# LM34910CSDX

**Texas Instruments** · DC-DC Converters · WSON-10-EP(4x4)

LM34910CSDX from Texas Instruments, in a WSON-10-EP(4x4). 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 | SW | output | Internally connected to the buck switch source; connect to the external inductor, diode, and boost capacitor. |
| 2 | BST | power_out | Boot-strap pin for the gate-drive capacitor; a 0.022 µF capacitor connects from SW to this pin and is charged by an internal diode during the off-time. |
| 3 | ISEN | input | Current sense input; the current sense resistor connects from this pin to SGND, and the current limit is set at 1.25A. |
| 4 | SGND | power_in | Sense ground; re-circulating current flows into this pin to the current sense resistor. |
| 5 | RTN | power_in | Ground for all internal circuitry other than the current limit detection. |
| 6 | FB | input | Feedback input connected internally to the regulation and over-voltage comparators; the regulation level is 2.5V. |
| 7 | SS | passive | An internal 11.5 µA current source charges an external soft-start capacitor to 2.5V to provide the soft-start function. |
| 8 | RON/SD | input | An external resistor from VIN to this pin sets the buck switch on-time; grounding this pin shuts down the regulator. |
| 9 | VCC | power_out | Output of the start-up regulator, nominally regulated to 7.0V; an external 8V-14V auxiliary voltage can be connected to this pin to reduce internal dissipation. |
| 10 | VIN | power_in | Input supply voltage; nominal input range is 8.0V to 50V. |
| 11 | EP (exposed pad) | passive | Exposed thermal pad on the package bottom, which should be soldered to a ground plane for heat dissipation and is internally connected to the IC substrate. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Texas Instruments |
| Package | WSON-10-EP(4x4) |
| Category | Power Supply Chip |
| Pins | 11 |

## CAD (KiCad official)

- Symbol: `LM34910CSDX`
- Footprint: `Package_SON:WSON-10-1EP_4x4mm_P0.8mm_EP2.6x3mm`
- 3D model: WSON-10-EP(4x4) (KiCad packages3D, STEP)
- 3D model files: `lm34910csdx-etched.step` / `lm34910csdx-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `lm34910csdx.step` / `lm34910csdx.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/lm34910c) (21 pp, sha256 `9316b05405136b7c`, retrieved 2026-10-09, 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/lm34910csdx-datasheet.pdf)