Inventors:
Larry Tichauer - La Palma CA
Rodger Erickson - Tarzana CA
Timothy Freitas - Culver City CA
Xianjun Mao - Monterey Park CA
Assignee:
Ophir RF, Inc. - Los Angeles CA
International Classification:
G05F 144
Abstract:
Methods and apparatus for the soft start of linear regulators for controlling inrush current. In linear regulators having a pass transistor controlled by a regulator control circuit, the regulator control circuit is disabled until the regulator output reaches a predetermined threshold level. On startup, an additional transistor is coupled with a resistor and capacitor to the control terminal of the pass transistor in such a way as to provide for the slow turn-on of the pass transistor. During this time, the control circuit for the pass transistor is held inoperative. After the regulator output reaches a predetermined threshold, the pass transistor control circuit becomes operative and the slow start circuitry becomes inoperative.