DESCRIPTION
The LTC®1708 is a dual adjustable 5-bit VID programmable step-down switching regulator controller that drives all N-Channel power MOSFET stages. A constant frequency current mode architecture allows adjustment of the frequency up to 300kHz. Power loss and noise due to the ESR of the input capacitance are minimized by operating the two main controller output stages out of phase.

FEATURES
■ Out-of-Phase Controllers Reduce Input Capacitance
   and Power Supply Induced Noise
■ OPTI-LOOPTM Compensation Minimizes COUT
■ Power Good Output Monitors Both Outputs
■ 5-Bit Mobile VID Control, VOUT: 0.9V to 2.0V
■ Dual N-Channel MOSFET Synchronous Drive
■ ±1% Output Voltage Accuracy
■ DC Programmed Fixed Frequency 150kHz to 300kHz
■ Wide VIN Range: 3.5V to 36V Operation
■ Very Low Dropout Operation: 99% Duty Cycle
■ Adjustable Soft-Start Current Ramping
■ Foldback Output Current Limiting
■ Latched Short-Circuit Shutdown with Defeat Option
■ Output Overvoltage Protection
■ Remote Output Voltage Sense
■ Low Shutdown Current: 20µA
■ 5V and 3.3V Standby Regulators
■ Selectable Constant Frequency, Burst ModeTM and
   Continuous Operation

APPLICATIONS
■ Notebook and Palmtop Computers, PDAs
■ Portable Instruments