SBAS988 November 2023 ADC34RF55
PRODUCTION DATA
Appropriate band limiting filters must be used to reject unwanted frequencies in the receive signal path.
A 1:2 (for 100 Ω effective termination impedance) or a 1:1 (for 50 Ω effective termination impedance) balun transformer is needed to convert the single ended RF input to differential for input to the ADC. The balun outputs must be AC coupled with 100 pF capacitors. The balun must have good amplitude (< 2 dB) and phase balance (less than 2 deg) within the frequency range of interest. A back-to-back balun configuration often times gives better SFDR performance. Table 7-1 lists a number of recommended baluns for different impedance ratios and frequency ranges.
The S-parameters of the ADC input is used to design the front end matching network.
PART NUMBER | MANURACTURER(1) | IMPEDANCE RATIO | AMPLITUDE BALANCE (dB) | PHASE BALANCE (°) | FREQUENCY RANGE |
---|---|---|---|---|---|
BAL-0009SMG | Marki Microwave | 1:2 | 0.6 | 5 | 0.5 MHz to 9 GHz |
TCM2-43X+ | Minicircuits | 1:2 | 0.5 | 7 | 10 MHz to 4 GHz |
TCM2-33WX+ | Minicircuits | 1:2 | 0.7 | 4 | 10 MHz to 3 GHz |
TC1-1-13M+ | Minicircuits | 1:1 | 0.5 | 2-3 | 10 MHz to 3 GHz |