component
LM3421MHX
Public Made by Adomby adom
Texas Instruments LED Drivers, TSSOP-16-EP. 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
markdownLM3421MHX
Texas Instruments · LED Drivers · TSSOP-16-EP
LM3421MHX from Texas Instruments, in a TSSOP-16-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 | VIN | power_in | Input voltage supply from 4.5V to 75V; bypass with 100-nF capacitor to AGND as close to the device as possible. |
| 2 | EN | input | Enable pin with 2.4V logic threshold; connect to AGND for zero-current shutdown or apply more than 2.4V to enable. |
| 3 | COMP | input | Compensation input; connect capacitor to AGND to set control loop compensation. |
| 4 | CSH | input | Current sense high input; connect resistor to AGND to set signal current or use as analog dimming control with potentiometer. |
| 5 | RCT | input | Resistor-capacitor timing input; external RC network sets predictive off-time and switching frequency. |
| 6 | AGND | power_in | Analog ground; connect to PGND through DAP copper pad to provide ground return for CSH, COMP, RCT, and related analog circuits. |
| 7 | OVP | input | Overvoltage protection input with 1.24V threshold; connect resistor divider from output voltage to program OVLO trip point. |
| 8 | nDIM | input | Dimming input and undervoltage protection with 1.24V threshold; accepts PWM signal for dimming or resistor divider for UVLO programming. |
| 9 | DDRV | output | Dim gate drive output; driven from internal PWM logic to control dimming MOSFET gate, sourcing 13.5Ω and sinking 3.5Ω typical. |
| 10 | PGND | power_in | Power ground; connect to AGND through DAP copper pad to provide ground return for GATE and DDRV driver outputs. |
| 11 | GATE | output | Main gate drive output; connects to main power switch MOSFET gate, sourcing 2Ω and sinking 1.3Ω typical at 1A peak. |
| 12 | VCC | power_out | Internal regulator output nominally 6.9V (min 6.3V, max 7.35V); bypass with 2.2-µF to 3.3-µF ceramic capacitor to PGND. |
| 13 | IS | input | Main switch current sense input; connect to MOSFET drain for RDS-ON sensing or to source-side sense resistor for cycle-by-cycle current limit at 245mV threshold. |
| 14 | RPD | output | Resistor pulldown open-drain output; connects bottom of external resistor dividers to ground for zero-current shutdown with 145Ω pulldown resistance typical. |
| 15 | HSP | input | LED current sense positive input; connect through series resistor to high side of LED string sense resistor for high-side differential current sensing. |
| 16 | HSN | input | LED current sense negative input; connect through series resistor to low side of LED string sense resistor for high-side differential current sensing. |
| 17 | DAP | power_in | Die attach pad thermal connection on bottom of IC; star ground connecting AGND and PGND for low-impedance power/ground return. |
Key specifications
| Parameter | Value |
|---|---|
| Manufacturer | Texas Instruments |
| Package | TSSOP-16-EP |
| Category | LED Drivers |
| Pins | 17 |
CAD (KiCad official)
- Symbol:
LM3421MHX - Footprint:
Package_SO:TSSOP-16-1EP_4.4x5mm_P0.65mm - 3D model: TSSOP-16-EP (KiCad packages3D, STEP)
- 3D model files:
lm3421mhx-etched.step/lm3421mhx-etched.glbcarry the MPN laser-etched on the die in a toggleableAdom.LaserEtchgroup (Fusion-ready);lm3421mhx.step/lm3421mhx.glbare the bare package body.
Provenance
Data extracted from the manufacturer datasheet, not a distributor listing:
- Datasheet: Texas Instruments datasheet (79 pp, sha256
37e8739d38bb6fd4, retrieved 2026-09-27, 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, primaryclaude-haiku-4-5-20251001(text), consensusclaude-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).