Texas Instruments LMG3626REQR

Overview

LMG3626REQR from Texas Instruments is a 700V, 220mΩ gallium nitride (GaN) power FET with integrated gate driver, current-sense emulation, and cycle-by-cycle overcurrent protection. It operates in high-frequency switch-mode power supplies, delivers 3.2A continuous drain current, supports programmable turn-on slew rates (20–150 V/ns), and uses an 8mm × 5.3mm 38-pin VQFN thermal-pad package for compact AC/DC charger designs.

For engineers reviewing the LMG3626REQR datasheet, LMG3626REQR pinout, LMG3626REQR application, or LMG3626REQR equivalent, key selection considerations include its GaN-specific switching capability (800V transient rating), integrated current-sense emulation gain (1.633 mA/A), open-drain FLT fault reporting, RDRV-programmable slew rate, and compatibility with burst-mode light-load operation in USB PD and TV auxiliary supplies.

Technical Context

The LMG3626REQR integrates a high-voltage GaN FET with a low-inductance driver to minimize common-source inductance and improve CMTI. Its current-sense emulation replaces discrete shunt resistors by sourcing a scaled replica of drain current (1.633 mA per 1 A) at the CS pin, enabling direct thermal-pad grounding to PCB power ground.

Turn-on slew rate is set at AUX power-up via external resistor on RDRV (0–120 kΩ), selecting one of four discrete settings (20–150 V/ns); turn-off timing (td(off) = 32 ns, tf(off) = 24 ns) is independent of RDRV but depends on load current. Protection includes UVLO (9.3 V typ), overtemperature detection (145–165 °C), and cycle-by-cycle current limit (3.6 A typ).

Key Specifications

Pinout & Package

LMG3626REQR uses an 8mm × 5.3mm 38-pin VQFN package (REQ) with exposed thermal pad (PAD) internally connected to source (S), analog ground (AGND), and NC2 pins. The thermal pad must be soldered to a non-solder-mask-defined PCB landing pad tied to system power ground for optimal thermal performance and current conduction.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar GaN FET applications.

Compared with LMG3626REQR, LMG3622R030 offers lower R_DS(on) but higher cost and thermal demand, while EPC2218 provides greater switching frequency headroom at the expense of system integration, protection, and current-sensing simplicity.

Availability

LMG3626REQR is available at Aetrix Electronics and suitable for USB-C PD chargers, TV auxiliary power supplies, and LED driver power supplies requiring stable component supply, long-term lifecycle assurance, and GaN-specific reliability validation.

Supply support for LMG3626REQR 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, specializing in analog, embedded processing, and power management ICs with broad industrial, automotive, and consumer applications.

The LMG3626REQR belongs to TI's high-voltage GaN power stage product line, designed specifically to replace silicon MOSFETs in high-density, high-efficiency AC/DC and DC/DC converters targeting USB PD, consumer adapters, and auxiliary power systems.

FAQ

What is the absolute maximum drain-source voltage rating for the LMG3626REQR?

The LMG3626REQR has an absolute maximum V_DS rating of 700 V under steady-state conditions. During transient surge events, it supports up to 800 V peak drain-source voltage (V_{DS(tr)(surge)}) for <100 ns, as validated in the GaN Power FET Switching Capability section of the datasheet. This exceeds typical silicon MOSFET avalanche limits and enables robust operation in offline SMPS with line surges.

How does the current-sense emulation function work in the LMG3626REQR?

The LMG3626REQR outputs a scaled replica of drain current at the CS pin with a gain of 1.633 mA per 1 A of ID. This current flows through an external resistor (RCS) to AGND, generating a voltage signal for the controller's current-sense input. The LMG3626REQR eliminates the need for a power-dissipating shunt resistor in series with the source, allowing the thermal pad to connect directly to PCB power ground for superior thermal performance and layout flexibility.

Can the LMG3626REQR be used in burst-mode operation for light-load efficiency?

Yes, the LMG3626REQR supports burst-mode operation with two low-power states: active quiescent current is 240 µA, and standby current drops to 50 µA when EN is pulled low. Its fast EN wake-up time (1.5 µs) ensures rapid reactivation from standby, making the LMG3626REQR compliant with stringent light-load efficiency standards such as DOE Level VI and EU CoC Tier 2 for AC/DC adapters and chargers.

What is the purpose of the RDRV pin on the LMG3626REQR?

The RDRV pin on the LMG3626REQR sets the GaN FET's turn-on slew rate by connecting an external resistor to AGND. Four discrete slew-rate settings (20–150 V/ns) are selected based on resistance value (0–120 kΩ). This configuration occurs once at AUX power-up and allows designers to optimize EMI, switching loss, and ringing without changing gate drive circuitry or firmware-directly addressing layout-sensitive high-frequency power design challenges.

Does the LMG3626REQR provide overtemperature protection, and how is it signaled?

Yes, the LMG3626REQR includes overtemperature protection that triggers at a junction temperature between 145 °C and 165 °C. When activated, it asserts the open-drain FLT pin low. The FLT pin requires an external pull-up resistor to VAUX or system logic rail and can be monitored by a microcontroller or supervisor IC to initiate thermal shutdown or derating. Hysteresis of 20 °C prevents chatter near the trip point.