# LP8861QPWPRQ1

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

LP8861QPWPRQ1 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 | VIN | power_in | Input power pin operating from 4.5 V to 40 V, also serving as positive input for optional current-sense resistor. |
| 2 | LDO | output | Output of internal low-dropout regulator; 1-μF decoupling capacitor must be connected between this pin and noise-free ground. |
| 3 | FSET | input | Boost/SEPIC switching frequency setting controlled by resistor value from 24 kΩ to 219 kΩ connected between this pin and ground. |
| 4 | VDDIO/EN | power_in | Enable input for the device and supply input for digital pins. |
| 5 | FAULT | tri_state | Open-drain fault signal output; may be left floating if unused. |
| 6 | SYNC | input | Synchronization input for boost/SEPIC converter; connect to GND to disable spread spectrum or to VDDIO/EN to enable spread spectrum. |
| 7 | PWM | input | PWM dimming input for LED brightness control. |
| 8 | TSENSE | input | Input for NTC thermistor bridge circuit for temperature sensing; must be left floating if unused. |
| 9 | TSET | input | Reference input for NTC thermistor bridge circuit; must be connected to GND if not used. |
| 10 | ISET | input | LED current setting input controlled by resistor value from 24 kΩ to 129 kΩ connected between this pin and ground. |
| 11 | GND | power_in | Ground reference pin. |
| 12 | OUT4 | output | LED current sink output channel 4; must be connected to GND if unused. |
| 13 | OUT3 | output | LED current sink output channel 3; must be connected to GND if unused. |
| 14 | OUT2 | output | LED current sink output channel 2; must be connected to GND if unused. |
| 15 | OUT1 | output | LED current sink output channel 1; must be connected to GND if unused. |
| 16 | FB | input | Feedback input for boost/SEPIC converter; must be connected to middle of resistor divider between VOUT and ground using feedback resistor values from 5 kΩ to 150 kΩ. |
| 17 | PGND | power_in | Boost/SEPIC converter power ground. |
| 18 | SW | output | Boost/SEPIC switching node connected to internal power FET and external inductor/diode. |
| 19 | SD | output | Power-line FET gate drive output for external MOSFET control; may be left floating if unused. |
| 20 | VSENSE_N | input | Input current sense pin; connect to VIN when optional input current-sense resistor is not used. |
| 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: `LP8861QPWPRQ1`
- Footprint: `Package_SO:TSSOP-20-1EP_4.4x6.5mm_P0.65mm_EP2.15x3.35mm`
- 3D model: HTSSOP-20-EP (KiCad packages3D, STEP)
- 3D model files: `lp8861qpwprq1-etched.step` / `lp8861qpwprq1-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `lp8861qpwprq1.step` / `lp8861qpwprq1.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/lp8861-q1) (43 pp, sha256 `ad8ad167d60c5bfc`, retrieved 2026-10-01, 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 0.3`, 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/lp8861qpwprq1-datasheet.pdf)