component
LM3423MHX
Public Made by Adomby adom
Texas Instruments LED Drivers, HTSSOP-20-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
markdownLM3423MHX
Texas Instruments · LED Drivers · HTSSOP-20-EP
LM3423MHX 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 | VIN | power_in | Input voltage, recommended 4.5 V to 75 V, to be bypassed with a 100-nF capacitor to AGND as close to the device as possible. |
| 2 | EN | input | Enable: connect to AGND for zero-current shutdown, or apply more than 2.4 V to enable the device. |
| 3 | COMP | input | Compensation pin: connect a capacitor to AGND to set the control loop compensation. |
| 4 | CSH | input | Current sense high: connect a resistor to AGND to set the signal current, or a controlled current source or potentiometer to AGND for analog dimming. |
| 5 | RCT | input | Resistor-capacitor timing: the external RC network sets the predictive off-time and therefore the switching frequency. |
| 6 | AGND | power_in | Analog ground, connected to PGND through the DAP copper pad to provide the ground return for CSH, COMP, RCT and TIMR. |
| 7 | OVP | input | Overvoltage protection: connect to a resistor divider from VO to program OVLO, with a precision 1.24 V turnoff threshold and 23 µA (typical) hysteresis current. |
| 8 | nDIM | input | Dimming input and undervoltage protection: accepts a PWM signal and/or a VIN UVLO divider, with a 1.24 V turn-on threshold and 23 µA hysteresis current source. |
| 9 | FLT | output | Fault flag: N-channel open-drain output that goes high when a fault condition is latched by the timer, to be pulled up from VIN through a resistor. |
| 10 | TIMR | input | Fault timer: connect a capacitor to AGND to set the time delay before a sensed fault condition is latched. |
| 11 | LRDY | output | LED ready flag: N-channel open-drain output that pulls down when the LED current is not in regulation, to be pulled up from VIN through a resistor. |
| 12 | DPOL | input | Dim polarity: connect to AGND when dimming with a series P-channel MOSFET, or leave open when dimming with a series N-channel MOSFET. |
| 13 | DDRV | output | Dim gate drive output: connect to the gate of the dimming MOSFET. |
| 14 | PGND | power_in | Power ground, connected to AGND through the DAP copper pad to provide the ground return for GATE and DDRV. |
| 15 | GATE | output | Main gate drive output: connect to the gate of the main switching MOSFET, which is driven by a 2 Ω, 1 A peak gate driver. |
| 16 | VCC | power_out | Internal regulator output: bypass with a 2.2 µF to 3.3 µF ceramic capacitor to PGND. |
| 17 | IS | input | Main switch current sense: connect to the drain of the main N-channel MOSFET for RDS(on) sensing, or to a sense resistor in its source. |
| 18 | RPD | input | Resistor pulldown: connect the low side of all external resistor dividers (VIN UVLO, OVP) to implement zero-current shutdown. |
| 19 | HSP | input | LED current sense positive: connect through a series resistor to the positive side of the LED current sense resistor. |
| 20 | HSN | input | LED current sense negative: connect through a series resistor to the negative side of the LED current sense resistor. |
| 21 | DAP | power_in | Thermal pad on the bottom of the IC, acting as a star ground that connects AGND and PGND. |
Key specifications
| Parameter | Value |
|---|---|
| Manufacturer | Texas Instruments |
| Package | HTSSOP-20-EP |
| Category | LED Drivers |
| Pins | 21 |
CAD (KiCad official)
- Symbol:
LM3423MHX - 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:
lm3423mhx-etched.step/lm3423mhx-etched.glbcarry the MPN laser-etched on the die in a toggleableAdom.LaserEtchgroup (Fusion-ready);lm3423mhx.step/lm3423mhx.glbare the bare package body.
Provenance
Data extracted from the manufacturer datasheet, not a distributor listing:
- Datasheet: Texas Instruments datasheet (79 pp, sha256
5b165c52968afc7c, retrieved 2026-10-08, 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 0.3, primaryclaude-haiku-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).