QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 1314A RF POWER DETECTOR LT5581 DESCRIPTION Demonstration Circuit 1314A is a Mean-Squared The 1314A Demo Circuit is optimized for wide frequency range of 10MHz to 2.2GHz. However, input Power Detector featuring the LT 5581 IC. match can be optimized up to 6GHz with simple The LT5581 is a wide dynamic range Mean Squared external matching. RF Power Detector, operational from 10MHz to 6GHz. Design files for this demo board are available. Call The input dynamic range at 6GHz, with 1dB the LTC factory. nonlinearity, is 40dB (from 34dBm to +6dBm, single-ended 50W input). The detector output voltage LTC is a trademark of Linear Technology Corporation slope is normally 31mV/dB, and the typical output variation over temperature is 0.5dB at 880MHz. Typical Performance Summary (V = 3.3V, ENBL = 3.3V, T = 25C, unless otherwise noted. Test circuit shown in Figure 1.) CC A PARAMETER CONDITION VALUE Supply Voltage 2.7V to 5.25V Supply Current 1.4mA Shutdown Current ENBL = Low 0.2A Low, Chip Disabled 0.3V max ENBL Voltage HIGH, Chip Enabled 2V min V = 0V 0A ENBL ENBL Input Current V = 5V 20A ENBL Output Start Voltage No Input Signal Present 0.2V Rise Time 0.2V to 1.6V, 10% to 90%, C1 = 22nF, F = 2140 MHz 1s RF Fall Time 1.6V to 0.2V, 90% to 10%, C1 = 22nF, F = 2140 MHz 8s RF Input Frequency Range Optimized for DC1314A demo board 10MHz to 6GHz f = 450MHz Linear Dynamic Range 1 dB linearity error 40 dB Slope 31mV/dB Logarithmic Intercept -42dBm Output Variation vs Temperature P = -34 to +6dBm 1 dB IN Deviation from CW Response 12 dB peak-to-average ratio (4 carrier WCDMA) 0.5 dB f = 5800MHz Linear Dynamic Range 1 dB linearity error 31dB Slope 31mV/dB Logarithmic Intercept -33dBm Output Variation vs Temperature P = -25 to +6dBm 1 dB IN Deviation from CW Response WiMAX OFDM Burst P = -25 to +6dBm 0.2dB IN 1 QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 1314A RF POWER DETECTOR QUICK START PROCEDURE Demonstration Circuit 1314A is easy to set up to NOTES: evaluate the performance of the LT5581. Refer to 1. The voltage on the EN test point must never Figure 1 for measurement equipment setup and follow exceed V + 0.3V. CC the procedure below: 2. For digitally modulated signals, an Connect voltmeters negative (-) lead to demo oscilloscope can be used to observe the AC board GND test point (E4). components of the output. Connect voltmeters positive (+) lead to the demo 3. Pins 4, 5 and 6 are internally connected to board OUTPUT test point (J2). ground. In the customer designs, the users Connect DC power supplys negative (-) output to have the choice to leave them as no connect demo board GND test point (E3 and E4). as in the demo board, or connect them to ground. Connect DC power supplys positive (+) output (2.7V to 5.25V) to demo board V test point (E1 Pin 8, C is the Optional Low Frequency Range CC SQ and E2). Extension Capacitor. Use this pin for frequencies below 250MHz. Connect 0.01uF from Pin 8 to Do not exceed 5.5V, the absolute maximum supply ground for 10MHz operation. voltage. Connect signal generators output to demo board INPUT port (SMA connector J1) via coaxial cable. Apply RF input signal and measure OUTPUT DC A 3dB attenuator may be inserted to improve input voltages. match. Do not exceed +15dBm, the absolute maximum RF Using a jumper cable, connect demo board V test input power. CC point (E1) to ENBL test point (E2). Now the detector is enabled (on) and is ready for measurement. 2