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Contents

README

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LM25117PMHX

Texas Instruments · DC-DC Converters · HTSSOP-20-EP

LM25117PMHX from Texas Instruments, in a HTSSOP-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 UVLO input Under-voltage lockout programming pin; regulator enters shutdown mode below 0.4V, standby mode between 0.4V and 1.25V, or normal operation above 1.25V threshold.
2 DEMB input Diode emulation mode control input; pull low or leave floating to enable diode emulation with reverse current blocking, or pull high to disable continuous conduction.
3 RES input Restart timer capacitor pin for discontinuous mode current limiting; determines restart delay after 256 consecutive PWM cycles of current limiting.
4 SS input Soft-start capacitor connection charged by internal 10µA sink current; controls error amplifier reference voltage ramp slope during startup sequence.
5 RT input Oscillator timing pin connected to external resistor to program switching frequency (50kHz to 750kHz) or AC-coupled to external clock for synchronization.
6 AGND power_in Analog ground return path for internal 0.8V reference circuit and all analog circuit grounds.
7 VCCDIS input VCC regulator disable control input; internal regulator disabled when voltage exceeds 1.25V threshold to enable external bias supply operation.
8 FB input Feedback input to inverting terminal of error amplifier; adjustable reference threshold is 0.8V, receives output voltage divider signal for regulation.
9 COMP output Error amplifier output; connects to feedback compensation network (RCOMP, CCOMP, CHF) and PWM comparator for loop compensation.
10 CM output Current monitor output providing average inductor current information; output gain 20.5V/V typical, bandwidth approximately fSW/10.
11 RAMP output PWM ramp signal output for slope compensation; external RRAMP (SW to RAMP) and CRAMP (RAMP to AGND) set inductor current slope compensation.
12 CS input Current sense amplifier input connected to high-side of external current sense resistor; detects peak inductor current for cycle-by-cycle limiting.
13 CSG input Kelvin return connection to current sense resistor low-side; must be directly connected to low-side of sense resistor for accurate current measurement.
14 PGND power_in Power ground return for low-side NMOS gate driver; direct connection to low-side MOSFET source and current sense resistor low-side.
15 LO output Low-side NMOS gate driver output; drives external low-side synchronous MOSFET gate via short low-inductance path, peak current ±3.3A.
16 VCC power_in Bias supply voltage input regulated to 7.6V; decoupled with 0.47µF to 10µF capacitor placed close to IC for gate driver and logic supply.
17 SW output Buck regulator switch node connecting high-side MOSFET source, low-side MOSFET drain, bootstrap capacitor, and serving as ramp voltage reference.
18 HO output High-side NMOS gate driver output; drives external high-side MOSFET gate via short low-inductance path, peak current ±3.3A, voltage swing from SW to HB.
19 HB power_out Bootstrap power supply for high-side gate driver; connected to bootstrap capacitor (≥0.1µF) and external bootstrap diode cathode.
20 VIN power_in VCC regulator power supply input accepting 4.5V to 42V; provides internal bias regulation and high-voltage startup current source.
21 EP passive Exposed pad (from the footprint; not named in the datasheet pin table).

Key specifications

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

CAD (KiCad official)

  • Symbol: LM25117PMHX
  • Footprint: Package_SO:TSSOP-20-1EP_4.4x6.5mm_P0.65mm_EP2.15x3.35mm
  • 3D model: HTSSOP-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: lm25117pmhx-etched.step / lm25117pmhx-etched.glb carry the MPN laser-etched on the die in a toggleable Adom.LaserEtch group (Fusion-ready); lm25117pmhx.step / lm25117pmhx.glb are the bare package body.

Provenance

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

  • Datasheet: Texas Instruments datasheet (39 pp, sha256 ebaf723e350b87ed, 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 0.2, 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