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Contents

README

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LM5117PSQE

Texas Instruments · DC-DC Controllers · WQFN-24-EP(4x4)

LM5117PSQE from Texas Instruments, in a WQFN-24-EP(4x4). Pinout and pin descriptions extracted from the manufacturer datasheet by ds2sf; symbol, footprint, and 3D from KiCad-official CAD.

Pinout

Pin Name Type Function
1 DEMB input Optional logic input that enables diode emulation mode when held low; internal 50-kΩ pull-down enables diode emulation if pin is left floating.
2 RES output Restart timer pin configured by external capacitor; 10-μA internal current source charges to 1.25-V threshold after 256 consecutive cycles of current limiting.
3 SS input Soft-start pin charged by 10-μA internal current source; determines ramp rate of output voltage and is held low when VCC < 5V or UVLO < 1.25V.
4 RT input Oscillator programming pin; single external resistor sets switching frequency from 50kHz to 750kHz and can be synchronized to external clock.
5 AGND power_in Analog ground return for internal 0.8-V precision reference and all analog circuits.
6 NC unconnected No electrical connection.
7 VCCDIS input VCC regulator disable input; internal regulator is disabled when voltage exceeds 1.25V threshold with 500-kΩ internal pull-down resistor.
8 FB input Error amplifier feedback input with 0.8-V regulation threshold; external resistor divider from output sets regulated output voltage.
9 COMP output Error amplifier output node; loop compensation network (RCOMP, CCOMP, CHF) is connected between COMP and FB pins.
10 CM output Current monitor output providing average of sensed inductor current; monitor directly between CM and AGND with bandwidth approximately one-tenth of switching frequency.
11 RAMP input PWM ramp signal pin; external RC network (RRAMP, CRAMP) between SW, RAMP, and AGND generates emulated inductor current ramp with slope proportional to input voltage.
12 CS input Current sense amplifier input with 10V/V gain and 120-mV sense voltage threshold; connect to high-side of external current sense resistor.
13 CSG power_in Kelvin ground connection for current sense resistor; connect directly to low-side of external current sense resistor for accurate current measurement.
14 PGND power_in Power ground return for low-side NMOS gate driver; connect directly to current sense resistor ground and system return.
15 LO output Low-side NMOS gate drive output with 3.3-A sink current and 2.5-A source current; adaptive dead-time logic prevents simultaneous conduction with HO.
16 VCC power_out Bias supply output regulated to 7.6V by internal regulator or supplied externally when VCCDIS exceeds 1.25V threshold.
17 NC unconnected No electrical connection.
18 SW output Switching node of the buck regulator; common connection point for bootstrap capacitor, high-side NMOS source terminal, and low-side NMOS drain terminal.
19 HO output High-side NMOS gate drive output with 3.3-A sink current and 2.2-A source current; maximum low-state voltage drop 100mV.
20 HB power_in Bootstrap supply pin for high-side gate driver; connect to bootstrap diode cathode and bootstrap capacitor, typically maintains 7.6V above SW node.
21 NC unconnected No electrical connection.
22 VIN power_in Supply voltage input for internal VCC regulator; minimum VIN of 5.5V required for VCC regulation, maximum 65V absolute maximum rating.
23 NC unconnected No electrical connection.
24 UVLO input Undervoltage lockout programming pin with external resistor divider setting threshold; regulator shutdown below 0.4V, standby 0.4V-1.25V, normal operation above 1.25V.
25 EP passive Exposed pad (from the footprint; not named in the datasheet pin table).

Key specifications

Parameter Value
Manufacturer Texas Instruments
Package WQFN-24-EP(4x4)
Category Power Supply Chip
Pins 25

CAD (KiCad official)

  • Symbol: LM5117PSQE
  • Footprint: Package_DFN_QFN:QFN-24-1EP_4x4mm_P0.5mm_EP2.7x2.7mm
  • 3D model: WQFN-24-EP(4x4) (KiCad packages3D, STEP)

Provenance

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

  • Datasheet: Texas Instruments datasheet (49 pp, sha256 9e27f24e84faebf5, retrieved 2026-09-17, 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-4-6 (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