Linear ADI Power LTC7871 Demo Manual

High Power PolyPhase
DESCRIPTION
Demonstration circuit 2886A is a high power, high effi-
ciency six-phase bidirectional converter featuring the
LTC 7871 and LTC7060. The terminals labeled V
®
and V are either inputs or outputs depending on the
LOW
direction of power flow. When the switch at SW1 is in the
BUCK position, V provides a 14V output and V
LOW
the input with a range of 30V to 70V. When the switch
is in the BOOST position, V
and V is the input with a range of 10V to 14V. The
LOW
maximum V current is 180A in both directions. The
LOW
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 cur-
rent 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 V
depending on the state of the BUCK pin. This current can
be programmed with the SETCUR pin and monitored with
the IMON pin.
®
HIGH
HIGH
provides a 48V output
HIGH
terminal
LOW
DEMO MANUAL DC2886A
Bidirectional Supply/Charger
The DC2886A provides a SPI compatible serial port. With
a DC2026C (Linduino
software on a host computer, the user can:
• Margin the regulated V
• Margin the DC current limit up or down with the
is
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
Design files for this circuit board are
All registered trademarks and trademarks are the property of their respective owners.
LTC7871/LTC7060
One) demo board and QuikEval™
®
or V up or down.
LOW HIGH
available.
®
Rev. 0
1