ZHCSJY0B June 2012 – June 2019 LMR12015 , LMR12020
PRODUCTION DATA.
When the input voltage is below 5V and the duty cycle is greater than 75 percent, the gate drive voltage developed across CBOOST might not be sufficient for proper operation of the NMOS switch. In this case, CBOOST should be charged via an external Schottky diode attached to a 5-V voltage rail, see Figure 23. This ensures that the gate drive voltage is high enough for proper operation of the NMOS switch in the triode region. Maintain VBOOST – VSW less than the 6-V absolute maximum rating.