1.5A, Low-Noise, 1MHz, Step-Up DC-DC Converter

The MAX1763 is a high-efficiency, low-noise, step-up DC-DC converter intended for use in battery-powered wireless applications. This device maintains exceptionally low quiescent supply current (110µA) despite its high 1MHz operating frequency. Small external components and a tiny package make this device an excellent choice for small hand-held applications that require the longest possible battery life.

The MAX1763 uses a synchronous-rectified pulse-width-modulation (PWM) boost topology to generate 2.5V to 5.5V outputs from a wide range of input sources, such as one to three alkaline or NiCd/NiMH cells or a single Lithium-ion (Li+) cell. Maxim's proprietary Idle Mode™ circuitry significantly improves efficiency at light load currents while smoothly transitioning to fixed-frequency PWM operation at higher load currents to maintain excellent full-load efficiency. Low-noise, forced-PWM mode is available for applications that require constant-frequency operation at all load currents. The MAX1763 may also be synchronized to an external clock to protect sensitive frequency bands in communications equipment.

The MAX1763 includes an on-chip linear gain block that can be used to build a high-power external linear regulator or as a low-battery comparator. Soft-start and current limit functions permit optimization of efficiency, external component size, and output voltage ripple.

The MAX1763 is available in a space-saving 16-pin QSOP package or a high-power (1.5W) 16-pin TSSOP-EP package.

Applications

* Digital Cordless Phones * Handheld Instruments (PDAs, Palmtops) * Palmtop Computers * PCS Phones * Personal Communicators * Wireless Handsets

* Up to 94% Efficiency

* +0.7V to +5.5V Input Voltage Range

* 1.1V Guaranteed Startup Input Voltage

* Up to 1.5A Output

* Fixed 3.3V Output or Adjustable (2.5V to 5.5V)

* 1MHz PWM Synchronous-Rectified Topology

* 1µA Logic-Controlled Shutdown

* Analog Gain Block for Linear-Regulator or Low-Battery Comparator

* Adjustable Current Limit and Soft-Start

* 1.5W TSSOP Package Available