The MAX639ESA+ is a high efficiency, low IQ, step down DC to DC converter in 8 pin NSOIC package. This step down switching regulator provides high efficiency over a wide range of load currents and delivers up to 225mA output current. A current limiting pulse frequency modulated (PFM) control scheme gives the devices the benefits of pulse width modulated (PWM) converters (high efficiency at heavy loads) while using only 10μA of supply current (2mA to 10mA for PWM converters). This results in high efficiency over wide range of loads. The MAX639 provides lower preset output voltage of 5V and the output can be user adjusted to any voltage from 1.3V to input voltage. It has an internal 1A power MOSFET switch which makes the device ideal for minimum component, low and medium power applications. It is typical used for 9V battery to 5V, 3.3V or 3V conversion, high efficiency linear regulator replacement and 5V to 3.3V converters.
Supply voltage range from 4V to 11.5V
Operating temperature range from -40°C to 85°C
Low supply current, high efficiency over wide load range
Quiescent current of 10μA
Low battery detection comparator
Efficiency of 94% (IOUT = 25mA, L = 470μH) and 91% (IOUT = 100mA, L = 100μH)
Switch on-time of 16.7μs (V+ = 6V, VOUT = 3V) and 12.5μs (V+ = 9V, VOUT = 5V)
Switch off-time of 19.5μs (V+ = 6V, VOUT = 3V) and 11.7μs (V+ = 9V, VOUT = 5V)
(EN)
