onsemi BUV26G

Overview

BUV26G from onsemi is an NPN silicon power transistor designed for high-speed switching in switch-mode power supplies and high-frequency converters. It supports 90 V_CEO(sus), 20 A continuous collector current, 85 W power dissipation at T_C = 25°C, and exhibits t_on ≤ 0.6 µs and t_f ≤ 0.15 µs under resistive load conditions. It is used in relay drivers and DC-DC converter output stages.

For engineers reviewing the BUV26G datasheet, pinout, applications, or equivalent options, key selection considerations include its 90 V sustaining voltage, 20 A I_C rating, TO-220 package thermal resistance of 1.76 °C/W, switching speed under inductive load (T_s ≤ 2.0 µs), and Pb-free RoHS-compliant construction.

Technical Context

The BUV26G operates as a rugged NPN bipolar junction transistor optimized for hard-switching in off-line SMPS and flyback converters. Its design emphasizes fast turn-off (t_f ≤ 0.15 µs) and controlled storage time (T_s ≤ 2.0 µs at 125°C) to minimize switching losses in high-frequency operation up to several hundred kHz.

It features a V_CE(sat) of 0.6 V at I_C = 6.0 A / I_B = 0.4 A and 1.5 V at I_C = 12 A / I_B = 1.2 A, with V_BE(sat) ≤ 2.0 V under full drive - enabling efficient base drive design using standard logic-level or discrete driver circuits.

Key Specifications

Pinout & Package

BUV26G is housed in a TO-220 (Case 221A, Style 1) package with insulated tab, lead-free plating, and standard through-hole mounting. The case serves as the collector terminal and must be electrically isolated from heatsink unless referenced to system ground.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar NPN power switching applications.

Compared with BUV27G and MJE13009, the BUV26G offers the best balance of 90 V rating, 20 A current, sub-2 µs storage time, and low saturation voltage - making it the preferred choice for compact, high-efficiency 48–60 V switch-mode power supplies operating above 100 kHz.

Availability

BUV26G is available at Aetrix Electronics and suitable for switch-mode power supplies, high-frequency DC-DC converters, and relay driver circuits requiring stable component supply, long-term manufacturability, and RoHS-compliant sourcing.

Supply support for BUV26G 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 (formerly ON Semiconductor) is a global semiconductor manufacturer specializing in energy-efficient power, analog, sensor, and connectivity solutions for automotive, industrial, cloud, and consumer markets.

The BUV26G belongs to onsemi's high-speed NPN power transistor product line, engineered specifically for demanding switch-mode power conversion applications where fast switching, high current, and rugged voltage handling are essential.

FAQ

What is the maximum safe operating junction temperature for the BUV26G?

The BUV26G has a specified operating junction temperature range of −65°C to +175°C. For reliable long-term operation, sustained junction temperatures should remain below 150°C under worst-case thermal conditions, especially when operating near maximum power dissipation. Derating curves in the official BUV26G datasheet define allowable power vs. case temperature, and thermal design must account for R_θJC = 1.76 °C/W and heatsink interface resistance to ensure the BUV26G stays within this limit.

Is the BUV26G pin-compatible with the BUV26 or BUV26A variants?

Yes, the BUV26G shares identical pinout, package (TO-220), and electrical specifications with BUV26 and BUV26A, differing only in Pb-free packaging (G-suffix). All three share the same marking diagram, terminal assignments (pin 1 = base, pins 2&4 = collector, pin 3 = emitter), and thermal/mechanical footprint - enabling direct replacement without PCB changes when RoHS compliance is required.

Does the BUV26G require a base resistor, and what value is recommended?

Yes, the BUV26G requires an external base resistor to limit drive current and prevent damage. For 12 A collector switching, a typical value is 10 Ω (1/4 W) when driven from a 5 V logic source, delivering ~0.4 A base current (I_B = (5 V − V_BE(sat)) / R_B). The BUV26G datasheet specifies I_B = 1.2 A for full saturation at 12 A, so R_B ≈ 3.3 Ω may be used with higher-drive sources - always verify with actual V_BE(sat) and driver capability.

Can the BUV26G be used in avalanche mode?

No, the BUV26G is not rated or characterized for repetitive avalanche operation. Its V_CEO(sus) = 90 V is a sustaining voltage under specified test conditions (I_C = 200 mA, I_B = 0, L = 25 mH), not an avalanche energy rating. Operation beyond V_CEO(sus) risks secondary breakdown or permanent damage. External clamping (e.g., TVS or RCD snubber) is required to protect the BUV26G against inductive voltage spikes exceeding 90 V.

What is the safe operating area (SOA) limitation for the BUV26G at 100°C case temperature?

At T_C = 100°C, the BUV26G's SOA is constrained by both second breakdown and thermal limits. The datasheet's Figure 4 shows that at 100°C, the device supports ≤ 8 A at 50 V or ≤ 4 A at 80 V in DC operation. Pulse operation (≤ 10 ms) extends the SOA slightly, but design must respect the derated P_D (≈ 45 W at 100°C) and avoid the "ruggedness-limited" region where localized heating can cause failure. Always validate SOA margins using the BUV26G's published SOA curves.