component
LM51231QRGRRQ1
Public Made by Adomby adom
Texas Instruments DC-DC Converters, VQFN-20(3.5x3.5). Pinout cross-checked by two models against the datasheet, KiCad symbol/footprint/3D.
3D Model
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Symbol & Footprint
Schematic Symbol
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PCB Footprint
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Datasheet
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README
markdownLM51231QRGRRQ1
Texas Instruments · DC-DC Converters · VQFN-20(3.5x3.5)
LM51231QRGRRQ1 from Texas Instruments, in a VQFN-20(3.5x3.5). 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 | CSP | input | Current sense amplifier positive input pin operating from 0.8 V to 42 V with 10 V/V gain. |
| 2 | CSN | input | Current sense amplifier negative input pin with 1 µA bias current operating from 0.8 V to 42 V. |
| 3 | VOUT/SENSE | input | Output voltage sensing input connected to high-side MOSFET drain through short low-inductance path with 0.1-μF bypass capacitor. |
| 4 | PGOOD | output | Open-drain power-good indicator output asserts when VOUT exceeds undervoltage threshold of 94% of regulation target. |
| 5 | HO | output | High-side MOSFET gate driver output with 2.2 A peak sourcing current and adaptive deadtime control. |
| 6 | SW | power_in | Switching node connection between high-side MOSFET source and low-side MOSFET drain connected through short low-inductance path. |
| 7 | HB | power_in | High-side driver bootstrap supply powered by internal boot diode from VCC with 2.5 V minimum HB-SW UVLO threshold and 0.1-μF bypass capacitor. |
| 8 | BIAS | power_in | Supply voltage input (3.8 V to 42 V) to VCC regulator with 1-μF bypass capacitor and 3 µA shutdown current. |
| 9 | VCC | power_in | 5-V regulated gate driver supply output with 100 mA sourcing current limit and 4.7-μF bypass capacitor. |
| 10 | PGND | power_in | Power ground pin connected directly to low-side MOSFET source and power ground plane through short low-inductance path. |
| 11 | LO | output | Low-side MOSFET gate driver output with 3.3 A peak sinking current and independent adaptive deadtime control. |
| 12 | MODE | input | Switching mode selection input; voltage less than 0.4 V selects diode emulation mode, greater than 2.0 V selects forced PWM mode. |
| 13 | UVLO/EN | input | Device enable input with 0.45 V rising threshold and 0.35 V falling threshold, or UVLO programming through resistor voltage divider to AGND. |
| 14 | SYNC/DITHER/VH | bidirectional | Synchronization clock input (200-2200 kHz), spread spectrum dithering capacitor connection, or VCC hold pin for fast restart when voltage exceeds 2.0 V. |
| 15 | RT | input | Switching frequency setting input regulated to 0.5 V with single resistor to AGND programming frequency from 100 kHz to 2.2 MHz. |
| 16 | VREF/RANGE | power_in | 1.0-V internal reference voltage output with 470-pF bypass capacitor and output voltage range selection through resistor divider (5-20 V or 15-57 V). |
| 17 | SS | bidirectional | Soft-start capacitor connection charged by 20-μA internal current source with 1.5 V mode transition threshold from forced diode emulation to FPWM. |
| 18 | TRK | input | Output voltage regulation target programming input accepting 0.25 V to 1.0 V from D/A converter or resistor divider to VREF. |
| 19 | AGND | power_in | Analog ground reference connected to analog ground plane through wide and short path. |
| 20 | COMP | output | Error amplifier output with 10 MΩ output impedance and 3 MHz bandwidth for external Type-2 compensation network. |
| 21 | EP | passive | Exposed pad (from the footprint; not named in the datasheet pin table). |
Key specifications
| Parameter | Value |
|---|---|
| Manufacturer | Texas Instruments |
| Package | VQFN-20(3.5x3.5) |
| Category | Power Management (PMIC) |
| Pins | 21 |
CAD (KiCad official)
- Symbol:
LM51231QRGRRQ1 - Footprint:
Package_DFN_QFN:QFN-20-1EP_3.5x3.5mm_P0.5mm_EP2x2mm - 3D model: VQFN-20(3.5x3.5), generated from the KiCad footprint (body from the F.Fab outline, terminals on the pads, 0.9 mm nominal QFN 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:
lm51231qrgrrq1-etched.step/lm51231qrgrrq1-etched.glbcarry the MPN laser-etched on the die in a toggleableAdom.LaserEtchgroup (Fusion-ready);lm51231qrgrrq1.step/lm51231qrgrrq1.glbare the bare package body.
Provenance
Data extracted from the manufacturer datasheet, not a distributor listing:
- Datasheet: Texas Instruments datasheet (44 pp, sha256
8614b882433fad2d, retrieved 2026-10-01, tier: lcsc) - Extractor: parts-factory
2.0.0/extract_pins 0.2, primaryclaude-haiku-4-5-20251001(text), consensusclaude-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).