component
LMR51403YDBVR
Public Made by Adomby adom
Texas Instruments , SOT-23-6. 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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Contents
README
markdownLMR51403YDBVR
Texas Instruments · IC · SOT-23-6
LMR51403YDBVR from Texas Instruments, in a SOT-23-6. 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 | CB | passive | Bootstrap capacitor connection for the high-side FET driver; connect a high quality 100nF capacitor from this pin to the SW pin. |
| 2 | GND | power_in | Power ground connected to the source of the low-side FET internally; connect to system ground and the ground side of CIN and COUT, with the path to CIN as short as possible. |
| 3 | FB | input | Feedback input to the converter; connect a resistor divider to set the output voltage and never short this terminal to ground during operation. |
| 4 | EN | input | Precision enable input (High = On, Low = Off) that must not be floated, can be tied to VIN, and allows an adjustable UVLO via an external resistor divider. |
| 5 | VIN | power_in | Supply input to the internal bias LDO and high-side FET (4V to 42V operating); connect to the input supply with input bypass capacitors CIN directly at this pin and GND. |
| 6 | SW | passive | Switching output of the converter, internally connected to the source of the high-side FET and drain of the low-side FET; connect to the power inductor. |
Key specifications
| Parameter | Value |
|---|---|
| Manufacturer | Texas Instruments |
| Package | SOT-23-6 |
| Category | |
| Pins | 6 |
Electrical characteristics
Limits as printed in the datasheet (page.json metadata.characteristics carries them as data).
| Parameter | Symbol | Min | Typ | Max | Unit | Conditions | Page |
|---|---|---|---|---|---|---|---|
| VIN quiescent current (non-switching) | IQ(VIN) | 26.5 | 40 | µA | VEN = 3V, PFM variant only | 5 | |
| VIN shutdown supply current | ISD(VIN) | 0.8 | 3 | µA | VEN = 0V | 5 | |
| VIN UVLO rising threshold | VIN_UVLO(R) | 3.82 | 4 | V | VIN rising | 5 | |
| VIN UVLO falling threshold | VIN_UVLO(F) | 3.4 | 3.56 | V | VIN falling | 5 | |
| EN voltage rising threshold | VEN(R) | 1.1 | 1.227 | 1.36 | V | EN rising, enable switching | 5 |
| EN voltage falling threshold | VEN(F) | 0.85 | 1 | 1.15 | V | EN falling, disable switching | 5 |
| EN pin sourcing current post EN rising threshold | IEN(P2) | 10 | 50 | nA | VEN = 3V | 5 | |
| Reference voltage | VFB | 0.788 | 0.8 | 0.812 | V | 5 | |
| Switching frequency, CCM operation, Y version | fSW(CCM) | 0.935 | 1.1 | 1.265 | MHz | "Y" Version | 5 |
| High-side peak current limit | IHS_PK(OC) | 0.4 | 0.55 | 0.7 | A | LMR51403 | 6 |
| Low-side valley current limit | ILS_V(OC) | 0.32 | 0.42 | 0.51 | A | LMR51403 | 6 |
| Input voltage VIN to GND | VIN | 4 | 42 | V | 4 | ||
| Input voltage EN | VEN | 0 | V | max = VIN | 4 | ||
| Input voltage FB | VFB | 0 | 4.5 | V | 4 | ||
| Output voltage | VOUT | 0.8 | 28 | V | 4 | ||
| Output current | IOUT | 300 | mA | 4 | |||
| Operating junction temperature | TJ | -40 | 150 | °C | 4 | ||
| Input voltage VIN to GND | VIN | -0.3 | 45 | V | 4 | ||
| Input voltage EN to GND | VEN | -0.3 | V | max = VIN + 0.3 V | 4 | ||
| Input voltage FB to GND | VFB | -0.3 | 5.5 | V | 4 | ||
| Output voltage SW to GND | VSW | -0.3 | 45 | V | 4 | ||
| Output voltage SW to GND, transients | VSW | -5 | 50 | V | less than 10ns transients | 4 | |
| Output voltage CBOOT to SW | VCBOOT | -0.3 | 5.5 | V | 4 | ||
| Junction temperature | TJ | -40 | 150 | °C | 4 | ||
| Storage temperature | Tstg | -55 | 150 | °C | 4 | ||
| ESD HBM | V(ESD) | -2500 | 2500 | V | Human-body model, ANSI/ESDA/JEDEC JS-001 | 4 | |
| ESD CDM | V(ESD) | -750 | 750 | V | Charged-device model, ANSI/ESDA/JEDEC JS-002 | 4 | |
| Junction-to-ambient thermal resistance | RθJA | 147.8 | °C/W | DBV (SOT-23-6), 6 pins | 5 | ||
| Junction-to-ambient thermal resistance with EVM | RθJA(Effective) | 95 | °C/W | DBV (SOT-23-6), 6 pins | 5 | ||
| Junction-to-case (top) thermal resistance | RθJC(top) | 71.1 | °C/W | DBV (SOT-23-6), 6 pins | 5 | ||
| Junction-to-board thermal resistance | RθJB | 36.6 | °C/W | DBV (SOT-23-6), 6 pins | 5 | ||
| Junction-to-top characterization parameter | ψJT | 14.2 | °C/W | DBV (SOT-23-6), 6 pins | 5 | ||
| Junction-to-board characterization parameter | ψJB | 36.4 | °C/W | DBV (SOT-23-6), 6 pins | 5 |
Materials and finish
As the datasheet states them (page.json metadata.appearance; the 3D model's colours follow it).
| Part | Material | Colour / plating | Datasheet says | Page |
|---|---|---|---|---|
| contacts | copper | The SW pin connecting to the inductor must be as short as possible, and just wide enough to carry the load current without excessive heating. Short, thick traces or copper pours (shapes) must be used | 21 |
CAD (KiCad official)
- Symbol:
LMR51403YDBVR - Footprint:
Package_TO_SOT_SMD:SOT-23-6 - 3D model: SOT-23-6 (KiCad packages3D, STEP)
- 3D model files:
lmr51403ydbvr-etched.step/lmr51403ydbvr-etched.glbcarry the MPN laser-etched on the die in a toggleableAdom.LaserEtchgroup (Fusion-ready);lmr51403ydbvr.step/lmr51403ydbvr.glbare the bare package body.
Provenance
Data extracted from the manufacturer datasheet, not a distributor listing:
- Datasheet: Texas Instruments datasheet (33 pp, sha256
a9add60e33040b51, retrieved 2026-10-23, tier: lcsc) - Extractor: parts-factory
2.0.0/extract_pins 0.3, primaryclaude-sonnet-5-5(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).