Buck-boost switching regulator and control method thereof
The present invention discloses a buck-boost switching regulator, comprising: (1) a first loop including: a first and a second switch electrically connected with each other, the first switch having an end electrically connected with an input voltage, and the second switch having an end electrically connected with ground; and a first control circuit controlling the operation of the first and the second switch; (2) a second loop including: a third and a fourth switch electrically connected with each other, the third switch having an end electrically connected with ground, and the fourth switch having an end electrically connected with an output voltage; and a second control circuit controlling the operation of the third and the fourth switch; and (3) an inductor electrically connected between a node between the first and the second switch, and a node between the third and the fourth switch.
1. A buck-boost switching regulator comprising:
(1) a first loop including:
a first and a second switch electrically connected with each other, the first switch having an end electrically connected with an input voltage, and the second switch having an end electrically connected with ground; and
a first control circuit controlling the operation of the first and the second switch;
(2) a second loop including:
a third and a fourth switch electrically connected with each other, the third switch having an end electrically connected with ground, and the fourth switch having an end electrically connected with an output voltage; and
a second control circuit controlling the operation of the third and the fourth switch; and
(3) an inductor electrically connected between a node between the first and the second switch, and a node between the third and the fourth switch;
wherein the first loop includes a first error amplifier which compares a first feedback voltage obtained from the output voltage with a first reference voltage;
wherein the second loop includes a second error amplifier which compares the first feedback voltage obtained from the output voltage with a second reference voltage.
2. The buck-boost switching regulator of claim 1 , wherein the second reference voltage is lower than the first reference voltage.
3. A method for controlling a buck-boost switching regulator, comprising the steps of:
providing a switching regulator including
a first and a second switch electrically connected with each other, the first switch having an end electrically connected with an input voltage, and the second switch having an end electrically connected with ground;
a third and a fourth switch electrically connected with each other, the third switch having an end electrical connected with ground and the fourth switch having an end electrically connected with an output voltage; and
an inductor electrically connected between a node between the first and the Second switch, and a node between the third and the fourth switch;
controlling the first and the second switch by a first control circuit, and controlling the third and the fourth switch by a second control circuit;
obtaining a first feedback voltage from the output voltage;
comparing the first feedback a first reference voltage;
controlling the first control circuit according to the comparison result between the first feedback voltage and the first reference voltage;
comparing the first feedback voltage with a second reference voltage; and
controlling the second control circuit according to the comparison result between the first feedback voltage and the second reference voltage.
4. The method of claim 3 , wherein the second reference voltage is lower than the first reference voltage.