Bootstrap voltage generating circuits

A bootstrap voltage generating circuit for generating a bootstrap voltage on a load circuit having a load capacitance, wherein the bootstrap voltage generating circuit comprises:

• a current source for providing a current;
• a bias circuit receiving the current, wherein the bias circuit has a first end, and a second end connected to a reference potential, and wherein a voltage at the first end of the bias voltage is a function of a resistance of a resistive device, and wherein the bias circuit comprises a diode;
• a PMOS transistor having a source coupled to the first end of the bias circuit;
• an NMOS transistor having a drain connected to a drain of the PMOS transistor, and a gate connected to a gate of the PMOS transistor, wherein the gates of the PMOS transistor and the NMOS transistor are coupled to a clock signal;
• a charging capacitor having a first end coupled to the drains of the PMOS transistor and the NMOS transistor, and a second end coupled to the load circuit;
• and
• a switch circuit connected to a second end of the charging capacitor for setting a voltage at the second end of the charging capacitor, wherein the switch circuit is responsive to the clock signal, and wherein the switch circuit is configured to control the bootstrap voltage generating circuit to output a positive voltage and a negative voltage at the second end of the charging capacitor.