Patent ID: 9171856
Filing Date: 2015-10-27
Classification: G11C,H01L

Abstract:
1. A bias voltage generator for a flash memory, the bias voltage generator generating a control voltage and a source line voltage to a memory array, the bias voltage generator comprising: a reference voltage generating circuit receiving a program signal or an erase signal, and generating a reference voltage, wherein if the program signal is received by the reference voltage generating circuit, the reference voltage has a first positive temperature coefficient, wherein if the erase signal is received by the reference voltage generating circuit, the reference voltage has a first negative temperature coefficient; and a voltage converting circuit receiving the reference voltage, and converting the reference voltage into the control voltage and the source line voltage; wherein the reference voltage generating circuit comprises: a base-emitter voltage generator for generating a base-emitter voltage with a second negative temperature coefficient; a thermal voltage generator for generating a thermal voltage with a second positive temperature coefficient; a gain unit for multiplying the thermal voltage by a first gain, thereby generating a gain-adjusted thermal voltage with a third positive temperature coefficient; and a summation unit for obtaining a sum of the base-emitter voltage and the gain-adjusted thermal voltage, thereby generating the reference voltage; and wherein the first gain is determined by the gain unit according to the program signal or the erase signal.