MAX1876

19-2431; Rev 0; 7/02 KIT ATION EVALU E L B A IL AVA Dual 180° Out-of-Phase PWM StepDown Controllers with POR General Description Features o Two Independent Output Voltages o 180° Out-of-Phase Operation o 90° Out-of-Phase Operation (Using Two MAX1875/MAX1876s) o Foldback Current Limit o 4.75V to 23V Input Supply Range o 0 to 18V Output-Voltage Range (Up to 10A) o >90% Efficiency o Fixed-Frequency Pulse-Width Modulation (PWM) Operation o Adjustable 100kHz to 600kHz Switching Frequency o External SYNC Input o Clock Output for Master/Slave Synchronization o Soft-Start and Soft-Stop o RST Output with 140ms Minimum Delay (MAX1876) o Lossless Current Limit (No Sense Resistor) MAX1875/MAX1876 The MAX1875/MAX1876 dual, synchronized, step-down controller generates two outputs from input supplies ranging from 4.75V to 23V. Each output is adjustable from sub-1V to 18V and supports loads of 10A or higher. Input voltage ripple and total RMS input ripple current are reduced by synchronized 180° out-of-phase operation. The switching frequency is adjustable from 100kHz to 600kHz with an external resistor. Alternatively, the controller can be synchronized to an external clock generated to another MAX1875/MAX1876 or a system clock. One MAX1875/MAX1876 can be set to generate an inphase, or 90° out-of-phase, clock signal for synchronization with additional controllers. This allows two controllers to operate either as an interleaved two- or four-phase system with each output shifted by 90°. Th...