DESCRIPTION
The LTC®1700 is a current mode synchronous step-up DC/DC controller that drives external N-channel and P-channel power MOSFETs using a constant frequency PWM architecture. Current limiting is provided by sensing the voltage drop across the main MOSFET, eliminating the need of a sense resistor. This No RSENSETM technique helps the LTC1700 maintain high efficiency at heavy loads while Burst Mode operation ensures high efficiency at light loads, thus providing high efficiencies over a wide range of load currents.

FEATURES
■ High Efficiency: Up to 95%
■ No Current Sense Resistor Required
■ Constant Frequency 530kHz Operation Allows
   Small Size, Surface Mount Inductors
■ OPTI-LOOPTM Compensation Minimizes COUT
■ Selectable Burst ModeTM Operation
■ Minimum Start-Up Voltage as low as 0.9V
■ Synchronizable Between 400kHz and 750kHz
■ Micropower Shutdown: 10µA
■ Current Mode Operation for Excellent Line and Load
   Transient Response
■ Soft-Start Reduces Supply Current Transients
■ 1.5% Output Voltage Accuracy
■ Uses Low Value, Small Size, Surface Mount Inductors
■ Available in 10-Lead MSOP Package

APPLICATIONS
■ Cellular Telephones
■ Wireless Modems
■ RF Communications
■ 2.5V to 3.3V, 2.5V to 5V Converters
■ Battery-Powered Equipment
■ Telecom/Network Systems