# TX4143B

**XDS** · DC-DC Converters · SOP-8

TX4143B from XDS, in a SOP-8. 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 | FB | input | Output feedback voltage pin: the FB voltage is compared with the 0.82 V internal reference by the error amplifier, with the output set by the external R1/R2 divider; FB absolute maximum is -0.3 to 6 V. |
| 2 | FS | input | Operating frequency setting pin: an external resistor to ground sets fSW (about 140 kHz when FS is left floating, 450 kHz with 470 kΩ to ground), with a recommended maximum fSW of 500 kHz; FS absolute maximum is -0.3 to 6 V. |
| 3 | EN | input | Chip enable pin: rising threshold 1.1 V and falling threshold 0.8 V, it must not be left floating (it can be tied directly to VIN when enable control is not used), and its sink current is limited to 100 µA. |
| 4 | VIN | power_in | Chip supply input: operating range 6 V to 40 V, with an absolute maximum of -0.3 to 45 V and an undervoltage lockout rising threshold of 5.5 V. |
| 5 | SW | output | Switching output pin that connects the internal power MOSFET to the inductor and external Schottky diode; SW voltage is limited to -0.3 V to VIN+0.3 V. |
| 6 | SW | output | Switching output pin (second SW pin, bonded in parallel with pin 5) that connects the inductor and external Schottky diode; SW voltage is limited to -0.3 V to VIN+0.3 V. |
| 7 | VSS | power_in | Ground pin for the device, to be connected with a large copper area together with VIN and SW for thermal performance. |
| 8 | VSS | power_in | Ground pin for the device (second VSS pin, bonded in parallel with pin 7), to be connected with a large copper area together with VIN and SW for thermal performance. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | XDS |
| Package | SOP-8 |
| Category | Power Management (PMIC) |
| Pins | 8 |

## CAD (KiCad official)

- Symbol: `TX4143B`
- Footprint: `Package_SO:SOIC-8_3.9x4.9mm_P1.27mm`
- 3D model: SOP-8 (KiCad packages3D, STEP)
- 3D model files: `tx4143b-etched.step` / `tx4143b-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `tx4143b.step` / `tx4143b.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [XDS datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8590237640030121984) (9 pp, sha256 `51f9374809a9ffc6`, retrieved 2026-10-09, 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-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/tx4143b-datasheet.pdf)