onsemi SBC847BLT1G General Purpose NPN/PNP Bipolar Transistor: Datasheet, Pinout, and Application Circuit Guide

The onsemi SBC847BLT1G is a fundamental component in modern electronics, integrating a matched pair of general-purpose NPN and PNP bipolar transistors in a single, ultra-compact SOT-563 surface-mount package. This device is engineered for applications requiring complementary transistor pairs with high gain and excellent performance matching, making it an ideal choice for a wide array of analog circuit designs.

This article provides a detailed overview of its datasheet specifications, pinout configuration, and a practical application circuit guide.

Datasheet Overview and Key Specifications

The SBC847BLT1G is part of onsemi's extensive portfolio of small-signal transistors. Its key electrical characteristics make it suitable for amplification and switching tasks.

Absolute Maximum Ratings:

Collector-Base Voltage (VCBO): NPN: 50V / PNP: -50V

Collector-Emitter Voltage (VCEO): NPN: 45V / PNP: -45V

Emitter-Base Voltage (VEBO): NPN: 5.0V / PNP: -5.0V

Continuous Collector Current (IC): 100mA

Total Power Dissipation: 300mW

Key Electrical Characteristics (TA = 25°C):

DC Current Gain (hFE): This is a critical parameter for amplification. The SBC847BLT1G offers high and closely matched gain across both transistors.

For the NPN (Q1) at IC = 2mA, VCE = 5V: hFE = 200 - 450

For the PNP (Q2) at IC = -2mA, VCE = -5V: hFE = 200 - 450

Collector-Emitter Saturation Voltage (VCE(sat)): Low saturation voltage ensures efficient switching.

For both transistors (IC = 10mA, IB = 0.5mA): VCE(sat) is typically 100mV (NPN) and -120mV (PNP), maximizing performance in low-voltage circuits.

Transition Frequency (fT): 100 MHz (typical) for both transistors, indicating its usefulness in high-frequency amplification stages.

Pinout Configuration

The device is housed in a space-saving 6-pin SOT-563 package. Correct connection is vital for circuit operation. The pinout is as follows:

Pin 1: NPN Transistor Base (Q1 Base)

Pin 2: NPN Transistor Emitter (Q1 Emitter)

Pin 3: NPN Transistor Collector (Q1 Collector)

Pin 4: PNP Transistor Collector (Q2 Collector)

Pin 5: PNP Transistor Emitter (Q2 Emitter)

Pin 6: PNP Transistor Base (Q2 Base)

Note: Always consult the manufacturer's datasheet for the recommended PCB land pattern and soldering guidelines to ensure reliability.

Application Circuit Guide

A classic application for a matched NPN/PNP pair like the SBC847BLT1G is in push-pull amplifier output stages and rail-to-rail signal shifting. Below is a guide for a simple complementary push-pull amplifier.

Circuit Function:

This configuration is highly efficient and minimizes crossover distortion by using the NPN transistor to source current to the load (on the positive half of the input waveform) and the PNP transistor to sink current from the load (on the negative half).

Basic Schematic:

1. The input signal is applied to the bases of both transistors through current-limiting resistors.

2. The emitters of both transistors are connected together and form the output node that drives the load (e.g., a speaker or another circuit stage).

3. The collector of the NPN transistor (Q1) is connected to the positive supply rail (VCC).

4. The collector of the PNP transistor (Q2) is connected to the negative supply rail or ground (GND).

How it Works:

When the input signal goes positive, it biases the NPN transistor (Q1) into conduction while the PNP (Q2) remains off. Q1 acts as a current source, pushing current through the load.

When the input signal goes negative, it biases the PNP transistor (Q2) into conduction while the NPN (Q1) turns off. Q2 acts as a current sink, pulling current from the load.

The close matching of the hFE values between the two transistors in the SBC847BLT1G ensures symmetrical amplification of both the positive and negative halves of the input signal, resulting in low distortion output.

This circuit is a building block for audio amplifiers, headphone drivers, and digital logic level converters.

ICGOODFIND Summary:

The onsemi SBC847BLT1G stands out as an exceptionally versatile and space-efficient solution for designs requiring a matched pair of complementary transistors. Its high gain, low saturation voltage, and compact form factor make it an excellent choice for engineers designing amplification stages, switching circuits, and signal processing systems where board space and performance are at a premium.

Keywords:

Bipolar Transistor

NPN PNP Pair

SOT-563

Current Gain

Push-Pull Amplifier