2SC2120 Transistor Pinout, Uses, Features, Equivalents and Other Details

This post explains 2SC2120 transistor pinout, uses, features, equivalents and other details such as how to use, safe operating guidelines etc.

Absolute Maximum Ratings:

• Package Type: TO-92
• Transistor Type: NPN
• Max Collector Current(I_C): 800mA
• Max Collector-Emitter Voltage (V_CE): 30V
• Max Collector-Base Voltage (V_CB): 35V
• Max Emitter-Base Voltage (VEBO): 5V
• Base Current is: 160mA
• Collector Power Dissipation (Pc): 600mW
• Transition Frequency (fT):  120MHz
• DC Current Gain (h_FE): 100 to 320
• Max Storage & Operating temperature Should Be: -55 to +150 Centigrade

 

PNP Complimentary:

PNP complimentary of 2SC2120 is 2SA950

 

Replacement and Equivalent:

BC337, 2SD863, 2SD1835, 2SD1207, 2SC3205, 2SC2710, TP3705, PN3704, PN2219/A, PN2219/A, NTE382, MPS3704, KTC3205, ECG315, BFR41, BDB05, BCX73, BCX38, BC879, BC875, BC639, BC635, BC487A/B, 2SD974, 2SD763, 2SD1835, 2SD1780, 2SD1388, 2SD1207, 2SD1146, 2SD1015, 2SC6043, 2SC4781, 2SC4145, 2SC3226.

 

2SA1145 Transistor Explained / Description:

2SC2120 is a very useful and interesting old transistor designed to be used in audio power amplifier applications. The transistor is having quite good characteristics which makes it a versatile device and makes it useable in wide variety of other applications. The transistor possesses some of very good features which are good DC current gain, upto 1 watt amplification power, high collector current in TO-92 package, good collector power dissipation and availability of its complimentary pair.

The absolute maximum ratings of the transistor are collector-emitter voltage of 30V, collector current is 800mA, collector-base voltage is 35V, emitter-base voltage is 5V, base current is 160mA, junction temperature is 150 ̊C and storage and operating temperature is from -55 ̊C to +150 ̊C.

The transistor is available in two different hFE variations and can be checked with the help of the alphabet written after the part number. If that alphabet is “O” then the gain value will be 100-200 and if the alphabet is “Y” then the gain value will be 160-320.

 

How to Use This Transistor:

2SC2120 can be used in wide variety of applications but here we will discuss only two of its major applications which are switch and amplifier.

Using the transistor as a switch is not very complicated and only requires few components. The signals through which you want to control the output load will be applied to its base pin through a current limiting resistor. A current limiting resistor is important here because base pin requires very low current. Any resistor value from 1K to 10K can be used but it also depends on how much current you want to provide to the load. The emitter pin will be connected with the ground or negative rail of the circuit and the load will be connected between the collector pin and the positive rail of the circuit.

Using it as an amplifier is little bit complicated because an amplifier circuit is not straight forward like the switch circuit and you have to use many passive components to enhance the output audio. Here we are describing a simple and basic amplifier circuit so you can understand the concept. You can make a simple amplifier circuit by providing signals you want to amplify at the base pin of the transistor through an electrolytic capacitor. In the above described switch circuit we have used a current limiting resistor because there we have to limit the current that is going in the transistor but here we have to filter the DC and only pass the audio signals which are in AC form so a capacitor is a best candidate for this work it blocks DC and only filters AC signals or only allows AC signals to pass. You can use an electrolytic capacitor of any value from 1uF to 10uF here. Connect the emitter pin with the positive rail of the circuit same as we have connected in the switch circuit and connect the sound device such as speaker between collector pin and positive rail of the circuit. You can also use a same value electrolytic capacitor that you have used at the input. The purpose of using the capacitor here is same as described above.

 

Applications:

Audio Amplifier Circuits

Audio Amplifier Stages

Audio Preamplifier Circuits

Tx and Rx Circuits

Switching Circuits

Signal Amplification

Darlington Pairs

and other general purpose applications

 

Safe Operating Guidelines:

Follow these guidelines to safely operate the transistor:

• Do not use the transistor to its absolute maximum ratings and it is recommended to stay at least 20% below from these ratings.
• The max collector current is 800mA but according to the above 20% below usage guidelines we will not go above 640mA.
• The maximum collector-emitter voltage is 30V so same as above by following the above guidelines we will not drive load of more than 24V.
• Always check pin layout before use/
• Storage and operate at temperatures above -55°C and below 150°C.

 

Datasheet:

To download the datasheet just copy and paste the below link in your browser.

https://www.alldatasheet.com/datasheet-pdf/view/30089/TOSHIBA/2SC2120.html