General Description
The MAX1700/MAX1701 are high-efficiency, low-noise, step-up DC-DC converters intended for use in battery-powered wireless applications. They use a synchro-nous-rectified pulse-width-modulation (PWM) boost topology to generate 2.5V to 5.5V outputs from batteryinputs such as one to three NiCd/NiMH cells or one Li-lon cell. Both devices have an internal 1A,130m2 N-
channel MOSFET switch and a 250mQ P-channel synchronous rectifier.With their internal synchronous rectifier, the MAX1700/MAX1701 deliver 5% better efficiency than similar non-synchronous converters. They also feature a pulse-frequency-modulation(PFM) standby mode to improve efficiency at light loads, and a 3uA shutdown mode.
The MAX1700/MAX1701 come in 16-pin QSOP pack-ages(which occupy the same space as an 8-pin SO).
The MAX1701 includes two comparators to generate power-good and low-battery warning outputs. It also contains a gain block that can be used to build a linear regulator using an external P-channel pass device.
For higher-power outputs, refer to the MAX1703. For dual outputs(step-up and linear requlator), refer to the MAX1705/MAX1706. For an on-board analog-to-digital converter, refer to the MAX848/MAX849.
The MAX1701 evaluation kit is available to speed design time.
Features
+Up to 96% Efficiency
1.1VIN Guaranteed Start-Up
+0.7V to 5.5V Input Range
+Up to 800mA Output
+Step-Up Output(adjustable from 2.5V to 5.5V)
PWM/PFM Synchronous-Rectified Topology External Clock or Internal 300kHz Oscillator
+3μA Logic-Controlled Shutdown
+Power-Good Output(MAX1701)
+Low-Battery Comparator(MAX1701)+Uncommitted Gain Block(MAX1701)
Applications
Digital Cordless Phones Personal Communicators
PCS PhonesPalmtop Computers
Wireless Handsets Hand-Held Instruments
Two-Way Pagers
