Adjustable, PWM, Step-Down Regulator

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.

Applications

* Cell Phones * Computer Peripherals * Portable Communications Equipment * Portable Instrumentation

* 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)