19-4759; Rev 1; 1/99
1-Cell to 3-Cell, High-Power (1A),
Low-Noise, Step-Up DC-DC Converters
Up to 96% Efficiency
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)
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 battery
inputs such as one to three NiCd/NiMH cells or one Li-
Ion cell. Both devices have an internal 1A, 130mΩ N-
channel MOSFET switch and a 250mΩ P-channel
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 3µA 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 regulator), 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
-40°C to +85°C
-40°C to +85°C
Digital Cordless Phones
Typical Operating Circuit
0.7V TO 5.5V
3.3V OR ADJ
UP TO 800mA
I.C. = INTERNAL CONNECTION. LEAVE OPEN OR CONNECT TO GND
Pin Configurations continued at end of data sheet.
Maxim Integrated Products
For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800.
For small orders, phone 1-800-835-8769.