Method and apparatus for maintaining an approximate constant current output characteristic in a switched mode power supply
First Claim
1. A regulator, comprising:
- a switch coupled between first and second terminals;
a control circuit coupled to the switch to control a current through the switch; and
a regulator circuit coupled to the control circuit and to a control terminal, the control terminal coupled to receive a control current including an internal supply current of the regulator and a feedback current, the regulator circuit to adjust a current limit threshold of the switch in response to the feedback current, the control circuit to control the current through the switch in response to the current limit threshold.
0 Assignments
0 Petitions
Accused Products
Abstract
A regulator circuit maintaining an approximate constant current output characteristic. In one aspect, a disclosed regulator controls a switch that has a current limit threshold. A supply terminal and feedback terminal of the regulator are connected together as a control terminal such that a shunt regulator current is the control terminal current in excess of the internal supply current consumed by the regulator. The current limit threshold of the switch is changed as a function of the shunt regulator current. In another aspect, a control input of the regulator circuit receives a current that is the sum of the internal supply current consumed by the regulator circuit and a feedback current. The feedback current is a fraction of the consumption current of the regulator circuit and the current limit threshold of the switch is changed as a function of the feedback current.
-
Citations
9 Claims
-
1. A regulator, comprising:
-
a switch coupled between first and second terminals; a control circuit coupled to the switch to control a current through the switch; and a regulator circuit coupled to the control circuit and to a control terminal, the control terminal coupled to receive a control current including an internal supply current of the regulator and a feedback current, the regulator circuit to adjust a current limit threshold of the switch in response to the feedback current, the control circuit to control the current through the switch in response to the current limit threshold. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
-
Specification