AD8519: Can ADI provide partial spice model for testing out-of spec issues

Document created by analog-archivist Employee on Feb 23, 2016
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Can ADI provide a partial SPICE model to cover the following out of spec
parameters:

Q1. Input voltages limitations, such as Vdifferential, VCM, Vabsolute (> VCC)
etc.

Q2. Output true behavior when violating the limitations of input voltages
(for example, what happens to output voltage when you supply input voltage that
is out of limit [below or above rails] etc.).

Q3. Transient behaviour – what happens in power up to output voltage etc.

Can ADI provide partial SPICE for the above parameters only?

 

ns 1. We have information on the absolute maximum ratings table. These are
limited by
fab processes, and we want to make sure we never violate these limitations.

Ans 2. You would never want to have an input below or above the rail of the
amplifier.
It may cause metal migration, which either damages the part instantly or over
the long run. Long term reliability would be compromised. If overvoltage is a
requirement, I suggest they look at the ADA4091-2 or the ADA4096-2 with on chip
input overvoltage protection.

Ans 3. You would never want to apply voltage to the output of the amplifier.
It's an output
pin, not input.

Unfortunately, we cannot provide a partial SPICE model for the above. We do not
test for these violations, and we advise customers against performing these
violations.

When using the amplifier in open loop condition. Amplifiers are designed to
operate in closed loop, not open loop. A lot of cons are associated with that.

http://www.analog.com/static/imported-files/tutorials/MT-084.pdf

Alternatively we suggest you have a look at the comparator, where we think a
comparator would
fit more in this open loop configuration.

We don’t test our amplifiers in open loop condition. Sometimes, weird things
happen when operating in open loop. For example, Isy might skyrocket when
operating in open loop.

http://www.analog.com/static/imported-files/tech_articles/MS-2212.pdf

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