DC1528A - Demo Manual

DEMO CIRCUIT 1528A
LTC5582
QUICK START
GUIDE
LTC5582
40 MHz to 10GHz RMS Power Detector
with 60dB Dynamic Range
DESCRIPTION
Demonstration circuit 1528A is a Mean-Squared Power
Detector featuring the LTC®5582 IC.
The LTC5582 is a wide dynamic range Mean Squared
RF Power Detector, operational from 40MHz to 6GHz.
The input dynamic range with ±1dB nonlinearity is
60dB depending on frequency(from –58dBm to
+2dBm, single-ended 50Ω input). The detector output
voltage slope is normally 30mV/dB, and the typical
output variation over temperature is ±0.5dB at
2140MHz.
The DC1528A Demo Circuit is optimized for wide frequency range of 40MHz to 5.5GHz. However, input
match can be optimized above 6GHz with simple external matching. Operating above 6GHz is possible
with reduced performance. Contact applications for
more information.
Design files for this demo board are available. Call
the LTC factory.
Typical Performance Summary (VCC = 3.3V, EN = 3.3V, TA = 25°C, unless otherwise noted. Test circuit shown in Figure 1.)
PARAMETER
CONDITION
VALUE
Supply Voltage
3.1V to 3.5V
Supply Current
41.6mA
Shutdown Current
EN = Low
0.1µA
EN Voltage
Low, Chip Disabled
HIGH, Chip Enabled
0.4V max
1V min
EN Input Current
VEN = 0V
VEN = 3.3V
0µA
125µA
Output DC Voltage
No Input Signal Present
0.69V
Rise Time
0.8V to 2.4V, C3 = 8nF, FRF = 100 MHz
90nS
Fall Time
2.4V to 0.8V, C3 = 8nF, FRF = 100 MHz
5uS
Input Frequency Range
Operation over wider frequency range with reduced performance
40MHz to 10GHz
RF Input Power Range
CW; Single-Ended, 50Ω
-56dB to 1dB
Linear Dynamic Range
±1 dB linearity error
57 dB
f = 2140MHz
Slope
29.5mV/dB
Logarithmic Intercept
-85dBm
Output Variation vs Temperature
Normalized to Output at 25°, PIN = -47 to +0dBm
±0.5 dB
Deviation from CW Response
12 dB peak-to-average ratio (4 carrier WCDMA)
0.1 dB
RF Input Power Range
CW; Single-Ended, 50Ω
-46dB to 3dB
Linear Dynamic Range
±1 dB linearity error
49dB
f = 5800MHz
Slope
30.9mV/dB
1
LTC5582
Logarithmic Intercept
-74.7
Output Variation vs Temperature
Normalized to Output at 25°C, PIN = -46 to +2dBm
±1 dB
Deviation from CW Response
12dB Peak to Average Ratio(WiMAX OFDM)
0.2dB
QUICK START PROCEDURE
Demonstration circuit 1528A is easy to set up to evaluate the performance of the LTC5582. Care should be
taken during VCC power up, to ensure the supply voltage
transient does not exceed the absolute maximum.
Refer to Figure 2 for measurement equipment setup
and follow the procedure below:
1. Connect voltmeter’s negative (-) lead to demo
board GND test point (TP2).
2. Connect voltmeter’s positive (+) lead to the
demo board VOUT test point (TP6).
APPLICATION NOTES:
Absolute maximum ratings
Supply voltage…………………………….…3.8V
Enable voltage……………..…-0.3V to VCC +0.3V
Input signal Power(Single-ended, 50Ω)…..18dBm
Input signal Power(Differential, 50Ω)……..24dBm
Operating Temperature Range….…-40°C to 85°C
NOTE. For digitally modulated signals, an oscilloscope can be
used to observe the AC components of the output.
3. Connect DC power supply’s negative (-) output
to demo board GND test point (TP2).
4. Connect DC power supply’s positive (+) output
(3.15V to 3.5V) to demo board VCC test point
(TP1).
5. Connect signal generator’s output to demo
board RFIN port (SMA connector J1) via coaxial
cable. An optional 3dB attenuator may be inserted to improve input match, the power range
will be shifted higher by 3dB.
6. Using a jumper cable, connect demo board VCC
test point (TP1) to EN1 test point (TP3). Now
the detector is enabled (on) and is ready for
measurement.
7. Apply RF input signal at RFIN and measure the
output DC voltage.
2
Figure 1. Standard demo board RF input return loss
LTC5582
Figure2
Proper Equipment Measurement Set-Up
Temperature compensation
R5 and R6 are optional external resistors used for temperature compensation. Short them to ground will disable the compensation circuitry. R6 controls the 1st
order compensation, and R5 controls the 2nd order
temperature compensation. Standard demo board is
optimized for the best temperature performance at
2140MHz.
Frequency(MHz) R6,RT1(kΩ) R5,RT2(kΩ)
450
12
2
800
12.4
1.4
880
12
2
2000
0
2
2140
0
2
2600
0
1.6
2700
0
1.6
3000
0
1.6
3600
0
1.6
5800
0
3
7000
10
1.43
8000
10
1.43
Table 1. Suggested R5, R6 values for optimal temperature
performance
at
various
frequencies.
3
VCC
RFIN
GND
3.1V - 3.5V
J1
TP2
1
1
C5
0.4pF
1.5
R1
3.3V
1uF
C1
270pF
C4
C9
100pF
R4
68.1
1%
1nF
C8
1nF
C2
3.3V
5
4
3
2
1
GND
IN-
DEC
IN+
VCC
U1
OUT
RT2
RT1
EN
FLTR
LTC5582IDD
GND
4
11
TP1
6
7
8
9
10
3.3V
C10
OPT
C3
100nF
R5
2k
R6
0
R3 100k
1%
1
1
TP6
TP3
VOUT
EN
LTC5582
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