Fast detection and discharge for charge pump controller

An improved circuit configured to provide a load current to a positive charge pump, including:

• (a) a linear regulator having a PFET pass device that includes a control input;
• (b) a rapid charge transfer circuit coupled to the control input of the PFET pass device and configured to be coupled to a source of a trigger voltage derived from the output of the positive charge pump, the rapid charge transfer circuit configured to transfer a charge to or from the control input of the PFET pass device when the trigger voltage falls sufficiently below a specified level so as to rapidly place the PFET pass device in a higher conduction state, and to automatically cease to transfer the charge after a settable amount of time, wherein the rapid charge transfer circuit further includes:
• (1) a high-pass filter configured to be coupled between the trigger voltage and a supply voltage;
• (2) a P-type MOSFET including a source coupled to the supply voltage, a gate coupled to the high-pass filter, and a drain;
• and
• (3) a current mirror including an input coupled to the drain of the P-type MOSFET and an output coupled to the control input of the pass device.

An improved circuit configured to provide a load current to a positive charge pump, including:

• (a) a linear regulator having an NFET pass device that includes a control input;
• (b) a rapid charge transfer circuit coupled to the control input of the NFET pass device and configured to be coupled to a source of a trigger voltage derived from the output of the positive charge pump, the rapid charge transfer circuit configured to transfer a charge to or from the control input of the NFET pass device when the trigger voltage falls sufficiently below a specified level so as to rapidly place the NFET pass device in a higher conduction state, and to automatically cease to transfer the charge after a settable amount of time, wherein the rapid charge transfer circuit further includes:
• (1) a high-pass filter configured to be coupled between the trigger voltage and a supply voltage;
• and
• (2) a P-type MOSFET including a source coupled to the supply voltage, a gate coupled to the high-pass filter, and a drain coupled to the control input of the pass device.