DC2076A-A Analog Devices

DEMO MANUAL DC2076A-A LTC6430-20 50MHz TO 350MHz Differential ADC Driver, IF/RF Amplifier Description Demonstration circuit 2076A-A features the LTC 6430-20 has 100 differential input and output impedances, so the differential ADC Driver/IF Amplifier. The LTC6430-20 has demo circuit uses 2:1 balun transformers to convert the a power gain of 20.8dB and is part of the LTC6430-YY differential I/O impedances to 50 single-ended imped- amplifier series. ance. Single ended SMA I/O connectors allows simple evaluation with most RF test equipment. The DC2076A-A Demo Board supports the LTC6430-YY amplifier family. The DC2076A-A demo board is optimized Design files for this circuit board are available at for the frequency range from 50MHz to 350MHz and utilizes DEMO MANUAL DC2076A-A Q K D Demo Circuit 2076A-A can be set up to evaluate the per- 4. Change the spectrum analyzers center frequency and formance of the LTC6430-20. Refer to Figure 2 for proper observe the two IM3 tones at 1MHz below and above equipment connections and follow the procedure below: the input frequencies. The frequencies of IM3 LOW and IM3 HIGH are 239MHz and 242MHz, respectively. The Two-Tone Measurement: measurement levels should be approximately 96dBc Connect all test equipment as suggested in Figure 2. +50 dBm is typical OIP3 performance for the DC2076A-A demo board at 240MHz. 1. The power labels of VCC 4.75V-5.25V and GND di- rectly correspond to the power supply. Typical current The OIP3 calculation is: consumption of the LTC6430-20 is about 165 mA. IMD3 2. Apply two independent signals f1 and f2 from signal OIP3=P + OUT 2 generator 1 and signal generator 2 at 240MHz and 241MHz, while setting the amplitude to 17dBm/tone Where: at the demo board input (J1). P is the lower output signal power of the fundamental OUT 3. Monitor the output tone level on the spectrum analyzer. products. Adjust the signal generator levels such that the output IMD3 = P P P is the higher Third-Order OUT IM3 IM3 power measures +2dBm/tone at the amplifier output intermodulation product. J2, after correcting for external cable losses and at- tenuations. Single-Tone Measurement: 5. Continue with step 4 above, turn off one signal source to measure gain and harmonic distortions. dc2076aaf 2 ure proce start uic