Patent ID: 6118329
Filing Date: 2000-09-12
Classification: H02M

Abstract:
A negative charge pump using a positive high voltage comprising:a positive charge pump to output a positive voltage through a first output terminal in response to a first clock signal and a second clock signal, wherein said positive charge pump comprises:a first, second and fourth transistors which are connected in series between a supply power source and said first output terminal, with said first, second and fourth transistors operating as a diode, respectively; a first capacitor connected to a connection node of said first and second transistors and receiving the first clock signal;a second capacitor connected to a connection node of said second and fourth transistors and receiving the second clock signal;a third transistor connected between said supply power source and the connection node and fourth transistors;a transfer circuit having a second output terminal, wherein said transfer circuit acts to transfer the positive voltage of said first output terminal to said second output terminal or to not transfer the positive voltage in response to a third clock signal;a negative charge pump circuit having a third output terminal which maintains a first potential while said second output terminal maintains the positive voltage and maintains a second potential in response to a fourth clock signal during the positive voltage is not supplied to said second output terminal; andan output circuit having a fourth output terminal, wherein said output circuit acts to discharge positive charges, which exist in an external equipment, to said third output terminal through said output circuit when the first potential charges to the second potential, whereby the fourth output terminal maintains a negative voltage.