LM395 POWER TRANSISTOR
LM395 power transistor had multiple applications at current and voltage stabilizing circuits, this is due to the terminal voltage value of the transistor maintain a limit. In this article, we explain LM395 power transistor specifications, features, and applications.
Electrical specification & features of LM395 transistor
- LM395 is a monolithic power integrated transistor component
- Collector to emitter voltage (VCE) is 36V
- Collector to base voltage (VCB) is 36V
- Base to emitter voltage (VBE) is 36V
- Base to emitter reverse voltage (VBE (REV)) is 20V
- Collector current (IC) is internally limited and also different for each package
- Power dissipation (PD) is internally limited
- Base to emitter breakdown voltage is 36V to 60V
- Saturation voltage is 8 to 2.2V
- Base current (IB) is 3 to 10µA
- Quiescent current (IQ) is 2 to 10mA
- Switching speed is 500ns
- Operating temperature is 0°C to +125°C
- Thermal limiting
- Protection against overload
- Excessive power dissipation
- High gain
PACKAGE & PINOUT of LM395 transistor
The LM395 power transistor is available in three different packages, so each of them had a different PINOUT configuration and current specification.
- TO-3 package is a metal can package and it had BCE PINOUT pattern, the emitter is the case of the package.
- TO-5 package is small size metal package and it had an EBC PINOUT pattern.
- TO-220 package is a plastic package and it had a CEB PINOUT pattern.
Electrical characteristics & application description of LM395 transistor
The main applications based on the LM395 power transistor are voltage and current regulator, the property to maintain a proper voltage and current values is the main function of the LM395 transistor.
The collector to emitter voltage, collector to base voltage, and base to emitter voltage values of the LM395 transistor are the same 36V, this is the reason why this transistor is used at current and voltage regulating applications.
The base to emitter reverse voltage is 20v and base to emitter breakdown voltage is 36v to 60v, both these voltage value is important for LM395 transistor at switching operations.
The collector current value of the LM395 transistor is different at each transistor package, so this is why TO-3 and TO-220 had 1.2 to 2.2A and TO-5 had 1 to 1.8A.
The base current is 3 to 10µA and the quiescent current is 2 to 10µA, the base current is the peak current used to trigger the transistor and the quiescent current had a main role in the switching circuits.
Switching time speed
The switching speed of the transistor is 500ns, this particular value is set by the 40v voltage.
Power dissipation & temperature
The power dissipation of the LM395 transistor can be internally limited and the operating temperature of the device is 0°C to 125°C.
Uses of the LM395 power transistor
- Switching regulators
- Solenoid drivers
- Limiter followers
- Low power application under 100mA
- Negative regulator
- Positive voltage regulator
- Current limiter
- CMOS or TTL lamp interface
- Shunt regulator
- Current regulator
- Low-level power switches
- Fast follower
- Variable output switching regulator
Saturation characteristics curves
The figure shows the saturation voltage characteristics curve, it is plotted with saturation voltage vs collector current.
The saturation voltage value will not change with the change in temperature value and also the current value will increases towards a limit, the saturation voltage value is very important for switching operations.
High impedance emitter follower using LM395
The figure shows the high impedance AC emitter follower circuit using the LM395 power transistor.
Generally, the emitter follower circuits are high gain circuits with high impedance, the LM395 transistor-based circuit will produce such a signal at the output.
Switching regulator using LM395 power transistor
The circuit is the switching regulator circuit from the LM395 datasheet, this is a model circuit based on the LM395 power transistor.