Overcurrent protection circuit and method

摘要

In an overcurrent protection circuit, when a control section (7) turns on a switch (3) in response to a signal from a microcomputer (5) so that power is supplied from a power source (1) to an IC card (4), a signal controlling section (6) prevents the overcurrent protection circuit from functioning even if a current greater than a predetermined level is detected by a current detecting section (2), until a voltage of the IC card is stabilized. When the control section (7) turns off the switch (3) in response to a signal from the microcomputer (5), power supply from the power source (1) to the IC card (4) is stopped, thereby preventing a malfunction of the overcurrent protection circuit, even if the microcomputer (5) goes out of control or malfunctions.