Internal voltage generator for low voltage, quarter-micrometer flash memories

摘要

A fabricated bandgap generator using 0.25-/spl mu/m Flash memory process generated a stable reference voltage under 4 V, boosted from an external power supply of 2.5 V. The generated voltage was 1.297/spl plusmn/0.025 V at a power supply of 4 V/spl plusmn/10%; the temperature dependence was +0.7 mV//spl deg/C. The characteristics of a triple-well bipolar transistor for the Flash memory process are sufficient for a reference voltage generator; f/sub T/ is 230 MHz, and H/sub FE/ is 70. Dynamic operation reduced the average current consumption from 306 to 8.6 /spl mu/A. Fabricated voltage-doubler circuits generated a voltage 1.8 times larger than that from conventional charge-pump circuits.