| 摘要 |
<p>Circuits and methods to prevent ringing of white LED drivers by adding a high voltage coil switch circuit, a high voltage edge detector circuit, and a boot strap circuit are disclosed. The coil switch circuit to short the coil of a boost converter when the current in it reaches zero during DCM, comprises a series of 2 identical HV enhancement NMOS with bulk switch system. The Edge Detector circuit senses the fast falling edge of the LX node. The Boost Strap circuit lifts the gate of coil switch circuit above the battery voltage level and turns on the coil switch a Boost Strap (BS) system to lift the gate of CS above the VBAT level and turn on CS</p> |
