BCP51-16 PNP Transistor from Slkor: 45V Rated Voltage 1A SOT‑223 Audio‑Drive Power Transistor

BCP51-16 is a PNP bipolar transistor belonging to the BCP51~BCP53 series with SOT-223 package. This device features relatively high collector current and low collector-emitter saturation voltage. Its DC current gain rank ranges from 100 to 250. It is suitable for audio-drive and output-stage circuits, and has complementary NPN devices BCP54~BCP56. This document sorts out key parameters, product features and application directions of the device, provides engineering application suggestions, and delivers a comprehensive product description.

I. Core Product Parameters

Unless otherwise specified, all tests are performed under ambient temperature of 25℃.

1. Maximum Ratings

1. Collector-base reverse voltage: -45V
2. Collector-emitter reverse voltage: -45V
3. Emitter-base reverse voltage: -5V
4. Continuous collector current: -1A
5. Collector power dissipation: 1.5W
6. Junction-to-ambient thermal resistance: 94℃/W
7. Storage temperature range: -65℃ ~ +150℃

2. Electrical Characteristics

1. Collector-emitter breakdown voltage: -45V, test condition: collector current -10mA, base open-circuit
2. Collector cut-off current: maximum value -100nA, test condition: base-collector voltage -30V, emitter open-circuit
3. DC current gain: - Collector current -5mA, collector-emitter voltage -2V, minimum value 25 - Collector current -150mA, collector-emitter voltage -2V, gain range 100-250 (rank of BCP51-16) - Collector current -500mA, collector-emitter voltage -2V, minimum value 25
4. Collector-emitter saturation voltage: maximum value -0.5V, test condition: collector current -500mA, base current -50mA
5. Base-emitter voltage: maximum value -1V, test condition: collector current -500mA, collector-emitter voltage -2V
6. Transition frequency: minimum value 100MHz, test condition: collector-emitter voltage -10V, collector current -50mA, test frequency 100MHz

3. Pin Definition (SOT-223 Package)

Pin 1: Base; Pin 2: Collector; Pin3: Emitter

II. Core Product Features

1. It is a PNP bipolar transistor. Complementary NPN devices BCP54 to BCP56 are available, which facilitates push-pull circuit design.
2. It supports 1A maximum continuous collector current and 1.5W power dissipation. The SOT-223 package delivers favorable heat dissipation performance.
3. Low collector-emitter saturation voltage reduces power loss under turn-on state.
4. BCP51-16 version has DC current gain ranging from 100 to 250 with strong amplification capacity for medium-current drive scenarios.
5. The transition frequency is no less than 100MHz to satisfy medium-and-high-frequency signal processing requirements.
6. Wide storage and operating temperature range adapts to environment from -65℃ to +150℃.

III. Main Application Fields

1. Audio amplifier drive circuits and audio output-stage circuits.
2. Small-and-medium-current switch control circuits.
3. Push-pull amplifier circuits requiring pairing of PNP and corresponding NPN devices.
4. Signal amplification and load-drive general-purpose circuits for industrial equipment.

IV. Suggestions for Engineering Design

1. Voltage selection: In practical circuits, actual working voltages of collector-base and collector-emitter shall keep sufficient safety margin and shall not approach the rated -45V directly, to avoid device damage caused by voltage surge.
2. Power dissipation and temperature management: The maximum power dissipation of 1.5W is defined at 25℃ ambient temperature. When ambient temperature exceeds 120℃, allowable power dissipation of the device needs de-rating. Based on junction-to-ambient thermal resistance of 94℃/W, actual temperature rise shall be evaluated to prevent junction temperature from exceeding device limit.
3. Current design: Continuous collector current shall not exceed 1A. For heavy-current saturation working conditions, sufficient base drive current shall be guaranteed to realize saturated turn-on, control saturation voltage drop and lower heat generation.
4. Notes on gain: DC current gain varies with collector current and ambient temperature. Gain decreases under heavy-current conditions. Circuit design shall not only rely on nominal gain from datasheet, sufficient design margin shall be reserved.
5. Cut-off leakage current: Collector cut-off leakage current rises significantly as temperature increases. Impacts brought by leakage current shall be considered for high-temperature applications.
6. Complementary pairing: For push-pull output applications, BCP54~BCP56 series NPN transistors can be selected as paired devices.

V. Product Summary

BCP51-16 is a PNP power transistor in SOT-223 package with 45V rated withstand voltage, 1A continuous current and 1.5W power dissipation. It features low saturation voltage drop, high amplification factor and corresponding complementary NPN models. This device is mainly targeted for audio drive and output circuits, and also applies to general-purpose circuits such as small-and-medium-current switches and push-pull amplifiers. For engineering applications, de-rating design of voltage, current and power dissipation shall be implemented according to temperature conditions. Variations of gain and leakage current against temperature and operating current should also be considered to guarantee long-term stable circuit operation.

About Slkor：

Slkor has research and development offices in Busan, South Korea, Beijing, China, and Suzhou, China. Most of the wafer manufacturing and packaging and testing are carried out within China. The company employs and collaborates with individuals and organizations worldwide, with a laboratory for product performance and reliability testing and a central warehouse located at its headquarters in Shenzhen. Slkor has filed for over a hundred invention patents, offers more than 2,000 product models, and serves over ten thousand customers globally. Its products are exported to countries and regions including Europe, the Americas, Southeast Asia, and the Middle East, making it one of the rapidly growing semiconductor companies in recent years. With well-established management systems and streamlined workflows, Slkor has rapidly enhanced the brand awareness and reputation of its "SLKOR" brand through its outstanding quality and standardized services. Its product range includes three major series: diodes, transistors, and power devices, with recent introductions of new products such as Hall elements and analog devices, expanding its presence in sensors, Risc-v microcontrollers, and other product categories.

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