onsemi BDW94CFTU

Overview

BDW94CFTU from ON Semiconductor is a PNP epitaxial silicon Darlington transistor designed for high-current linear and switching power applications. It features a -100 V collector-emitter sustaining voltage (V_CEO(sus)), -12 A DC collector current, 80 W collector dissipation at T_C = 25°C, and TO-220 package with integrated emitter-base diode. It serves as the complement to BDW93C in push-pull output stages of audio amplifiers and motor drivers.

For engineers reviewing the BDW94CFTU datasheet, pinout, applications, or equivalent options, key selection criteria include safe operating area (SOA) at elevated case temperatures, V_CE(sat) under high-current switching conditions, h_FE consistency across -3 A to -10 A, and thermal derating behavior per the published power derating curve.

Technical Context

The BDW94CFTU implements a monolithic PNP Darlington pair with built-in emitter-base shunt diode, enabling robust turn-off in inductive load switching. Its high h_FE (min 750 at I_C = -5 A) reduces required base drive current while maintaining low V_CE(sat) (-2 V typical at I_C = -5 A, I_B = -20 mA).

Rated for T_J up to 150°C and T_STG from -65°C to 150°C, it supports industrial-grade thermal cycling. The device's SOA curve defines maximum simultaneous V_CE and I_C limits across pulse widths from 100 µs to DC, critical for snubberless relay/motor control designs.

Key Specifications

Pinout & Package

BDW94CFTU is housed in a through-hole TO-220 package with standard 3-pin configuration and metal tab electrically connected to collector. Mounting hole enables mechanical fixation and thermal coupling to heatsink.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BDW94BFTU and MJD127G, BDW94CFTU offers the highest voltage rating and integrated diode in through-hole TO-220, making it optimal for legacy industrial controls and repair replacements where board-level compatibility and inductive spike suppression are critical.

Availability

BDW94CFTU is available at Aetrix Electronics and suitable for industrial motor drives, audio power amplifiers, linear power supplies, and relay replacement modules requiring stable component supply and long-term obsolescence management.

Supply support for BDW94CFTU 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 supplier delivering energy-efficient, intelligent power and sensing solutions for automotive, industrial, cloud, medical, and IoT applications.

BDW94CFTU belongs to ON Semiconductor's legacy power bipolar transistor portfolio, originally developed by Fairchild Semiconductor to address high-current linear and switching needs in industrial analog systems.

FAQ

What is the maximum continuous collector current rating for BDW94CFTU?

The BDW94CFTU has a maximum DC collector current rating of -12 A at case temperature T_C = 25°C. This rating decreases linearly with rising case temperature per the published power derating curve, reaching zero at approximately 105°C. For sustained operation above 25°C, thermal design must ensure T_C remains within limits to avoid exceeding the safe operating area.

Does BDW94CFTU include an integrated diode, and what is its function?

Yes, BDW94CFTU integrates an emitter-base shunt diode. Its forward voltage is -1.3 V typical at -5 A, and it functions as a freewheeling path for inductive loads-such as relay coils or motor windings-during turn-off. This eliminates the need for an external clamp diode in many switching applications, simplifying design and improving reliability in BDW94CFTU-based circuits.

What is the collector-emitter sustaining voltage (V_CEO(sus)) of BDW94CFTU, and how does it differ from V_CEO?

The BDW94CFTU has a V_CEO(sus) of -100 V, measured with I_C = -100 mA and open base. Unlike standard V_CEO, this parameter guarantees voltage blocking capability under active switching conditions with defined leakage, making it the appropriate rating for designing BDW94CFTU into 80 V rail systems with safety margin. It reflects actual ruggedness in real-world switching scenarios.

Is BDW94CFTU pin-compatible with BDW93C, and how are they used together?

No, BDW94CFTU is not pin-compatible with BDW93C-they are complementary devices, not drop-in replacements. BDW94CFTU is PNP while BDW93C is NPN. In quasi-complementary output stages (e.g., audio amplifiers), BDW94CFTU serves as the upper device and BDW93C as the lower device, sharing identical TO-220 pinout (Base–Collector–Emitter) but opposite polarity, enabling matched thermal and electrical performance in BDW94CFTU/BDW93C pairs.

What thermal considerations apply when using BDW94CFTU in high-power applications?

BDW94CFTU requires a properly sized heatsink due to its 80 W P_C rating at T_C = 25°C. Thermal resistance from junction-to-case is 1.56°C/W (calculated from 150°C max T_J and 80 W). To maintain T_J ≤ 150°C, total thermal resistance (junction-to-ambient) must be kept below the value dictated by ambient temperature and power dissipation. Insulating hardware and thermal compound are essential when mounting BDW94CFTU to grounded heatsinks.