LTC7822-1

• 98.4% Peak Efficiency in 48V to 12V Application
• 97.7% Full Load Efficiency at 1kW Output Power
• 10V Gate Drive for Optimal Efficiency
• ±1.25% Output Voltage Accuracy
• Inductor DCR Current Sensing
• CLKOUT Pin for Multi-ICs Parallel Operation
• Overtemperature and OC/OV Protection
• 46-Lead (48-Lead Body) 7mm x 7mm Plastic Side-Solderable QFN
• AEC-Q100 Qualified for Automotive Applications

The evaluation circuit EVAL-LTC7822-1-AZ features LTC7822-1: an automotive dual-phase hybrid step-down synchronous controller with a load current monitor. The LTC7822-1 uses an ADI-proprietary architecture that merges a soft switching charge pump topology with a dual-phase interleaved synchronous step-down converter to provide superior efficiency and low EMI performance. The LTC7822-1 can operate at a wide VIN Range: 19V to 90V (100V ABS Max), output voltage up to 35V and a phase-lockable fixed frequency from 150kHz to 1.5MHz, enabling flexible configuration for different applications.

The EVAL-LTC7822-1-AZ operates from 36V to 60V input voltage with full power capabilities from 42V to 60V and produces an output of 12V. Utilizing airflow or a heat sink, more than 1kW of output power delivery is achieved within a quarter-brick solution size. Peak efficiency of 98.4% is achieved at 48 V_IN and 30A. Optimized at 150kHz, the EVAL-LTC7822-1-AZ is ideal for 48V to 12V applications with high efficiency and high-power density.

Due to the proprietary architecture, the dual-phase EVAL-LTC7822-1-AZ features a minimum total CMID capacitance value compared with traditional paralleled single-phase hybrid switch cap solutions. 10V gate drive voltage of the LTC7822-1 reduced MOSFETs’ power loss. The EXTVCC pin allows LTC7822-1’s internal LDO to utilize a lower power supply voltage than the lossy V_IN. Furthermore, the coupled inductor applied on the board enables minimum solution size and the highest efficiency performance. All components on the EVAL-LTC7822-1-AZ are automotive AEC-Q qualified.

The output voltage and V_IN ENABLE/UVLO voltage are both programmed by resistor dividers on the FB pin and RUN pin, respectively. FAULT and PGOOD status flags indicate MID_SNS voltage, die temperature, and V_OUT voltage deviation. IMON and IMON_REF reports output current and can be easily accessed on the board for system monitoring purpose.

The EVAL-LTC7822-1-AZ allows paralleling multiple boards to achieve higher output power. For more details, follow the instructions in this user guide. The LTC7822AUKM-1#WPBF is in a 48-Lead 7mm x 7mm plastic QFN package. The LTC7822-1 data sheet gives a complete description of the part operation and application information. The LTC7822-1 data sheet must be read in conjunction with this user guide to properly use the evaluation circuit EVAL-LTC7822-1-AZ.