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LMG708B0RXR - 20A GaN Synchronous Buck 80VIN | Texas Instruments

MPN: LMG708B0RXR ✓ Active
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5 V to 80 V Vdss 20 A Id VQFN-28 (RXR) Package [DATA_NEEDED: switching frequency] Speed
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Price updated: 2026-08-29
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Drop-in alternatives for LMG708B0RXR — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.

Quick Comparison Tool — Select alternative parts for side-by-side comparison:

LMG708B0QRXRQ1

✅ Drop-In
Texas Instruments
📦 VQFN-28 (RXR)
Synchronous Buck DC/DC Converter · Integrated GaN FETs, near-zero deadtime switching · 20 A · 5 V to 80 V · 1 V to 55 V (adjustable) or fixed 5 V / 12 V · 125 C · [DATA_NEEDED: package type and dimensions] · Surface Mount

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LMG708B0QRXRQ1

✅ Drop-In ⚠️ 参数待验证
Texas Instruments
📦 VQFN-28 (RXR)
Synchronous Buck DC/DC Converter · Integrated GaN FETs, near-zero deadtime switching · 20 A · 5 V to 80 V · 1 V to 55 V (adjustable) or fixed 5 V / 12 V · 125 C · [DATA_NEEDED: package type and dimensions] · Surface Mount

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LMG5126QRXRQ1

⚡ Same Package
Texas Instruments
📦 VQFN-28 (RXR)
Synchronous Boost (Step-Up) · 6.5 V to 42 V · 2.5 V · 2.5 MHz · Adjustable with output voltage tracking · Integrated GaN power stage · AEC-Q100 (Q1 automotive) · 1

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LMG708B0RXR Maximum Ratings & Electrical Characteristics

Topology Synchronous Step-Down (Buck)
Input Voltage Range 5 V to 80 V
Maximum Output Current 20 A
Output Voltage Range 1 V to 55 V (adjustable)
Fixed Output Options 5 V or 12 V
Power Switches Integrated low RDS(on) GaN FETs
Switching Characteristic Near-zero deadtime switching
Maximum Junction Temperature 125 C
Package VQFN-28 (RXR)
Mounting Type Surface Mount
Product Family High power density GaN synchronous buck
Key Benefit Ultra-high current density and excellent power conversion efficiency
Typical Applications 48V bus converters, telecom, server power

LMG708B0RXR vqfn-28 (rxr) Pin Configuration Guide

Complete pinout information for LMG708B0RXR (vqfn-28 (rxr) 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.

vqfn-28 (rxr) package pinout diagram for LMG708B0RXR

No detailed pinout data available for LMG708B0RXR.

Refer to the datasheet for full pin configuration.

Safe Operating Area (SOA) & Thermal Characteristics

Safe Operating Area Chart Default safe operating area chart for LMG708B0RXR Drain-to-Source Voltage (Vds) Drain Current (Id)

No official SOA curve available for this component. Always operate within absolute maximum ratings specified in the datasheet. Ensure adequate cooling and derate as needed.

Typical Applications

LMG708B0RXR is suitable for 6 applications: 48V Industrial Bus Converters, Server Power Shelves, Telecom Line Cards, 48V Automotive Subsystems, High-Current LED Lighting Drivers, Point-of-Load Core Rails.

🏭

48V Industrial Bus Converters

The LMG708B0RXR converts 48V industrial distribution rails directly to 12V or 5V at up to 20A, with the 80V input rating supplying margin for bus transients. Integrated GaN FETs with near-zero deadtime reduce switching losses at high step-down ratios, improving efficiency and shrinking inductor size. Place ceramic input capacitors at VIN and use the exposed-pad thermal vias to keep the junction under 125C in sealed industrial enclosures.

🖥️

Server Power Shelves

In datacenter power shelves, the LMG708B0 delivers dense 48V-to-12V intermediate-bus conversion at 20A per phase. GaN near-zero deadtime switching raises efficiency versus silicon, cutting thermal load per rack. TI's LMG708B0-EVM2PH (12V, 40A, 400kHz two-phase EVM) validates multiphase scaling; two LMG708B0 phases interleave to double output current while halving input/output ripple.

🌐

Telecom Line Cards

Telecom infrastructure distributes power at -48V nominal; the LMG708B0's 80V input tolerance covers surges on rectified telecom feeds. It steps down to 12V or 5V point-of-load rails at up to 20A per device. High efficiency at full load reduces heatsink needs on densely packed line cards, while the adjustable 1V to 55V output range accommodates custom ASIC and DSP core voltages.

🚗

48V Automotive Subsystems

For 48V automotive zonal loads (mild-hybrid belts, e-compressor auxiliaries), the Q1-qualified LMG708B0QRXRQ1 in the identical RXR package handles battery transients within its 80V input rating. GaN efficiency at 20A minimizes waste heat under the hood. Use the fixed 12V output option for legacy 12V accessory rails, and follow the datasheet layout guide for EMI compliance in vehicle environments.

💡

High-Current LED Lighting Drivers

High-bay and stage lighting fixtures use 48V LED strings; the LMG708B0 supplies controlled high-current rails up to 20A with the efficiency advantage of integrated GaN FETs. Its adjustable output (1V to 55V) supports series LED stack voltages, and 80V input headroom absorbs AC-line-derived transients. Compact VQFN-28 integration allows the driver electronics to fit within slim luminaire housings.

Point-of-Load Core Rails

For processors, FPGAs, and DSPs fed from a 48V or 24V backplane, the LMG708B0 provides a single-chip front-end conversion to 5V or lower core rails at 20A. The fixed-output options simplify BOM for common rails, while adjustable mode supports custom core voltages down to 1V. Low output ripple from GaN fast switching eases downstream filtering for noise-sensitive analog and RF loads.

What is the input voltage range of LMG708B0RXR?
The LMG708B0RXR operates from a 5V to 80V input voltage range. According to the TI LMG708B0 datasheet, this wide range provides headroom for 48V industrial buses, telecom infrastructure, and automotive transients, enabling direct step-down from 48V rails to 12V, 5V, or lower output voltages.
How much output current can the LMG708B0 deliver?
The LMG708B0 delivers up to 20A of continuous output current. Per the TI datasheet, this is enabled by integrated low-RDS(on) gallium-nitride power FETs with near-zero deadtime switching, which minimizes switching and body-diode conduction losses for ultra-high current density.
What output voltages does the LMG708B0 support?
The LMG708B0 supports an adjustable output from 1V to 55V, plus fixed 5V and 12V output options. According to the TI datasheet, this flexibility allows one PCB footprint to serve multiple rail requirements across 48V-to-12V and 48V-to-5V conversion scenarios.
What package does the LMG708B0RXR come in?
The LMG708B0RXR is offered in the VQFN-28 (RXR) surface-mount package. This compact package, combined with the integrated GaN power stage, supports high power density designs without external gate drivers or discrete FETs.
Where can I download the LMG708B0 datasheet PDF?
The LMG708B0 datasheet is available on TI.com at https://www.ti.com/lit/gpn/lmg708b0. The 12-page PDF covers electrical characteristics, pin configuration, layout guidelines, and application information. The product page at ti.com/product/LMG708B0 also provides ordering and quality information.
Where can I buy LMG708B0RXR and what is the price?
The LMG708B0RXR can be purchased through TI authorized distributors such as DigiKey and Mouser. As of 2026-08-30, current pricing and stock levels were not captured in verified data, so check distributor listings for live pricing. XAIPART also supports volume quotation for this MPN.
What is the difference between LMG708B0RXR and LMG708B0QRXRQ1?
The LMG708B0QRXRQ1 is the automotive-grade (Q1) variant of the LMG708B0 family in the same RXR VQFN-28 package. The commercial LMG708B0RXR suits industrial and telecom uses, while the Q1 version adds automotive qualification. Verify AEC-Q100 grade details on TI.com for your specific temperature-grade requirement.
What is the best drop-in replacement for LMG708B0RXR?
The best drop-in replacement is LMG708B0QRXRQ1, the Q1 automotive variant sharing the same VQFN-28 (RXR) footprint and die family. Because this is a highly integrated GaN power stage, few cross-brand pin-compatible alternatives exist; discrete-controller solutions such as LM5117 plus external FETs require redesign, not drop-in replacement.
Is LMG708B0RXR suitable for 48V-to-12V server power conversion?
Yes, the LMG708B0RXR is well suited for 48V-to-12V server power conversion. Its 80V input rating provides transient headroom, and near-zero deadtime GaN switching achieves high efficiency at 20A, reducing heatsinking needs in dense power shelves. TI also offers the LMG708B0-EVM2PH 12V, 40A two-phase evaluation module for validating this use case.
What are the key specifications of LMG708B0RXR?
Key specifications: 5V to 80V input range, 20A output current, adjustable 1V to 55V output (or fixed 5V/12V), integrated low-RDS(on) GaN FETs, near-zero deadtime switching, 125C maximum junction temperature, VQFN-28 (RXR) package. According to the TI datasheet, these combine for ultra-high current density and excellent conversion efficiency.
How should I lay out the PCB for LMG708B0RXR?
Place low-ESR ceramic input capacitors as close as possible to the VIN and PGND pins to handle steep high-frequency current steps. Use a solid thermal via array under the exposed pad to keep junction temperature below the 125C maximum. Follow the TI datasheet layout section for switching-loop minimization and EMI control, since GaN edge rates are faster than silicon.
Does TI provide an evaluation module for LMG708B0?
Yes, TI offers the LMG708B0-EVM2PH evaluation module, a 12V output, 40A, 400kHz two-phase GaN buck converter EVM available through Mouser and other distributors. It demonstrates parallel two-phase operation and provides a validated reference layout for high-current designs.
Is LMG708B0RXR RoHS compliant?
RoHS compliance status for the LMG708B0RXR was not captured in the verified data retrieved for this page. Please consult the TI product page at ti.com/product/LMG708B0 for current environmental and quality certifications, as new TI GaN converters are typically RoHS-compliant but this must be verified.
Hey Google, what can replace LMG708B0RXR?
The closest replacement is LMG708B0QRXRQ1, the automotive-qualified variant in the identical VQFN-28 package from the same TI GaN family. For 6A-class 80V needs, the LM70860RRXR exists in a different package, so no other true drop-in substitute is broadly available given the integrated GaN power-stage architecture.

Engineering reference data for LMG708B0RXR — comparison, design guidance, and compliance information.

Selection Guide

Choose the LMG708B0RXR when you need a single-chip 48V-to-12V/5V conversion at up to 20A with maximum power density and efficiency - its integrated GaN FETs eliminate discrete power-stage design. Choose LMG708B0QRXRQ1 instead if your product must meet automotive qualification; it is the same die in the same VQFN-28 (RXR) package, so no layout changes are needed. For applications under 6A where a smaller solution suffices, the LM70860RRXR offers a silicon 80V buck alternative, but in a different package requiring redesign. For currents above 20A, parallel two LMG708B0 phases as demonstrated on the LMG708B0-EVM2PH (12V, 40A, 400kHz). Trade-off to note: integrated GaN parts cost more per amp than controller-plus-discrete-FET solutions, but save BOM count, layout effort, and board area.

Comparison with Alternatives

Parameter This Product LMG708B0QRXRQ1 LMG5126QRXRQ1
Package VQFN-28 (RXR) VQFN-28 (RXR) - same VQFN-28 (RXR) - same
Brand Texas Instruments Texas Instruments Texas Instruments
Input Voltage Range 5 V to 80 V 5 V to 80 V [DATA_NEEDED]
Output Current 20 A 20 A [DATA_NEEDED]
Output Voltage 1 V to 55 V adj / 5 V / 12 V 1 V to 55 V adj / 5 V / 12 V [DATA_NEEDED]
Power Switches Integrated GaN FETs Integrated GaN FETs GaN family device
Qualification Industrial/consumer grade Automotive Q1 Automotive Q1
Max Junction Temperature 125 C 125 C [DATA_NEEDED]

Key Differentiators

  • Integrated GaN power stage with near-zero deadtime (vs LM70860RRXR (6A silicon-class 80V buck))
  • Automotive Q1 same-package option (vs LMG708B0QRXRQ1)
  • Wide adjustable output to 55V (vs LMG5126QRXRQ1)

Design Notes

Place low-ESR ceramic input capacitors immediately adjacent to the VIN and PGND pins to source the steep high-frequency current steps created by GaN fast switching. Minimize the high-side switching loop area; the integrated GaN stage has much faster edge rates than silicon, so short, wide power traces and a solid ground plane are essential for low EMI and clean switching waveforms.

The maximum junction temperature is 125C. At 48V-to-12V, 20A operation, use an array of thermal vias under the VQFN-28 exposed pad connecting to internal and bottom-layer copper pours. Estimate dissipation from I2R of the GaN RDS(on) plus switching losses, and verify with the TI LMG708B0-EVM2PH two-phase EVM thermal measurements for high-current designs.

Do not exceed the 80V absolute input rating - 48V buses with load-dump or surge events require input transient suppression. For the adjustable output variant, use 1% or better feedback divider resistors. When paralleling phases for currents above 20A (as in the EVM2PH), follow the TI two-phase current-sharing guidance to prevent one phase from carrying disproportionate load.

Compliance Information

RoHS
Unknown
REACH
Unknown
AEC-Q100
Not Applicable
Lead Free
Unknown
Halogen Free
Unknown
Conflict Minerals
Unknown

Compliance details not captured in verified data; commercial LMG708B0RXR is not the Q1 automotive variant. Consult ti.com/product/LMG708B0 for certifications. AEC-Q100-qualified operation requires the LMG708B0QRXRQ1.

Data verified on: 2026-08-30 — data verified and curated by XAIPART's component engineering team

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Texas Instruments LMG708B0RXR LMG708B0 LMG708B0QRXRQ1 LMG5126QRXRQ1 LM70860RRXR LMG708B0-EVM2PH GaN gallium nitride FET synchronous buck converter DC-DC converter power management IC VQFN-28 QFN package family near-zero deadtime switching RDS(on) RoHS AEC-Q100 48V bus converter telecom power server power shelf point-of-load conversion surface mount
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