MAX1966

19-2286; Rev 1; 9/03 Low-Cost Voltage-Mode PWM Step-Down Controllers General Description The MAX1966/MAX1967 are voltage-mode pulse-widthmodulated (PWM), step-down DC-DC controllers that are ideal for a variety of cost-sensitive applications. They drive low-cost N-MOSFETs for both the high-side switch and synchronous rectifier and require no external Schottky power diode or current-sense resistor. Shortcircuit and current-limit protection is provided by sensing the drain-to-source voltage on the low-side FET. Both devices can supply outputs as low as 0.8V and are well suited for DSP cores and other low-voltage logic. The MAX1966 has an input range of 2.7V to 5.5V while the MAX1967 has an input range of 2.7V to 28V. In ultra-low-cost designs, the MAX1966/MAX1967 can provide efficiency exceeding 90% and can achieve 95% efficiency with optimized component selection. The MAX1966/MAX1967 operate at 100kHz and accommodate aluminum electrolytic capacitors and powdered-iron core magnetics in minimum-cost designs. They also provide excellent performance with high-performance surface-mount components. The MAX1966 is available in a low-cost 8-pin SO package. The MAX1967 is available in a 10-pin µMAX package. o Cost-Optimized Design o No Schottky Diode or Current-Sense Resistor Required o >95% Efficiency o Low-Cost External Components o All N-Channel FET Design o 2.7V to 5.5V Input Range (MAX1966) o 2.7V to 28V Input Range (MAX1967) o 0.8V Feedback for Low-Voltage Outputs o 100kHz Switc...