isolation amplifier and we are really interested in using the AD215
since it implements an isolation amplifier with an output range of +/-
10V and have in the same time a built-in isolated isolated power supply
of +/-15Vdc @ +/-10mA.
For our application, the circuit connected to the isolated power supply
will request more than +10mA. Actually, the final current consumption
will be between 12 and 20mA. But only the V+ ISO will be loaded,
nothing will be connected to V- ISO.
I believe this will be OK although we do not guarantee this in our datasheet.
I configured a module with a 650 Ohm load (slightly over the 20mA desired) on
the +Viso supply and the following is what I observed no load to 650 Ohm load:
• Power supply current increased by about 25mA.
• The +Viso supply dropped by about 800mV
• The ripple on the +Viso power supply increased by about 60mV
• The offset of the module shifted by about 2mV
• The gain error changed slightly.
• The temperature of the case increased. Observed by touching the case with
I do not know how the MTBF compares between this configuration verses a 10mA
load on each Viso supply.
The module continued to operate as it did last night.
I also discovered that the test card I used for this testing also had a load
configured on the Viso supplies as well as additional bypass caps. The test
card already had a 10mA load configured on both the + & - Viso supply, so my
testing was based on adding an additional 20mA load on the +Viso supply
resulting in a 10mA load on the –Viso supply and a 30mA load on the +Viso
Given these results I think the customer should not have a problem; however we
do not guarantee the performance under these conditions.