Texas Instruments LM3404HVMAX

Overview

LM3404HVMAX from Texas Instruments is a monolithic 1-A constant-current buck regulator IC designed for high-power LED driving, featuring integrated high-side N-channel MOSFET (R_DS(on) = 0.75 Ω typ), 6–75 V input range, 200 mV current-sense threshold, hysteretic controlled-on-time architecture, and thermal shutdown at 165°C. It delivers stable LED current in automotive headlamps and industrial high-bay lighting.

For engineers reviewing the LM3404HVMAX datasheet, LM3404HVMAX pinout, LM3404HVMAX application, or LM3404HVMAX equivalent, key selection considerations include VIN range compatibility (up to 75 V), CS pin sensitivity (200 mV reference), RON-programmable on-time, PWM dimming support via DIM pin, and SO PowerPAD-8 thermal performance (R_θJB = 24.5°C/W).

Technical Context

The LM3404HVMAX implements a controlled-on-time (COT) architecture combining hysteretic current sensing with an external resistor (RON)-programmed one-shot timer. Its CS comparator monitors voltage across RSNS to regulate valley inductor current, while BOOT-driven gate control enables high-side switching up to 75 V input.

It operates exclusively in continuous conduction mode (CCM), maintains constant switching frequency over input voltage variation when in steady state, and uses internal 7-V linear regulator (VCC) with undervoltage lockout (5.3 V) and bypass threshold (8.8 V) to power internal circuitry and bootstrap capacitor charging.

Key Specifications

Pinout & Package

LM3404HVMAX is housed in an 8-pin SO PowerPAD™ package (3.90 mm × 4.89 mm) with exposed thermal pad (DAP) requiring direct connection to PCB ground plane via ≥4 vias for optimal thermal performance (R_θJB = 24.5°C/W).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar constant-current LED driver applications.

Compared with LM3404MAX and MPQ4425HGQ-P, LM3404HVMAX uniquely combines 75 V input tolerance, capacitor-less operation, and integrated open-LED protection in a thermally enhanced SO PowerPAD package - making it optimal for ruggedized, space-constrained LED drivers where reliability under overvoltage stress is critical.

Availability

LM3404HVMAX is available at Aetrix Electronics and suitable for automotive lighting, industrial high-bay fixtures, and outdoor streetlight systems requiring stable component supply, long-term manufacturability, and AEC-Q100 alignment (design-qualified).

Supply support for LM3404HVMAX includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Texas Instruments is a global semiconductor company headquartered in Dallas, Texas, delivering analog and embedded processing solutions across industrial, automotive, and personal electronics markets.

The LM3404HVMAX belongs to TI's LED Driver product line, engineered specifically for high-reliability, high-efficiency constant-current regulation in demanding lighting applications - emphasizing input voltage robustness, thermal resilience, and minimal external component count.

FAQ

What is the maximum input voltage rating for LM3404HVMAX?

The LM3404HVMAX has an absolute maximum input voltage (VIN to GND) rating of 76 V, with recommended operating range from 6 V to 75 V. This 75 V upper limit enables use in 48 V industrial systems and automotive applications subject to ISO 7637-2 load-dump transients. Exceeding 76 V risks permanent damage per Absolute Maximum Ratings table in the SNVS465G datasheet.

How does the LM3404HVMAX achieve constant LED current without external compensation?

The LM3404HVMAX uses a controlled-on-time (COT) hysteretic architecture: the CS pin compares sensed voltage across RSNS to a 200-mV internal reference, triggering a fixed-duration on-pulse set by RON and VIN. This eliminates small-signal loop stability concerns. The LM3404HVMAX datasheet confirms "No Control Loop Compensation Required" as a core feature, validated across –40°C to 125°C.

Can LM3404HVMAX operate without an output capacitor?

Yes, LM3404HVMAX supports capacitor-less operation per Section 8.1.3 of the datasheet. As a constant-current buck regulator, it inherently regulates LED current without needing output capacitance to maintain voltage. The typical application diagram shows direct LED string connection to SW and GND; adding a small 10-nF capacitor across the LED array damps switching-node oscillation but is not required for regulation.

What thermal performance can be expected from LM3404HVMAX in SO PowerPAD-8 package?

In SO PowerPAD-8 package, LM3404HVMAX achieves R_θJB = 24.5°C/W (junction-to-board) and R_θJA = 44.7°C/W (junction-to-ambient, with 2-in² 2-oz copper). With proper DAP grounding via ≥4 thermal vias to inner ground plane, it sustains 1 A output current at 70°C ambient without heatsink - verified in Thermal Information Table 6.4 of SNVS465G.

Does LM3404HVMAX provide protection against LED open-circuit failure?

Yes, LM3404HVMAX includes open-LED protection via its CS comparator. When an LED string opens, VSNS falls below 200 mV, causing the controller to disable the high-side MOSFET. Additionally, the OVP/OCP comparator triggers at 300 mV on CS, limiting output voltage rise. Section 7.3.9 and Figure 18 of the datasheet detail Zener-based open-circuit clamping implementation using Z1 and RZ.