Method and apparatus for trimming current limit and frequency to maintain a constant maximum power
First Claim
1. A circuit, comprising:
- a transistor coupled between first and second terminals;
a control circuit coupled to the transistor;
an oscillator coupled to the control circuit;
a control current sensor circuit coupled to a control terminal and to the control circuit, the control current sensor circuit to sense an excess control current through the control terminal, the control circuit to switch the transistor in response to the oscillator and the control current sensor;
a current limit circuit coupled to the transistor and the control circuit to limit a current through the transistor; and
a trim circuit coupled to the oscillator and the current limit circuit, the trim circuit to be trimmed during manufacture of the circuit to determine a maximum deliverable power value of a power supply.
0 Assignments
0 Petitions
Accused Products
Abstract
Methods and apparatuses to trim current limit (Ip) and frequency (f) to maintain a constant maximum power. In one aspect of the invention, a power supply regulator having a peak current limit detection threshold and an operating frequency is disclosed. The peak current limit threshold or the operating frequency are adjusted specifically to maintain the Ipm·fn product substantially constant from one power supply controller to another where m is substantially equal to 2 and n is substantially equal to 1. In another aspect of the invention, the power supply regulator has a control circuit having a control threshold current. The peak current limit threshold or the operating frequency are adjusted specifically to maintain the product of Ipm·fn divided by the control threshold current substantially constant from one power supply controller to another where m is substantially equal to 2 and n is substantially equal to 1.
-
Citations
9 Claims
-
1. A circuit, comprising:
-
a transistor coupled between first and second terminals; a control circuit coupled to the transistor; an oscillator coupled to the control circuit; a control current sensor circuit coupled to a control terminal and to the control circuit, the control current sensor circuit to sense an excess control current through the control terminal, the control circuit to switch the transistor in response to the oscillator and the control current sensor; a current limit circuit coupled to the transistor and the control circuit to limit a current through the transistor; and a trim circuit coupled to the oscillator and the current limit circuit, the trim circuit to be trimmed during manufacture of the circuit to determine a maximum deliverable power value of a power supply. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
-
Specification