Maxim Integrated MAX1742EEE T

Description
Constant-off-time, pulse-width-modulated (PWM) step-down DC-DC converters
Ideal for 5V and 3.3V to low-voltage conversion in notebook and subnotebook computers
Internal synchronous rectification for high efficiency and reduced component count
No external Schottky diode required
Internal 90mΩ PMOS power switch and 70mΩ NMOS synchronous-rectifier switch
Deliver continuous load currents up to 1A
Preset 2.5V, 1.8V, or 1.5V output voltage or adjustable output from 1.1V to VIN
Efficiencies as high as 95%
Unique current-mode, constant-off-time, PWM control scheme with Idle Mode™ for high efficiency during light-load operation
Programmable constant-off-time architecture sets switching frequencies up to 1MHz
Adjustable soft-start to limit surge currents during startup
100% duty cycle mode for low-dropout operation
Low-power shutdown mode that disconnects the input from the output and reduces supply current below 1μA
Available in 16-pin QSOP packages

Features
3V to 5.5V input voltage range
600μA (max) operating supply current
<1μA shutdown supply current
Programmable constant-off-time operation
1MHz (max) switching frequency
Idle-Mode operation at light loads
Thermal shutdown
Adjustable soft-start inrush current limiting
100% duty cycle during low-dropout operation
Output short-circuit protection

Applications
5V or 3.3V to low-voltage conversion
±1% output accuracy
95% efficiency
CPU I/O ring
Chipset supplies
Notebook and subnotebook computers