C945 NPN Transistor Pinout Datasheet

Introduction

The C945 (also known as KSC945) is a small-signal NPN silicon transistor frequently used in signal amplification, switching, audio circuits, and oscillators. It offers a balance of gain, frequency response, and moderate voltage rating, making it popular in many general-purpose electronics designs.

Its compact TO-92 plastic package allows easy integration into printed circuit boards and breadboards. The C945’s moderate collector current and voltage capability make it suitable for use in low-power amplifier stages, preamps, and driver circuits. Its use is common in hobbyist, educational, and consumer electronics because of its availability, affordability, and dependable performance.

C945 NPN Transistor

Because of its low noise, reasonable gain at small currents, and decent frequency response, the C945 often shows up in microphone preamplifiers, radio IF stages, small signal drivers, and switching tasks where the signal is not too large. Designers often compare it to transistors like 2SC945 or KSC945 variants.

Pinout of C945

Key Features

• Small-signal NPN silicon transistor suited for amplification and switching
• Compact TO-92 plastic package for easy mounting
• Low noise operation in small-signal stages
• Good linear response at low collector currents
• Wide availability and cost-effectiveness
• Useful in audio, radio, and general-purpose circuits

Specifications/Characteristics

• Collector-Emitter Voltage (VCEO): 50 V
• Collector-Base Voltage (VCBO): 60 V
• Emitter-Base Voltage (VEBO): 5 V
• Continuous Collector Current (IC): 150 mA
• Power Dissipation (Ptot): 200 mW
• DC Current Gain (hFE): 70 (minimum) to 700 (maximum) depending on gain group
• Collector-Emitter Saturation Voltage (VCE(sat)): 0.3 V (typical)
• Base-Emitter Saturation Voltage (VBE(sat)): 1.0 V (typical)
• Transition Frequency (fT): 200 MHz
• Noise Figure (NF): ~4 dB
• Operating Temperature Range: -55 °C to +150 °C

Pin Configuration

More Circuit Layouts

Key Applications of C945 NPN Transistor

• Audio preamplifier and driver stages
• Small-signal amplification in radio and communication circuits
• Oscillators and waveform generators
• Low-power switching for LEDs, relays
• Voltage regulation and signal conditioning
• Sensor interface circuits and low-current drivers

PNP Complimentary Transistor

• The typical PNP complementary transistor for C945 / 2SC945 is 2SA733.

Equivalent Transistors of C945 NPN Transistor

• 2SC945 / KSC945 (variants of the same type)
• 2N2222 (for general-purpose switching, if current/voltage margins allow)
• BC547 (in many audio and small-signal use cases)
• BC337 (for slightly higher current capability)
• 2N3904 (for standard low-power switching and amplification)

(Pin configuration of some transistors mentioned here may different from C945).

Datasheet of C945 NPN Transistor

Click the following Button below to download the datasheet of C945 Transistor :

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