Texas Instruments OPA928EVM Evaluation Module

     The Texas Instruments OPA928EVM Evaluation module is a four-layer PCB in a Rogers 4350B and FR-4 hybrid stack. The EVM is based on an OPA928 36V nanoampere-level, input-bias current operational amplifier optimized for very low current and high impedance applications.

     The OPA928EVM's internal ESD protection structure and unique package pin allocation isolate input from output and power pins. The internal protection buffer is accessible through the protection pin, extending the protection structure to the input trace and feedback element.

     The TI OPA928EVM uses advanced protection and shielding technology to maintain nanoampere-level PCB layout performance. High impedance (Hi-Z) buffers and cross-impedance amplifiers are configured to evaluate the OPA928 in common application circuits. These configurations are divided into two separate circuits on the board. By default, the 0Ω resistor Rgnd is installed at the bottom of the board and connects the analog ground of the two circuits.

     The two OPA928 amplifiers (U1 and U2) are located at the bottom of the EVM and are packaged in a grounded RF shield to protect them from pollution, noise and electromagnetic interference (EMI). The top of the OPA928EVM features a variety of pin sockets, jumpers, and other components for easy configuration while limiting potential degradation contamination on sensitive nodes.