Patent ID: 8278971

Claim:
A detection circuit comprising: a current source; a voltage-current converter, coupled to the current source and a reference voltage, the voltage-current converter configured to acquire a receiving current from the current source by comparing the reference voltage with an input voltage of a detecting terminal, wherein the current source comprises: a first current mirror configured to provide a first current and a second current into the voltage-current converter; and a current supply circuit configured to provide a third current being the receiving current into the voltage-current converter, wherein the voltage-current converter comprises: a first PMOS configured to receive the reference voltage; a first NMOS connected to the first PMOS for acquiring the first current responsive to the reference voltage; a second PMOS connected to the detecting terminal; and a second NMOS connected to the second PMOS for acquiring the second and third currents responsive to the input voltage of the detecting terminal, wherein the second current plus the third current essentially equal to the first current, wherein the voltage-current converter further comprises: a first current-limiting resistor coupled to the first NMOS; and a second current-limiting resistor coupled to the second NMOS; and a current comparator, coupled to the current source, the voltage-current converter and a steady current, the current comparator configured to output an output voltage by comparing the steady current with an output current based on the receiving current.