ADM1075-1ACPZ AD [Analog Devices], ADM1075-1ACPZ Datasheet - Page 27

• Manufacturer Part Number: ADM1075-1ACPZ
• Description: ?48 V Hot Swap Controller and Digital
• Manufacturer: AD [Analog Devices]

Data Sheet
be powered from the secondary side and can provide power
across the isolation barrier via the integrated dc-to-dc
converter. Therefore, the
primary side of the
Some extra care is required if using the
the ADuM3200. If the power at the secondary side is enabled by
the ADM1075, the iso Power solution may not work. Because
iso Power is unpowered in this case, the
in an undefined state. If the SHDN input comes from the
ADuM3200
on the FET or enables power at the secondary side.
iso Power uses high frequency switching elements to transfer
power through its transformer. Special precautions must be
taken during printed circuit board (PCB) layout to meet
emissions standards. See the
board layout recommendations.
Powering the i Couplers from the secondary side is usually
straightforward because there is often a suitable voltage rail
available. However, there is not always a suitable voltage rail
available on the primary side (−48 V side). If the
not used on the system, the
primary side in a number of different ways.
, it may be held low, and the
ADuM1250
ADuM5404
ADuM1250
AN-0971 Application Note
if both are used on the board.
can be used to power the
ADuM5404
ADuM3200
ADM1075
can be powered on the
ADuM5404
never turns
to power
outputs are
for
Rev. A | Page 27 of 52
is
If a voltage rail is available on the primary side (3.3 V or 5 V
referenced to VEE), that can be used to power the chip directly.
Otherwise, the
supply can be regulated down to power the part. A simple
emitter follower circuit achieves this, as shown in Figure 54.
Figure 54. Powering iCoupler from −48 V Supply
ADM1075
20kΩ
12V (SHUNT)
20k
–48V
6V
shunt voltage and/or the −48 V
–48V RTN
–48V
1kΩ
0.33W
1µF
5V AUX
ADM1075