LTC1700

LTC1700 No RSENSE Synchronous Step-Up DC/DC Controller FEATURES s s s DESCRIPTIO s s s s s s s s s s U APPLICATIO S s s s s s s 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 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. The LTC1700 operates at a minimum input voltage as low as 0.9V. The device boasts a ±1.5% output voltage accuracy and consumes only 200µA of quiescent current. In shutdown, it only draws 10µA. To prevent inductor current runaway, the duty cycle is limited to 90%. Overvoltage protection is also pr...