DC2032A Analog Devices

DEMO MANUAL DC2032A LTC6430-15 50MHz to 1000MHz 75 Input/Output CATV Amplifier Description Demonstration circuit 2032A is a 75 input and 75 out- amplifier for the CATV applications with 75 input and put push-pull CATV amplifier featuring the LTC 6430-15. output impedance. The LTC6430-15 has a power gain of 15.2dB and is part Design files for this circuit board are available at of the LTC643X-YY amplifier series. DEMO MANUAL DC2032A Quick s p D Demo circuit 2032A can be set up to evaluate the perfor- 2. Apply to J1 two independent signals f1 and f2 from SG1 mance of the LTC6430-15. Refer to Figures 2 and 3 for and SG2 at 400MHz and 401MHz respectively. proper equipment connections and follow this procedure: 3. Monitor the output tone level on the spectrum analyzer. Adjust signal generator levels such that output power Single-Tone Measurement: measures 1dBm/tone at the amplifier output J2, after Connect all test equipment as suggested in Figure 2. correcting for external cable losses, minimum loss matching pads and attenuations. 1. The power labels of 5V and GND directly correspond to the power supply. Typical current consumption of the 4. Change the spectrum analyzers center frequency and LTC6430-15 is about 160mA. observe the two IM3 tones at 1MHz below and above the input frequencies. The frequencies of IM3 and LOW 2. Apply an input signal to J1. A low distortion, low noise IM3 are 399MHz and 402MHz, respectively. The HIGH signal source with an external high order low pass filter measurement levels should be approximately 90dBc will yield the best performance. The input CW signal is 46dBm is a typical performance of OIP3 at 400MHz. For 10dBm. this setup, the Rohde and Schwarz FSEM30 spectrum 3. Observe the output via J2. The measured power at the analyzer was used. This SA has a typical 20dBm third- J2 connector should be about 4dBm. order intercept point (TOI). So, the SA input attenuation is set to 20dB with an external 14dB attenuation pad Two-Tone Measurement: (matches DUT gain), resulting in an attenuation total Connect all test equipment as suggested in Figure 3. of 34dB. The system as described can measure OIP3 up to 50dBm. 1. The power labels of 5V and GND directly correspond to the power supply. Typical current consumption of the LTC6430-15 is about 160mA. DC POWER SUPPLY + GND V V = 4.75V TO 5.25V CC (HP8644A) COAXIAL CABLE SIGNAL GENERATOR 5.7dB 5.7dB MINIMUM LOSS MINIMUM LOSS MATCHING PAD MATCHING PAD SPECTRUM 75 50 ANALYZER 50 75 LOW PASS FILTER (OPTIONAL) MINI-CIRCUITS ROHDE AND MINI-CIRCUITS BMP-5075R SCHWARZ BMP-5075R OR FSEM30 3dB ATTENUATION PAD OR EQUIVALENT (OPTIONAL) DC2032a F02 EQUIVALENT Figure 2. Proper Equipment Setup for Gain and Single-Tone Measurement dc2032af 2 ure roce tart