component

LM3421Q1MHX

Public Made by Adom

by adom

Texas Instruments LED Drivers, HTSSOP-16-EP. Pinout cross-checked by two models against the datasheet, KiCad symbol/footprint/3D.

componentnixie tube driver-led driverlm3421q1mhxfactory-2.0.0extractor-text

Verified LM3421Q1MHX

by Ray · last 5 Nov 2026 · 1 record · files match
SymbolFootprint3D modelPins

Verification log 1 record

5 Nov 2026RayPublished by the parts factory: tier mfr, 17 pinsfiles match
SymbolFootprint3D modelPinsfor all variants
  • ✓component-page-verify: PASS
  • ✓cad_props: Datasheet, MPN and distributor properties match page.json
  • ✓component: LM3421Q1MHX · HTSSOP-16-EP · 17 pins
  • ✓copper: 24 copper pads, none touching another net
  • ✓datasheet: all 17 pin names found in the 80-page datasheet
  • •distributor (warn): no ['digikey', 'mouser'] number
  • ✓family: TSSOP-16-1EP_4.4x5mm_P0.65mm
  • ✓files: 7 declared files present
  • ✓hero: docs/hero.png 4000x2500
  • ✓lbr: OK: /tmp/cpv-p03n04th/x.lbr is a valid EAGLE .lbr with complete deviceset
  • ✓license: CC-BY-SA-4.0
  • ✓models_3d: 2 records
  • •package_fit (skip): no component.package_dims on the page: the model is unchecked against the datasheet drawing
  • ✓pads: 17 pins = 17 pads
  • ✓pose: 2 STEP(s) Z-up, seated, centred
  • ✓symbol: 17 pins agree
  • ✓symbol_text: no pin names collide
  • ✓visibility: public, source open
Evidencedatasheet
Verified files✓ lm3421q1mhx.kicad_sym✓ lm3421q1mhx.kicad_mod✓ lm3421q1mhx.step
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Made with KiCad 10.0 · needs KiCad 10.0 or later to open · KiCad file format 20260206
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docs Publish 0.1.0 · Ray 2h ago
viewers lm3421q1mhx: viewers · Ray 2h ago
lm3421q1mhx-etched.glb Publish 0.1.0 · Ray 2h ago
lm3421q1mhx-etched.step lm3421q1mhx: factory component page (tier=mfr) · Ray 2h ago
lm3421q1mhx-hero.glb lm3421q1mhx: hero GLB from the etched model (keeps the MPN mark) · Ray 2h ago
lm3421q1mhx-hero.overlay.json Publish 0.1.0 · Ray 2h ago
lm3421q1mhx.glb Publish 0.1.0 · Ray 2h ago
lm3421q1mhx.kicad_mod Publish 0.1.0 · Ray 2h ago
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lm3421q1mhx.lbr Publish 0.1.0 · Ray 2h ago
lm3421q1mhx.step Publish 0.1.0 · Ray 2h ago
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page.json Set visibility: public · Ray 2h ago
README.md Publish 0.1.0 · Ray 2h ago
verification.json Verified: Published by the parts factory: tier mfr, 17 pins · Ray 2h ago

LM3421Q1MHX

Texas Instruments · LED Drivers · HTSSOP-16-EP

LM3421Q1MHX from Texas Instruments, in a HTSSOP-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 with a 4.5 V to 75 V range; bypass with a 100-nF capacitor to AGND as close to the device as possible.
2 EN input Enable pin; 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 compensation.
4 CSH input Current sense high; connect a resistor to AGND to set the signal current.
5 RCT input Resistor capacitor timing; the external RC network sets the predictive off-time and thus the switching frequency.
6 AGND power_in Analog ground; connect to PGND through the DAP copper pad to provide ground return for CSH, COMP, RCT, and TIMR.
7 OVP input Overvoltage protection; connect to a resistor divider from VO to program output overvoltage lockout with a 1.24 V turnoff threshold.
8 nDIM input Dimming input and undervoltage protection; turnon threshold is 1.24 V with turnoff hysteresis provided by a 23-µA current source.
9 DDRV output Dim gate drive output; connect to the gate of the dimming MOSFET.
10 PGND power_in Power ground; connect to AGND through the DAP copper pad to provide ground return for GATE and DDRV.
11 GATE output Main gate drive output; connect to the gate of the main switching MOSFET.
12 VCC power_out Internal regulator output; bypass with a 2.2-µF to 3.3-µF ceramic capacitor to PGND.
13 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.
14 RPD input Resistor pulldown; connect the low side of all external resistor dividers (VIN UVLO, OVP) to implement zero-current shutdown.
15 HSP input LED current sense positive; connect through a series resistor to the positive side of the LED current sense resistor.
16 HSN input LED current sense negative; connect through a series resistor to the negative side of the LED current sense resistor.
17 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-16-EP
Category Nixie Tube Driver/LED Driver
Pins 17

Electrical characteristics

Limits as printed in the datasheet (page.json metadata.characteristics carries them as data).

Parameter Symbol Min Typ Max Unit Conditions Page
Input voltage VIN 4.5 75 V 6
Operating junction temperature (LM3421-Q1) TJ -40 125 °C LM3421-Q1 6
VCC regulation VCCREG 6.3 7.35 V ICC = 0 mA 7
VCC current limit ICCLIM 20 mA VCC = 0 V 7
Quiescent current (LM3421-Q1) IQ 3 mA VEN = 3 V, Static 7
Shutdown current ISD 1 µA VEN = 0 V 7
VCC UVLO threshold (increasing) VCCUV 4.5 V VCC Increasing 7
VCC UVLO hysteresis VCCHYS 0.1 V TA = 25°C 7
EN start-up threshold (increasing, LM3421-Q1) ENST 2.4 V VEN Increasing 7
EN start-up hysteresis ENSTHYS 0.1 V TA = 25°C 7
EN pulldown resistance REN 0.245 2.85 MΩ VEN = 1 V 7
OVP OVLO threshold OVPCB 1.185 1.285 V OVP Increasing 7
OVP hysteresis source current (LM3421-Q1) OVPHYS 20 25 µA OVP Active (high) 7
DPOL logic threshold DPOLTHRSH 2 2.6 V DPOL Increasing 8
FAULT threshold (LM3421-Q1) VFLTTH 1.185 1.285 V 8
FAULT pin source current (LM3421-Q1) IFLT 10 13 µA 8
CSH reference voltage VREF 1.21 1.26 V w/r/t to AGND 8
Error amplifier input bias current -0.6 0 0.6 µA TJ = 25°C 8
COMP sink or source current (LM3421-Q1) 22 35 µA 8
Linear input range -125 125 mV TJ = 25°C; specified by design 8
VRCT VIN/25 reference voltage (LM3421-Q1) VRCT 540 585 mV VIN = 14 V 8
COMP-to-PWM offset voltage 700 900 mV 9
Current limit threshold ILIM 215 275 mV 9
Leading edge blanking time tLEB 115 325 ns 9
Input offset current -1.5 1.5 µA 9
Input offset voltage -7 7 mV 9
nDIM / UVLO threshold nDIMVTH 1.185 1.285 V 9
nDIM hysteresis current (LM3421-Q1) nDIMHYS 20 25 µA 9
GATE sourcing resistance RSRC(GATE) 6 Ω GATE = High 9
GATE sinking resistance RSNK(GATE) 4.5 Ω GATE = Low 9
DDRV sourcing resistance RSRC(DDRV) 30 Ω DDRV = High 9
DDRV sinking resistance RSNK(DDRV) 10 Ω DDRV = Low 9
RPD pulldown resistance (LM3421-Q1) RRPD 300 Ω 10
FLT pulldown resistance (LM3421-Q1) RFLT 300 Ω 10
LRDY pulldown resistance (LM3421-Q1) RLRDY 300 Ω 10
Thermal shutdown threshold (LM3421-Q1) TSD 165 °C TJ = 25°C 10
Thermal shutdown hysteresis THYS 25 °C TJ = 25°C 10
Junction-to-ambient thermal resistance (PWP HTSSOP 16 pins) RθJA 38.9 °C/W PWP (HTSSOP), 16 pins 6
Junction-to-case (top) thermal resistance (PWP HTSSOP 16 pins) RθJC(top) 23.1 °C/W PWP (HTSSOP), 16 pins 6
Junction-to-board thermal resistance (PWP HTSSOP 16 pins) RθJB 16.8 °C/W PWP (HTSSOP), 16 pins 6
Junction-to-top characterization parameter (PWP HTSSOP 16 pins) ψJT 0.6 °C/W PWP (HTSSOP), 16 pins 6
Junction-to-board characterization parameter (PWP HTSSOP 16 pins) ψJB 16.6 °C/W PWP (HTSSOP), 16 pins 6
Junction-to-case (bottom) thermal resistance (PWP HTSSOP 16 pins) RθJC(bot) 1.7 °C/W PWP (HTSSOP), 16 pins 6
Absolute maximum voltage: VIN, EN, RPD, nDIM -0.3 76 V 5
Absolute maximum voltage: OVP, HSP, HSN, LRDY, FLT, DPOL -0.3 76 V 5
Absolute maximum voltage: IS -0.3 76 V 5
Absolute maximum voltage: VCC -0.3 8 V 5
Absolute maximum voltage: TIMR -0.3 7 V 5
Absolute maximum voltage: COMP, CSH -0.3 6 V 5
Absolute maximum voltage: GATE, DDRV -0.3 V Maximum printed as VCC 5
Absolute maximum voltage: PGND -0.3 0.3 V 5
Storage temperature -65 150 °C 5
Maximum lead temperature (solder and reflow) 260 °C 5

CAD (KiCad official)

  • Symbol: LM3421Q1MHX
  • Footprint: Package_SO:TSSOP-16-1EP_4.4x5mm_P0.65mm
  • 3D model: HTSSOP-16-EP (KiCad packages3D, STEP)
  • 3D model files: lm3421q1mhx-etched.step / lm3421q1mhx-etched.glb carry the MPN laser-etched on the die in a toggleable Adom.LaserEtch group (Fusion-ready); lm3421q1mhx.step / lm3421q1mhx.glb are the bare package body.

Provenance

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

  • Datasheet: Texas Instruments datasheet (80 pp, sha256 e82ddb4d986b65c0, retrieved 2026-11-05, tier: manufacturer)
  • Extractor: parts-factory 2.0.0 / extract_pins 0.3, primary claude-haiku-5-5 (text), consensus claude-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).

Datasheet PDF