Detection circuit for power load and method for detection thereof
The present application relates to a detection circuit for power load and a method for detection thereof. The detection circuit comprises a sensing circuit and a signal generation circuit. The signal generation circuit includes a calibration circuit. The sensing circuit senses an output power signal of a power supply unit for obtaining a sensing impedance. Thereby, a corresponding power sensing signal is generated according to the sensing impedance and the output power signal. The signal generation circuit generates a power ratio signal. The calibration circuit generates a calibrating signal according to the power ratio signal for driving the signal generation circuit to perform feedback control for generating the power ratio signal. The power ratio signal will match the load condition and be applied to provide the output power signal with less error.
1 . A detection circuit for power load, comprising:
a sensing circuit, coupled to a power supply, including a plurality of impedance devices, detecting an output power signal of the power supply to obtain a load sensing signal, obtaining a sensing impedance according to the impedance devices and the load sensing signal, and generating a power sensing signal according to the sensing impedance and the output power signal load sensing signal; and
a signal generation circuit, coupled to the sensing circuit, including an input circuit, a second conversion circuit, and a calibration circuit, the input circuit coupled to the sensing circuit, the second conversion circuit coupled to the input circuit, the input circuit generating an input signal according to the power sensing signal, the second conversion circuit generating a power ratio signal according to the input signal, and the calibration circuit generating a calibrating signal according to the power ratio signal and feeding the calibrating signal to the second conversion circuit for driving the second conversion circuit further generating the power ratio signal according to the calibrating signal;
where the power sensing signal is corresponding to an output power of the power supply, and the output power of the power supply is controlled according to the power ratio signal.
2 . The detection circuit for power load of claim 1 , wherein the sensing circuit includes:
an amplification circuit, coupled to a load sensing device and including the impedance devices, the load sensing device sensing the output power signal and obtaining the load sensing signal, the amplification circuit obtaining the sensing impedance according to the load sensing signal and the impedance devices, and the amplification circuit amplifying the load sensing signal according to the sensing impedance, for generating a gain signal; and
a first conversion circuit, generating the power sensing signal based on the gain signal.
3 . The detection circuit for power load of claim 2 , wherein the sensing circuit further includes a summation circuit, coupled to the first conversion circuit and summing the power sensing signal.
4 . The detection circuit for power load of claim 2 , wherein the amplification circuit includes:
a first amplifier, coupled to the load sensing device, and amplifying the load sensing signal;
an impedance selection circuit, coupled to the first amplifier, including the impedance devices, obtaining the sensing impedance according to the load sensing signal and the impedance devices; and
a second amplifier, coupled to the impedance selection circuit, and generating the gain signal according to the sensing impedance and the load sensing signal.
5 . The switch control module of claim 4 , wherein said active switch comprises a snubber coupled to said second node; and said snubber guides a spike absorption current to flow through said biased switch when said second switch unit is turned off by said control unit.
6 . The detection circuit for power load of claim 1 , wherein the signal generation circuit further includes a trigger circuit coupled to the calibration circuit and generating a trigger signal to the calibration circuit according to a start signal.
7 . The detection circuit for power load of claim 6 , wherein the start signal corresponds to the output power signal, the power sensing signal, or the power ratio signal.
8 . A method for detection of a detection circuit for power load, comprising steps of:
sensing an output power signal of a power supply by a sensing circuit to obtain a load sensing signal and obtaining a sensing impedance according to a plurality of impedance devices and the load sensing signal, and generating a power sensing signal according to the sensing impedance and the load sensing signal;
an input circuit of a signal generation circuit generating an input signal according to the power sensing signal;
a second conversion circuit of the signal generation circuit generating a power ratio signal according to the input signal; and
a calibration circuit generating a calibrating signal based on the power ratio signal for driving the second conversion circuit to perform a feedback control and generate the power ratio signal;
where the power sensing signal is corresponding to an output power of the power supply, and the output power of the power supply is controlled according to the power ratio signal.
9 . The method for detection of a detection circuit for power load of claim 8 , wherein the step of obtaining a sensing impedance by a sensing circuit sensing an output power signal of a power supply and according to the corresponding one of a plurality of impedance devices of the output power signal for generating a power sensing signal includes steps of:
a load sensing device sensing the output power signal to obtain the load sensing signal;
an amplification circuit selecting the sensing impedance according to the load sensing signal and the impedance devices and amplifying the load sensing signal according to an impedance value of the sensing impedance to generate a gain signal; and
a first conversion circuit generating the power sensing signal based on the gain signal.
10 . The method for detection of a detection circuit for power load of claim 9 , wherein the step of an amplification circuit selecting the sensing impedance according to the load sensing signal and the impedance devices and amplifying the load sensing signal according to the impedance value for generating a gain signal, further comprising steps of:
a first amplifier amplifying the load sensing signal;
an impedance selection circuit obtaining the sensing impedance according to the load sensing signal and the impedance devices; and
a second amplifier generating the gain signal based on the sensing impedance and the load sensing signal.
11 . The method for detection of a detection circuit for power load of claim 9 , where in the step of a first conversion circuit generating the power sensing signal based on the gain signal, the first conversion circuit generating the power sensing signal further based on a signal conversion ratio.