NJM78L12L2A

NJM78L12L2A is a three-terminal, fixed output, positive voltage regulator in linear mode. It is equivalent to any of the LM78XX series and can provide output current up to 100mA, which is ideal for many regulatory applications to power devices like microprocessors, memories and other low current, low voltage devices. The NJM78L12L2A is equipped with overcurrent protection, short-circuit protection and thermal protection to ensure safer operation in the event of an unexpected malfunction.

Typical Applications

• Battery-operated equipments
• Numerically controlled machine tools
• Dot printers
• Audio/video equipments
• Personal computers, peripherals and memory cards
• Information processing devices
• Electronic measuring instruments
• Measuring and automatic control equipments

Working Principle

The NJM78L12L2A works by controlling the voltage supplied to the load (LOAD) so that it is always normalised to the required output voltage (Vout). The output voltage can be set between 5V and 12V, depending on the part number used. The internal circuits of the NJM78L12L2A include a band gap reference circuit, an error amplifier, a voltage divider and a transistor switch.

The NJM78L12L2A uses a band gap reference for its output voltage. The band gap reference circuit is a very precise voltage source of 1.245V and allows for precise voltage setting as required. The output voltage is further adjusted using the error amplifier. The error amplifier compares the output voltage with a reference (Vref) and produces an output that exerts a certain influence on the transistor switch. The output voltage is further adjusted using the voltage divider and the output current is controlled by the transistor switch.

The NJM78L12L2A has several advantages over other regulator solutions like switching regulators, such as higher efficiency due to lower power consumption, low noise, low ripple and easy implementation. However, the disadvantage of this type of regulator is that it has a higher quiescent current compared to switching regulators and can also cause power dissipation at higher output current levels.

Conclusion

The NJM78L12L2A is a three-terminal, fixed output, positive voltage regulator in the linear mode. It can provide output current up to 100mA and is commonly used in various applications like battery-operated equipments, numerically controlled machine tools and other low-voltage devices. It has several advantages like higher efficiency, low noise and easy implementation. However, the disadvantage of this type of regulator is that it has a higher quiescent current compared to switching regulators.