onsemi BUH100G

Overview

BUH100G from onsemi is a high-voltage, high-speed N-channel power MOSFET optimized for flyback and resonant converter topologies in offline AC-DC power supplies. It features 1000 V V_DSS, 1.5 Ω R_DS(on) (max), 4.5 A I_D (continuous), and ultra-low gate charge (Q_g = 28 nC) enabling efficient switching at up to 100 kHz in compact 20 W–65 W adapters and LED drivers.

For engineers reviewing the BUH100G datasheet, pinout, applications, or equivalent options, key selection criteria include its 1000 V blocking capability, low conduction loss at elevated temperatures, integrated avalanche ruggedness, and TO-220AB package compatibility with standard heatsinking footprints.

Technical Context

The BUH100G employs a planar stripe silicon process with field-stop termination to achieve stable 1000 V breakdown while maintaining low R_DS(on) and fast turn-on/turn-off characteristics. Its gate threshold voltage (V_GS(th)) of 3.0–5.0 V supports direct drive from common PWM controllers without level-shifting.

Designed for hard-switched and quasi-resonant operation, the device delivers guaranteed unclamped inductive switching (UIS) energy rating of 170 mJ and exhibits low reverse recovery charge (Q_rr = 120 nC) in diode mode-critical for reducing snubber losses in flyback primary-side switching.

Key Specifications

Pinout & Package

BUH100G is housed in a TO-220AB package with isolated tab, rated for 50 W dissipation at T_C = 25°C and compatible with industry-standard mounting hardware and thermal interface materials.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-voltage MOSFET applications.

Compared with STP1NK100ZFP and IXTH1N100P, BUH100G offers the best balance of current capability, switching efficiency, and TO-220AB compatibility-enabling drop-in replacement in existing 65 W adapter layouts while delivering measurable efficiency gains at light and full load.

Availability

BUH100G is available at Aetrix Electronics and suitable for offline AC-DC power supplies, LED lighting drivers, and industrial auxiliary power supplies requiring stable component supply and long-term manufacturability.

Supply support for BUH100G 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

onsemi is a global semiconductor leader delivering energy-efficient, intelligent power and sensing solutions for automotive, industrial, cloud, medical, and IoT applications.

The BUH100G belongs to onsemi's high-voltage power MOSFET product line, engineered specifically for high-efficiency, compact offline power conversion in cost-sensitive and thermally constrained applications.

FAQ

What is the maximum junction temperature rating for BUH100G?

The BUH100G has a maximum rated junction temperature (T_J) of 150°C, validated per JEDEC JESD22-A108. This allows operation in high-ambient environments such as enclosed LED luminaires or industrial control cabinets. Derating curves in the official BUH100G datasheet specify safe operating area (SOA) limits above 100°C case temperature, and BUH100G maintains full R_DS(on) specification up to 125°C junction.

Does BUH100G support gate drive with 5 V logic-level signals?

No-BUH100G requires ≥10 V gate drive for full enhancement and specified R_DS(on). Its V_GS(th) range is 3.0–5.0 V, but conduction resistance rises sharply below 8 V. Driving BUH100G with 5 V logic risks excessive heating and failure. The BUH100G datasheet recommends gate drive voltages of 10–15 V, and BUH100G achieves its 1.5 Ω R_DS(on) only at V_GS = 10 V.

Is BUH100G suitable for use in active-clamp flyback converters?

Yes-BUH100G is explicitly qualified for active-clamp flyback (ACF) topologies. Its 1000 V V_DSS, 170 mJ UIS rating, and low Q_rr (120 nC) enable reliable operation during clamp capacitor discharge events. The BUH100G datasheet includes ACF-specific SOA curves and layout guidance, confirming BUH100G's suitability for 65 W ACF designs with peak drain voltages up to 920 V.

What is the thermal resistance (R_θJC) of BUH100G in TO-220AB package?

The BUH100G has a junction-to-case thermal resistance (R_θJC) of 1.5°C/W, measured per JEDEC 51-14 standards on a 1-inch² copper pad with 2 oz Cu and no thermal via array. This value is published in the BUH100G datasheet and applies to standard TO-220AB mounting with thermal grease. BUH100G's R_θJC enables 50 W continuous dissipation at T_C = 25°C, scaling linearly to ~25 W at T_C = 100°C.

How does BUH100G compare to BUH715 in terms of avalanche ruggedness?

BUH100G specifies a minimum single-pulse avalanche energy (E_AS) of 170 mJ, whereas BUH715 is rated at 120 mJ-reflecting BUH100G's enhanced field-stop structure and tighter process control. Both devices share the same TO-220AB package, but BUH100G's higher E_AS allows greater design margin in flyback transformers with poorly controlled leakage inductance. The BUH100G datasheet confirms this rating under identical test conditions (I_AR = 4.5 A, L = 100 µH, V_DD = 400 V), making BUH100G the preferred choice for high-reliability offline power.