MAX1703

Up to 95% Efficiency
Up to 1.5A Output
Fixed 5V or Adjustable Step-Up Output (2.5V to 5.5V)
0.7V to 5.5V Input Range
Low-Power Mode (300W)
Low-Noise, Constant-Frequency Mode (300kHz)
Synchronizable Switching Frequency (200kHz to 400kHz)
1A Logic-Controlled Shutdown
Power-Good Comparator
Uncommitted Gain Block

Digital Cordless Phones                                           Personal Communicators
PCS Phones                                                                     Palmtop Computers
Wireless Handsets                                                     Hand-Held Instruments
Two-Way Pagers

OUT, ON , AO, POK to GND .............................................................-0.3V to +6V
PGND to GND............................................................................................±0.3V
LXP, LXN to PGND .........................................................-0.3V to (VPOUT + 0.3V)
POUT, CLK/SEL, AIN, REF, FB,
POKIN to GND..................................................................-0.3V to (VOUT + 0.3V)
Continuous Power Dissipation (TA = +70°C)
Narrow SO (derate 8.70mW/°C above +70°C) ....................................696mW
Operating Temperature Range ................................................-40°C to +85°C
Junction Temperature.............................................................................+150°C
Storage Temperature Range .................................................-65°C to +160°C
Lead Temperature (soldering, 10sec) ....................................................+300°C

The MAX1703 is a high-efficiency, low-noise, step-up DC-DC converter intended for use in battery-powered wireless applications. It uses a synchronous-rectified pulse-width-modulation (PWM) boost topology to generate a 2.5V to 5.5V output from battery inputs, such as one to three NiCd/NiMH cells or one Li-Ion cell. The device includes a 2A, 75m½, N-channel MOSFET switch and a 140m½, P-channel synchronous rectifier.

With its internal synchronous rectifier, the MAX1703 delivers up to 5% better efficiency than similar nonsynchronous converters. It also features a pulse-frequencymodulation (PFM) low power mode to improve efficiency at light loads, and a 1A shutdown mode.

The MAX1703 comes in a 16-pin narrow SO package and includes an uncommitted comparator that generates a power-good or low-battery-warning output. It also contains a linear gain block that can be used to build a linear regulator.

For lower-power outputs and a smaller package, refer to the MAX1700/MAX1701. For dual outputs (step-up plus linear regulator), refer to the MAX1705/MAX1706. For an on-board analog-to-digital converter, refer to the MAX848/MAX849.

The MAX1703 evaluation kit is available to speed designs.