DESCRIPTION
The LTC®1628/LTC1628-PG are high performance dual step-down switching regulator controllers that drive all N-channel synchronous 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 capacitors are minimized by operating the two controller output stages out of phase.

FEATURES
■ Out-of-Phase Controllers Reduce Required Input Capacitance and Power Supply Induced Noise
■ OPTI-LOOP™ Compensation Minimizes COUT
■ Dual N-Channel MOSFET Synchronous Drive
■ ±1% Output Voltage Accuracy
■ Power Good Output Voltage Monitor (LTC1628-PG)
■ DC Programmed Fixed Frequency 150kHz to 300kHz
■ Wide VINRange: 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 IQ: 20µA
■ 5V and 3.3V Standby Regulators
■ Small 28-Lead SSOP Package
■ Selectable Constant Frequency or Burst Mode™ Operation