19-3501; Rev 0; 11/04
KIT ATION EVALU E L B A IL AVA
www.DataSheet4U.com
High-Efficiency, 5x Output, Main Power-Suppl...
19-3501; Rev 0; 11/04
KIT ATION EVALU E L B A IL AVA
www.DataSheet4U.com
High-Efficiency, 5x Output, Main Power-Supply Controllers for Notebook Computers
General Description
The MAX1533/MAX1537 are dual step-down, switchmode power-supply (SMPS) controllers with synchronous rectification, intended for main 5V/3.3V power 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. Output current sensing provides accurate current limit using a sense resistor. Alternatively, power dissipation can be reduced using lossless inductor current sensing. Internal 5V and 3.3V linear
regulators power the MAX1533/MAX1537 and their gate drivers, as well as external keep-alive loads, up to a total of 100mA. When the main PWM
regulators are in regulation, automatic bootstrap switches bypass the internal linear
regulators, providing currents up to 200mA from each linear output. An additional 5V to 23V adjustable internal 150mA linear
regulator is typically used with a secondary winding to provide a 12V supply. The MAX1533/MAX1537 include on-board power-up sequencing, a power-good (PGOOD) output, digital soft-start, and internal soft-shutdown output discharge tha...