The MAX8716/MAX8717/MAX8756/MAX8757 are dual,
step-down, interleaved, fixed-frequency, switch-mode
power-supply (SMPS) controllers with synchronous rectification.
The MAX8716/MAX8717/MAX8756/MAX8757
are intended for main (5V/3.3V) power generation, while
the MAX8756 is optimized for I/O power rails 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 in 5V/3.3V applications, 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/MAX8756/MAX8757 are available
in a 28-pin thin QFN package.
Applications
- 2 to 4 Li+ Cell Battery-Powered Devices
- Main or I/O Power Supplies
- Notebook and Subnotebook Computers
- PDAs and Mobile Communicators
