Patent ID: 9595871
Date: 2017-03-14
CPC Classifications: G05F,H02M,Y02B

Claim:
1. A DC-DC converter circuit to provide a DC output voltage signal, comprising: a first converter stage, including: a first switch including a first terminal coupled with a first node, and a second terminal coupled with a switch node, an inductor including a first terminal coupled with the switch node, and a second terminal, and a second switch including a first terminal coupled with the switch node, and a second terminal coupled with a second node; a second converter stage, including: a third switch including a first terminal coupled with a third node, and a second terminal coupled with a fourth node, a capacitor including a first terminal coupled with the fourth node, and a second terminal coupled with the switch node, and a fourth switch including a first terminal coupled with the fourth node, and a second terminal coupled with the second node; and a control circuit operative in a first mode when an absolute value of the output voltage signal is less than a threshold to turn off the third and fourth switches of the second converter stage, and to provide pulse width modulated switching control signals to the first and second switches of the first converter stage in alternating fashion to regulate the output voltage signal according to a setpoint signal; the control circuit operative in a second mode when the absolute value of the output voltage signal is greater than the threshold to turn off the second switch, and to provide pulse width modulated switching control signals to the first, third and fourth switches to regulate the output voltage signal according to the setpoint signal.