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SN74HC191DR
Public Made by Adomby adom
Texas Instruments Counters, Dividers, SOIC-16. Pinout cross-checked by two models against the datasheet, KiCad symbol/footprint/3D.
3D Model
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Symbol & Footprint
Schematic Symbol
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PCB Footprint
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Datasheet
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README
markdownSN74HC191DR
Texas Instruments · Counters, Dividers · SOIC-16
SN74HC191DR 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 | B | input | Data input B for parallel load of counter bit 1; active when LOAD is low, allowing the data to be transferred to output QB asynchronously. |
| 2 | QB | output | Counter output bit 1; asynchronously affected by LOAD input data and synchronously affected by CLK when CTEN is low. |
| 3 | QA | output | Counter output bit 0 (least significant bit); asynchronously affected by LOAD input data and synchronously affected by CLK when CTEN is low. |
| 4 | CTEN | input | Count enable input; when low, enables counting; when high, inhibits counting and holds the counter outputs. |
| 5 | D/U | input | Down/up direction control input; when low, counter counts up; when high, counter counts down. |
| 6 | QC | output | Counter output bit 2; asynchronously affected by LOAD input data and synchronously affected by CLK when CTEN is low. |
| 7 | QD | output | Counter output bit 3 (most significant bit); asynchronously affected by LOAD input data and synchronously affected by CLK when CTEN is low. |
| 8 | GND | power_in | Ground reference (0 V connection). |
| 9 | D | input | Data input D for parallel load of counter bit 3 (most significant bit); active when LOAD is low, allowing the data to be transferred to output QD asynchronously. |
| 10 | C | input | Data input C for parallel load of counter bit 2; active when LOAD is low, allowing the data to be transferred to output QC asynchronously. |
| 11 | LOAD | input | Parallel load control input; when low, asynchronously loads data from inputs A, B, C, D into outputs QA, QB, QC, QD, overriding the count operation. |
| 12 | MAX/MIN | output | Maximum/minimum count output; produces a high-level pulse approximately one clock cycle duration when count reaches zero (all outputs low) while counting down or maximum (binary 15) while counting up. |
| 13 | RCO | output | Ripple clock output; produces a low-level pulse under the same conditions as MAX/MIN but only while CLK is low, used for cascading multiple counters. |
| 14 | CLK | input | Clock input; counter outputs change on the low-to-high transition when CTEN is low; operating frequency 2 V to 6 V per recommended operating conditions. |
| 15 | A | input | Data input A for parallel load of counter bit 0 (least significant bit); active when LOAD is low, allowing the data to be transferred to output QA asynchronously. |
| 16 | VCC | power_in | Positive power supply voltage ranging from 2 V to 6 V per recommended operating conditions. |
Key specifications
| Parameter | Value |
|---|---|
| Manufacturer | Texas Instruments |
| Package | SOIC-16 |
| Category | Logic |
| Pins | 16 |
CAD (KiCad official)
- Symbol:
SN74HC191DR - Footprint:
Package_SO:SOIC-16_3.9x9.9mm_P1.27mm - 3D model: SOIC-16 (KiCad packages3D, STEP)
- 3D model files:
sn74hc191dr-etched.step/sn74hc191dr-etched.glbcarry the MPN laser-etched on the die in a toggleableAdom.LaserEtchgroup (Fusion-ready);sn74hc191dr.step/sn74hc191dr.glbare the bare package body.
Provenance
Data extracted from the manufacturer datasheet, not a distributor listing:
- Datasheet: Texas Instruments datasheet (22 pp, sha256
ca8f1cf1eb9fc572, retrieved 2026-09-26, tier: manufacturer) - Extractor: parts-factory
2.0.0/extract_pins 0.2, primaryclaude-haiku-4-5-20251001(text), consensusclaude-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).