SBOS293H December 2003 – December 2015 OPA695
PRODUCTION DATA.
Achieving optimum performance with a high-frequency amplifier like the OPA695 requires careful attention to board layout parasitics and external component types. Recommendations that will optimize performance include:
The OPA695 is built using a very high-speed, complementary bipolar process. The internal junction breakdown voltages are relatively low for these small geometry devices. These breakdowns are reflected in the Absolute Maximum Ratings where an absolute maximum ±6.5-V supply is reported. All device pins have limited ESD protection using internal diodes to the power supplies, as shown in Figure 67.
These diodes also provide moderate protection to input overdrive voltages above the supplies. The protection diodes can typically support 30-mA continuous current. Where higher currents are possible (for example, in systems with ±15-V supply parts driving into the OPA695), current-limiting series resistors must be added into the two inputs. Keep these resistor values as low as possible as high values degrade both noise performance and frequency response.
As detailed in Layout Guidelines and illustrated in Figure 68, the input termination resistor, output resistor and bypass capacitors must be placed close to the amplifier. Power and ground planes are placed under the amplifier, but must be removed under the input and output pins as shown in Figure 68.