DC730A - Demo Manual

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