# LM25085ASD

**Texas Instruments** · DC-DC Controllers · WSON-8-EP(3x3)

LM25085ASD from Texas Instruments, in a WSON-8-EP(3x3). 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 | ADJ | passive | Current limit adjust: the current limit threshold is set by an external resistor from VIN to ADJ, together with the external sense resistor or the PFET RDS(ON), and the ADJ pin carries an internal 40 µA current sink with a recommended CADJ of 1000 pF. |
| 2 | RT | input | On-time control and shutdown: an external resistor from VIN to RT sets the buck switch on-time and switching frequency, and grounding this pin shuts down the controller. |
| 3 | FB | input | Voltage feedback from the regulated output to the regulation and over-voltage comparators, with the regulation level at 0.9V. |
| 4 | GND | power_in | Circuit ground, the reference for all internal circuitry. |
| 5 | ISEN | input | Current sense input for current limit detection: connect to the PFET drain when using RDS(ON) sensing, or to the PFET source and sense resistor when using a sense resistor, with Kelvin connections required for accuracy. |
| 6 | PGATE | output | Gate driver output that connects to the gate of the external PFET, swinging between VIN (Q1 off) and the VCC pin voltage (Q1 on). |
| 7 | VCC | power_out | Output of the gate driver bias regulator, regulated approximately 7.7V below VIN with at least 20 mA capability, requiring a low ESR capacitor (0.47 µF) placed close to VIN and VCC. |
| 8 | VIN | power_in | Input supply voltage with an operating range of 4.5V to 42V, requiring a low ESR bypass capacitor located as close as possible to the VIN and GND pins. |
| 9 | EP | passive | Exposed pad (from the footprint; not named in the datasheet pin table). |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Texas Instruments |
| Package | WSON-8-EP(3x3) |
| Category | Power Supply Chip |
| Pins | 9 |

## CAD (KiCad official)

- Symbol: `LM25085ASD`
- Footprint: `Package_SON:WSON-8-1EP_3x3mm_P0.5mm_EP1.6x2.0mm`
- 3D model: WSON-8-EP(3x3) (KiCad packages3D, STEP)
- 3D model files: `lm25085asd-etched.step` / `lm25085asd-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `lm25085asd.step` / `lm25085asd.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/lm25085a) (36 pp, sha256 `941a26173c0d4ed5`, retrieved 2026-10-08, tier: lcsc)
- **Extractor:** parts-factory `2.0.0` / `extract_pins 0.3`, primary `claude-haiku-5-5` (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/lm25085asd-datasheet.pdf)