28V, PWM, Step-Up DC-DC Converter

The MAX618 CMOS, PWM, step-up DC-DC converter generates output voltages up to 28V and accepts inputs from +3V to +28V. An internal 2A, 0.3Ω switch eliminates the need for external power MOSFETs while supplying output currents up to 500mA or more. A PWM control scheme combined with Idle Mode™ operation at light loads minimizes noise and ripple while maximizing efficiency over a wide load range. No-load operating current is 500µA, which allows efficiency up to 93%.

A fast 250kHz switching frequency allows the use of small surface-mount inductors and capacitors. A shutdown mode extends battery life when the device is not in use. Adaptive slope compensation allows the MAX618 to accommodate a wide range of input and output voltages with a simple, single compensation capacitor.

The MAX618 is available in a thermally enhanced 16-pin QSOP package that is the same size as an industry-standard 8-pin SO but dissipates up to 1W. An evaluation kit (MAX618EVKIT) is available to help speed designs.

Applications

* Industrial +24V and +28V Systems * LCD Displays * Palmtop Computers

* Adjustable Output Voltage Up to +28V

* Up to 93% Efficiency

* Wide Input Voltage Range (+3V to +28V)

* Up to 500mA Output Current at +12V