Low power self refresh timer oscillator

摘要

A low power oscillator circuit for a self-refresh timer in a memory array is disclosed. When a voltage (V 1 ) of a comparison node (N 1 ) exceeds a first reference voltage (Vref 1 ), a differential amplifier ( 101 ) in an oscillator ( 1 ) causes a pulse generator ( 110 ) to output a pulse. A charge/discharge circuit ( 105 ) discharges the comparison node (N 1 ) in response to pulse. In this event, a control circuit ( 4 ) disables a first control signal (CT 1 ) to halt operation of the differential amplifier ( 101 ). When the voltage (V 1 ) exceeds a second reference voltage (Vref 2 ) equivalent to the sum of threshold voltages of a discharge circuit ( 43 ) in consequence of gradually charging the comparison node (N 1 ) by the charge/discharge circuit ( 105 ) after it was discharged, the control circuit ( 4 ) activates the first control signal (CT 1 ) to operate the differential amplifier ( 101 ).