DC1314A - Demo Manual

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