ADA4927 output current

Document created by analog-archivist Employee on Feb 23, 2016
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We have an XMC card application which uses ADA4927-1 to interface between an
SMA 50ohm input and an A/D converter. The A/D converter accepts 0 to 2V peak at
its inputs but can withstand higher voltages without latch-up provided the
current is limited to less than 100mA. We are considering this from the point
of view of protection in case over-sized signals are accidentally input to the
XMC card. The AD4927-1 design is very similar to the datasheet for a
single-ended 50ohm input and uses resistors in the 300ohms range and
unity-gain. The datasheet doesn't specify the maximum output current if loaded
with these value resistors and a low-impedance load (e.g. 25 ohms in each
output lead). What would be the worst-case output voltage or current under
these circumstances e.g. what is the short-circuit current or how does the
output impedance of the amplifier vary with output voltage swing etc.

 

ADA4927-1 should sink about 100mA and source about 75mA.

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