A VOLTAGE DOWN CONVERTER WITH SUBMICROAMPERE STANDBY CURRENT FOR LOW-POWER STATIC RAMS

A submicroampere standby current voltage down converter (VDC) for high-density, low-power static RAM's is described. The current consumption of the VDC in standby mode can be decreased by using a new low-current and temperature-independent current source circuit. The total current is less than 0.5-mu-A at external voltage ranging from 3 to 5 V and at temperatures ranging from -20 to 80-degrees-C. The voltage-follower circuits for standby and operation modes are stable despite the low current consumption in the standby mode. The phase margin of the voltage follower for standby mode is 50-degrees and that for operation mode is 90-degrees. This indicates that the VDC is a promising circuit for battery-backup and high-density static RAM's.