Patent ID: 7436160

Claim:
An adaptive dead-time circuit for an oscillator-driven half-bridge circuit, comprising: a sensing circuit for sensing a voltage at a midpoint of a switching half-bridge, the switching half-bridge having a high side and a low side transistor connected at said midpoint, the high side transistor driven by a high side driver and the low side transistor driven by a low side driver; a first circuit for generating a first signal indicative of a high to low transition of said voltage; a second circuit for generating a second signal indicative of a low to high transition of said voltage; and an output circuit for generating an adaptive dead-time output signal; wherein said output circuit generates said adaptive dead-time output signal based on both said second signal and said first signal; wherein said first circuit generates a first pulse near the beginning of said high-to-low transition and a second pulse near the end of said transition, and generates said first signal based on said first and second pulses; and wherein said second circuit generates said second signal by reproducing said first signal; and wherein said sensing circuit for sensing the voltage at the midpoint of the switching half-bridge comprises: a high voltage device, coupled to the midpoint of the switching half-bridge to provide a detection voltage related to the voltage at the midpoint of the switching half-bridge; said high voltage device comprising a level shifting transistor that level shifts the voltage at said midpoint of the switching half-bridge to the detection voltage, said detection voltage having a range between zero volts and a power supply voltage for the low side driver; and a voltage detection output circuit coupled to the high voltage device for receiving the detection voltage and outputting a signal to contribute to operation of the half-bridge circuit to avoid hard-switching.