QThe ADG5248F offers ±55V over-voltage protection. What are the keys things I
need to understand about this Over-voltage protected switch compared to
using a standard switch in my application?
AThe ADG5248F is ideally suited as a protective element in signal chains that
are sensitive to both charge injection and overvoltage signals. During normal
operation the ADG5248F behaves like a standard multiplexer and can pass signals
within the secondary supply rails, thereby protecting sensitive downstream
components. The ADG5248F offers 0.8pC charge injection with excellent leakage
and switch capacitance specs ensuring optimum performance in multiplexed
systems (e.g. instrumentation and process control applications).
The ADG5248F offers ±55V protection on the inputs with respect to GND. When
the voltages on the Sx inputs exceed either rail by ~0.7V the switch will turn
off and present high impedance to the input. The inputs can withstand up to
±55V; exceeding this limit may damage the ESD protection on the part.
One other point to note, 80V is the maximum voltage that can be present across
the OFF switch, (Sx to Dx = 80V) and 80V is the maximum voltage that can be
present from the Sx inputs to the supplies, (Sx to VDD or VSS = 80V).
Therefore, if you are using the part with 40V Single Supply the maximum voltage
allowed on Sx is -40V and not -55V.
If you are switching signals with a bandwidth of 1MHz or greater, please
reference the datasheet to understand the relationship between signal amplitude
and bandwidth to ensure signal integrity.