DC2886A - Schematic8/26/2020
Demonstration circuit DC2886A is a high power, high efficiency six-phase bidirectional converter featuring the LTC7871 and LTC7060. The terminals labeled VHIGH and VLOW are either inputs or outputs depending on the direction of power flow. When the switch at SW1 is in the BUCK position, VLOW provides a 14V output and VHIGH is the input with a range of 30V to 70V. When the switch is in the BOOST position, VHIGH provides a 48V output and VLOW is the input with a range of 10V to 14V. The maximum VLOW current is 180A in both directions. The maximum output power is 2.5kW when operating as a buck within the input voltage range. When operating as a boost, the maximum output power is 2.4kW when the input voltage is 14V. External airflow is required when operating at maximum power. The MOSFETs in each phase are driven by the LTC7060 half bridge driver. Each LTC7060 gate driver is placed next to the MOSFETs and receives a PWM signal from the LTC7871.
The inductor current for each phase is sensed with a low 1mΩ sense resistor using a highly accurate AC/DC current sensing architecture with low power dissipation. The LTC7871’s constant-current loop provides a DC current limit for the current flowing in or out of the VLOW terminal depending on the state of the BUCK pin. This current can be programmed with the SETCUR pin and monitored with the IMON pin.
The DC2886A provides a SPI compatible serial port. With a DC2026C (Linduino® One) demo board and QuikEval™ software on a host computer, the user can:
- Margin the regulated VLOW or VHIGH up or down.
- Margin the DC current limit up or down with the SETCUR pin.
- Adjust the frequency spread and modulation rate of the spread spectrum circuit, when spread spectrum is enabled.
- Monitor the operational status and faults of the LTC7871.
Additional features of the DC2886A include:
- Pin selectable light load operating modes
- Buck: FCM, pulse-skipping and Burst Mode® Operation
- Boost: FCM and pulse-skipping
- SYNC and CLKOUT pins
- Optional jumper to enable spread spectrum modulation
- RUN, FAULT, PGOOD and PWNEN pins
- BUCK pin to externally control the direction of power flow
- Footprint for an optional heatsink
Pricing displayed is based on 1-piece.
Pricing displayed is based on 1-piece. The USA list pricing shown is for budgetary use only, shown in United States dollars (FOB USA per unit), and is subject to change. International prices may vary due to local duties, taxes, fees and exchange rates.