Low distortion filters are part of the TTE product line for ADC and DAC testing. The call-out for low THD (Total Harmonic Distortion) filters is listed in the bandpass, lowpass and highpass product information; refer to the part number derivation within the relevant data page.
The case selection guide does not apply to the low THD filters, as they require larger than standard cases. Nevertheless, many of these filters are available with expedited lead times of 3 to 5 days.
TTE’s higher frequency filters are designed with specific PCB case sizes and pin layouts. These cases offer 4 ground pins and 2 signal pins. The input and output are bi-directional and are not marked. The finish of these cases is fused tin plate over copper; the sides may be hand-soldered to the boards for additional grounding.
The re-designed SMT cases in TTE’s product line are all brass, providing shielding on all six sides. These too are fused tin plate and may be hand-soldered on the case sides for additional grounding. If at all possible, it is always better to hand-solder filters to the board, whether they are PCB or SMT.