JAJSEC4E September 2012 – January 2018
PRODUCTION DATA.
Similar to charge mode operation, in boost mode, the IC provides an integrated, fixed 3 MHz frequency voltage-mode controller to regulate output voltage at PMID pin (VPMID). The voltage control loop is internally compensated using a Type-III compensation scheme that provides enough phase margin for stable operation with a wide load range and battery voltage range.
In boost mode, the input N-FET (Q1) prevents battery discharge when VBUS pin is over loaded. Cycle-by-cycle current limit is sensed through the internal sense FET for Q3. The cycle-by-cycle current limit threshold for Q3 is set to a nominal 1.0-A peak current. Synchronous operation is used in PWM mode to minimize power losses.