MAX1623 Datasheet | Maxim Integrated

Description The MAX1623 switch-mode buck regulator with synchronous rectification provides local CPU and bus-termination power in notebook and desktop puters. An internal 55mΩ (typ), 3A PMOS power switch and 60m Ω (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. The MAX1623 features constant-off-time, current-mode pulse-width-modulation (PWM) control with switching frequencies as high as 350k Hz. An external resistor at the TOFF pin sets the off-time, allowing optimum design flexibility in terms of switching frequency, output switching noise, and inductor size. This device is available in a space-saving 20-pin SSOP package. ____________________________Features o ±1% Output Accuracy, Including Line and Load Regulation o 94% Efficiency o Internal Switches 55mΩ PMOS Power Switch 60mΩ NMOS Synchronous-Rectifier Switch o Guaranteed 3A Load Capability o Minimal External ponents o Pin-Selectable Fixed 3.3V, 2.5V, or Adjustable (1.1V to 3.8V) Output Voltage o +4.5V to +5.5V Input Voltage Range o 400µA (typ) Supply Current o <1µA Shutdown Supply Current o Constant-Off-Time PWM Operation o Switching Frequencies Up to 350k Hz o Idle Mode™ Operation at Light Loads o Thermal Shutdown Protection o Available in 20-Pin SSOP ________________________Applications 5V to 3.3V Conversion Notebook puter CPU I/O Supply Desktop puter Bus-Termination Supply CPU Daughter Card Supply DSP Supply Ordering Information PART MAX1623EAP TEMP. RANGE -40°C to +85°C PIN-PACKAGE 20 SSOP Typical Operating Circuit TOP VIEW +5V INPUT +2.5V OUTPUT IN LX Pin Configuration LX 1 IN 2 20 LX 19 PGND 18 LX 17 PGND LX 3 VCC FBSEL SHDN TOFF P FB GND REF PGND IN 4 LX 5 IN 6 SHDN 7 FBSEL 8 TOFF 9 FB 10 16 LX 15 PGND 14 VCC 13 P 12 REF 11 GND SSOP Idle Mode is a trademark of Maxim Integrated...