The MAX1623EAP+ is a 3A, low voltage, step-down regulator with synchronous rectification and internal switches in 20 pin SSOP package. This switch-mode buck regulator with synchronous rectification provides local CPU and bus-termination power in notebook and desktop computers. An internal 55Mohm (typ), 3A PMOS power switch and 60Mohm (typ), 3A NMOS synchronous-rectifier switch deliver continuous load currents up to 3A from a 5V supply with 95% typical efficiency. Output accuracy is ±1%, including line and load regulation. It features constant-off-time, current-mode pulse-width-modulation (PWM) control with switching frequencies as high as 350KHz. An external resistor at TOFF pin sets off-time allowing optimum design flexibility in terms of switching frequency, output switching noise and inductor size. It is used in CPU daughter card supply, DSP supply and desktop computer bus-termination supply.
● Input voltage range from 4.5V to 5.5V
● Operating temperature range from -40°C to +85°C
● Minimal external components
● Pin-selectable fixed 3.3V and 2.5V output voltage
● Typical supply current is 400µA
● Shutdown supply current is < 1µA
● Constant-off-time PWM operation
● Idle Mode operation at light loads
● Thermal shutdown protection
