7
DEMO MANUAL DC116
HOT SWAP CONTROLLER
OPERATIO
U
1. Close S3, S5 and S8: monitor V
DD2
at 10.8V; reset V
CC2
at 4.65V.
2. Close S1, S3, S6 and S8: monitor V
CC2
at 4.65V; reset
V
CC2
at 2.9V.
3. Close S4, S5 and S8: reset V
DD2
at 10.8V; reset V
CC2
at
4.65V.
4. Close S2, S3, S4 and S8: reset V
CC2
at 4.5V.
5. Close S3 and S7: monitor V
EE2
at – 10.8V; reset V
CC2
at
4.65V.
Connector
A staggered-pin connector (HM1V41HPR000H6) from
FCI is used on the boards for hot swapping. The ground
pins are the longest, making connection first and breaking
connection last. This will prevent ESD damage on the rest
of the pins when a huge ground potential difference exists
between the two boards. The connect pins (CON1 and
CON2) are shortest, and are placed on the opposite end of
the connector. The LTC1421 will not start turning on the
pass transistors until the whole connector is plugged in
and both CON1 and CON2 are connected.
PCB LAYOUT A D FIL
U
W
DC116A
Silkscreen Top
DC116A ASY
Assembly Top
LEDs
Several LEDs are included on the demo board to indicate
the status of the input and output voltages and the circuit
breaker. D2, D4 and D6, when turned on, indicate that the
input supplies (V
DD1
, V
EE1
and V
CC1
) from the connector
are ready. The green LEDs (D3, D5 and D7), when turned
on, indicate that the pass transistors are on and the input
supplies have been routed to the outputs. D8 is connected
from the RESET pin to V
CC1
through a 470
Ω
resistor. D8
turns on immediately after the board is inserted into the
system power supplies and turns off 200ms after the
PWRGD pin goes high. When the red LED (D1) lights up,
a general fault condition has occurred: either the circuit
breaker has tripped, a power failure has occurred or the
gate driver is turned off.
Dip Switches (S1 to S8)
Eight dip switches on the demo board provide users with
a convenient way to configure the output voltage(s) to be
monitored and the trip levels for the RESET output. Five
different configurations are listed below:
DC116A SLK
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