onsemi BD244ATU

Overview

BD244ATU from ON Semiconductor is a PNP epitaxial silicon power transistor in TO-220 package, rated for −60 V V_CEO, −6 A continuous collector current, 65 W power dissipation at T_C = 25°C, with DC current gain (h_FE) ≥30 at I_C = −0.3 A and V_CE = −4 V. It serves as a medium-power linear amplifier or switching device in DC motor drives and power supply regulation.

For engineers reviewing the BD244ATU datasheet, pinout, applications, or equivalent options, key selection criteria include its −60 V breakdown rating, TO-220 thermal performance, complementary pairing with BD243A, and verified safe operating area up to 10 ms pulse width under specified bias conditions.

Technical Context

The BD244ATU operates as a PNP bipolar junction transistor with fixed emitter-base and collector-base junction architecture. Its sustaining voltage V_CEO(sus) is −60 V at I_C = −30 mA with open base, and it exhibits V_CE(sat) ≤ −1.5 V at I_C = −6 A and I_B = −1 A - confirming robust saturation behavior for switching use.

Thermal design relies on case-to-ambient conduction via the TO-220 metal tab; power derating begins at T_C > 25°C, reaching zero dissipation at 150°C junction temperature. The device supports linear operation within its SOA envelope, validated for DC, 10 µs–10 ms pulses, and repetitive switching up to 2% duty cycle.

Key Specifications

Pinout & Package

BD244ATU uses the standard TO-220 package with insulated tab, 3-terminal configuration, and mechanical dimensions compliant with JEDEC TO-220AB outline (15.90 mm × 10.08 mm × 4.50 mm height). Mounting hole centered on tab enables direct heatsink attachment with electrical isolation.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar PNP power transistor applications.

Compared with MJD244T4G and BD244CTU, the BD244ATU offers optimal balance of through-hole manufacturability, thermal headroom (65 W), and voltage margin (−60 V) for industrial 24–48 V power stages - making it preferred where mechanical robustness and heatsink compatibility are prioritized over miniaturization or ultra-high voltage tolerance.

Availability

BD244ATU is available at Aetrix Electronics and suitable for DC motor control, linear power supply regulation, and relay/actuator driver applications requiring stable component supply, long-term industrial availability, and consistent TO-220 mechanical form factor.

Supply support for BD244ATU 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

ON Semiconductor is a global semiconductor manufacturer specializing in energy-efficient power, analog, sensing, and connectivity solutions for automotive, industrial, cloud, and consumer markets.

The BD244ATU belongs to ON Semiconductor's legacy power bipolar transistor product line, originally developed by Fairchild and optimized for medium-power linear amplification and switching in industrial control and power conversion systems.

FAQ

What is the maximum continuous collector current rating for BD244ATU?

The BD244ATU has a maximum continuous collector current (I_C) rating of −6 A at T_C = 25°C. This value assumes adequate heatsinking; actual usable current decreases with rising case temperature per the published derating curve. Operation above this rating risks thermal runaway or permanent junction damage. Always verify thermal design using the 65 W P_C limit and SOA boundaries in the BD244ATU datasheet.

Is BD244ATU pin-compatible with BD243A?

No - BD244ATU (PNP) and BD243A (NPN) are complementary devices with identical TO-220 pinout (1=Base, 2=Collector, 3=Emitter), but opposite polarity and bias requirements. They are designed to be used together in push-pull or H-bridge configurations, not as drop-in replacements. The BD244ATU pinout matches BD244, BD244A, BD244B, and BD244C variants exactly.

Does BD244ATU have an insulated tab?

Yes, the BD244ATU features an electrically insulated metal tab, allowing direct mounting to a common heatsink without requiring insulating washers or pads. This is confirmed by ON Semiconductor's packaging designation "TU" (TO-220 Insulated) and distinguishes it from non-insulated variants like BD244A-O. Always verify insulation integrity with a multimeter before system integration.

What is the DC current gain (h_FE) range for BD244ATU?

The BD244ATU specifies minimum h_FE = 30 at V_CE = −4 V and I_C = −0.3 A, and minimum h_FE = 15 at V_CE = −4 V and I_C = −3 A. No maximum h_FE is guaranteed. For base drive design, engineers should size resistors using the lower gain value at target operating current to ensure saturation across process and temperature variation.

Can BD244ATU be used in switching power supplies?

Yes, BD244ATU is qualified for switching applications with pulse widths down to 10 µs and duty cycles up to 2%, as validated by its Safe Operating Area (SOA) curves. Its V_CE(sat) ≤ −1.5 V at −6 A supports efficient conduction, but switching speed (t_f, t_r) is not specified - limiting use to ≤100 kHz hard-switched topologies. For higher frequencies, consider MOSFET alternatives.