Patent ID: 7612605
Filing Date: 2009-11-03
Classification: G11C,H02M

Abstract:
1. A bootstrap voltage generating circuit for generating a bootstrap voltage on a load circuit having a load capacitance, wherein the bootstrap voltage generating circuit comprises: a bias circuit having a first end coupled to a first power source node having an operation voltage, and a second end coupled to a low voltage reference potential, wherein a voltage at the first end is related to the operation voltage in a non-linear way, and wherein the bias circuit comprises a diode; a charging capacitor having a first end coupled to the load circuit; a charging path between a second end of the charging capacitor and the first end of the bias circuit, wherein the charging path is responsive to a clock signal; a discharging path between the second end of the charging capacitor and the low voltage reference potential, wherein the discharging path is responsive to the clock signal; and a switch circuit connected to the first end of the charging capacitor for setting a voltage at the first end of the charging capacitor, wherein the switch circuit is responsive to the clock signal, and wherein the switch circuit is configured to control the bootstrap voltage generating circuit to output both a positive voltage and a negative voltage at the first end of the charging capacitor.