DESCRIPTION
The LT®1941 is a triple current mode DC/DC converter with internal power switches. Two of the regulators are step-down converters with 3A and 2A power switches. The third regulator can be configured as a boost, inverter or SEPIC converter and has a 1.5A power switch. All three converters are synchronized to a 1.1MHz oscillator. The two step-down converters run with opposite phase, reducing input ripple current. The output voltages are set with external resistor dividers and each regulator has independent shutdown and soft-start circuits. Each regulator generates a power good signal when its output is in regulation, easing power supply sequencing and interfacing with microcontrollers and DSPs.
FEATURES
■ Wide Input Range: 3.5V to 25V
■ Three Switching Regulators with Internal Power Switches: 3A Step-Down, 2A Step-Down, 1.5A Inverting/Boost
■ Antiphase Switching Reduces Ripple
■ Independent Shutdown/Soft-Start Pins
■ Independent Power Good Indicators Ease Supply Sequencing
■ Input Voltage Power Good Indicators Monitor Input Supply
■ Uses Small Inductors and Ceramic Capacitors
■ Constant 1.1MHz Switching Frequency
■ Thermally Enhanced 28-Lead TSSOP Package
APPLICATIONS
■ Cable Modems
■ DSL Modems
■ Distributed Power Regulation
■ Wall Transformer Regulation
■ Disk Drives
■ DSP Power