Datasheet

ADA4096-2 Data Sheet
Rev. A | Page 16 of 20
INPUT OVERVOLTAGE PROTECTION
The ADA4096-2 inputs are protected from input voltage
excursions up to 32 V outside each rail. This feature is of
particular importance in applications with power supply
sequencing issues that could cause the signal source to be active
before the supplies to the amplifier.
Figure 47 shows the input current limiting capability of the
ADA4096-2 (green curves) compared to using a 5 kΩ series
resistor (red curves).
7
–48 –40
–32 –24 –16 –8 0 8 16 24 32 40 48
–7
–6
–5
–4
–3
–2
–1
0
1
2
3
4
5
6
INPUT BIAS CURRENT (mA)
V
IN
(V)
V
EE
= –15V
V
EE
= 0V
V
CC
= +15V
LOW RDS
ON
SERIES FET
5kΩ SERIES RESISTOR
09241-047
Figure 47. Input Current Limiting Capability
Figure 47 was generated with the ADA4096-2 in a buffer configu-
ration with the supplies connected to GND (or ±15 V) and the
positive input swept until it exceeds the supplies by 32 V. In general,
input current is limited to 1 mA during positive overvoltage con-
ditions and 200 μA during negative undervoltage conditions. For
example, at an overvoltage of 20 V, the ADA4096-2 input current is
limited to 1 mA, providing a current limit equivalent to a series
20 kΩ resistor. Figure 47 also shows that the current limiting
circuitry is active whether the amplifier is powered or not.
Note that Figure 47 represents input protection under abnormal
conditions only. The correct amplifier operation input voltage
range (IVR) is specified in Table 2 to Table 4.