Laptop Chip MAX8717E Dual Power-Supply Controllers for Notebook Computers
Description:
The MAX8716 / MAX8717
/ MAX8757 are dual, stepdown,interleaved, fixed-frequency, switch-mode
power-supply (SMPS) controllers with synchronous rectification.
They are intended for
main (5V/3.3V) and I/Opower generation in battery-powered systems.
Fixed-frequency operation with optimal interleaving minimizes input ripple
current from the lowest input voltages up to the 26V maximum input. Optimal
40/60 interleaving allows the input voltage to go down to 8.3V before
duty-cycle overlap occurs, compared to 180°out-of-phase regulators where the
duty-cycle overlap occurs when the input drops below 10V.
Accurate output
current limit is achieved using a sense resistor. Alternatively, power
dissipation can be reduced using lossless inductor current sensing.Independent
ON/OFF controls and power-good signals allow flexible power sequencing.
Soft-start reduces inrush current, while soft-stop gradually ramps the output
voltage down preventing negative voltage dips.
A low-noise mode
maintains high light-load efficiency while keeping the switching frequency out
of the audible range.
The MAX8716 is available in a 24-pin thin QFN
package,and the MAX8717/MAX8757 are available in a 28-pin thin QFN package. 
