# TLC5971PWPR

**Texas Instruments** · LED Drivers · HTSSOP-20-EP

TLC5971PWPR from Texas Instruments, in a HTSSOP-20-EP. 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 | IREF | input | Maximum current programming terminal; external resistor between IREF and GND sets maximum output current (60 mA max), or direct connection to GND forces all outputs off. |
| 2 | GND | power_in | Power ground terminal with exposed thermal PowerPAD on bottom side of package. |
| 3 | OUTR0 | output | RED constant-current sink output channel 0; 60 mA maximum per channel. |
| 4 | OUTG0 | output | GREEN constant-current sink output channel 0; 60 mA maximum per channel. |
| 5 | OUTB0 | output | BLUE constant-current sink output channel 0; 60 mA maximum per channel. |
| 6 | OUTR1 | output | RED constant-current sink output channel 1; 60 mA maximum per channel. |
| 7 | OUTG1 | output | GREEN constant-current sink output channel 1; 60 mA maximum per channel. |
| 8 | OUTB1 | output | BLUE constant-current sink output channel 1; 60 mA maximum per channel. |
| 9 | SDTI | input | Serial data input for 224-bit shift register; data shifted to LSB on SCKI rising edge. |
| 10 | SCKI | input | Serial data shift clock input; maximum frequency 20 MHz; controls shifting of data toward MSB in shift register. |
| 11 | SCKO | output | Serial data shift clock output; input SCKI signal adjusted to timing of SDTO and output at SCKO. |
| 12 | SDTO | output | Serial data output of 224-bit shift register; connected to MSB and clocked out on SCKI rising edge. |
| 13 | OUTR2 | output | RED constant-current sink output channel 2; 60 mA maximum per channel. |
| 14 | OUTG2 | output | GREEN constant-current sink output channel 2; 60 mA maximum per channel. |
| 15 | OUTB2 | output | BLUE constant-current sink output channel 2; 60 mA maximum per channel. |
| 16 | OUTR3 | output | RED constant-current sink output channel 3; 60 mA maximum per channel. |
| 17 | OUTG3 | output | GREEN constant-current sink output channel 3; 60 mA maximum per channel. |
| 18 | OUTB3 | output | BLUE constant-current sink output channel 3; 60 mA maximum per channel. |
| 19 | VCC | power_in | Power-supply input terminal; operating range 6 V to 17 V with internal regulator or 3 V to 5.5 V when VREG supplied externally. |
| 20 | VREG | power_out | Internal linear voltage regulator output providing 3.3 V nominal; requires 1 µF minimum decoupling capacitor; can supply external devices or accept external 3 V to 5.5 V supply. |
| 21 | EP | passive | Exposed pad (from the footprint; not named in the datasheet pin table). |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Texas Instruments |
| Package | HTSSOP-20-EP |
| Category | Nixie Tube Driver/LED Driver |
| Pins | 21 |

## CAD (KiCad official)

- Symbol: `TLC5971PWPR`
- Footprint: `Package_SO:TSSOP-20-1EP_4.4x6.5mm_P0.65mm_EP2.15x3.35mm`
- 3D model: HTSSOP-20-EP, generated from the KiCad footprint (body from the F.Fab outline, terminals on the pads, 1.2 mm nominal TSSOP height). Neither the vendor nor KiCad ships a 3D model for this package, so the dimensions are nominal, not the manufacturer's CAD (STEP)
- 3D model files: `tlc5971pwpr-etched.step` / `tlc5971pwpr-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `tlc5971pwpr.step` / `tlc5971pwpr.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [Texas Instruments datasheet](https://www.ti.com/cn/lit/gpn/tlc5971) (47 pp, sha256 `9314545e14dcae46`, retrieved 2026-10-01, tier: lcsc)
- **Extractor:** parts-factory `2.0.0` / `extract_pins 0.3`, primary `claude-haiku-4-5-20251001` (text), consensus `claude-sonnet-5-5` (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](docs/tlc5971pwpr-datasheet.pdf)