
Linear Technology
DESCRIPTION
The LTC®1874 is a dual constant frequency current mode step-down DC/DC controller with excellent AC and DC load and line regulation. Each controller has an accurate undervoltage lockout that shuts down the individual controller when the input voltage falls below 2.0V.
FEATURES
■ High Efficiency: Up to 94%
■ High Output Currents Easily Achieved
■ Wide VIN Range: 2.5V to 9.8V
■ Constant Frequency 550kHz Operation
■ Burst ModeTM Operation at Light Load
■ Low Dropout: 100% Duty Cycle
■ 0.8V Reference Allows Low Output Voltages
■ Current Mode Operation for Excellent Line and Load Transient Response
■ Low Quiescent Current: 270µA (Each Controller)
■ Separate Shutdown Pin for Each Controller
■ Shutdown Mode Draws Only 8µA Supply Current (Each Controller)
■ ±2.5% Reference Accuracy
■ Available in 16-Lead Narrow SSOP
■ Each Controller Functions Independent of the Other
APPLICATIONS
■ 1- or 2-Cell Lithium-Ion-Powered Applications
■ Personal Information Appliances
■ Portable Computers
■ Distributed 3.3V, 2.5V or 1.8V Power Systems