A programmable current limit circuit for LDO

Abstract

A programmable current limit circuit applied to LDO was presented, the current can achieve the accurate sense of the power MOSFET. The current can be operated under different input-output voltage and different load current by adjusting the current limiting resistor outside of the chip to change the current limit. The circuit was designed based on 0.25 μm BCD process and simulated with H-spice. Simulation results showed that LDO achieves maximum 3 A load current in the range of 2~5.5 V supply voltage and 1.2~5 V output voltage. The programmable current limiting was adjustable from 0.2 A to 4.5 A.

Keywords

• LDO
• current sense
• programmable current limit