet (29 pp, sha256 d8caefbacd746d02, retrieved 2026-09-21, tier: manufacturer)
  • Extractor: parts-factory 2.0.0 / extract_pins 0.2, primary claude-sonnet-4-6 (text+vision), consensus claude-opus-4-7 (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