150V dual output DC-DC controller eliminates external surge protection devices
The Power by Linear LTC7810 has a 4.5V to 140V (150V abs max) input voltage range to cope with voltage surges, while the output voltage can be set from 1V to 60V at output currents up to at least 20A per channel with efficiencies as high as 96%.
The LTC7810 operates at up to 100% duty cycle during input voltage dips down to 4.1V, suitable for transportation, industrial, robotic and datacom applications, and draws only 16µA in sleep mode from a 48V input while regulating outputs at 12V and 3.3V, suitable for always-on systems. An internal charge pump allows for 100% duty cycle operation in dropout when powered from a battery.
The 1Ω N-channel MOSFET gate drivers can be programmed to 6V, 8V or 10V to enable the use of logic-level or standard-threshold MOSFETs to maximize efficiency, and can drive the gate of an optional external N-channel MOSFET, acting as a low dropout linear regulator, to supply IC power and prevent high on-chip power dissipation. The EXTV CC pin allows the controller to be powered from the output of the regulator or another available source, further reducing power dissipation and improving efficiency.
The LTC7810 operates with a selectable fixed frequency between 50kHz and 750kHz and is synchronizable to an external clock from 75kHz to 720kHz. The user can select from forced continuous operation, pulse-skipping or low ripple Burst Mode operation during light loads anf the current mode architecture provides easy loop compensation, fast transient response and excellent line regulation. Current sensing is accomplished by measuring the voltage drop across the output inductor (DCR) for highest efficiency or by using an optional sense resistor.
A low 90ns minimum on-time allows for high step-down ratios at high switching frequency while current foldback limits the MOSFET heat dissipation during overload conditions. Additional features include adjustable input overvoltage lockout and soft-start.
The LTC7810 is available in a 48-lead 7mm x 7mm plastic eLQFP thermally enhanced package with no connect pins for high voltage spacing. Two operating junction temperature grades are available from –40°C to 125°C and a high temp automotive version from –40°C to 150°C.
www.linear.com/product/LTC7810