150V Dual Synchronous Step-Down DC/DC Controller with 16µA IQ Eliminates External Surge Protection Devices
Analog Devices announces the Power by Linear™ LTC7810, a high voltage non-isolated dual output synchronous step-down DC/DC controller that drives all N-channel MOSFET power stages. Its 4.5V to 140V (150V abs max) input voltage range is designed to operate from a high input voltage or from an input that has high voltage surges, eliminating the need for external surge suppression devices. The LTC7810 operates at up to 100% duty cycle during input voltage dips down to 4.1V, ideal for transportation, industrial, robotic and datacom applications.
• View the LTC7810 product page, download data sheet, order samples and evaluation boards: www.linear.com/product/LTC7810
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%. This part draws only 16µA in sleep mode from a 48V input while regulating outputs at 12V and 3.3V, well suited for always-on systems. An internal charge pump allows for 100% duty cycle operation in dropout, a useful feature when powered from a battery during discharge. Optional spread spectrum reduces radiated and conducted emissions. The LTC7810’s powerful 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. To prevent high on-chip power dissipation in high input voltage applications, the LTC7810 can drive the gate of an optional external N-channel MOSFET, acting as a low dropout linear regulator, to supply IC power. The EXTVCC pin permits the LTC7810 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. Its 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. Current foldback limits 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 eLQFP thermally enhanced package with no connect pins for high voltage spacing. Two operating junction temperature grades are available with extended and industrial versions from –40°C to 125°C and a high temp automotive version from
–40°C to 150°C. For more information, visit www.linear.com/product/LTC7810.
Summary of Features: LTC7810
• Wide Input Voltage Range: 4.5V to 140V, 150V Abs Max
• Wide Output Voltage Range: 1V to 60V
• Output Current up to 20 Amps per Channel
• Synchronous Rectification for up to 96% Efficiency
• Low 16µA Quiescent Current Regulating 12VOUT and 3.3VOUT from 48VIN
• 100% Duty Cycle Capability
• Adjustable 6V, 8V or 10V Gate Drive Voltage for Logic-Level or Standard-Threshold MOSFETs
• DCR or RSENSE Current Sensing
• Low 90ns Minimum On-Time for High Step-Down Ratios
• Selectable Continuous, Pulse-Skipping or Low Ripple Burst Mode® Operation at Light Loads
• Selectable Fixed Operating Frequency from 50kHz to 750kHz
• PLL Synchronizable Operating Frequency from 75kHz to 720kHz
• Current Mode Control for Fast Transient Response & Easy Loop Compensation
• Adjustable Input Overvoltage Lockout
Pricing & Availability
Product Sample Availability Production
Availability Price Each Per 1,000 Package
Now Now Starts at $5.20 48-Lead Plastic eLQFP 7mm x 7mm
About Analog Devices
Analog Devices is the leading global high-performance analog technology company dedicated to solving the toughest engineering challenges. We enable our customers to interpret the world around us by intelligently bridging the physical and digital with unmatched technologies that sense, measure, power, connect and interpret. Visit http://www.analog.com.