Power controller with multi-function pin and power supply using the same
AssigneeLeadtrend Technology Corp.
InventorsChin-Ho Wu, Ren-Yi Chen, Yi-Shan Chu
Life of this patent
Estimating the term…
Abstract
Power supplies and power controllers are disclosed. A disclosed power supply has a power controller, a power switch, an auxiliary winding, a first circuit and a second circuit. The power controller is a monolithic integrated circuit with a multi-function pin and a gate pin. A control node of the power switch is coupled to the gate pin. The first circuit is coupled between the multi-function pin and the auxiliary winding and has a diode. The second circuit is coupled between the multi-function pin and a ground line, and has a thermistor.
Claims10
A power supply, comprising:
- a power controller having a multi-function pin, an FB pin, a CS pin, and a gate pin, wherein the power controller is a monolithic integrated circuit;
- a power switch having a control terminal coupled to the gate pin, wherein the FB pin different to the CS pin and the multi-function pin is used for receiving a feedback signal corresponding to a voltage of an output terminal of the power supply;
- an auxiliary winding;
- a first circuit coupled between the multi-function pin and the auxiliary winding, wherein the first circuit has a diode;
- and
- a second circuit coupled between the multi-function pin and a ground line, wherein the second circuit has a thermistor coupled between the multi-function pin and the ground line, a resistance of the second circuit is varied with a resistance of the thermistor, and the resistance of the second circuit is used for determining whether an over temperature protection signal is enabled;
- wherein when a voltage signal of the CS pin exceeds a value corresponding to the feedback signal, the power switch is turned off, and when the power switch is turned off, the power controller detects a discharge time of the auxiliary winding through the multi-function pin.
A power controller being a monolithic integrated circuit, the power controller comprising:
- a gate pin for outputting a gate signal;
- a CS pin for detecting a current flowing through a power switch controlled by the gate signal;
- an FB pin for receiving a feedback signal corresponding to a voltage of an output terminal of a power supply which the power controller is applied to, wherein when a voltage signal of the CS pin exceeds a value corresponding to the feedback signal, the power switch is turned off;
- a multi-function pin different to the FB pin and the CS pin coupled to a ground line through a thermistor;
- a resistance detector for detecting a resistance between the multi-function pin and the ground line when the gate signal is enabled, and enabling an over temperature protection signal when the resistance is lower than a predetermined value, wherein the resistance is varied with a resistance of the thermistor;
- and
- a quadrature resonance (QR) detector for detecting a discharge time of an external inductor through the multi-function pin to enable a trigger signal when the gate signal is disabled;
- wherein the trigger signal enables the gate signal, and the enabled protection signal keeps the gate signal not being enabled.
Dependencies are inferred from the claim text.