SBOU327 December 2025 OPA598
The OPA598 features output enable-disable capability. The OPA598 is enabled or operates by floating the E/D pin, which is the normal mode for the OPA598EVM. However, shorting the E/D pin to the E/D Com pin (labeled EDcom on the EVM board) disables the device output. JP11 on the EVM is used to control the enable-disable function. The OPA598 output is automatically enabled when JP11 is left open. However, adding a shorting jumper shunt across JP11 disables the OPA598 output. When the OPA598 is disabled, the op amp power consumption is reduced significantly.
JP11 can be driven externally from a digital source producing 3-V logic levels. An EVM input jack for that purpose is not provided, but JP11 can be used to access the enable-disable control circuitry input, if needed. The enable-disable opto-isolator circuit portion is not optimized for speed, but rather versatility; therefore, keep the switching seeds low.
A jumper shunt across JP17 sets the voltage on the E/D Com pin (EDcom), to which the E/D pin is referenced. The 3-pin, 2-positiion jumper block is located near the OPA598, and is used to connect the E/D Com pin (EDcom) to either negative supply VSS, or GND (0 V). Setting E/D Com (EDcom) to one or the other is of no consequence for the OPA598EVM because the enable-disable function behaves very much the same with either reference level. However, having the choice built into the EVM allows the OPA598 to be set to one or the other of the two most-common reference levels used for OPA598 applications.