Descriptions: 2SC-945 NPN General Purpose Transistor.

C945 2SC945 2SC-945 2SC 945 NPN Transistor 50V 0.1A 0.25W TO-92 Package 3 Pin Leads Bipolar NPN General Purpose Transistor

C945 is a general purpose NPN transistor used in wide variety of commercial and educational electronic circuits. It is manufactured in TO-93 package, the max load this transistor can drive is around 150mA or 0.15A that is enough to operate many devices in a circuit for example LEDs, Relays, ICs, transistors and other parts of a circuit. The saturation voltage of the transistor is only 0.3V which is also a good feature of this transistor. Moreover the transistor is also low noise device, and has a good DC current gain that is 70 to 700.

C945 Transistor Pinout Configuration

C945 Transistor Features

• Japanese High frequency amplifier NPN Transistor
• Current Gain (hFE) is 70 to 700 (high linearity)
• Continuous Collector current (IC) is 150mA
• Collector-Emitter voltage (VCEO) is 50 V
• Collector-Base voltage (VCB0) is 60V
• Emitter Base Voltage (VBE0) is 5V
• Transition Frequency is 150MHz
• Available only in To-92 Package

Technical specifications:

• Package Type: TO-92
• Transistor Type: NPN
• Max Collector Current(IC): 150mA
• Max Collector-Emitter Voltage (VCE): 50V
• Max Collector-Base Voltage (VCB): 60V
• Max Emitter-Base Voltage (VEBO): 5V
• Max Collector Dissipation (Pc): 400 miliWatt
• Max Transition Frequency (fT): 200 MHz
• Minimum & Maximum DC Current Gain (hFE): 70 – 700
• Max Storage & Operating temperature Should Be: -55 to +150 Centigrade

Complementary PNP for 2SC945

A733

Modern Replacement by ON Semiconductor

2N3904 (Pinouts are different)

Alternative for 2SC945

BC546, C1815, KSC945C

Warning: The C945 is a Japanese NPN transistor and hence the C945 pinout will be in Emitter, Collector, Base order. But for European transistors like BC546 the order will be as Emitter, Base and Collector. Normally during such replacements heat shrink tubes are used to cross over the Base and Collector pins without them getting into contact.

Where We Can Use it & How to Use:

As discussed above the transistor has a good DC current gain and low noise type due to which it is ideal to use in audio preamplifier & audio amplifier circuits stages or amplification of other signals in electronic circuits. The saturation voltage of most BJT transistors are 0.6V but the C945 has only 0.3V therefore it can perform well in low voltage circuits or in any circuit where low base voltage is available and other BJT transistors are not saturating. It can also be used in RF circuits under 200MHz frequency.

About C945 transistors

The C945 is an age old Japanese Bipolar audio frequency NPN transistor. It has a decent gain value (hfe) of maximum 700 and is highly linear. Hence it was widely used in amplifier applications for pre-amplifying purpose, in high frequency circuits. It is also used as oscillators with is complementary A733 PNP transistor.

When used as a switch it can easily by controlled by a MCU/MPU since it has a base voltage of only 5V. It can switch loads upto 50V but has a very low collector current rating of only 150mA so this transistor is not really a good choice to be used as a switch. A better alternative for switching applications will be 2N2222.

However this transistor is outdated and will not be easily available if you are in Asian or European countries. In that case you can try the 2N3904 transistor from ON semiconductors, but do remember to deal with the pinouts as mentioned in the warning section above.

Applications

• Low current switches
• Pre-amplifiers
• H-bridge circuits for low power motors
• Audio frequency amplifier circuits
• Oscillator circuits

• Collector-Emitter Volt (Vceo): 50V
• Collector-Base Volt (Vcbo): 60V
• Collector Current (Ic): 0.15A
• hfe: 70-700 @ 1mA
• Power Dissipation (Ptot): 400mW
• Current-Gain-Bandwidth (ftotal): 150MHz
• Type: NPN