Power
60V Input, 50µA Dual Synchronous Step-Down DC/DC Controller Features -55°C to 150°C Operating Junction Temperature Range
Linear Technology has announced the H- and MP-grade versions of the LTC3890/-1. This high voltage dual output synchronous step-down DC/DC controller draws only 50µA when one output is active and 60µA when both outputs are enabled.
The The LTC3890/-1 has powerful on-chip 1.1Ohm MOSFET gate drivers. The device operates with a selectable fixed frequency between 50kHz and 900kHz, and can be synchronized to an external clock from 75kHz to 850kHz with its phased-locked loop (PLL). The user can select from continuous operation, pulse skipping and low ripple Burst Mode operation during light loads. The LTC3890/-1's 2-phase operation reduces input filtering and capacitance requirements. Its current mode architecture provides easy loop compensation, fast transient response and excellent line regulation. Output current sensing is accomplished by measuring the voltage drop across the output inductor (DCR) for the highest efficiency or by using an optional sense resistor.
Summary of Features of the LTC3890/-1:
· Wide Input Voltage Range: 4V to 60V
· 50µA Quiescent Current with One Output Active & 60µA with Both Outputs Active
· 14µA Shutdown Current
· Wide Output Voltage Range: 0.8V to 24V
· Synchronous Rectification for up to 95% Efficiency
* DCR or RSENSE Current Sense
· Selectable Low Ripple Burst Mode Operation, Pulse Skipping or Continuous Operation
· Selectable Fixed Operating Frequency from 50kHz to 900kHz
· Synchronizable Operating Frequency from 75kHz to 850kHz with PLL
· Current-Mode Control for Fast Transient Response & Easy Loop Compensation
· Adjustable Soft-Start & Output Voltage Tracking
· ±1% Voltage Reference Accuracy Over -40°C to 125°C
· Output Overvoltage & Overcurrent Foldback Protection