Oscillatorless substrate bias generator.

摘要

The circuit of the present invention provides a voltage (100) regulator having a self-timed clock circuit (200) in place of an oscillator, therefore saving considerable power when in the standby mode. A DC regulator (100), which itself is designed to drive low current and consume low power, is the only circuit which is constantly running and consuming power. When the charge pump (600) is not pumping, the current in the circuit can be less than a few microamperes. The DC regulator (100) enables a self-timed clock circuit (200) when the substrate voltage (Vbb) is too high. The self-timed clock circuit (200) controls the charge pump (600) which pumps the substrate voltage (VBB) to a more negative value. This self-timed clock circuit (200) clocks the charge pump (600) until VBB has reached a desired level and the DC regulator (100) signals it to stop pumping. <IMAGE>