# LM25576MHX

**Texas Instruments** · DC-DC Converters · TSSOP-20-EP

LM25576MHX from Texas Instruments, in a TSSOP-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 | VCC | power_in | Bias regulator output, regulated 7V nominal when Vin >9V, tracks Vin when 6V <Vin <9V, requires 0.1µF-1µF ceramic bypass capacitor. |
| 2 | SD | input | Shutdown/UVLO input; voltage <0.7V disables regulator, 0.7V-1.225V standby mode, >1.225V normal operation, 0.1V hysteresis. |
| 3 | VIN | power_in | Input power supply voltage, 6V to 42V nominal operating range, absolute maximum 45V. |
| 4 | VIN | power_in | Input power supply voltage, 6V to 42V nominal operating range, absolute maximum 45V. |
| 5 | SYNC | bidirectional | Oscillator sync input/output; internal oscillator syncs with external clock via pulldown, minimum pulse width 15ns, multiple devices share single SYNC line. |
| 6 | COMP | output | Error amplifier output; loop compensation network connects between this pin and FB pin for Type II compensation. |
| 7 | FB | input | Feedback input from regulator output to error amplifier inverting input, 1.225V internal regulation threshold. |
| 8 | RT | input | Oscillator frequency setting input; external resistor to AGND determines operating frequency from 50kHz to 1MHz. |
| 9 | RAMP | output | Ramp signal output for current mode control; external capacitor 50pF-2000pF to AGND sets ramp slope. |
| 10 | AGND | power_in | Analog ground, internal reference for regulator control functions and low-side reference for analog signals. |
| 11 | SS | output | Soft start output; 10µA internal current source charges external capacitor, held low during standby/Vcc UVLO/thermal shutdown. |
| 12 | OUT | output | Output voltage connection pin directly connected to regulator output voltage. |
| 13 | PGND | power_in | Power ground; low-side reference for PRE switch and IS sense resistor, connects to output filter capacitor ground. |
| 14 | PGND | power_in | Power ground; low-side reference for PRE switch and IS sense resistor, connects to output filter capacitor ground. |
| 15 | IS | input | Current sense input for recirculation diode anode current; internal sense ratio 0.5V/A, sample/hold circuit updates at end of off-time. |
| 16 | IS | input | Current sense input for recirculation diode anode current; internal sense ratio 0.5V/A, sample/hold circuit updates at end of off-time. |
| 17 | SW | output | Switch node, internal buck MOSFET source terminal, -1.5V to 14V, connects to external Schottky diode cathode and inductor. |
| 18 | SW | output | Switch node, internal buck MOSFET source terminal, -1.5V to 14V, connects to external Schottky diode cathode and inductor. |
| 19 | PRE | tri_state | Bootstrap capacitor precharge assist; open-drain output conducts for 265ns per cycle before switch on-time to pre-charge bootstrap capacitor. |
| 20 | BST | input | Bootstrap capacitor input; 0.022µF ceramic capacitor required between BST and SW, charges from Vcc during switch off, absolute maximum 60V. |
| 21 | EP | passive | Exposed pad (from the footprint; not named in the datasheet pin table). |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Texas Instruments |
| Package | TSSOP-20-EP |
| Category | Power Management (PMIC) |
| Pins | 21 |

## CAD (KiCad official)

- Symbol: `LM25576MHX`
- Footprint: `Package_SO:TSSOP-20-1EP_4.4x6.5mm_P0.65mm_EP2.15x3.35mm`
- 3D model: TSSOP-20-EP, generated from the KiCad footprint (body from the F.Fab outline, terminals on the pads, 1.2 mm nominal TSSOP height). Neither the vendor nor KiCad ships a 3D model for this package, so the dimensions are nominal, not the manufacturer's CAD (STEP)
- 3D model files: `lm25576mhx-etched.step` / `lm25576mhx-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `lm25576mhx.step` / `lm25576mhx.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/lm25576) (37 pp, sha256 `ed0031dc76d29d88`, 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/lm25576mhx-datasheet.pdf)