PI2002 Datasheet, PDF (8/23 Pages) Vicor Corporation – Active ORing Controller IC with Load Disconnect Feature

When the input source voltage is applied and before
the MOSFET is fully enhanced, a voltage greater
than the Forward Over-Current (FOC) Threshold
may be present across the MOSFET. To avoid an
erroneous FOC detection, a VGS detector blanks
the FOC and FWD comparators from initiating a
fault, until the GATE pin reaches 45% of V_G-CLMP. If
VC is too low to establish the Gate Clamp condition
the reference for detection is 45% of {VC-V(SN) -
0.25V}.
The GATE pin pulls low under the following fault
conditions:
• Reverse Current
• Forward Over-Current “AND” clamp detector is
cleared
• Over Temperature
• Input Under-Voltage
• Input Over-Voltage “AND” nominal Forward
Current
• VC pin Under-Voltage
Fault:
The fault circuit output is an open collector with 40μs
delay to prevent any false triggering. The FT pin
will be pulled low when any of the following faults
occurs:
• Reverse Current
• Forward Over-Current “AND” clamp detector is
cleared
• Forward Low Current “AND” clamp detector is
cleared
• Over Temperature
• Input Under-Voltage
• Input Over-Voltage “AND” nominal Forward
Current
• VC pin Under-Voltage
The Forward Current fault condition occurs when the
MOSFETs gates are high but are not conducting a
significant level of forward current or may indicate
the MOSFETs are shorted either internally or
externally (V_D1-D2 < 6mV).
The VGS detector prevents FOC or FWD from
initiating a fault when the MOSFET gate is low. The
gate to SN voltage has to reach sufficient voltage to
establish the Rds(on) condition before these faults
are detected.
Picor Corporation • picorpower.com
PI2002
Rev1.1 Page 8 of 23