LR645N5-G Datasheet PDF - Microchip

The LR645N5-G is a high input voltage low output Current Linear Regulator has a 3-terminal fixed output voltage version. The 3-terminal version functions like any other low voltage 3-terminal regulator except it allows the use of much higher input voltages. When used in a SMPS startup circuit, it eliminates the need for large power resistors. In this application, current is drawn from the high voltage line only during start-up. Only leakage current flows after start-up, thereby reducing the continuous power dissipation to a few milliwatts. The adjustable voltage version allows trimming of the output voltage from 8 to 12V. This version can also be connected to an external depletion mode MOSFET for increased output current. When used in conjunction with Supertex depletion mode MOSFET DN2540N5, an output current of up to 150mA is achieved.

● Accepts inputs from 15 to 450V

● Output currents up to 3mA continuous, 30mA peak

● 50µA Typically supply current

● 0.1mV/V Typically line regulation

●When operated from an AC line, potentially lethal voltages can be present on the IC. Adequate means of protecting the end user from such voltages must be provided by the circuit developer.