DC1599A - Demo Manual

DEMO CIRCUIT 1599A
LTC5583
QUICK START
GUIDE
LTC5583
DUAL 6GHz RMS POWER DETECTOR
DESCRIPTION
Demonstration circuit 1599A is a Mean-Squared Power
Detector featuring the LTC®5583 IC. LTC5583 is a
dual-channel RMS power detector, capable of
measuring two AC signals. It provides 40dB of
channel to channel isolation with no frequency
separation at 2140MHz that is suited for measuring
VSWR.
The LTC5583 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 50 input). The detector output
voltage slope is normally 30mV/dB, and the typical
output variation over temperature is ±0.5dB at
880MHz.
The DC1599A Demo Circuit is ideal for frequency
operation below 3.0GHz. It has the single ended input
drive to LTC5583. The input A to output B (or input B
to output A) isolation is 33dB at 2.7GHz, and degrades
as input frequency increases. As a result, operating
above 3GHz may require differential input matching for
improved isolation. Temperature performance is
optimized for 2140MHz. Contact LTC applications for
more information.
LTC is a trademark of Linear Technology Corporation
Design files for this circuit board are available. Call the
LTC factory.
Typical Performance Summary (VCC = 3.3V, EN = HIGH, TA = 25°C, unless otherwise noted. Test circuit shown in Figure 1.)
PARAMETER
CONDITION
Supply Voltage
Supply Current
VALUE
3.1V to 3.5V
Envelope detector off
80.5mA
Envelope detector on
90.1mA
Shutdown Current
EN = Lo
0.1μA
EN Voltage
Low, Chip Disabled
HIGH, Chip Enabled
0.3V max
2V min
EN Input Current
VEN = 0V
VEN = 3.3V
0μA
100μA
Output Start Voltage
No Input Signal Present
0.45V
Rise Time
0.5V to 2.2V, 10% to 90%, CFLTRA=CFLTRB = 8.2nF, FRF = 100 MHz
140nS
Fall Time
2.2V to 0.5V, 90% to 10%, CFLTRA=CFLTRB =8.2nF, FRF = 100 MHz
3.5uS
Input Frequency Range
Operation over wider frequency range with reduced performance
40MHz to 6GHz
Linear Dynamic Range
±1 dB linearity error
63 dB
RF Input Power Range
CW, 50Ω, ±1dB Linearity Error
-59 to 4 dBm
f =450MHz
Slope
29.6mV/dB
Logarithmic Intercept
-78.5dBm
1
LTC5583
Deviation from CW Response
12 dB peak-to-average ratio (4 carrier WCDMA)
0.4
INA to VOB isolation
PINB = -45dBm, VOB= VOB pINB ±1 dB, Frequency Separation=0Hz
50dB
INB to VOA isolation
PINA = -45dBm, VOA= VOA pINA ±1 dB, Frequency Separation=0Hz
50dB
Linear Dynamic Range
±1 dB linearity error
60 dB
RF Input Power Range
CW, 50Ω, ±1dB Linearity Error
-58 to 2 dBm
f =2140MHz
Slope
29.6mV/dB
Logarithmic Intercept
-77.4dBm
Deviation from CW Response
12 dB peak-to-average ratio (4 carrier WCDMA)
0.3
INA to VOB isolation
PINB = -45dBm, VOB= VOB pINB ±1 dB, Frequency Separation=0Hz
40dB
INB to VOA isolation
PINA = -45dBm, VOA= VOA pINA ±1 dB, Frequency Separation=0Hz
40dB
Linear Dynamic Range
±1 dB linearity error
59 dB
RF Input Power Range
CW, 50Ω, ±1dB Linearity Error
-56 to 3 dBm
f =2700MHz
Slope
30mV/dB
Logarithmic Intercept
-74.9dBm
Deviation from CW Response
12 dB peak-to-average ratio (WiMAX OFDM)
0.6dB
INA to VOB isolation
PINB = -45dBm, VOB= VOB pINB ±1 dB, Frequency Separation=0Hz
33dB
INB to VOA isolation
PINA = -45dBm, VOA= VOA pINA ±1 dB, Frequency Separation=0Hz
33dB
Table 1. Jumper Description
JUMPER FUNCTION
JP1
Chip Enable. EN for High, DIS for Lo
JP2
VCCN. Power supply to the envelop detector for both channels. HI=on, LO=off
JP3
INV. Swap control for the polarity of VODF. HI=(VOB-VOA)+VOS, LO=(VOA-VOB)+VOS
RANGE/SETTING (DEFAULT)
EN
LO
LO
QUICK START PROCEDURE
Demonstration circuit 1599A is easy to set up to
evaluate the performance of the LTC5583. Refer to
Figure 1 for measurement equipment setup and follow
the procedure below:
1. Connect voltmeter’s negative (-) lead to demo
board GND test point(TP8 or TP9).
2. Connect voltmeter’s positive (+) lead to the demo
board VOA(TP2) and VOB(TP5) to measure
channel A and channel B output respectively.
3. Connect DC power supply’s negative (-) output to
demo board GND(TP8 or TP9).
2
4. Connect DC power supply’s positive (+) output
(3.1V to 3.5V) to demo board VCC test point(TP7).
Do not exceed 3.8V, the absolute maximum
supply voltage.
Set VCCN jumper to LO, to turn off the envelope
detector if not needed.
Set the Swap jumper to LO for:
VODF= (VOA-VOB)+VOS.
Set swap to HI for:
VODF=(VOB-VOA)+VOS
5. Connect signal generator’s output to demo board
INPUT port (SMA connector J1 for channel A
input, or J2 for channel B input) via coaxial cable.
LTC5583
6. A 3dB attenuator may be inserted for broadband
input match, the detected power range is shifted
higher by 3dB.
7. Set the JP1 to EN to enable the IC. Now the detector is enabled (on) and is ready for measurement.
8. Apply RF input signal and measure OUTPUT DC
voltages at VOA and VOB.
Do not exceed +18dBm, the absolute maximum RF input
power.
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. Suggest to set VCCN LO when envelope detector is not used. This will result in lower power consumption.
4. Temperature compensation values for RT1 and RT2 may be different at different frequencies. See table 1 for
additional information.
Figure 1. Proper Test Equipment Setup
3
LTC5583
Frequency (MHz) RP1 (kΩ) RP2 RT1 (kΩ) (kΩ) RT2 (kΩ) 450 Open 0 11.5 1.13
880 Open 0 11.5 1.13
900 Open 0 11 0.953
1800 Open 0 12.1 1.5
2140 Open 0 9.76 1.1
2300 Open 0 10.5 1.43
2500 Open 0 10.5 1.43
2700 Open 0 8.87 1.21
Table 2. Suggested RT1 and RT2 values for the
optimum temperature performance at various RF
input frequencies.
4
TP7
GND
GND
TP9
TP8
3.1V - 3.5V
VCC
INB
J2
J1
1
1
0603
R3
1
0.3pF
C29
0.3pF
C24
VCC
1nF
C11
1uF
C27
L2 0
DIS
1
EN
C28
10nF
JP1
VCC
L1 0
3
INA
2
C22 1nF
1nF
C17
VCC
C15
1nF
1nF
C12
C4 1nF
VCC
C21 1nF
C18 20pF
C9 20pF
C6 1nF
75
R10
DECB
VCCB
EN
VCCR
VCCA
DECA
C26 20pF
C25 1nF
6
5
4
3
2
1
75
R2
C3 20pF
INPA
24
INPB
7
R8
OPT
R11
0
RP1
23
INNB
8
INNA
22
RP2
9
FLTRA
21
FLTRB
10
100nF
C2
13
14
15
16
17
18
1nF
C23
100nF
C30 100pF
VCC
1nF
C20
R4
OPT
LO
1
1nF
R9 0
R7 OPT
1%
R6 1.10k
1%
R5 9.76k
R13 OPT
1. ALL CAPACITORS AND RESISTORS ARE 0402.
NOTE: UNLESS OTHERWISE SPECIFIED,
HI
INV
VCC
C16
1nF
C32 OPT
1nF
1nF
1
1nF
C19
1
C14
C13
1
1
1nF
C8
C5 OPT
LO
C10
R12 OPT
1
1
JP3
2
C7 1
R1 0
HI
VCCN
VCC
JP2
2
U1
LTC5583IUF
VOB
RT2
VOS
VODF
RT1
VOA
C31 100pF
ENVA
20
ENVB
11
VCCN
19
INV
12
3
C1 1nF
3
VCC
ENVA
ENVB
VOB
VOS
VODF
VOA
TP6
TP5
TP4
TP3
TP2
TP1
LTC5583
5
LTC5583
Bill of Materials:
6
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