2SA1943 is a popular PNP power transistor used in Audio frequency amplifiers and High-power audio circuits. It has a high Collector to Emitter breakdown voltage of -230 V, high collector current of -15 A, and an output gain of -160. Hence, a power transistor.
2SA1943 transistor was first manufactured by company TOSHIBA from Japan but now it’s obsolete due to their new TTA1943 Transistor which is better and costs less than 2SA1943. Some companies still manufacture 2SA1943(except for Toshiba) so you might find it online easily.
2SA1943 PNP power transistor is complementary to 2SC5200 which is an NPN transistor with the same features as 2SA1943. Since they have similar specs and work well together, these two components are used to construct amplifier circuits in a push-pull configuration.
2SA1943 Transistor Pinout
Just like any other transistor, 2SA1943 has 3 pins: Emitter, Base, and Collector.

Given below is the pin diagram of the 2SA1943 transistor.
Pin Name | Description | |
B | Base | Controls the transistor’s biasing, used to turn it on and off. |
C | Collector | Current comes out of the transistor through the collector, usually connected to a load. |
E | Emitter | Current flows through the Emitter into the transistor. |
2SA1943 Specifications
The power dissipation rating of the 2SA1943 transistor is 150 watts which makes it suitable for AF amplifier circuits. Due to this high power usage, it is always used with a heatsink in a circuit.
Given below are the detailed specs of the 2SA1943 Transistor.
Characteristics | Symbol | Rating(Max.) |
---|---|---|
Collector-base voltage | VCBO | -230 V |
Collector-emitter voltage | VCEO | -230 V |
Emitter-base voltage | VEBO | -5 A |
Collector current | IC | -15 A |
Base current | IB | -1.5 A |
Collector output capacitance | Cob | 200 pF |
DC current gain | hFE | 360(VCE= -5V, IC= -1 A) |
Collector power dissipation | PC | 150 W |
Junction temperature(TC = 25°C) | Tj | 150 °C |
Operating temperature range | Tstg | −55 to 150 |
2SA1943 Equivalent Transistor
Transistors that are exactly similar or equivalent to 2SA1943 and can be replaced with it are TTA1943, 2SA1962, FJL421, MJL1302A, and KTA1962 PNP power transistors.
Datasheet of 2SA1943
The 2SA1943 is manufactured only in the TO-3P(L) Package. Hence there is no SMD version of the transistor. Given below is the datasheet of 2SA1943.
Note: Some companies manufacture 2SA1943 in the TO-264 package like ON Semiconductors.
To download the datasheet of 2SA1943, click here.
How to check 2SA1943 transistor ?
To check whether the 2SA1943 transistor is working or not, you need a multimeter.
Step1: Turn ON and set the multimeter in continuity checker mode.
Step 2: Place 2SA1943 on the workbench.
Step 3: Connect the positive and negative probes of the multimeter to the any two adjacent terminals of 2SA1943.
Step 4: Repeat this process for all the possible combinations of two terminals of the transistor.
RESULT: If the multimeter produces sound indicating continuity or a short circuit between transistor terminals, 2SA1943 transistor should be replaced with a new one
Applications of 2SA1943
Applications of 2SA1943 transistor are listed below:
- 2SA1943 is used mainly in audio frequency amplifiers
- Used in radio frequency circuits as well.
- Switch-mode power supplies (SMPS)
- Relays
- Used with its complementary transistor in a push-pull configuration
- Power supply
- Switching a load with high current rating
- Power amplifiers
- Inverters
- Converters
- Power control circuits
- DC to AC converters
Where to Buy 2SA1943?
You can easily find this transistor in your local electronics store. For online purchases, we recommend this best deal on Amazon:
Dimensions
Given below is the 2D diagram of the 2SA1943 PNP Transistor.
1. Dimensions of 2SA1943 in TO-3P(L) package

2. Dimensions of 2SA1943 in TO-264 package

FAQ’s
What is transistor 2SA1943?
2SA1943 is a popular PNP Power transistor used in High power audio circuits and Audio frequency amplifiers. It was originally manufactured by TOSHIBA in JAPAN and soon became one of the most popular power transistor. Its maximum ratings are: Collector to Emitter breakdown voltage is -230V, the collector current is -15A, and the current gain is 160.
What is 2SC5200 2SA1943?
2SC52000 and 2SA1943 are two different transistors that are complementary to each other. 2SC5200 is an NPN whereas 2SA1943 is a PNP transistor. They are used together in push-pull configuration circuits such as Class B amplifiers.
What is the difference between 2SA1943 and TTA1943?
TTA1943 power transistor is the new and improved version of 2SA1943. It came out in 2011, designed by TOSHIBA, which replaced 2SA1943 as a cheaper option that was superior to it. Hence, TTA1943 should be the first choice between these two transistors.