8.1.1.1 ESD Sensitivity

RF devices may be extremely sensitive to electrostatic discharge (ESD). To prevent damage from ESD, devices should be stored and handled in a way that prevents the build-up of electrostatic voltages that exceed the rated level. Rated ESD levels should also not be exceeded while the device is installed on a printed circuit board (PCB). Follow these guidelines for optimal ESD protection:

• Low ESD performance is not uncommon in RF ICs; see the Absolute Maximum Ratings table. Therefore, customers’ ESD precautions should be consistent with these ratings.
• The device should be robust once assembled onto the PCB unless external inputs (connectors, etc.) directly connect the device pins to off-board circuits.

Table 1. Pin Termination Requirements and Limitations

Table 2. Bill of Materials for TRF370x EVM

8.2.2.1 DAC-to-Modulator Interface Network

For optimum linearity and dynamic range, the digital-to-analog converter (DAC) can interface directly with the modulator; however, the common-mode voltage of each device must be maintained. A passive interface circuit is used to transform the common-mode voltage of the DAC to the desired set-point of the modulator. The passive circuit invariably introduces some insertion loss between the two devices. In general, it is desirable to keep the insertion loss as low as possible to achieve the best dynamic range. Figure 41 shows the passive interconnect circuit for two different topologies. One topology is used when the DAC (such as the DAC568x) common-mode is larger than the modulator. The voltage V_ee is nominally set to ground, but can be set to a negative voltage to reduce the insertion loss of the network. The second topology is used when the DAC (such as the DAC56x2) common-mode is smaller than the modulator. Note that this passive interconnect circuit is duplicated for each of the differential I/Q branches.

Figure 41. Passive DAC-to-Modulator Interface Network