Patent ID: 11860709
Assignee: REALTEK SEMICONDUCTOR CORPORATION
Field: Computer technology (Electrical engineering)
Classification: CPC G | IPC G

Claim 0:
1. A power supply apparatus having power limiting mechanism, comprising:
a switch transistor electrically coupled in series with a powered device and controlled by a control voltage to form a conduction path when being conducted such that a power supply unit supplies a power to the powered device, wherein the switch transistor has an operation current, an operation voltage and an operation power when being conducted;
a voltage detection circuit configured to detect the operation voltage;
a power-limiting circuit comprising:
an analog-to-digital conversion circuit configured to perform analog-to-digital conversion on the operation voltage;
a calculation circuit configured to generate a current-limiting signal related to a current-limiting value according to the operation voltage based on a predetermined voltage-current curve, wherein the predetermined voltage-current curve limits the operation power to be not larger than a predetermined value; and
a digital-to-analog conversion circuit configured to perform digital-to-analog conversion on the current-limiting signal to generate a reference voltage; and

a current-limiting circuit configured to receive the reference voltage and perform comparison with a feedback voltage generated according to the operation current to generate the control voltage accordingly to control the switch transistor, so as to keep the operation current at the current-limiting value.