DC730A Analog Devices

QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 730 7 GHZ RF DETECTOR WITH OUTPUT COMPARATOR LTC5536ES6 DESCRIPTION Demonstration circuit 730 is used to evaluate the When the RF signal is applied, and depending on ref- LTC 5536ES6, RF power detector with integrated erence (Vm) settings, the output voltage will stay output comparator. The LTC5536ES6 has provisions LOW, or will go to HIGH level, typically Vcc-0.4V. for comparator reference settings. The RF input fre- The optional R1 and R3 termination resistors, C3 quency range is 600 MHz to 7000 MHz. Maximum output shunt capacitor and R2 pull-up resistor are not input power is 12 dBm. The output voltage at Vout is placed on the PCB. C5 shunt capacitor (0.22 uF) at either logic HIGH or logic LOW. Logic LOW can be Vm pin is used to reduce noise and voltage spikes 800mV while sinking 20mA. Logic HIGH is within from power supply. 0.4V of Vcc when sourcing 20mA. Vm (pin E3) Design files for this circuit board are available. Call should be set for desired reference voltage (about the LTC factory. 125mV or higher) for initial tests and measurements. LTC is a trademark of Linear Technology Corporation QUICK START PROCEDURE Demonstration circuit 730 is easily set up for evaluat- 3. Set Vm (pin E3) to desired reference voltage, ing the LTC5536ES6 RF power detector performance. 125mV or higher. Connect LEN (Latch Enable) pin Follow the procedures outlined below and connec- to ground. Increase RF input level to the point tions on the attached diagram for proper operation. when output voltage will go to HIGH level, typical- ly Vcc-0.4V. 1. Connect the power supply ground to E4 or E6. Connect the DC power supply (2.7V to 5.5V) to Optional measurements can be done by increasing E1. The typical current consumption is about Vm reference level. During the measurements, when 2.1mA. Connect J1 to the RF signal generator via Vout is HIGH, connect LEN to Vcc. Remove the RF in- coaxial cable with an SMA connector. It is com- put signal and the Vout will continue to stay HIGH. mon practice to include a 2dB or 3dB pad to mi- NOTE: For timing measurements at Vm pin C5 capa- nimize reflections back into the signal generator. citor (0.22 uF) should be removed. 2. Apply an RF input signal and measure the Vout DC voltage at E2. 1 QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 730 7 GHZ RF DETECTOR WITH OUTPUT COMPARATOR Figure 1. LTC5536 Measurements Setup 2