General Description

The MAX750A/MAX758A are adjustable-output, CMOS, step-down, DC-DC switching regulators. The MAX758A accepts inputs from 4V to 16V and delivers 750mA, while the MAX750A accepts inputs from 4V to 11V and delivers 450mA. Typical efficiencies are 85 to 90. Typical quiescent current is 1.7mA, or only 6µA in shutdown mode. The output does not exhibit any ripple at subharmonics of the switching frequency over its specified range.

Pulse-width-modulation (PWM) current-mode control

provides precise output regulation and excellent transient responses. Output voltage accuracy is guaranteed to be ±4.5 plus feedback-resistor tolerance over line, load, and temperature variations. Fixed-frequency switching and absence of subharmonic ripple allows easy filtering of output ripple and noise, as well as the use of small external components. These regulators require only a single inductor value to work in most applications, so no inductor design is necessary.

Features

♦ Up to 750mA Load Currents

♦ 160kHz High-Frequency, Current-Mode PWM

♦ 85 to 96 Efficiencies

♦ 33µH or 100µH Pre-Selected Inductor Value,

   No Component Design Required

♦ 1.7mA Quiescent Supply Current

♦ 6µA Shutdown Supply Current

♦ Adjustable Output Voltage

♦ Overcurrent, Soft-Start, and Undervoltage

   Lockout Protection

♦ Cycle-by-Cycle Current Limiting

♦ 8-Pin DIP/SO Packages (MAX750A)

Applications

   Cellular Phones & Radios

   Portable Communications Equipment

   Portable Instruments

   Computer Peripherals