LMG5126QRXRQ1 - 42V 2.5MHz GaN Boost Converter | TI
MPN: LMG5126QRXRQ1 ✓ Active| Qty | Unit Price | Extended |
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LMG5126QRXRQ1 Overview
A boost converter is a type of switching DC-DC voltage regulator, belonging to the broader power management IC hierarchy. A boost (step-up) regulator converts a lower input voltage into a higher regulated output voltage by storing energy in an inductor during the switch on-time and transferring it to the output during the off-time. Synchronous boost converters replace the output rectifier diode with a controlled switch to improve efficiency, while GaN (gallium nitride) power technology enables the very high 2.5MHz switching frequency that shrinks inductor and capacitor sizes.
Key features include the wide 6.5V to 42V input range supporting automotive cold-crank and load-dump environments, 2.5MHz operation allowing very small magnetics, and output voltage tracking for controlled power-up and power-down sequencing. TI's integrated GaN power stage approach eliminates external gate-driver complexity compared to discrete GaN solutions, improving EMI and layout robustness in automotive power supplies.
Technically, the LMG5126 family pairs a wide-input boost controller with internal power switches, achieving high power density for pre-boost and regulated high-voltage rail applications. The high switching frequency reduces the energy storage requirement per cycle, enabling compact inductors, and the synchronous topology improves light-load and full-load efficiency versus diode-rectified designs.
Typical applications include automotive pre-boost regulators for audio amplifiers, headlight and display LED rail supplies, 48V-derived auxiliary rails, and communication equipment requiring a regulated rail from an automotive 12V or 24V battery bus.
When designing with the LMG5126QRXRQ1, keep the switching loop and compensation network per the TI datasheet layout guidelines to control EMI at 2.5MHz, and verify the input range margin against transient requirements such as cold crank.
Drop-in alternatives for LMG5126QRXRQ1 — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with LMG5126QRXRQ1 (same form factor and footprint) — differing in Qualification, Switching Frequency.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
LMG5126QRXR
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
LMG5126QRXRQ1 Maximum Ratings & Electrical Characteristics
| Topology | Synchronous Boost (Step-Up) |
| Input Voltage Range | 6.5 V to 42 V |
| Minimum Input (VBIAS >= 6.5V or VOUT >= 6V) | 2.5 V |
| Switching Frequency | 2.5 MHz |
| Output Type | Adjustable with output voltage tracking |
| Power Technology | Integrated GaN power stage |
| Qualification | AEC-Q100 (Q1 automotive) |
| Number of Outputs | 1 |
| Synchronous Rectification | Yes |
| Mounting Type | Surface Mount |
| Peak Output Current (family, LMG5126VBTR) | 35 A |
| Output Voltage Tracking | Yes |
LMG5126QRXRQ1 standard Pin Configuration Guide
Pin configuration for LMG5126QRXRQ1 (standard package). This power device features gate, drain, and source terminals. For non-polarized packages, refer to the manufacturer datasheet for exact pin 1 orientation and footprint details. Common applications include power supply design, motor driving, and load switching.
No detailed pinout data available for LMG5126QRXRQ1.
Refer to the datasheet for full pin configuration.
Typical Applications
LMG5126QRXRQ1 is suitable for 6 applications: Automotive Pre-Boost for Audio Amplifiers, Automotive LED Headlight and Display Supply, 48V-Derived Auxiliary Rails, Automotive Infotainment and Display Power, ADAS Domain Controller Pre-Regulation, Industrial 24V Bus Boost Regulation.
Automotive Pre-Boost for Audio Amplifiers
The LMG5126QRXRQ1's 6.5V to 42V input range and Q1 automotive qualification make it ideal for pre-boosting a 12V automotive battery bus to a stable higher rail feeding class-D audio amplifiers. Output voltage tracking provides clean, sequenced power-up that avoids amplifier pop and clamp conditions during key-off and key-on transients. At 2.5MHz switching, the inductor and output capacitance shrink dramatically compared to 400kHz solutions, saving board area in tight head-unit or amplifier module layouts. Place the GaN converter between the battery rail and amplifier HVDD, and note that synchronous operation maintains efficiency even at light idle volumes.
Recommended
Automotive LED Headlight and Display Supply
Headlight modules and automotive display backlights need a stable boosted rail from a battery bus that can sag below 8V during cold crank and spike above 40V during load dump. The LMG5126QRXRQ1 covers this window with its 6.5V to 42V input range while the AEC-Q100 Q1 qualification satisfies automotive reliability flows. The 2.5MHz GaN switching frequency keeps the inductor small enough to fit within lamp housings, and output voltage tracking lets the LED rail ramp in sync with a controller enable signal, avoiding brightness overshoot at startup. Efficiency from synchronous rectification reduces thermal load in sealed enclosures.
Recommended
48V-Derived Auxiliary Rails
In 48V mild-hybrid and zonal architecture vehicles, auxiliary electronics often need a locally boosted or regulated rail derived from intermediate buses. The LMG5126QRXRQ1's wide input range, GaN power stage, and 2.5MHz operation let designers build compact auxiliary converters with high power density. Output voltage tracking enables sequencing with upstream DC-DC stages, and synchronous topology limits switching losses at the high frequency. The integrated GaN approach also removes gate-drive layout sensitivity that plagues discrete GaN designs, improving EMI margins in EMC-tested vehicle modules. Verify thermal performance per the TI datasheet layout guidance.
Recommended
Automotive Infotainment and Display Power
Infotainment head units combine processors, displays, and audio on multiple rails, requiring a pre-boost stage that is quiet, compact, and sequenced. The LMG5126QRXRQ1 supplies a regulated intermediate rail from the battery, with 2.5MHz GaN switching pushing EMI harmonics above sensitive AM/FM bands where filtering is easier, a key advantage for radio performance. Output voltage tracking coordinates power-up with SoC and display enable signals. The Q1 automotive grade and wide 6.5V to 42V input handle cold crank and jump-start profiles defined in automotive lab environments, while synchronous rectification limits self-heating in enclosed dash electronics.
Recommended
ADAS Domain Controller Pre-Regulation
ADAS domain controllers draw multi-amp loads at low voltages from a 12V bus that can sag during high-current transients. A front-end boost based on the LMG5126QRXRQ1 holds the intermediate rail steady so downstream point-of-load converters such as LP87524-Q1 and TPS659039-Q1 remain in regulation. The 2.5MHz switching frequency allows a fast control loop, improving transient response to radar-processor load steps, and the Q1 qualification meets automotive deployment requirements. GaN integration reduces layout inductance sensitivity compared to discrete solutions, keeping radiated emissions within CISPR-style test budgets in sensor modules.
Recommended
Industrial 24V Bus Boost Regulation
Industrial control panels and communications equipment running from 24V bus supplies benefit from the LMG5126's wide input range and high-frequency operation when a higher rail is needed for actuators, displays, or RF front ends. Although this variant carries Q1 automotive qualification, that same AEC-Q100 level of robustness translates into margin for industrial environments with surges and wide temperature excursions. The 2.5MHz GaN switching keeps magnetic components small for DIN-rail and fanless enclosures, and output tracking simplifies power sequencing with programmable-logic and processor rails that must not come up unregulated.
Recommended
Recommended Products Summary
Engineering reference data for LMG5126QRXRQ1 — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | LMG5126QRXR | LMG5126VBTR | LM5126AQRHBRQ1 |
|---|---|---|---|---|
| Package | QXR (VQFN family) | QXR (VQFN family) - same | 22-PowerVFQFN - different | 32-VQFN (5x5) - different |
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments |
| Topology | Synchronous GaN boost converter | Synchronous GaN boost converter | Synchronous GaN boost converter | Boost controller (external FETs) |
| AEC-Q100 Qualified | Yes (Q1) | No (standard grade) | No (standard grade) | Yes (Q1) |
Key Differentiators
- Integrated GaN power stage eliminates external gate-driver design (vs LM5126AQRHBRQ1)
- Automotive AEC-Q100 Q1 qualification with output voltage tracking (vs LMG5126VBTR)
- Wide 6.5V-42V input with extended low-VIN operation (vs LM5126AQRHBRQ1)
Design Notes
At 2.5MHz switching frequency, parasitic inductance in the SW loop causes voltage ringing and radiated EMI. Keep the GaN converter SW, input capacitor, and ground return loop as tight as possible per the TI LMG5126 datasheet layout section. Because the GaN power stages are integrated, the critical hot loop is fully on-chip, but the input capacitor loop and output sense routing still demand short, wide traces and solid ground planes.
The 2.5MHz switching frequency pushes primary harmonics well above the AM broadcast band (530-1700kHz), which is advantageous for automotive radio performance, but conductive emissions in the 2-30MHz range must still be managed. Use input pi-filtering and verify conducted emissions against your automotive EMC test plan; the TI datasheet application section provides recommended filter components for automotive environments.
The 42V maximum input rating leaves limited headroom above automotive load-dump transients; confirm whether front-end transient suppression (TVS or upstream clamp) is required for your OEM load-dump profile. Also, the 6.5V minimum input applies unless VBIAS >= 6.5V or VOUT >= 6V, which permits 2.5V operation - miswiring the bias path is a common startup failure. Verify the tracking reference ramp against downstream load sequencing requirements.
Compliance Information
AEC-Q100 Q1 qualification indicated by the Q1 suffix per TI product page. RoHS/REACH status not stated in retrieved data - confirm on TI.com quality pages.
