Infineon MMBT2907ALT1HTSA1 PNP Bipolar Junction Transistor: Datasheet, Pinout, and Application Circuits

The Infineon MMBT2907ALT1HTSA1 is a popular surface-mount PNP Bipolar Junction Transistor (BJT) designed for general-purpose amplification and switching applications. Housed in a compact SOT-23 package, this device is known for its high current gain and low saturation voltage, making it a versatile component in modern electronic design.

Datasheet Overview and Key Specifications

The transistor is characterized by its ability to handle a continuous collector current (IC) of -600 mA and a collector-emitter voltage (VCEO) of -60 V. Key parameters from the datasheet include:

DC Current Gain (hFE): Ranges from 100 to 300 at IC = -10 mA and VCE = -1 V, ensuring good amplification.

Collector-Emitter Saturation Voltage (VCE(sat)): Typically -0.4 V at IC = -10 mA and IB = -1 mA, which is crucial for efficient switching with minimal power loss.

Total Power Dissipation (Ptot): 225 mW at room temperature.

These specifications make it suitable for driving relays, LEDs, and as an interface between microcontrollers and higher-power devices.

Pinout Configuration

The pinout for the SOT-23 package is standard for many small-signal transistors. When viewing the component with the flat side facing you and the pins downward:

Pin 1 (Emitter): This is the source of the charge carriers in this PNP device.

Pin 2 (Base): The control terminal; current applied here controls the flow between emitter and collector.

Pin 3 (Collector): The terminal that collects the charge carriers; it is typically connected to the load.

Application Circuits

1. Low-Side Switch: The most common application is as a low-side switch. Here, the emitter is connected directly to the positive supply voltage (VCC). The load (e.g., an LED or relay coil) is placed between the collector and ground. A control signal from a microcontroller or logic circuit, typically through a current-limiting resistor (e.g., 1kΩ - 10kΩ), is applied to the base to turn the transistor ON (saturated) or OFF. This circuit is ideal for controlling high-current devices with low-power logic signals.

2. Simple Amplifier: The MMBT2907A can be configured in a common-emitter amplifier setup to amplify small AC signals. Resistors are used to bias the transistor into its linear region of operation. A small AC input signal at the base results a larger, inverted AC signal at the collector. This circuit is fundamental in audio pre-amplifiers and signal processing stages.

ICGOODFIND: The Infineon MMBT2907ALT1HTSA1 is a highly reliable and efficient PNP BJT that excels in both switching and amplification roles. Its robust electrical characteristics, combined with the compact SOT-23 package, make it an excellent choice for space-constrained PCBs. Designers value it for its ability to effectively interface low-power control circuits with higher-power loads, simplifying design and improving overall system efficiency.

Keywords: PNP Transistor, SOT-23, Saturation Voltage, Low-Side Switch, Current Gain.