BC638 Transistor Pinout, Equivalent, Uses, Usage Guidelines and Other Details

BC638 is another member of BC63X series of high current TO-92 package transistors. In this article we will understand BC638 transistor pinout, equivalent, uses, usage guidelines and other details about this device.

Absolute Maximum Ratings:

• Package Type: TO-92
• Transistor Type: PNP
• Max Collector Current(I_C): –1A
• Max Collector-Emitter Voltage (V_CEO): –60V
• Max Emitter-Base Voltage (VEBO): –5V
• Max Base Current (I_B): –100mA
• Max Collector Power Dissipation (Pc): 1W
• Max Transition Frequency (fT): 100 MHz
• Minimum & Maximum DC Current Gain (h_FE): 40 – 160
• Max Storage & Operating temperature Should Be: –65 to +150 Centigrade

NPN Complementary:

NPN Complementary of BC638 is BC637

Replacement and Equivalent:

BC538, BC328, 2N4403, 2N2907, BC327

BC638 Transistor Explained / Description:

BC638 is a TO-92 package PNP transistor packed with lot of good features which are -1A of collector current, peak collector current of upto -1.5A,  collector-emitter voltage of -60V which is enough for most of the applications, small package, availability of its complimentary transistor that is BC637 and transition frequency of upto 100MHz. These features make this transistor a good candidate for a huge list of applications.

Looking at the pin layout of the transistor as shown in the image above the first pin is Emitter, second pin is Collector and the third pin is Base.

The absolute maximum ratings of the transistor are as follows: As discussed the collector current of the transistor is -1A, collector-emitter voltage is -60V, emitter-base voltage is -5V, base current is -100V, junction temperature is 150°C, and storage temperature is -65 °C to 150 °C.

The transistor is designed to be used in amplifiers and switching applications and due to its good overall specs it can also be used in other applications such as RF circuits.

Where We Can Use it & How to Use:

This transistor can be used in RF circuits, controller circuits, load driving circuits, digital circuits, etc. The detailed list of its applications can be found under the applications heading below. The using procedure of the transistor is the same as any other PNP BJT transistor.  

Applications:

PWM Circuits (For Small Motors and Other Loads)

Signal Amplification Circuits

Darlington Pairs

Active Filters

Audio Amplifier Stages

Radio Circuits (Up to around 100MHz)

Sensor Circuits

Audio Amplifier Circuit

Transmitter Circuits (Up to around 100MHz)

Active Filters

Switching Loads under 1A

Safe Operating Guidelines:

Here are the safe operating guidelines of the transistor.

• For good long term performance always use the transistor 20% below from its absolute maximum ratings.
• So the maximum collector current is -1A but according to the above 20% below usage guideline we will only use -800mA.
• Same procedure will be applied in the collector-emitter voltage. The maximum collector-emitter voltage is -60V but we will not drive load of more than -48V.
• Always check the pin layout before using in the circuit.
• Store or use the transistor at temperatures above -65°C and below 150°C.

Datasheet:

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

https://www.mouser.com/datasheet/2/149/BC638-106714.pdf?srsltid=AfmBOoo5cQ2j3aFP-nJ8a1G-Rkp-ATbbapLfL3Njkp4j7iuFy1oqVwCx