INPUT AND ESD PROTECTION
The OPA681 is built using a very high speed complemen-
tary bipolar process. The internal junction breakdown volt-
ages are relatively low for these very small geometry de-
vices. These breakdowns are reflected in the Absolute Maxi-
mum Ratings table. All device pins have limited ESD
protection using internal diodes to the power supplies as
shown in Figure 13.
+VCC
External
Pin
Internal
Circuitry
These diodes provide moderate protection to input overdrive
voltages above the supplies as well. The protection diodes
can typically support 30mA continuous current. Where higher
currents are possible (e.g., in systems with ±15V supply
parts driving into the OPA681), current-limiting series resis-
tors should be added into the two inputs. Keep these resistor
values as low as possible since high values degrade both
noise performance and frequency response.
–VCC
FIGURE 13. Internal ESD Protection.
®
21
OPA681
BB [ BURR-BROWN CORPORATION ]
