DC795A Analog Devices

DC795A DEMO BOARD QUICK START GUIDE Description: The DC795A demo circuit board is intended to demonstrate the capabilities of the LT5527 high- signal-level downconverting mixer IC for cable and wireless infrastructure applications. The LT5527 (Figure 1) is a broadband high signal level active mixer optimized for high linearity downconverter receiver/transmitter applications for cable and wireless infrastructure. The IC includes a high-speed differential LO buffer amplifier driving a double-balanced mixer. The LO buffer is internally 50ohm-matched for wideband, single-ended operation with no external components. The LT5527 ICs RF input port incorporates an integrated transformer and is internally matched to 50ohms over the 1.7GHz to 2.7GHz frequency range. The RF input match can be shifted down to 400MHz, or up to 3.7GHz, with a single shunt capacitor or inductor, respectively. The high level of integration minimizes the total solution cost, board space and system-level variation. The LT5527 delivers high performance and small size without excessive power consumption. The DC795A demo board allows evaluation of the LT5527 downconverting mixer IC for various receiver and transmitter applications. Its RF input is optimized for 1.7GHz to 2.7GHz frequency range. The IF output frequency range is centered at 240MHz. The LO is internally matched for range of frequencies from 1200MHz to 4000MHz. 1515 LOLO Exposed Pad 1717 REGULATO Limiting 1212 Amplifiers GNDGND 1111 ++ IFIF -- 33 IFIF 1010 RFRF DoubleDouble--BalanBalancedced MixerMixer GNDGND 99 BIAS BIA ENEN VV VV CC2CC2 CC1CC1 5 66 77 5 Figure 1. LT5527 IC Block Diagram LT5527 Downconverting Mixer Single-Tone Measurements. 1. Connect all test equipment as shown in Figure 2. 2. Set the Power Supply voltage to 5V, and set the current limit to 100mA. 3. Connect TP1 (EN) to the 5V power supply the mixer is enabled (on). 4. Set the Signal Generator 2 to provide a 1900MHz, -10 dBm CW signal to the demo board RFin port. 5. Set the Signal Generator 1 to provide a -3dBm CW signal, at the desired LO frequency (HIGH side LO=2140MHz, or LOW side LO=1660MHz) to the demo board LOin port 6. Set the Spectrum Analyzer center frequency to the IF output frequency (240MHz). (e.g., 500MHz). Perform mixer conversion gain, and 1dB compression measurements. 7. Set the Spectrum Analyzer center frequency to the LO frequency. Perform mixer LO to IF leakage measurement. SIGNAL GENERATOR 1 SIGNAL GENERATOR 2 SPECTRUM ANALYZER POWER SUPPLY Figure 2. Test Set-Up for Mixer Single-Tone Measurements.