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LTC5582 40MHz to 10GHz RMS Power Detector with 57dB Dynamic Range FeaTures
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DescripTion
The LTC(R)5582 is a 40MHz to 10GHz RMS responding power detector. It is capable of accurate power measurement of an AC signal with wide dynamic range, from -60dBm to 2dBm depending on frequency. The power of the AC signal in an equivalent decibel-scaled value is precisely converted into DC voltage on a linear scale, independent of the crest factor of the input signal waveforms. The LTC5582 is suitable for precision RF power measurement and level control for a wide variety of RF standards, including LTE, WiMAX, W-CDMA, CDMA2000, TD-SCDMA, and EDGE. The DC output is buffered with a low output impedance amplifier capable of driving a high capacitance load. Consult factory for more information. The part is packaged in a 10-lead 3mm x 3mm DFN. It is pin-to-pin compatible with the LT5570.
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. Protected by U.S. Patents including 7262661, 7317357, 7622981.
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Frequency Range: 40MHz to 10GHz Linear Dynamic Range: Up to 57dB Accurate RMS Power Measurement of High Crest Factor Modulated Waveforms Exceptional Accuracy Over Temperature: 0.5dB (Typ) Low Linearity Error within Dynamic Range Single-Ended or Differential RF Inputs Fast Response Time: 90ns Rise Time Low Supply Current: 41.6mA at 3.3V (Typ) Small 3mm x 3mm DFN10
applicaTions
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RMS Power Measurement PA Power Control Receive and Transmit Gain Control LTE, WiMAX, W-CDMA, CDMA2K, TD-SCDMA, EDGE Basestations Point-to-Point Microwave Links RF Instrumentation
Typical applicaTion
40MHz to 6GHz RMS Power Detector
3.3V 1F 1nF VCC IN+ 270pF 68 DEC IN- 1nF GND LTC5582 100nF LINEARITY ERROR (dB) FLTR EN RT1 RT2 OUT
5582 TA01a
Linearity Error vs RF Input Power 2140MHz Modulated Waveforms
3 2 1 0 -1 -2 -3 -65 4-CARRIER WCDMA CW 3-CARRIER CDMA2K -55 -45 -35 -25 -15 RF INPUT POWER (dBm) -5 5 TA = 25C
ENABLE
VOUT
5582 TAO1b
5582f
LTC5582 absoluTe MaxiMuM raTings
(Note 1)
pin conFiguraTion
TOP VIEW VCC IN+ DEC IN- GND 1 2 3 4 5 11 GND 10 FLTR 9 EN 8 RT1 7 RT2 6 OUT
Supply Voltage .........................................................3.8V Enable Voltage ................................ -0.3V to VCC + 0.3V Input Signal Power (Single-Ended, 50) .............18dBm Input Signal Power (Differential, 50) .................24dBm TJMAX .................................................................... 150C Operating Temperature Range .................-40C to 85C Storage Temperature Range .................. -65C to 125C
DD PACKAGE 10-LEAD (3mm 3mm) PLASTIC DFN TJMAX = 150C, JA = 43C/W EXPOSED PAD (PIN 11) IS GND, MUST BE SOLDERED TO PCB
orDer inForMaTion
LEAD FREE FINISH LTC5582IDD#PBF TAPE AND REEL LTC5582IDD#TRPBF PART MARKING LFGZ PACKAGE DESCRIPTION 10-Lead 3mm x 3mm Plastic DFN TEMPERATURE RANGE -40C to 85C Consult LTC Marketing for parts specified with wider operating temperature ranges. Consult LTC Marketing for information on non-standard lead based finish parts. For more information on lead free part marking, go to: http://www.linear.com/leadfree/ For more information on tape and reel specifications, go to: http://www.linear.com/tapeandreel/
The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25C. VCC = 3.3V, EN = 3.3V. Test circuit is shown in Figure 1. (Notes 2 and 3).
PARAMETER AC Input Input Frequency Range (Note 4) Input Impedance fRF = 450MHz RF Input Power Range Linear Dynamic Range Output Slope Logarithmic Intercept Output Variation vs Temperature Deviation from CW Response 2nd Order Harmonic Distortion 3rd Order Harmonic Distortion Normalized to Output at 25C, Pin = -50dBm to 0dBm 11dB Peak to Average Ratio (3-Carrier CDMA2K) 12dB Peak to Average Ratio (4-Carrier WCDMA) At RF Input; CW Input; PIN = 0dBm At RF Input; CW Input; PIN = 0dBm
l
elecTrical characTerisTics
CONDITIONS
MIN
TYP 40 to 10000
MAX
UNITS MHz //pF dBm dB mV/dB dBm dB dB dB dBc dBc
Differential CW; Single-Ended, 50 1dB Linearity Error
400//0.5 -57 to 2 59 29.5 -86.2 0.5 0.1 0.1 67 62
5582f
LTC5582 elecTrical characTerisTics
PARAMETER fRF = 880MHz RF Input Power Range Linear Dynamic Range Output Slope Logarithmic Intercept Output Variation vs Temperature Deviation from CW Response 2nd Order Harmonic Distortion 3rd Order Harmonic Distortion fRF = 2140MHz RF Input Power Range Linear Dynamic Range (Note 5) Output Slope Logarithmic Intercept Output Variation vs Temperature Deviation from CW Response fRF = 2700MHz RF Input Power Range Linear Dynamic Range Output Slope Logarithmic Intercept Output Variation vs Temperature Deviation from CW Response fRF = 3800MHz RF Input Power Range Linear Dynamic Range Output Slope Logarithmic Intercept Output Variation vs Temperature Deviation from CW Response fRF = 5800MHz RF Input Power Range Linear Dynamic Range Output Slope Logarithmic Intercept Output Variation vs Temperature Deviation from CW Response Normalized to Output at 25C, Pin = -46dBm to 2dBm 12dB Peak to Average Ratio (WiMAX OFDM)
l
The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25C. VCC = 3.3V, EN = 3.3V. Test circuit is shown in Figure 1. (Notes 2 and 3).
CONDITIONS CW; Single-Ended, 50 1dB Linearity Error MIN TYP -57 to 2 59 29.3 -86.4 Normalized to Output at 25C, Pin = -50dBm to 0dBm 11dB Peak to Average Ratio (3-Carrier CDMA2K) 12dB Peak to Average Ratio (4-Carrier WCDMA) At RF Input; CW Input; PIN = 0dBm At RF Input; CW Input; PIN = 0dBm CW; Single-Ended, 50 1dB Linearity Error 50 26 -98 Normalized to Output at 25C, Pin = -47dBm to 0dBm 11 dB Peak to Average Ratio (3-Carrier CDMA2K) 12dB Peak to Average Ratio (4-Carrier WCDMA) CW; Single-Ended, 50 1dB Linearity Error
l l
MAX
UNITS dBm dB mV/dB dBm dB dB dB dBc dBc dBm dB
0.5 0.1 0.1 69 59 -56 to 1 57 29.5 -85 0.5 0.1 0.1 -55 to 1 56 29.8 -83.8 33 -72
mV/dB dBm dB dB dB dBm dB mV/dB dBm dB dB dBm dB mV/dB dBm dB dB dBm dB mV/dB dBm dB dB
Normalized to Output at 25C, Pin = -47dBm to 0dBm 12dB Peak to Average Ratio (WiMAX OFDM) CW; Single-Ended, 50 1dB Linearity Error
l
0.5 0.2 -51 to 2 53 30.3 -81
Normalized to Output at 25C, Pin = -51dBm to 2dBm 12dB Peak to Average Ratio (WiMAX OFDM) CW; Single-Ended, 50 1dB Linearity Error
l
1 0.2 -46 to 3 49 30.9 -74.7 1 0.2
5582f
LTC5582
The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25C. VCC = 3.3V, EN = 3.3V. Test circuit is shown in Figure 1. (Notes 2 and 3).
PARAMETER Output Interface Output DC Voltage Output Impedance Output Current Rise Time, 10% to 90% Fall Time, 90% to 10% Enable (EN) Low = Off, High = On EN Input High Voltage (On) EN Input Low Voltage (Off) Enable Pin Input Current Turn ON Time Turn OFF Time Power Supply Supply Voltage Supply Current Shutdown Current EN = 0V, VCC = 3.5V Note 1: Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. Exposure to any Absolute Maximum Rating condition for extended periods may affect device reliability and lifetime. Note 2: The LTC5582 is guaranteed functional over the temperature range -40C to 85C. Note 3: Logarithmic Intercept is an extrapolated input power level from the best fitted log-linear straight line, where the output voltage is 0V. 3.1 3.3 41.6 0.1 3.5 52 10 V mA A EN = 3.3V VOUT within 10% of Final Value, C3 = 8nF VOUT < 0.8V, C3 = 8nF
l l
elecTrical characTerisTics
CONDITIONS No RF Signal Present Maximum
MIN
TYP 0.69 100 5 90 5
MAX
UNITS V mA nS S V
0.8V to 2.4V, C3 = 8nF fRF = 100MHz , 2.4V to 0.8V, C3 = 8nF fRF = 100MHz , 1
0.4 125 2.8 40 200
V A s s
Note 4: Operation over a wider frequency range is possible with reduced performance. Consult the factory for information and assistance. Note 5: The linearity error is calculated by the difference between the incremental slope of the output and the average output slope from -50dBm to -5dBm. The dynamic range is defined as the range over which the linearity error is within 1dB.
noted. Test circuits shown in Figure 1.
Typical perForMance characTerisTics
Output Voltage vs RF Input Power
2.8 2.4 2.0 1.6 1.2 0.8 0.4 -65 450MHz 880MHz 2140MHz 2700MHz 3800MHz 5800MHz -55 -45 -35 -25 -15 RF INPUT POWER (dBm) -5 5
5582 G01
VCC = 3.3V, EN = 3.3V, TA = 25C unless otherwise
Linearity Error vs RF Input Power
3 2 1 0 -1 -2 -3 -65 450MHz 880MHz 2140MHz 2700MHz 3800MHz 5800MHz -55 -45 -35 -25 -15 RF INPUT POWER (dBm) -5 5
5582 G02
Supply Current vs Supply Voltage
60 55 SUPPLY CURRENT (mA) 50 45 40 35 30 25 20 3.0 3.1 3.3 3.2 3.4 SUPPLY VOLTAGE (V) 3.5 3.6
5582 G27
TA = 25C
TA = 25C
TA = 85C TA = 25C TA = -40C
LINEARITY ERROR (dB)
OUTPUT VOLTAGE (V)
5582f
LTC5582
noted. Test circuits shown in Figure 1.
Typical perForMance characTerisTics
Output Voltage, Linearity Error vs RF Input Power, 450MHz
2.8 2.4 Rt1 = 12k Rt2 = 2k 3 2 LINEARITY ERROR (dB) VOUT VARIATION (dB) 1 0 -1 TA = 85C TA = 25C TA = -40C -55 -45 -35 -25 -15 RF INPUT POWER (dBm) -5 5
5582 G03
VCC = 3.3V, EN = 3.3V, TA = 25C unless otherwise Linear Error vs RF Input Power, Modulated Waveforms, 450MHz
3 2 LINEARITY ERROR (dB) 1 0 -1 -2 -3 -65 4-CARRIER WCDMA CW 3-CARRIER CDMA2K -55 -45 -35 -25 -15 RF INPUT POWER (dBm) -5 5
5582 G05
Output Voltage Temperature Variation from 25C, 450MHz
3 2 1 0 TA = -40C -1 -2 -3 -65 Rt1 = 12k Rt2 = 2k
TA = 25C
OUTPUT VOLTAGE (V)
2.0 1.6 1.2 0.8 0.4 -65
TA = 85C
-2 -3
-55
-45 -35 -25 -15 RF INPUT POWER (dBm)
-5
5
5582 G04
Output Voltage, Linearity Error vs RF Input Power, 880MHz
2.8 2.4 OUTPUT VOLTAGE (V) 2.0 1.6 1.2 0.8 0.4 -65 TA = 85C TA = 25C TA = -40C -55 -45 -35 -25 -15 RF INPUT POWER (dBm) -5 5
5582 G06
Output Voltage Temperature Variation from 25C, 880MHz
3 2 LINEARITY ERROR (dB) VOUT VARIATION (dB) 1 0 -1 -2 -3 3 2 1 0 -1 -2 -3 -65 Rt1 = 12k Rt2 = 2k LINEARITY ERROR (dB) 3 2 1 0 -1 -2
Linear Error vs RF Input Power, Modulated Waveforms, 880MHz
TA = 25C
Rt1 = 12k Rt2 = 2k
TA = 85C TA = -40C
-55
-45 -35 -25 -15 RF INPUT POWER (dBm)
-5
5
5582 G07
-3 -65
4-CARRIER WCDMA CW 3-CARRIER CDMA2K -55 -45 -35 -25 -15 RF INPUT POWER (dBm) -5 5
5582 G08
Output Voltage, Linearity Error vs RF Input Power, 2140MHz
2.8 2.4 OUTPUT VOLTAGE (V) 2.0 1.6 1.2 0.8 0.4 -65 TA = 85C TA = 25C TA = -40C -55 -45 -35 -25 -15 RF INPUT POWER (dBm) -5 5
5582 G09
Output Voltage Temperature Variation from 25C, 2140MHz
3 2 LINEARITY ERROR (dB) 1 0 -1 -2 -3 VOUT VARIATION (dB) 3 2 1 0 -1 -2 -3 -65 Rt1 = 0 Rt2 = 2k LINEARITY ERROR (dB) 3 2 1 0 -1 -2
Linear Error vs RF Input Power, Modulated Waveforms, 2140MHz
TA = 25C
Rt1 = 0 Rt2 = 2k
TA = 85C TA = -40C
-55
-45 -35 -25 -15 RF INPUT POWER (dBm)
-5
5
5582 G10
-3 -65
4-CARRIER WCDMA CW 3-CARRIER CDMA2K -55 -45 -35 -25 -15 RF INPUT POWER (dBm) -5 5
5582 G11
5582f
LTC5582 Typical perForMance characTerisTics
noted. Test circuits shown in Figure 1. Output Voltage, Linearity Error vs RF Input Power, 2700MHz
2.8 2.4 OUTPUT VOLTAGE (V) 2.0 1.6 1.2 0.8 0.4 -65 TA = 85C TA = 25C TA = -40C -55 -45 -35 -25 -15 RF INPUT POWER (dBm) -5 5
5582 G12
VCC = 3.3V, EN = 3.3V, TA = 25C unless otherwise Linear Error vs RF Input Power, Modulated Waveforms, 2700MHz
3 2 LINEARITY ERROR (dB) 1 0 -1 -2 -3 -65 CW WiMAX TA = 25C
Output Voltage Temperature Variation from 25C, 2700MHz
3 2 LINEARITY ERROR (dB) VOUT VARIATION (dB) 1 0 -1 -2 -3 3 2 1 0 -1 -2 -3 -65 Rt1 = 0 Rt2 = 1.6k TA = 85C TA = -40C
Rt1 = 0 Rt2 = 1.6k
-55
-45 -35 -25 -15 RF INPUT POWER (dBm)
-5
5
5582 G13
-55
-45 -35 -25 -15 RF INPUT POWER (dBm)
-5
5
5582 G14
Output Voltage, Linearity Error vs RF Input Power, 3800MHz
2.8 2.4 OUTPUT VOLTAGE (V) 2.0 1.6 1.2 0.8 0.4 -65 TA = 85C TA = 25C TA = -40C -55 -45 -35 -25 -15 RF INPUT POWER (dBm) -5 5
5582 G15
Output Voltage Temperature Variation from 25C, 3800MHz
3 2 LINEARITY ERROR (dB) VOUT VARIATION (dB) 1 0 -1 -2 -3 3 2 1 0 -1 -2 -3 -65 Rt1 = 0 Rt2 = 1.6k TA = -40C TA = 85C LINEARITY ERROR (dB) 3 2 1 0 -1 -2
Linear Error vs RF Input Power, Modulated Waveforms, 3800MHz
TA = 25C
Rt1 = 0 Rt2 = 1.6k
CW WiMAX
-55
-45 -35 -25 -15 RF INPUT POWER (dBm)
-5
5
5582 G16
-3 -65
-55
-45 -35 -25 -15 RF INPUT POWER (dBm)
-5
5
5582 G17
Output Voltage, Linearity Error vs RF Input Power, 5800MHz
2.8 2.4 OUTPUT VOLTAGE (V) 2.0 1.6 1.2 0.8 0.4 -65 TA = 85C TA = 25C TA = -40C -55 -45 -35 -25 -15 RF INPUT POWER (dBm) -5 5
5582 G18
Output Voltage Temperature Variation from 25C, 5800MHz
3 2 LINEARITY ERROR (dB) 1 0 -1 -2 -3 VOUT VARIATION (dB) 3 2 1 0 -1 -2 -3 -65 Rt1 = 0 Rt2 = 3k LINEARITY ERROR (dB) 3 2 1 0 -1 -2
Linear Error vs RF Input Power, Modulated Waveforms, 5800MHz
TA = 25C
Rt1 = 0 Rt2 = 3k
TA = 85C TA = -40C
CW WiMAX
-55
-45 -35 -25 -15 RF INPUT POWER (dBm)
-5
5
5582 G19
-3 -65
-55
-45 -35 -25 -15 RF INPUT POWER (dBm)
-5
5
5582 G20
5582f
LTC5582
noted. Test circuits shown in Figure 1.
Typical perForMance characTerisTics
Output Voltage, Linearity Error vs RF Input Power, 8GHz
2.8 2.4 3 2 LINEARITY ERROR (dB) 1 0 -1 TA = 85C TA = 25C TA = -40C -35 -25 -5 -15 RF INPUT POWER (dBm) 5 10
5582 G30
VCC = 3.3V, EN = 3.3V, TA = 25C unless otherwise Output Voltage Linearity Error vs RF Input Power, 10GHz
2.8 2.4 OUTPUT VOLTAGE (V) 2.0 1.6 1.2 0.8 0.4 -45 TA = 85C TA = 25C TA = -40C -35 -25 -15 -5 RF INPUT POWER (dBm) 5 10
5582 G32
Output Voltage Temperature Variation from 25C, 8GHz
3 2 VOUT VARIATION (dB) 1 0 -1 -2 -3 -45
3 2 LINEARITY ERROR (dB) 1 0 -1 -2 -3
OUTPUT VOLTAGE (V)
2.0 1.6 1.2 0.8 0.4 -45
TA = 85C TA = -40C
-2 -3
-35
-25 -15 -5 RF INPUT POWER (dBm)
5 10
5582 G31
Output Voltage Temperature Variation from 25C, 10GHz
3 2 VOUT VARIATION (dB) SLOPE (mV/dB) 1 0 -1 -2 TA = 85C TA = -40C 31.0 30.5 30.0 29.5 29.0 28.5 28.0
Slope vs Frequency
TA = 85C TA = 25C TA = -40C INTERCEPT (dBm) -72 -75 -78 -81 -84 -87 -90
Logarithmic Intercept vs Frequency
TA = 85C TA = 25C TA = -40C
-45
-35
-25 -15 -5 RF INPUT POWER (dBm)
5 10
5582 G33
0
1
2 4 3 FREQUENCY (GHz)
5
6
5582 G21
0
1
2 4 3 FREQUENCY (GHz)
5
6
5582 G22
Slope Distribution vs Temperature, 2140MHz
35 PERCENTAGE DISTRIBUTION (%) 30 25 20 15 10 5 PERCENTAGE DISTRIBUTION (%) TA = 85C TA = 25C TA = -40C 25
Logarithmic Intercept Distribution vs Temperature, 2140MHz
TA = 85C TA = 25C TA = -40C OUTPUT VOLTAGE (V) 4.8 4.4 4.0 3.6 3.2 2.8 2.4 2.0 1.6 1.2 0.8 0.4
Output Transient Response, C3 = 8nF
RF PULSE ON fRF = 100MHz RF PULSE OFF RF PULSE OFF PIN = 0dBm PIN = -10dBm PIN = -20dBm PIN = -30dBm PIN = -40dBm PIN = -50dBm
20
15
10
5
0
27.9
28.5
29.1 29.7 SLOPE (mV/dB)
30.3
5582 G23
0
-90
-88 -86 -84 -82 -80 LOGRITHMIC INTERCEPT (dBm)
5582 G24
0
1
2
3
456 TIME (s)
7
8
9
10
5582 G25
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LTC5582 Typical perForMance characTerisTics
noted. Test circuits shown in Figure 1. Output Transient Response, C3 = 1F
4.8 4.4 4.0 OUTPUT VOLTAGE (V) 3.6 3.2 2.8 2.4 2.0 1.6 1.2 0.8 0.4 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 TIME (ms)
5582 G26
VCC = 3.3V, EN = 3.3V, TA = 25C unless otherwise RF Input Return Loss vs Frequency
0
Supply Current vs RF Input Power
60 55 SUPPLY CURRENT (mA) TA = 85C TA = 25C TA = -40C RETURN LOSS (dB) -45 -35 -25 -15 RF INPUT POWER (dBm) -5
RF PULSE ON
fRF = 100MHz RF PULSE OFF
50 45 40 35 30 25 20 -65 -55 5
5582 G28
-5
RF PULSE OFF
PIN = 0dBm PIN = -10dBm PIN = -20dBm PIN = -30dBm PIN = -40dBm PIN = -50dBm
-10
-15
-20
-25
0
1
3 2 4 FREQUENCY (GHz)
5
6
5582 G22
pin FuncTions
VCC (Pin 1): Power Supply Pin. Typical current consumption is 41.6mA at room temperature. This pin should be externally bypassed with 1nF and 1F chip capacitors. IN+, IN- (Pins 2, 4): Differential Input Signal Pins. Either one can be driven with a single-ended signal while the other is AC-coupled to ground. These pins can also be driven with a differential signal. The pins are internally biased to 1.585V and should be DC blocked externally. The differential impedance is typically 400. The impedance of each pin to the DEC pin is 200. DEC (Pin 3): Input Common Mode Decoupling Pin. This pin is internally biased to 1.585V and connected to an onchip 50pF capacitor to ground. The impedance between DEC and IN+ (or IN-) is 200. The pin can be connected to the center tap of an external balun when terminated differentially. The pin can be floating or connected to ground via an AC-decoupling capacitor when driven either in single-ended or differential input configuration. GND (Pin 5, Exposed Pad Pin 11): Circuit Ground Return for the Entire IC. This must be soldered to the printed circuit board ground plane. OUT (Pin 6): DC Output Pin. The output impedance is mainly determined by an internal 100 series resistance which provides protection if the output is shorted to ground. RT2 (Pin 7): Optional Control Pin for 2nd-Order Output Temperature Compensation. Connect this pin to ground to disable it. The output voltage will decrease with respect to the room temperature (25C) by connecting it to ground via an off-chip resistor when the ambient temperature is either higher or lower. RT1 (Pin 8): Optional Control Pin for 1st-Order Output Temperature Compensation. Connect this pin to ground to disable it. The output voltage will increase inversely proportional to ambient temperature. EN (Pin 9): Enable Pin. An applied voltage above 1V will activate the bias for the IC. For an applied voltage below 0.4V, the circuits will be shut down (disabled) with a reduction in power supply current. If the enable function is not required, then this pin can be connected to VCC. Typical enable pin input current is 100A for EN = 3.3V. Note that at no time should the Enable pin voltage be allowed to exceed VCC by more than 0.3V. FLTR (Pin 10): Connection for an External Filtering Capacitor C3. A minimum of 8nF capacitance is required for stable AC average power measurement. This capacitor should be connected to VCC.
5582f
LTC5582 TesT circuiTs
R1 1.5 C3 100nF C2 1nF C1 1F 3.3V 1 2 R4 68 C8 1nF NC C9 100pF 3 4 5 10 9 8 7 6 OUT R5 2k R6 0 R3 100k
C4 270pF J1 RF INPUT C5 0.4pF
VCC IN+ DEC IN- GND 11 LTC5582
FLTR EN RT1 RT2 OUT
5582 F01
EN
EXPOSED PAD
C10 OPTIONAL
REF DES C1 C2, C8 C3 C4 C5 C9 R1 R3 R4 R5 R6
VALUE 1uF 1nF 100nF 270pF 0.4pF 100pF 1.5 100K 68 2k 0
SIZE 0402 0402 0402 0402 0402 0402 0603 0402 0402 0402 0402
PART NUMBER MURATA GRM155R60J105KE19 MURATA GRM155R71H102KA01 TDK CID05X7R1C104K MURATA GRM155CIH271JA01 MURATA GJM1555C1HR40BB01 AVX 0402YC101KAT VISHAY CRCW06031R50JNEA VISHAY CRCW0402100KFKED VISHAY CRCW040268R1FKED VISHAY CRCW04022K00FKEA VISHAY CRCW0402020000Z0ED
Figure 1. Test Schematic Optimized for 40MHz to 5500MHz in Single-Ended Input Configuration
Figure 2. Top Side of Evaluation Board
5582f
LTC5582 applicaTions inForMaTion
The LTC5582 is a true RMS RF power detector, capable of measuring an RF signal over the frequency range from 40MHz to 10GHz, independent of input waveforms with different crest factors such as CW, CDMA2K, WCDMA, LTE and WiMAX signals. Up to 60dB dynamic range is achieved with a very stable output within the full temperature range from -40C to 85C. Its sensitivity can be as low as -57dBm up to 2.7GHz even with single-ended 50 input termination. RF Inputs The differential RF inputs are internally biased at 1.585V. The differential impedance is 400. These pins should be DC blocked when connected to ground or other matching components. The LTC5582 can be driven in a single-ended configuration as illustrated in Figure 3. The single-ended input impedance vs frequency is detailed in Table 1. The DEC Pin can be either left floating or AC-coupled to ground via an external capacitor. While the RF signal is applied to the IN+ (or IN-) Pin, the other pin IN- (or IN+) should be AC-coupled to ground. By simply terminating a 68 resistor between the IN+ and IN- Pins and coupling the non-signal side to ground using a 1nF capacitor, broadband 50 input matching can be achieved with typical return loss better than 10dB from 40MHz to 5.5GHz. At higher RF frequencies, additional matching components may be needed.
J1 RF INPUT C5 R4 68 3 C4 1nF 2 LTC5582 IN+ DEC 200 50pF 4 IN- 200 VCC
Table 1. Single-Ended Input Impedance (DEC Floating)
FREQUENCY (MHZ) 40 100 200 400 600 800 1000 1200 1400 1600 1800 2000 2200 2400 2600 2800 3000 3200 3400 3600 3800 4000 4200 4400 4600 4800 5000 5200 5400 5600 5800 6000 INPUT IMPEDANCE () 220.7-j63.0 195.2-j47.3 175.1-j37.6 200.9-j42.2 159.8-j52.9 154.8-j52.4 158.6-j57.1 164.1-j81.1 138.1-j110.5 102.7-j113.3 80.1-j103.1 67.1-j92.0 58.4-j82.3 52.9-j74.5 48.5-j67.6 44.8-j61.5 41.8-j56.1 41.8-j56.3 37.3-j47.0 35.4-j42.9 33.9-j39.1 32.4-j35.5 31.1-j32.3 29.9-j29.1 28.9-j26.2 27.9-j23.3 27.0-j20.5 26.2-j17.8 25.4-j15.2 24.7-j12.6 24.0-j10.0 23.3-j7.5 S11 MAG 0.655 0.611 0.571 0.618 0.563 0.554 0.568 0.612 0.650 0.659 0.647 0.628 0.607 0.586 0.566 0.546 0.526 0.508 0.490 0.473 0.457 0.445 0.429 0.416 0.405 0.395 0.388 0.382 0.376 0.376 0.377 0.377 ANGLE () -7.0 -7.1 -7.3 -6.3 -11.5 -12.2 -12.4 -14.7 -21.0 -28.5 -35.3 -41.3 -46.7 -52.0 -57.0 -62.0 -66.9 -72.0 -77.1 -80.2 -87.7 -93.1 -98.8 -104.7 -110.7 -117.0 -123.5 -130.2 -136.9 -144.1 -151.3 -158.4
C9 OPTIONAL
C8 1nF
5582 F03
Figure 3. Single-Ended Input Configuration
The LTC5582 differential inputs can also be driven from a fully balanced source as shown in Figure 4. When the signal source is a single-ended 50, conversion to a differential signal can be achieved using a 1:8 balun to match the internal 400 input impedance to the 50 source. This impedance transformation results in 9dB voltage gain, thus 9dB improvement in sensitivity is obtained
5582f
0
LTC5582 applicaTions inForMaTion
while the overall dynamic range remains the same. At high frequency, additional LC elements may be needed for the input impedance matching due to the parasitics of the transformer and PCB traces.
LTC5582 J1 RF INPUT IN+ DEC 200 50pF T1 1:8 4 IN- 200 VCC MATCHING NETWORK CS1 6.8pF RF INPUT CS2 6.8pF LM 66nH TO IN-
5582 F05
TO IN+
2
Figure 5. Single-Ended-to-Differential Conversion
0 -5 RETURN LOSS (dB) -10 -15 -20 -25 -30
3
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Figure 4. Differential Input Configuration
OUTPUT VOLTAGE (V)
Due to the high input impedance of the LTC5582, a narrow band L-C matching network can be also used to convert a single-ended input to differential signal as shown in Figure 5. By this means, the sensitivity and overall linear dynamic range of the detector will be very similar to the one using 1:8 RF input balun. The conversion gain is strongly dependent on the loss (or Q) of the matching network, particularly at high frequency. The lower the Q, the lower the conversion gain. However, the matching bandwidth is correspondingly wider. The following formulas are provided to calculate the input matching network for single-ended-to-differential conversion at low RF frequency (i.e., below 1GHz). CS1 = CS2 = 1 2.25 * 10 = fc fc 50RIN
9
0 100 200 300 400 500 600 700 800 900 1000 FREQUENCY (MHz)
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Figure 6. RF Input Return Loss
2.8 2.4 2.0 1.6 SINGLE-ENDED 1.2 0.8 0.4 -75 -65 -55 -45 -35 -25 -15 RF INPUT POWER (dBm) SINGLE-ENDED-TODIFFERENTIAL INPUTS
(pF )
50RIN 2.25 * 1010 LM = = 2fc fc
(nH)
-5
5
where RIN is the differential input resistance (400) and fc is the center RF operating frequency. As an example, Figure 6 shows that good input return loss is achieved from 300MHz to 400MHz when Cs1= Cs2 = 6.8pF and LM = 66nH. Figure 7 show the sensitivity is also improved by 8dB at 350MHz while the dynamic range remains the same.
Figure 7. Output Voltage vs RF Input Power
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Although these equations give a good starting point, it is usually necessary to adjust the component values after building and testing the circuit. As the RF operating frequency increases, the real values of CS1, CS2, LM will deviate from the above equations due to parasitics of the components, device and PCB layout. For a 50 input termination, the approximate RF input power range of the LTC5582 is from -60dBm to 2dBm, 5582f
LTC5582 applicaTions inForMaTion
RIPPLE (mVP-P), FALL TIME (s)
even with high crest factor signals such as a 4-carrier W-CDMA waveform, and the minimum detectable RF power level varies as the input RF frequency increases. The linear dynamic range can also be shifted to suit a particular application need. By simply inserting an attenuator in front of the RF input, the power range is shifted higher by the amount of the attenuation. The sensitivity of LTC5582 is dictated by the broadband input noise power that also determines the output DC offset voltage. When the inputs are terminated differently, the DC output voltage may vary slightly. When the input noise power is minimized, the DC offset voltage is also reduced to the minimum. And the detector's sensitivity and dynamic range will be improved accordingly. External Filtering (FLTR) Capacitor This pin is internally biased at VCC - 0.43V via a 1.2k resistor from the voltage supply, VCC. To assure stable operation of the LTC5582, an external capacitor C3 with a value of 8nF or higher is required to connect from the FLTR Pin to VCC to avoid an abnormal start-up condition. Don't connect this filtering capacitor to ground or any other low voltage reference at any time. This external capacitor value has a dominant effect on the output transient response. The lower the capacitance, the faster the output rise and fall times. For signals with AM content such as W-CDMA, significant ripple can be observed when the loop bandwidth set by C3 is close to the modulation bandwidth of the signal. A 4-carrier W-CDMA RF signal is used as an example in this case. The trade-offs of the residual ripple vs the output transient times are as shown in Figure 8. In general, the LTC5582 output ripple remains relatively constant regardless of the RF input power level for a fixed C3 and modulation format of the RF signal. Typically, C3 must be selected to smooth out the ripple to achieve the desired accuracy of RF power measurement. Output Interface The output buffer amplifier of the LTC5582 is shown in Figure 9. This Class AB buffer amplifier can source and sink 5mA current to and from the load. The output impedance is determined primarily by the 100 series resistor
500 450 400 350 300 250 200 150 100 50 0 0 RISE TIME 200 400 600 800 FILTERNING CAPACITOR C3 (nF) RIPPLE FALL TIME
50 45 40 35 RISE TIME (s) 30 25 20 15 10 5 0 1000
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Figure 8. Residual Ripple, Output Transient Times vs Filtering Capacitor C3
LTC5582
VCC
INPUT
100
OUT
RSS
VOUT CLOAD
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Figure 9. Simplified Schematic of the Output Interface
connected to the output of the buffer amplifier inside the chip. This will prevent overstress on internal devices in the event that the output is shorted to ground. The -3dB small-signal bandwidth of the buffer amplifier is about 22.4MHz and the full-scale rise/fall time can be as fast as 80ns, limited by the slew rate of the internal circuit instead. When the output is resistively terminated or open, the fastest output transient response is achieved when a large signal is applied to the RF input. The rise time of the LTC5582 is about 90ns and the fall time is 5s, respectively, . for full-scale pulsed RF input power when C3 = 8nF The speed of the output transient response is dictated mainly by the filtering capacitor C3 (at least 8nF) at the FLTR Pin. See the detailed output transient response in the Typical Performance Characteristics section. When the RF input has AM content, residual ripple may be present at the output depending upon the low frequency content of the modulated RF signal. This ripple can be reduced with a larger filtering capacitor C3 at the expense of a slower transient response.
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LTC5582 applicaTions inForMaTion
Since the output buffer amplifier of the LTC5582 is capable of driving an arbitrary capacitive load, the residual ripple can be further filtered at the output with a series resistor RSS and a large shunt capacitor CLOAD. See Figure 9. This lowpass filter also reduces the output noise by limiting the output noise bandwidth. When this RC network is designed properly, a fast output transient response can be maintained with a reduced residual ripple. For example, we can estimate CLOAD with an output voltage swing of 1.7V at 2140MHz. In order not to allow the maximum 5mA souring current to limit the fall time (about 5s), the maximum value of CLOAD can be chosen as follows: CLOAD 5mA * 5mA * allowable additional time = 1.7 V TC2 are shown as functions of the tuning resistors RT1 and RT2 in Figures 11 and 12, respectively.
VCC LTC5582
250
RT1 OR RT2 RT1 OR RT2
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Figure 10. Simplified Interface Circuit Schematic of the Control Pins RT1 and RT2
0.25s = 735pF 1.7 V
Once CLOAD is determined, RSS can be chosen properly to form a RC low-pass filter with a corner frequency of 1/[2(RSS + 100) * CLOAD]. In general, the rise time of the LTC5582 is much shorter than the fall time. However, when the output RC filter is used, the rise time can be dominated by the time constant of this filter. Accordingly, the rise time becomes very similar to the fall time. Although the maximum sinking capability of the LTC5582 is 5mA, it is recommended that the output load resistance should be greater than 1.2k in order to achieve the full output voltage swing. Temperature Compensation of Logarithmic Intercept The simplified interface schematic of the intercept temperature compensation is shown in Figure 10. The adjustment of the output voltage can be described by the following equation with respect to the ambient temperature: VOUT = -TC1 * (TA - TNOM) - TC2 * (TA - TNOM)2- detV1 - detV2 where TC1 and TC2 are the 1st-order and 2nd-order temperature compensation coefficients, respectively; TA is the actual ambient temperature; and TNOM is the reference room temperature; detV1 and detV2 are the output voltage variations when RT1 and RT2 are not set to zero at room temperature. The temperature coefficients TC1 and
When Pins RT1 and RT2 are shorted to ground, the temperature compensation circuit is disabled automatically. Table 2 lists the suggested RT1 and RT2 values at various RF frequencies for the best output performance over temperature.
1.2 1.0 0.8 0.6 0.4 0.2 0 TC1 120 100 80 detV1 (mV) 60 40 20 0 40
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TC1 (mV/C)
detV1 5 10 15 20 25 RT1 (k ) 30 35
Figure 11. 1st-Order Temperature Compensation Coefficient TC1 vs RT1 Value Table 2. Suggested RT1 and RT2 Values for Optimal Temperature Performance vs RF Frequency
FREQUENCY (MHz) 450 880 2140 2700 3600 5800 RT1 (k) 12 12 0 0 0 0 RT2 (k) 2 2 2 1.6 1.6 3
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LTC5582 applicaTions inForMaTion
20 200
Enable Interface A simplified schematic of the EN Pin interface is shown in Figure 13. The enable voltage necessary to turn on the LTC5582 is 1V. To disable or turn off the chip, this voltage should be below 0.4V. It is important that the voltage applied to the EN pin should never exceed VCC by more than 0.3V. Otherwise, the supply current may be sourced through the upper ESD protection diode connected at the EN pin. Under no circumstances should voltage be applied to the EN Pin before the supply voltage is applied to the VCC pin. If this occurs, damage to the IC may result. Supply Voltage Ramping Fast ramping of the supply voltage can cause a current glitch in the internal ESD protection circuits. Depending on the supply inductance, this could result in a supply voltage overshooting at the initial transient that exceeds the maximum rating. A supply voltage ramp time of greater than 1ms is recommended. In case this voltage ramp time is not controllable, a small (i.e., 1.5) series resistor should be inserted in-between VCC Pin and the supply voltage source to mitigate the problem and self-protect the IC. The R1 shown in Figure 1 is served for this purpose.
16
160
TC2 (V/C)
12 TC2 8
120
detV2 (mV)
80
4
detV2 0 1 2 3 4 5 RT2 (k ) 6 7 8
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40
0
0
Figure 12. 2nd-Order Temperature Compensation Coefficient TC2 vs RT2 Value
VCC
EN 52k 52k
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Figure 13. Enable Pin Simplified Circuit
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LTC5582 package DescripTion
(Reference LTC DWG # 05-08-1699 Rev B)
DD Package 10-Lead Plastic DFN (3mm x 3mm)
0.70 0.05
3.55 0.05 1.65 0.05 2.15 0.05 (2 SIDES) PACKAGE OUTLINE 0.25 0.05
0.50 BSC 2.38 0.05 (2 SIDES) R = 0.125 TYP 6 0.40 10 0.10
RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS
3.00 0.10 (4 SIDES) PIN 1 TOP MARK (SEE NOTE 6)
1.65 0.10 (2 SIDES)
5 0.200 REF 0.75 0.05 2.38 0.10 (2 SIDES)
1
(DD) DFN REV B 0309
0.25 0.05 0.50 BSC
0.00 - 0.05
BOTTOM VIEW--EXPOSED PAD
NOTE: 1. DRAWING TO BE MADE A JEDEC PACKAGE OUTLINE M0-229 VARIATION OF (WEED-2). CHECK THE LTC WEBSITE DATA SHEET FOR CURRENT STATUS OF VARIATION ASSIGNMENT 2. DRAWING NOT TO SCALE 3. ALL DIMENSIONS ARE IN MILLIMETERS 4. DIMENSIONS OF EXPOSED PAD ON BOTTOM OF PACKAGE DO NOT INCLUDE MOLD FLASH. MOLD FLASH, IF PRESENT, SHALL NOT EXCEED 0.15mm ON ANY SIDE 5. EXPOSED PAD SHALL BE SOLDER PLATED 6. SHADED AREA IS ONLY A REFERENCE FOR PIN 1 LOCATION ON THE TOP AND BOTTOM OF PACKAGE
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Information furnished by Linear Technology Corporation is believed to be accurate and reliable. However, no responsibility is assumed for its use. Linear Technology Corporation makes no representation that the interconnection of its circuits as described herein will not infringe on existing patent rights.
LTC5582 Typical applicaTion
40MHz to 6GHz Infrastructure Power Amplifier Level Control
DIRECTIONAL COUPLER PA 3.3V 100nF 1 50 270pF 2 3 4 1nF 5 VCC IN+ DEC IN- GND 11 LTC5582 FLTR EN RT1 RT2 OUT
5582 TA02
RFIN
1F DIGITAL POWER CONTROL
10 9 8 7 6 1nF OUT ADC
68
EXPOSED PAD
relaTeD parTs
PART NUMBER DESCRIPTION RF Power Detectors LTC5505 RF Power Detectors with >40dB Dynamic Range LTC5507 100kHz to 1000MHz RF Power Detector LTC5508 300MHz to 7GHz RF Power Detector LTC5509 300MHz to 3GHz RF Power Detector LTC5530 300MHz to 7GHz Precision RF Power Detector LTC5531 300MHz to 7GHz Precision RF Power Detector LTC5532 300MHz to 7GHz Precision RF Power Detector LT5534 50MHz to 3GHz Log RF Power Detector with 60dB Dynamic Range LTC5536 Precision 600MHz to 7GHz RF Power Detector with Fast Comparator Output LT5537 Wide Dynamic Range Log RF/IF Detector LT5538 75dB Dynamic Range 3.8GHz Log RF Power Detector LT5570 60dB Dynamic Range RMS Detector LT5581 6GHz RMS Power Detector with 40dB Dynamic Range Infrastructure LTC5540/LTC5541/ 600MHz to 4GHz High Dynamic Range LTC5542/LTC5543 Downconverting Mixer LT5579 1.5GHz to 3.8GHz High Linearity Upconverting Mixer LTC5598 5MHz to 1600MHz High Linearity Direct Quadrature Modulator COMMENTS 300MHz to 3GHz, Temperature Compensated, 2.7V to 6V Supply 100kHz to 1GHz, Temperature Compensated, 2.7V to 6V Supply 44dB Dynamic Range, Temperature Compensated, SC70 Package 36dB Dynamic Range, Low Power Consumption, SC70 Package Precision VOUT Offset Control, Shutdown, Adjustable Gain Precision VOUT Offset Control, Shutdown, Adjustable Offset Precision VOUT Offset Control, Adjustable Gain and Offset 1dB Output Variation over Temperature, 38ns Response Time, Log Linear Response 25ns Response Time, Comparator Reference Input, Latch Enable Input, -26dBm to +12dBm Input Range Low Frequency to 1GHz, 83dB Log Linear Dynamic Range 0.8dB Accuracy Over Temperature 40MHz to 2.7GHz, 0.5dB Accuracy Over Temperature 1dB Accuracy Over Temperature, Log Linear Response, 1.4mA at 3.3V
IIP3 = 26dBm, 8dB Conversion Gain, <10dB NF 3.3V, 190mA Supply Operation , 27.3dBm OIP3 at 2.14GHz, 9.9dB NF 2.6dB Conversion Gain, -35dBm LO , Leakage 27.7dBm OIP3 at 140MHz, -161.2dBm/Hz Noise Floor, 0.5VDC Baseband Interface, -55dBm LO Leakage and 50.4dBc Image Rejection at 140MHz
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Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900
LT 0510 * PRINTED IN USA
FAX: (408) 434-0507 www.linear.com
LINEAR TECHNOLOGY CORPORATION 2010

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