Loads on click. Unloads only if this page sits in the background.

Symbol & Footprint

Schematic Symbol

Open full view ↗
Loads on click. Unloads only if this page sits in the background.

PCB Footprint

Open full view ↗
Loads on click. Unloads only if this page sits in the background.
Loads on click. Unloads only if this page sits in the background.
Download PDF
Contents

README

markdown

SN74F161ADR

Texas Instruments · Counters, Dividers · SOIC-16

SN74F161ADR 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 CLR input Asynchronous clear input; low logic level sets all four flip-flop outputs to low, independent of clock, load, and count-enable inputs.
2 CLK input Buffered clock input; triggers all four flip-flops on the rising (positive-going) edge, providing synchronous operation.
3 A input Preset data input A; loaded into QA output on next clock pulse when LOAD is low.
4 B input Preset data input B; loaded into QB output on next clock pulse when LOAD is low.
5 C input Preset data input C; loaded into QC output on next clock pulse when LOAD is low.
6 D input Preset data input D; loaded into QD output on next clock pulse when LOAD is low.
7 ENP input Count enable parallel input; counter counts only when both ENP and ENT are high.
8 GND power_in Ground; circuit return and negative terminal of power supply.
9 VCC power_in Positive supply voltage; recommended operating range 4.5 V to 5.5 V, nominal 5 V.
10 RCO output Ripple-carry output; produces high-logic-level pulse while count is 15 (HHHH) when ENT is high, for cascading counters.
11 QA output Output for bit A of the 4-bit binary counter; changes synchronously with clock when counter is enabled.
12 QB output Output for bit B of the 4-bit binary counter; changes synchronously with clock when counter is enabled.
13 QC output Output for bit C of the 4-bit binary counter; changes synchronously with clock when counter is enabled.
14 QD output Output for bit D of the 4-bit binary counter; changes synchronously with clock when counter is enabled.
15 ENT input Count enable trickle input; fed forward to enable RCO output, counter counts only when both ENP and ENT are high.
16 LOAD input Synchronous load/preset input; low logic level causes outputs to agree with preset data after next clock pulse, disabling count function.

Key specifications

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

CAD (KiCad official)

  • Symbol: SN74F161ADR
  • Footprint: Package_SO:SOIC-16_3.9x9.9mm_P1.27mm
  • 3D model: SOIC-16 (KiCad packages3D, STEP)
  • 3D model files: sn74f161adr-etched.step / sn74f161adr-etched.glb carry the MPN laser-etched on the die in a toggleable Adom.LaserEtch group (Fusion-ready); sn74f161adr.step / sn74f161adr.glb are the bare package body.

Provenance

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

  • Datasheet: Texas Instruments datasheet (19 pp, sha256 7d7adc74f7e40595, retrieved 2026-09-27, tier: manufacturer)
  • 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