LMG708B0RXR - 20A GaN Synchronous Buck 80VIN | Texas Instruments
MPN: LMG708B0RXR ✓ نشطLMG708B0RXR نظرة عامة
A GaN synchronous buck converter is a step-down DC-DC switching regulator that uses gallium-nitride FETs as the power switches. In the power-management hierarchy it sits within the DC-DC converter subsystem, converting higher-voltage distribution rails to lower point-of-load voltages for processors, logic, and mixed-signal loads. GaN transistors exhibit very low gate charge and output capacitance, enabling faster switching transitions and dramatically lower switching losses than silicon MOSFETs, which is especially valuable at high step-down ratios such as 48V-to-12V and 48V-to-5V.
Key features include the fully integrated controller-plus-GaN power-stage architecture, 20A continuous output current, and near-zero deadtime that minimizes body-diode conduction loss. The integrated approach eliminates external high-side/low-side FET selection and simplifies gate-drive PCB layout. Low RDS(on) reduces conduction loss at full load, yielding high efficiency across a broad load range, while high-frequency capability permits smaller inductors and output capacitors for maximum power density.
The 80V maximum input rating provides substantial headroom for 48V industrial distribution buses, telecom -48V infrastructures, and automotive load-dump transients. Output configuration flexibility - resistor-divider adjustable or fixed 5V/12V - allows one footprint to serve multiple rail requirements.
Typical applications include 48V industrial bus converters, telecom line cards, server power shelves, 48V automotive subsystems, and high-current LED lighting drivers. The wide input and output ranges make it an effective front-end point-of-load solution for 12V, 5V, or lower core rails at currents up to 20A.
Design tip: place low-ESR ceramic input capacitors close to VIN and PGND to handle steep high-frequency current steps, and use thermal vias under the exposed pad to hold junction temperature below 125C. Follow the TI datasheet layout guidelines for optimum switching performance and EMI behavior.
بدائل مباشرة لـ LMG708B0RXR — نفس الحزمة، متوافق دبوس بدبوس. تُستثنى القطع ذات الحزم المختلفة التي تتطلب تعديل PCB.
الطرازات في هذه السلسلة
طرازات من نفس السلسلة متوافقة تمامًا مع LMG708B0RXR (نفس عامل الشكل والبصمة) — يختلف في Output Voltage Range, Topology.
LMG708B0QRXRQ1
✅ بديل مباشرتواصل لمعرفة السعر
عرض ورقة البيانات ←LMG708B0QRXRQ1
✅ بديل مباشر ⚠️ مواصفات غير مُتحقق منهاتواصل لمعرفة السعر
عرض ورقة البيانات ←LMG5126QRXRQ1
⚡ نفس الحزمةتواصل لمعرفة السعر
عرض ورقة البيانات ←LMG708B0RXR الحدود القصوى والخصائص الكهربائية
| البنية الطوبولوجية | Synchronous Step-Down (Buck) |
| نطاق جهد الدخل | 5 V to 80 V |
| أقصى تيار خرج | 20 A |
| نطاق جهد الخرج | 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 |
| العلبة | VQFN-28 (RXR) |
| نوع التركيب | 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 |
دليل تكوين أطراف LMG708B0RXR vqfn-28 (rxr)
تكوين الأطراف لـ LMG708B0RXR (حزمة vqfn-28 (rxr)). يتميز جهاز الطاقة هذا بأطراف البوابة والمصرف والمصدر. بالنسبة للحزم غير المستقطبة، راجع ورقة بيانات الشركة المصنعة لمعرفة الاتجاه الدقيق للطرف 1 وتفاصيل البصمة. تشمل التطبيقات الشائعة تصميم مصادر الطاقة وتشغيل المحركات وتبديل الأحمال.
لا تتوفر بيانات مفصلة لمخطط التوصيلات لـ LMG708B0RXR.
راجع ورقة البيانات للحصول على تكوين الأطراف الكامل.
التطبيقات النموذجية
LMG708B0RXR مناسب لـ 6 التطبيقs: 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.
موصى به
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.
موصى به
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.
موصى به
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.
موصى به
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.
موصى به
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.
موصى به
ملخص المنتجات الموصى بها
بيانات مرجعية هندسية لـ LMG708B0RXR — المقارنة وإرشادات التصميم ومعلومات الامتثال.
دليل الاختيار
المقارنة مع البدائل
| المعامل | هذا المنتج | LMG708B0QRXRQ1 | LMG5126QRXRQ1 |
|---|---|---|---|
| Package | VQFN-28 (RXR) | VQFN-28 (RXR) - same | VQFN-28 (RXR) - same |
| Brand | Texas Instruments | Texas Instruments | Texas Instruments |
| Power Switches | Integrated GaN FETs | Integrated GaN FETs | GaN family device |
| Qualification | Industrial/consumer grade | Automotive Q1 | Automotive Q1 |
أبرز الفروقات
- Integrated GaN power stage with near-zero deadtime (مقابلLM70860RRXR (6A silicon-class 80V buck))
- Automotive Q1 same-package option (مقابلLMG708B0QRXRQ1)
- Wide adjustable output to 55V (مقابلLMG5126QRXRQ1)
ملاحظات التصميم
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.
معلومات الامتثال
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.
