A power-control device for generating and controlling a supply voltage (Vsupply) provided to a processing module , comprising: a power manager configured to select an expected operation frequency from a dynamic voltage-frequency scaling (DVFS) table according to expected performance of the processing module and to generate a control signal (S101B) according to the selected operation frequency; a clock generator configured to generate a clock signal (CLK) according to the control signal (S101B); an initial signal generation circuit configured to generate an initial signal (S1003) according to the clock signal (CLK); a variant delay chain with a delay length, wherein the variant delay chain is configured to receive the initial signal (S1003) and to perform a delay operation to the initial signal (S1003) according to the delay length to generate a delay signal (S1000); a sampling circuit configured to receive the delay signal (S1000) and to perform a sampling operation to the delay signal (S1000) to generate a sampled signal (S1001); a comparison circuit configured to receive the sampled signal (S1001) and to compare the sampled signal (S1001) with a reference signal (S1004) to generate a comparison result signal (S1002), wherein the power manager is configured to receive the comparison result signal (S1002) and to adjust the supply voltage (Vsupply) according to the comparison result signal (S1002); and a temperature sensor configured to sense an ambient temperature of the temperature sensor and to generate a temperature signal (S1005) according to the sensed ambient temperature; wherein the power manager is configured to determine whether the ambient temperature reaches an upper threshold according to the temperature signal (S1005); and wherein when the power manager determines that the ambient temperature reaches the upper threshold according to the temperature signal (S1005), the power manager is further configured to lower a level of the supply voltage (Vsupply). a power manager configured to select an expected operation frequency from a dynamic voltage-frequency scaling (DVFS) table according to expected performance of the processing module and to generate a control signal (S101B) according to the selected operation frequency; a clock generator configured to generate a clock signal (CLK) according to the control signal (S101B); an initial signal generation circuit configured to generate an initial signal (S1003) according to the clock signal (CLK); a variant delay chain with a delay length, wherein the variant delay chain is configured to receive the initial signal (S1003) and to perform a delay operation to the initial signal (S1003) according to the delay length to generate a delay signal (S1000); a sampling circuit configured to receive the delay signal (S1000) and to perform a sampling operation to the delay signal (S1000) to generate a sampled signal (S1001); a comparison circuit configured to receive the sampled signal (S1001) and to compare the sampled signal (S1001) with a reference signal (S1004) to generate a comparison result signal (S1002), wherein the power manager is configured to receive the comparison result signal (S1002) and to adjust the supply voltage (Vsupply) according to the comparison result signal (S1002); and a temperature sensor configured to sense an ambient temperature of the temperature sensor and to generate a temperature signal (S1005) according to the sensed ambient temperature; wherein the power manager is configured to determine whether the ambient temperature reaches an upper threshold according to the temperature signal (S1005); and wherein when the power manager determines that the ambient temperature reaches the upper threshold according to the temperature signal (S1005), the power manager is further configured to lower a level of the supply voltage (Vsupply). <EOS>