MPSA92 Transistor : Pin Configuration & Its Applications

High voltage MPSA92 transistor can switch up to 300V of loads with an extremely less trigger voltage like 5V. So due to this feature, this transistor is used in digital electronics because it operates with 5V. Generally, a transistor is used like an amplifier or a switch but this transistor is used only for switching due to less gain value.

Apart from this maximum voltage rating, the operating speed of this transistor is 50MHz through 3pF less output capacitance. This article discusses an overview of the MPSA92 PNP transistor, Pinout, features, specifications, circuit working with applications.

What is MPSA92 Transistor?

MPSA92 transistor is a bipolar junction transistor, designed to use in high voltage-based applications. This PNP transistor is available in different packages but most of the designers use the TO-92 package apart from other packages.

MPSA92 Transistor
MPSA92 Transistor

As compared to another general-purpose transistor, this is a unique transistor due to its maximum voltage from collector to emitter terminal like 300V. In addition, the maximum current of the collector terminal in the transistor is 200mA to 500 mA based on the manufacture.

Pin Configuration

The pin configuration of the MPSA92 transistor with the symbol is shown below. This transistor includes three terminals like a normal transistor such as emitter (E), base (B), and collector (C) where each terminal and its functionality are discussed below.

MPSA92 Transistor Pin Configuration
MPSA92 Transistor Pin Configuration
  • Pin1 (Emitter): This emitter terminal is connected to GND where the flow of current drains out through this terminal.
  • Pin2 (Base): This terminal is used to operate the transistor by switching ON/OFF by controlling the transistor biasing.
  • Pin3 (Collector): This collector terminal is connected to load where the current supplies throughout this terminal.

Features & Specifications

The features & specifications of the MPSA92 transistor include the following.

  • This is a PNP type transistor with high voltage
  • The voltage from collector terminal to emitter or VCE is 300 V
  • The voltage from collector to base terminal or VCB is 300V
  • The voltage from emitter to base or VBE is 5V
  • Collector current (IC) is 500mA
  • Typical DC gain or hFE is 40 whenever IC=10mA
  • Transition Frequency is 50MHz
  • The available package is To-92
  • Max collector current (IC) ranges from 200mA to 500mA
  • Collector to emitter voltage (MAX) or VCE is 300V
  • Collector to base voltage (MAX) or VCB is 300V
  • Emitter to base voltage (Max) is 5V
  • Collector dissipation (Max) or Pc is 625 mW
  • Transition frequency (Max) or fT is 50 MHz
  • Max and min DC Current Gain or hFE ranges from 25 to 40
  • Maximum operating temperature ranges from -55 to +150 C

Equivalent NPN MPSA92 transistor is MPSA42. Equivalent PNP MPSA92 transistors are NTE288, MPSA43, KST92 (SMD), 2SC3468 & 2SA1371 and Other PNP transistors are BD136, 2N6107, SA1943, etc. SMD versions of MPSA92 PNP transistor are; MMBTA92 (SOT-23), KST92 (SOT-23) & PZTA92 (SOT-223).


How to use MPSA92 Transistor/Circuit Diagram

The negative keying inverter circuit using the MPSA92 transistor is shown below. In the continuous wave radar systems, the designing of all the circuits can be done with a positive key so that any electronic keyer can work with them. But, many transmitters/transceivers in vintage stations work with negative keying otherwise grid block keying.

So the following negative keying inverter circuit utilizes a high voltage-based PNP MPSA92 transistor to switch (key) a negative key-based vintage transmitter while providing a positive voltage at the input of the key. The required components to build this negative keying circuit are; MPSA92 transistor, current limiting resistor (200 Ohms), bias resistor (390 Ohms), protective diode (1N4002), positive voltage supply, and negative keypad transmitter (XMTR).

Negative Keying Inverter with MPSA92 Transistor
Negative Keying Inverter with MPSA92 Transistor

When the key is opened, the collector to the base junction of the MPSA92 transistor is reverse biased, so there is no flow of current throughout this transistor. When this PNP transistor is switched OFF, then there is no flow of current through the 390 or 200-ohm resistors. So, the voltage drop across them is zero.


Similarly, once the key is pressed, then the flow of current will be there throughout the 390-ohm resistor from the +Ve power supply to GND, so there is a voltage drop across it. So, some of this voltage drop receives throughout the 200-ohm resistor to the base to emitter junction, so now the voltage will be there across the base to emitter junction.

Thus, this base to emitter junction is forward biased, so the transistor will be turned ON and causes to flow of the current from the XMTR throughout the 200-ohm resistor & transistor. This eliminates the negative (-Ve) voltage with the help of the key jack of the transmitter.

How to Get Long-Term Performance of MPSA92 Transistor?

This transistor can be used for the long term in a circuit very securely by following the above-mentioned specifications. It is recommended to use this transistor as a minimum of below 20% from its highest ratings. The maximum voltage from collector to emitter terminal is 300V so we should not drive load above 240V. This transistor’s storage & operating temperature range must be below -55 degree C to above +150 degree C.

Where to use MPSA92 Transistor/Applications

The applications of the MPSA92 transistor include the following.

  • MPSA92 transistor is applicable in high voltage-based applications like the circuits which operate under 300V.
  • Once this transistor is used as a switch then it drives loads from -200mA to -500mA range.
  • This transistor is used as an amplifier or in audio amplifier stages
  • It is used in RF-based applications below 50MHz
  • In UPS (Uninterrupted power supply) circuits
  • High voltage based power supply circuits
  • Inverter based circuits
  • Transformerless power supplies
  • Battery chargers
  • DC High Voltage based Switching
  • Audio Amplifiers
  • Computer circuits & Telecommunication

Please refer to this link to know more about MPSA92 Transistor Datasheet

Thus, the MPSA92 transistor is a PNP-type high voltage transistor that is used simply for switching purposes due to less gain (30) value. So if you are seeking a PNP transistor to switch high voltages then it is the best choice for your requirement in different application circuits. Here is a question for you, what is the main difference between NPN and PNP transistor?

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