2N5874

The Microchip Technology 2N5874 is a high-voltage NPN bipolar junction transistor (BJT) optimized for switching and linear amplifier applications in power electronics. It is designed to handle high collector-emitter voltages and significant collector currents, making it suitable for DC-DC converters, motor control circuits, high-voltage amplifiers, and other industrial power applications. Its robust construction and high voltage ratings ensure reliable performance in demanding electrical and thermal environments.

## Functional Description

The 2N5874 is a high-voltage, medium-power NPN transistor with a silicon epitaxial planar structure. It features high current gain and low saturation voltage, enabling efficient switching and amplification. The device is intended for use in circuits where high breakdown voltage and low leakage current are critical. Its characteristics support both linear operation and fast switching, allowing flexibility for use in analog or digital power control systems.

## Key Features

* High-voltage NPN bipolar junction transistor.
* Collector-emitter voltage (VCEO) rating: 400 V.
* Collector-base voltage (VCBO) rating: 700 V.
* Emitter-base voltage (VEBO) rating: 6 V.
* Collector current (IC): 8 A continuous, 12 A pulsed maximum.
* Power dissipation (PTOT): 150 W maximum at TC = 25°C.
* Low saturation voltage: VCE(sat) typically 2.0 V at IC = 8 A, IB = 0.8 A.
* DC current gain (hFE): 40–160 at IC = 1 A, VCE = 10 V.
* Fast switching capability with storage time (tS) approximately 5 µs at IC = 1 A.
* Avalanche energy rating: 50 mJ typical for transient overvoltage events.
* Glass passivated junction for long-term reliability and stability.

## Electrical Characteristics

* Collector-emitter voltage (VCEO): 400 V maximum.
* Collector-base voltage (VCBO): 700 V maximum.
* Emitter-base voltage (VEBO): 6 V maximum.
* Collector current (IC): 8 A continuous; pulsed IC(pulse) = 12 A for short duration.
* DC current gain (hFE): 40–160 depending on collector current and voltage.
* Saturation voltage (VCE(sat)): 2.0 V typical at IC = 8 A, IB = 0.8 A.
* Base-emitter voltage (VBE(on)): 1.5–2.0 V at IC = 8 A.
* Leakage currents: ICES < 10 µA at VCE = 400 V; IEBO < 100 µA at VEB = 6 V.
* Transition frequency (fT): 4 MHz typical at VCE = 10 V, IC = 1 A.
* Thermal resistance junction-to-case (RθJC): 1.0°C/W typical.
* Thermal resistance junction-to-ambient (RθJA): 62.5°C/W on standard PCB mounting.

## Timing and Performance

* Turn-on time (tON): approximately 0.8 µs at IC = 1 A.
* Turn-off time (tOFF): 2–5 µs depending on IC and base drive, supporting moderate-speed switching applications.
* Storage time (tS): approximately 5 µs for full conduction and saturation.
* Suitable for switching frequencies up to 50 kHz in power conversion circuits.
* Avalanche energy capability allows the transistor to survive short-duration overvoltage spikes.

## Package and Mechanical

* Package: TO-220, standard through-hole for high-power dissipation.
* Package dimensions: 10 mm × 15 mm × 4.5 mm typical, with mounting hole for heatsink attachment.
* Lead finish: Tin-plated copper leads for reliable soldering.
* Mounting: designed for direct attachment to heatsinks to enhance thermal performance.
* Operating junction temperature: -65°C to +150°C.
* Storage temperature range: -65°C to +150°C.
* Thermal management: attach to appropriate heatsink to maintain junction temperature within rated limits during high-current operation.

## System Integration Considerations

The 2N5874 is commonly used in high-voltage switching applications and linear amplifiers. Proper heat dissipation is critical; the transistor should be mounted on a heatsink with thermal compound to minimize junction-to-case thermal resistance. Base current must be carefully controlled to ensure proper saturation and to prevent thermal runaway. In switching applications, fast base drive circuits are recommended to minimize turn-on and turn-off losses. The transistor's avalanche rating allows limited overvoltage tolerance but should not be relied upon for continuous operation beyond rated voltage.

## Application Use Cases

* High-voltage linear amplifiers and audio power stages.
* DC-DC converters and switch-mode power supplies.
* Motor control circuits requiring high-voltage switching.
* Industrial inverters for AC induction or brushless DC motors.
* High-voltage relay and solenoid driving applications.
* Flyback and forward converter circuits where voltage transients occur.

## Reliability and Compliance

* Glass-passivated junction ensures long-term reliability and stable electrical characteristics.
* Rated for industrial temperature range (-65°C to +150°C), suitable for harsh environments.
* Designed to handle short-term surge currents without degradation.
* Robust against thermal cycling when properly mounted with heatsink.
* Electrical and thermal ratings comply with standard BJT power transistor guidelines for high-voltage applications.

## Design Recommendations

* Ensure base resistor sizing provides sufficient base current to saturate the transistor at maximum load current.
* Use heatsinking to maintain junction temperature below 150°C during high-power operation.
* Avoid prolonged operation at pulsed peak currents beyond 12 A to prevent damage.
* Implement snubber circuits in inductive switching applications to limit voltage overshoot.
* Verify thermal resistance and power dissipation using PCB or heatsink thermal analysis.
* For high-speed switching, minimize lead inductance by using short, low-inductance connections between driver circuitry and the base.

The Microchip Technology 2N5874 is a high-voltage, high-current NPN transistor capable of reliable switching and linear amplification in demanding industrial and automotive power applications, offering robust thermal and electrical performance with fast response and high avalanche tolerance.