Apparatus and Methods of N-Type Load Switch Using Bootstrap Gate Drive for Wireless Power Receiver

摘要

Apparatus and methods are provided to power an N-type load switch using a bootstrap capacitor. In one embodiment, an integrated circuit for a wireless power receiver comprises a first rectifier input terminal RX1, a second rectifier input terminal RX2, a first bootstrap terminal HSB1, a second bootstrap terminal HSB2. A first and a second bootstrap circuit are coupled with HSB1 and HSB2 to power the rectifier circuit in a regular mode. A LSW driver circuit is coupled between the LSW terminal and either HSB1 or HSB2. In the regular mode the LSW driver circuit powers a load switch through a corresponding bootstrap circuit. In an output shutdown mode, an output shutdown circuit is turned on to turn off the load switch. In one embodiment, the load switch is external to the integrated circuit. In another embodiment, the load switch is internal to the integrated circuit.

主权项

1. An apparatus comprising:
a first rectifier input terminal RX1; a second rectifier input terminal RX2; a rectifier output terminal RECTOUT; a rectifier circuit coupled between RX1 and RX2, wherein the rectifier circuit outputs a rectified voltage onto RECTOUT; a first bootstrap terminal HSB1; a first bootstrap circuit coupled to HSB1, wherein in a regular mode the first bootstrap circuit supplies power to the rectifier circuit; a second bootstrap terminal HSB2; a second bootstrap circuit coupled to HSB2, wherein in the regular mode the second bootstrap circuit supplies power to the rectifier circuit; a LSW driver circuit coupled to either HSB1 or HSB2, wherein in the regular mode the LSW driver circuit provides a control voltage to a load switch; a load switch (LSW) terminal coupled to the load swtich; and an output shutdown circuit, wherein the output shutdown circuit is turned on in an output shutdown mode to turn off the load switch.