# LM20125MHX

**Texas Instruments** · DC-DC Converters · HTSSOP-16-EP

LM20125MHX from Texas Instruments, in a HTSSOP-16-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 | SS/TRK | input | Soft-start or tracking control input charged by an internal 5 µA source; if driven externally below 800 mV it overrides the internal reference, and if left open an internal 1 ms soft-start ramp is used. |
| 2 | FB | input | Feedback input to the inverting input of the internal transconductance error amplifier, which regulates against the internal 800 mV reference. |
| 3 | PGOOD | output | Open-drain power-good output that indicates the output is regulating within tolerance and requires a 10 kΩ to 100 kΩ pull-up resistor for most applications. |
| 4 | COMP | passive | External compensation pin where a resistor and capacitor are connected to compensate the device. |
| 5 | NC | unconnected | Not internally connected; the datasheet states this pin must be connected to GND to ensure proper operation. |
| 6 | PVIN | power_in | Input voltage to the internal power switches, specified for 2.95 V to 5.5 V; tie PVIN pins 6 and 7 together at the device with a low-ESR capacitor placed nearby. |
| 7 | PVIN | power_in | Input voltage to the internal power switches, specified for 2.95 V to 5.5 V; tie PVIN pins 6 and 7 together at the device with a low-ESR capacitor placed nearby. |
| 8 | SW | output | PWM switch output of the internal power switches; pins 8 and 9 are tied together. |
| 9 | SW | output | PWM switch output of the internal power switches; pins 8 and 9 are tied together. |
| 10 | PGND | power_in | Power ground for the internal power switches. |
| 11 | PGND | power_in | Power ground for the internal power switches. |
| 12 | EN | input | Precision enable input with hysteresis; an external divider sets the turn-on threshold, and it should be tied to PVIN if not used. |
| 13 | VCC | power_out | Output of the internal 2.7 V sub-regulator, which must be bypassed with a 1 µF ceramic capacitor. |
| 14 | AVIN | power_in | Analog supply that generates the internal bias and must be connected to VIN through a low-pass RC filter. |
| 15 | AGND | power_in | Quiet analog ground for the internal bias circuitry. |
| 16 | NC | unconnected | Not internally connected; the datasheet states this pin must be connected to GND to ensure proper operation. |
| 17 | EP | passive | Exposed pad (from the footprint; not named in the datasheet pin table). |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Texas Instruments |
| Package | HTSSOP-16-EP |
| Category | Power Supply Chip |
| Pins | 17 |

## CAD (KiCad official)

- Symbol: `LM20125MHX`
- Footprint: `Package_SO:TSSOP-16-1EP_4.4x5mm_P0.65mm`
- 3D model: HTSSOP-16-EP (KiCad packages3D, STEP)
- 3D model files: `lm20125mhx-etched.step` / `lm20125mhx-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `lm20125mhx.step` / `lm20125mhx.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/lm20125) (32 pp, sha256 `bd9ed15653c896bc`, 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/lm20125mhx-datasheet.pdf)