Specifications
| Type | Description |
|---|---|
| Part Number | LM3421 |
| Manufacturer | Texas Instruments |
| Product Type | LDO Regulator |
| Category | Power Management |
| Component Type | Power_IC |
| Package Case | 16-pin HTSSOP (PWP), 5.00 mm x 4.40 mm body |
| Input Voltage Range | 4.5 to 75 V; recommended operating conditions |
| Operating Junction Temperature | -40 to 125 °C; LM3421, LM3423 recommended operating conditions |
| MOSFET Gate Driver Peak Current | 1 A peak; feature list |
| MOSFET Gate Driver Resistance | 2 ohm; feature list |
| Maximum Switching Frequency | Up to 2 MHz; internal PWM controller adjustable switching frequency |
| Control Topologies | Buck, boost, buck-boost, SEPIC; application configurations supported |
| Current Sense Type | High-side adjustable current sense; LED current regulation feature |
| Package Body Size | 5.00 mm x 4.40 mm; LM3421 HTSSOP(16) device information |
| Package Pin Count | 16 pins; LM3421 HTSSOP package |
| Absolute Maximum VIN, EN, RPD, nDIM Voltage | -0.3 to 76 V; absolute maximum ratings over operating free-air temperature range |
| Absolute Maximum VIN, EN, RPD, nDIM Continuous Current | -1 mA continuous; absolute maximum ratings |
| Absolute Maximum OVP, HSP, HSN Voltage | -0.3 to 76 V; LRDY, FLT, DPOL also listed for LM3423 |
| Absolute Maximum OVP, HSP, HSN Continuous Current | -100 uA continuous; LRDY, FLT, DPOL also listed for LM3423 |
| Absolute Maximum RCT Voltage | -0.3 to 76 V; absolute maximum ratings |
| Absolute Maximum RCT Continuous Current | -1 to 5 mA continuous; absolute maximum ratings |
| Absolute Maximum IS Voltage | -0.3 to 76 V; -2 V for 100 ns; absolute maximum ratings |
| Absolute Maximum IS Continuous Current | -1 mA continuous; absolute maximum ratings |
| Absolute Maximum VCC Voltage | -0.3 to 8 V; absolute maximum ratings |
| Absolute Maximum TIMR Voltage | -0.3 to 7 V; LM3423 only |
| Absolute Maximum TIMR Continuous Current | -100 to 100 uA continuous; LM3423 only |
| Absolute Maximum COMP, CSH Voltage | -0.3 to 6 V; absolute maximum ratings |
| Absolute Maximum COMP, CSH Continuous Current | -200 to 200 uA continuous; absolute maximum ratings |
| Absolute Maximum GATE, DDRV Voltage | -0.3 to VCC V; -2.5 V for 100 ns; VCC + 2.5 V for 100 ns |
| Absolute Maximum GATE, DDRV Continuous Current | -1 to 1 mA continuous; absolute maximum ratings |
| Absolute Maximum PGND Voltage | -0.3 to 0.3 V; -2.5 to 2.5 V for 100 ns |
| Maximum Lead Temperature | 260 °C; solder and reflow |
| Storage Temperature | -65 to 150 °C; absolute maximum ratings |
| ESD HBM Rating | ±2000 V; human-body model per ANSI/ESDA/JEDEC JS-001 |
| ESD CDM Rating | ±500 V; charged-device model per JEDEC JESD22-C101 |
| Junction-to-Ambient Thermal Resistance | 38.9 °C/W; LM3421 PWP HTSSOP 16-pin package |
| Junction-to-Case Top Thermal Resistance | 23.1 °C/W; LM3421 PWP HTSSOP 16-pin package |
| Junction-to-Board Thermal Resistance | 16.8 °C/W; LM3421 PWP HTSSOP 16-pin package |
| Junction-to-Top Characterization Parameter | 0.6 °C/W; LM3421 PWP HTSSOP 16-pin package |
| Junction-to-Board Characterization Parameter | 16.6 °C/W; LM3421 PWP HTSSOP 16-pin package |
| Junction-to-Case Bottom Thermal Resistance | 1.7 °C/W; LM3421 PWP HTSSOP 16-pin package |
| VCC Regulation Voltage | 6.3 to 7.35 V; ICC = 0 mA, VIN = 14 V, -40 °C <= TJ <= 125 °C |
| VCC Regulation Voltage Typical | 6.9 V; ICC = 0 mA, TA = 25 °C, VIN = 14 V |
| VCC Current Limit | 20 mA; VCC = 0 V, VIN = 14 V, -40 °C <= TJ <= 125 °C |
| VCC Current Limit Typical | 25 mA; VCC = 0 V, TA = 25 °C, VIN = 14 V |
| Quiescent Current | 3 mA; VEN = 3 V, static, VIN = 14 V, -40 °C <= TJ <= 125 °C |
| Quiescent Current Typical | 2 mA; VEN = 3 V, static, TA = 25 °C, VIN = 14 V |
| Shutdown Current | 1 uA; VEN = 0 V, VIN = 14 V, -40 °C <= TJ <= 125 °C |
| Shutdown Current Typical | 0.1 uA; VEN = 0 V, TA = 25 °C, VIN = 14 V |
| VCC UVLO Threshold Rising | 4.5 V; VCC increasing, VIN = 14 V, -40 °C <= TJ <= 125 °C |
| VCC UVLO Threshold Rising Typical | 4.17 V; VCC increasing, TA = 25 °C, VIN = 14 V |
| VCC UVLO Threshold Falling | 3.7 V; VCC decreasing, VIN = 14 V, -40 °C <= TJ <= 125 °C |
| VCC UVLO Threshold Falling Typical | 4.08 V; VCC decreasing, TA = 25 °C, VIN = 14 V |
| VCC UVLO Hysteresis Typical | 0.1 V; TA = 25 °C, VIN = 14 V |
| EN Start-up Threshold Rising | 2.4 V; VEN increasing, VIN = 14 V, -40 °C <= TJ <= 125 °C |
| EN Start-up Threshold Rising Typical | 1.75 V; VEN increasing, TA = 25 °C, VIN = 14 V |
| EN Start-up Threshold Falling | 0.8 V; VEN decreasing, VIN = 14 V, -40 °C <= TJ <= 125 °C |
| EN Start-up Threshold Falling Typical | 1.63 V; VEN decreasing, TA = 25 °C, VIN = 14 V |
| EN Start-up Hysteresis Typical | 0.1 V; TA = 25 °C, VIN = 14 V |
| EN Pulldown Resistance | 0.245 to 2.85 Mohm; VEN = 1 V, VIN = 14 V, -40 °C <= TJ <= 125 °C |
| EN Pulldown Resistance Typical | 0.82 Mohm; VEN = 1 V, TA = 25 °C, VIN = 14 V |
| CSH High Fault Threshold Typical | 1.6 V; CSH increasing, TA = 25 °C, VIN = 14 V |
| CSH Low Condition on LRDY Pin Typical | 1 V; CSH increasing, TA = 25 °C, LM3423 only |
| OVP OVLO Threshold | 1.185 to 1.285 V; OVP increasing, VIN = 14 V, -40 °C <= TJ <= 125 °C |
| OVP OVLO Threshold Typical | 1.24 V; OVP increasing, TA = 25 °C, VIN = 14 V |
| OVP Hysteresis Source Current | 20 to 25 uA; OVP active high, VIN = 14 V, -40 °C <= TJ <= 125 °C |
| OVP Hysteresis Source Current Typical | 23 uA; OVP active high, TA = 25 °C, VIN = 14 V |
| DPOL Logic Threshold | 2 to 2.6 V; DPOL increasing; LM3423 only |
| nDIM Turn-on Threshold | 1.24 V; pin functions description |
| nDIM Turn-off Hysteresis Source Current | 23 uA; input undervoltage lockout hysteresis current source |
| OVP Turn-off Threshold | 1.24 V; output overvoltage lockout threshold from OVP pin function |
| OVP Turn-on Hysteresis Source Current | 23 uA; output overvoltage lockout hysteresis current source |
| VCC Bypass Capacitance | 2.2 to 3.3 uF; ceramic capacitor to PGND recommended for internal regulator output |
| VIN Bypass Capacitance | 100 nF; capacitor to AGND placed close to device |
| Datasheet Status | request_only |
Product Overview
The Texas Instruments LM3421 is a constant-current LED driver controller categorized under Power_Management. It is specified for buck, boost, buck-boost, and SEPIC application configurations, with high-side adjustable current sense for LED current regulation. Recommended operating conditions list a 4.5 to 75 V input voltage range and an operating junction temperature range of -40 to 125 °C.
The device integrates a MOSFET gate driver rated at 1 A peak with 2 ohm driver resistance, and its internal PWM controller supports adjustable switching frequency up to 2 MHz. Electrical parameters include a VCC regulation range of 6.3 to 7.35 V, 20 mA VCC current limit, 3 mA quiescent current, and 1 uA shutdown current under the stated datasheet conditions.
LM3421 is supplied in a 16-pin HTSSOP (PWP) package with a 5.00 mm x 4.40 mm body. Thermal data for this package includes 38.9 °C/W junction-to-ambient resistance and 1.7 °C/W junction-to-case bottom resistance. Assembly and layout-related facts include a 260 °C maximum lead temperature, 100 nF VIN bypass capacitance, and 2.2 to 3.3 uF VCC bypass capacitance.
Key Features
- 4.5 to 75 V recommended input voltage range
- -40 to 125 °C operating junction temperature range
- 1 A peak MOSFET gate driver current
- 2 ohm MOSFET gate driver resistance
- Adjustable switching frequency up to 2 MHz
- Supports buck, boost, buck-boost, and SEPIC topologies
- High-side adjustable current sense for LED regulation
- 16-pin HTSSOP package with 5.00 mm x 4.40 mm body
- VCC regulation range of 6.3 to 7.35 V
- OVP OVLO threshold range of 1.185 to 1.285 V
Typical Applications
- Buck LED driver controllers
- Boost LED driver controllers
- Buck-boost LED driver controllers
- SEPIC LED driver controllers
- High-side current-sensed LED regulation
- Constant-current LED power stages
- PWM-controlled LED driver designs
Procurement Notes
When requesting a quote for LM3421, buyers should confirm the manufacturer, package or case, required quantity, target date code, compliance documents, packing method, destination country and expected delivery schedule.
If alternatives are acceptable, buyers should share the approved vendor list, required electrical or optical limits, package constraints and qualification requirements. Any alternative part should be reviewed by the buyer's engineering team before production use.
For power IC and power device sourcing, voltage rating, current rating, power dissipation, package thermal performance, protection features, qualification grade and application conditions should be reviewed before approval.
FAQ
What input voltage range is specified for LM3421?
The LM3421 recommended operating conditions specify an input voltage range from 4.5 to 75 V. Absolute maximum ratings list VIN, EN, RPD, and nDIM voltage from -0.3 to 76 V.
Which LED driver topologies does LM3421 support?
The LM3421 supports buck, boost, buck-boost, and SEPIC application configurations. The datasheet facts describe it as a constant-current LED driver controller with high-side adjustable current sense for LED current regulation.
What package is used for the LM3421?
The LM3421 is listed in a 16-pin HTSSOP PWP package. The package body size is 5.00 mm x 4.40 mm, with thermal data including 38.9 °C/W junction-to-ambient resistance.
What switching frequency and gate driver values are specified?
The internal PWM controller supports adjustable switching frequency up to 2 MHz. The MOSFET gate driver is specified with 1 A peak current and 2 ohm gate driver resistance in the feature list.
Technical Review & Sourcing Note
Prepared by LDeepAI Component Sourcing Team. Reviewed for RFQ, documentation and alternative sourcing use. Last updated: July 7, 2026.
This page is based on manufacturer datasheet information and LDeepAI sourcing review. Specifications should be verified against the official manufacturer datasheet before final procurement or design approval. Final electrical, optical and reliability approval should be confirmed by the buyer's engineering team.