Patent ID: 7180757

Claim:
A sequential soft-start circuit for applying a first to an n-th soft-start signals to a first to an n-th circuit channels, respectively, wherein the constant n is an integer and satisfies an inequality of n≧2, the circuit comprising: a first to an n-th current sources for supplying a first to an n-th charging currents; a capacitor; and a sequence control circuit for allowing an x-th charging current of the first to the n-th charging currents to charge the capacitor so as to generate an x-th soft-start signal of the first to the n-th soft-start signals, the x-th soft-start signal being representative of a potential difference across the capacitor, wherein the variable x is an integer and satisfies an inequality of n≧x≧1, characterized in that: before the sequence control circuit allows a y-th charging current of the first to the n-th charging currents to charge the capacitor so as to generate a y-th soft-start signal of the first to the n-th soft-start signals, the sequence control circuit stops charging the capacitor by the x-th charging current and discharges the capacitor toward a ground potential, wherein the variable y is an integer different from the variable x and satisfies an inequality of n≧y≧1.