SWITCHED CAPACITOR DC-DC CONVERTER WITH REDUCED IN-RUSH CURRENT AND FAULT PROTECTION

摘要

To reduce in-rush currents into a switched capacitor DC/DC converter and detect voltage and current faults, a converter controller is housed along with a current limit series transistor and fault detection circuitry. The series transistor is controlled to limit the in-rush current to a predetermined maximum level during start-up. If the duration of the current limit level, or the time for Vout to achieve a target voltage, exceeds a first threshold time, a first fault detector in the package shuts off the series transistor. During steady state operation, if the input current reaches the limit for a second threshold time or if Vout extends outside a certain range for the second threshold time, a second fault detector in the package shuts off the series transistor.

主权项

1. A circuit for controlling a switched capacitor DC/DC converter to generate an output voltage Vout comprising:
a controller circuit for generating control signals for controlling switches in the switched capacitor DC/DC converter to generate Vout; an input terminal for an input voltage Vin1; an input current sensor for generating an input current signal corresponding to an input current; and a current limit circuit coupled to the input current sensor for detecting when the input current has reached a current limit level and for controlling in-rush current into the converter so as not to exceed the current limit level.