Patent ID: 6617828
Filing Date: 2003-09-09
Classification: H02M

Abstract:
A circuit assembly for doubling the voltage of a battery comprising a charge pump fed by battery voltage and controlled by a clock generator whose supply voltage is the voltage output by said charge pump (12), a source/drain circuit of a field-effect transistor (P4) being inserted in the connection between the output of said charge pump (12) and the battery (26), said field-effect transistor (P4) being ON when its gate voltage is smaller than its source voltage, an output circuit branch of a current mirror circuit (32) through which a limited small current is derivable from the gate to ground is connected to the gate of said field-effect transistor (P4) and an auxiliary charge pump (22) being provided which receives its supply voltage from the output of said charge pump (12) and which is likewise controlled by said clock generator (10), the voltage generated by said auxiliary charge pump (22) being applied to the gate of said field-effect transistor (P4).