LTC5582
1
5582f
RF INPUT POWER (dBm)
–65
LINEARITY ERROR (dB)
3
2
0
–2
1
–1
–3 –25–45 –5
5582 TAO1b
5–35–55 –15
TA = 25°C
4-CARRIER WCDMA
CW
3-CARRIER CDMA2K
Typical applicaTion
FeaTures DescripTion
40MHz to 10GHz
RMS Power Detector with
57dB Dynamic Range
The LTC
®
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. Con-
sult factory for more information. The part is packaged in
a 10-lead 3mm × 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.
40MHz to 6GHz RMS Power Detector
applicaTions
n Frequency Range: 40MHz to 10GHz
n Linear Dynamic Range: Up to 57dB
n Accurate RMS Power Measurement of High Crest
Factor Modulated Waveforms
n Exceptional Accuracy Over Temperature: ±0.5dB (Typ)
n Low Linearity Error within Dynamic Range
n Single-Ended or Differential RF Inputs
n Fast Response Time: 90ns Rise Time
n Low Supply Current: 41.6mA at 3.3V (Typ)
n Small 3mm × 3mm DFN10
n RMS Power Measurement
n PA Power Control
n Receive and Transmit Gain Control
n LTE, WiMAX, W-CDMA, CDMA2K, TD-SCDMA,
EDGE Basestations
n Point-to-Point Microwave Links
n RF Instrumentation
VCC
IN+
IN–
VOUT
GND
FLTR
EN ENABLE
OUT
RT2
DEC RT1
100nF
1nF
1nF
3.3V
5582 TA01a
LTC5582
1µF
270pF 68Ω
Linearity Error vs RF Input Power
2140MHz Modulated Waveforms
LTC5582
2
5582f
pin conFiguraTionabsoluTe 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
TJMAX .................................................................... 150°C
Operating Temperature Range .................–40°C to 85°C
Storage Temperature Range .................. –65°C to 125°C
(Note 1)
TOP VIEW
DD PACKAGE
10-LEAD (3mm s 3mm) PLASTIC DFN
11
GND
10
9
6
7
8
4
5
3
2
1FLTR
EN
RT1
RT2
OUT
VCC
IN+
DEC
IN–
GND
TJMAX = 150°C, θJA = 43°C/W
EXPOSED PAD (PIN 11) IS GND, MUST BE SOLDERED TO PCB
elecTrical characTerisTics
The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C. VCC = 3.3V, EN = 3.3V. Test circuit is shown in Figure 1. (Notes 2 and 3).
orDer inForMaTion
LEAD FREE FINISH TAPE AND REEL PART MARKING PACKAGE DESCRIPTION TEMPERATURE RANGE
LTC5582IDD#PBF LTC5582IDD#TRPBF LFGZ 10-Lead 3mm × 3mm Plastic DFN –40°C to 85°C
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/
PARAMETER CONDITIONS MIN TYP MAX UNITS
AC Input
Input Frequency Range (Note 4) 40 to 10000 MHz
Input Impedance Differential 400//0.5 Ω//pF
fRF = 450MHz
RF Input Power Range CW; Single-Ended, 50Ω –57 to 2 dBm
Linear Dynamic Range ±1dB Linearity Error 59 dB
Output Slope 29.5 mV/dB
Logarithmic Intercept –86.2 dBm
Output Variation vs Temperature Normalized to Output at 25°C, Pin = –50dBm to 0dBm l±0.5 dB
Deviation from CW Response 11dB Peak to Average Ratio (3-Carrier CDMA2K)
12dB Peak to Average Ratio (4-Carrier WCDMA)
0.1
0.1
dB
dB
2nd Order Harmonic Distortion At RF Input; CW Input; PIN = 0dBm 67 dBc
3rd Order Harmonic Distortion At RF Input; CW Input; PIN = 0dBm 62 dBc
LTC5582
3
5582f
elecTrical characTerisTics
PARAMETER CONDITIONS MIN TYP MAX UNITS
fRF = 880MHz
RF Input Power Range CW; Single-Ended, 50Ω –57 to 2 dBm
Linear Dynamic Range ±1dB Linearity Error 59 dB
Output Slope 29.3 mV/dB
Logarithmic Intercept –86.4 dBm
Output Variation vs Temperature Normalized to Output at 25°C, Pin = –50dBm to 0dBm l±0.5 dB
Deviation from CW Response 11dB Peak to Average Ratio (3-Carrier CDMA2K)
12dB Peak to Average Ratio (4-Carrier WCDMA)
0.1
0.1
dB
dB
2nd Order Harmonic Distortion At RF Input; CW Input; PIN = 0dBm 69 dBc
3rd Order Harmonic Distortion At RF Input; CW Input; PIN = 0dBm 59 dBc
fRF = 2140MHz
RF Input Power Range CW; Single-Ended, 50Ω –56 to 1 dBm
Linear Dynamic Range (Note 5) ±1dB Linearity Error 50 57 dB
Output Slope 26 29.5 33 mV/dB
Logarithmic Intercept –98 –85 –72 dBm
Output Variation vs Temperature Normalized to Output at 25°C, Pin = –47dBm to 0dBm l±0.5 dB
Deviation from CW Response 11 dB Peak to Average Ratio (3-Carrier CDMA2K)
12dB Peak to Average Ratio (4-Carrier WCDMA)
0.1
0.1
dB
dB
fRF = 2700MHz
RF Input Power Range CW; Single-Ended, 50Ω –55 to 1 dBm
Linear Dynamic Range ±1dB Linearity Error 56 dB
Output Slope 29.8 mV/dB
Logarithmic Intercept –83.8 dBm
Output Variation vs Temperature Normalized to Output at 25°C, Pin = –47dBm to 0dBm l±0.5 dB
Deviation from CW Response 12dB Peak to Average Ratio (WiMAX OFDM) 0.2 dB
fRF = 3800MHz
RF Input Power Range CW; Single-Ended, 50Ω –51 to 2 dBm
Linear Dynamic Range ±1dB Linearity Error 53 dB
Output Slope 30.3 mV/dB
Logarithmic Intercept –81 dBm
Output Variation vs Temperature Normalized to Output at 25°C, Pin = –51dBm to 2dBm l±1 dB
Deviation from CW Response 12dB Peak to Average Ratio (WiMAX OFDM) 0.2 dB
fRF = 5800MHz
RF Input Power Range CW; Single-Ended, 50Ω –46 to 3 dBm
Linear Dynamic Range ±1dB Linearity Error 49 dB
Output Slope 30.9 mV/dB
Logarithmic Intercept –74.7 dBm
Output Variation vs Temperature Normalized to Output at 25°C, Pin = –46dBm to 2dBm l±1 dB
Deviation from CW Response 12dB Peak to Average Ratio (WiMAX OFDM) 0.2 dB
The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C. VCC = 3.3V, EN = 3.3V. Test circuit is shown in Figure 1. (Notes 2 and 3).
LTC5582
4
5582f
Typical perForMance characTerisTics
Output Voltage vs RF Input Power Linearity Error vs RF Input Power
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
–40°C to 85°C.
Note 3: Logarithmic Intercept is an extrapolated input power level from the
best fitted log-linear straight line, where the output voltage is 0V.
elecTrical characTerisTics
PARAMETER CONDITIONS MIN TYP MAX UNITS
Output Interface
Output DC Voltage No RF Signal Present 0.69 V
Output Impedance 100 Ω
Output Current Maximum ±5 mA
Rise Time, 10% to 90% 0.8V to 2.4V, C3 = 8nF, fRF = 100MHz 90 nS
Fall Time, 90% to 10% 2.4V to 0.8V, C3 = 8nF, fRF = 100MHz 5 μS
Enable (EN) Low = Off, High = On
EN Input High Voltage (On) l1 V
EN Input Low Voltage (Off) l0.4 V
Enable Pin Input Current EN = 3.3V 125 200 μA
Turn ON Time VOUT within 10% of Final Value, C3 = 8nF 2.8 μs
Turn OFF Time VOUT < 0.8V, C3 = 8nF 40 μs
Power Supply
Supply Voltage 3.1 3.3 3.5 V
Supply Current 41.6 52 mA
Shutdown Current EN = 0V, VCC = 3.5V 0.1 10 μA
The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C. VCC = 3.3V, EN = 3.3V. Test circuit is shown in Figure 1. (Notes 2 and 3).
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.
VCC = 3.3V, EN = 3.3V, TA = 25°C unless otherwise
noted. Test circuits shown in Figure 1.
RF INPUT POWER (dBm)
–65 –25–45 –5
5582 G01
5–35–55 –15
450MHz
880MHz
2140MHz
2700MHz
3800MHz
5800MHz
TA = 25°C
OUTPUT VOLTAGE (V)
2.8
2.4
1.6
0.8
2.0
1.2
0.4
RF INPUT POWER (dBm)
–65
LINEARITY ERROR (dB)
3
2
0
–2
1
–1
–3 –25–45 –5
5582 G02
5–35–55 –15
TA = 25°C
450MHz
880MHz
2140MHz
2700MHz
3800MHz
5800MHz
Supply Current vs Supply Voltage
SUPPLY VOLTAGE (V)
3.0
SUPPLY CURRENT (mA)
60
55
45
35
25
50
40
30
20 3.33.1 3.5
5582 G27
3.63.2 3.4
TA = 85°C
TA = 25°C
TA = –40°C
LTC5582
5
5582f
Typical perForMance characTerisTics
Output Voltage, Linearity Error vs
RF Input Power, 880MHz
Output Voltage Temperature
Variation from 25°C, 880MHz
Linear Error vs RF Input Power,
Modulated Waveforms, 880MHz
Output Voltage, Linearity Error vs
RF Input Power, 2140MHz
Output Voltage Temperature
Variation from 25°C, 2140MHz
Linear Error vs RF Input Power,
Modulated Waveforms, 2140MHz
Output Voltage, Linearity Error vs
RF Input Power, 450MHz
Output Voltage Temperature
Variation from 25°C, 450MHz
Linear Error vs RF Input Power,
Modulated Waveforms, 450MHz
VCC = 3.3V, EN = 3.3V, TA = 25°C unless otherwise
noted. Test circuits shown in Figure 1.
RF INPUT POWER (dBm)
–65
OUTPUT VOLTAGE (V)
2.8
2.4
1.6
0.8
2.0
1.2
0.4
LINEARITY ERROR (dB)
3
2
0
–2
1
–1
–3
–25–45 –5
5582 G03
5–35–55 –15
TA = 85°C
TA = 25°C
TA = –40°C
Rt1 = 12k
Rt2 = 2k
RF INPUT POWER (dBm)
–65
OUTPUT VOLTAGE (V)
2.8
2.4
1.6
0.8
2.0
1.2
0.4
LINEARITY ERROR (dB)
3
2
0
–2
1
–1
–3
–25–45 –5
5582 G06
5–35–55 –15
Rt1 = 12k
Rt2 = 2k
TA = 85°C
TA = 25°C
TA = –40°C
RF INPUT POWER (dBm)
–65
VOUT VARIATION (dB)
3
2
0
–2
1
–1
–3 –25–45 –5
5582 G04
5–35–55 –15
TA = 85°C
TA = –40°C
Rt1 = 12k
Rt2 = 2k
RF INPUT POWER (dBm)
–65
LINEARITY ERROR (dB)
3
2
0
–2
1
–1
–3 –25–45 –5
5582 G05
5–35–55 –15
TA = 25°C
4-CARRIER WCDMA
CW
3-CARRIER CDMA2K
RF INPUT POWER (dBm)
–65
VOUT VARIATION (dB)
3
2
0
–2
1
–1
–3 –25–45 –5
5582 G07
5–35–55 –15
TA = 85°C
TA = –40°C
Rt1 = 12k
Rt2 = 2k
RF INPUT POWER (dBm)
–65
LINEARITY ERROR (dB)
3
2
0
–2
1
–1
–3 –25–45 –5
5582 G08
5–35–55 –15
TA = 25°C
4-CARRIER WCDMA
CW
3-CARRIER CDMA2K
RF INPUT POWER (dBm)
–65
OUTPUT VOLTAGE (V)
2.8
2.4
1.6
0.8
2.0
1.2
0.4
LINEARITY ERROR (dB)
3
2
0
–2
1
–1
–3
–25–45 –5
5582 G09
5–35–55 –15
Rt1 = 0
Rt2 = 2k
TA = 85°C
TA = 25°C
TA = –40°C
RF INPUT POWER (dBm)
–65
VOUT VARIATION (dB)
3
2
0
–2
1
–1
–3 –25–45 –5
5582 G10
5–35–55 –15
TA = 85°C
TA = –40°C
Rt1 = 0
Rt2 = 2k
RF INPUT POWER (dBm)
–65
LINEARITY ERROR (dB)
3
2
0
–2
1
–1
–3 –25–45 –5
5582 G11
5–35–55 –15
TA = 25°C
4-CARRIER WCDMA
CW
3-CARRIER CDMA2K
LTC5582
6
5582f
VCC = 3.3V, EN = 3.3V, TA = 25°C unless otherwise
noted. Test circuits shown in Figure 1.
Typical perForMance characTerisTics
Output Voltage, Linearity Error vs
RF Input Power, 3800MHz
Output Voltage Temperature
Variation from 25°C, 3800MHz
Linear Error vs RF Input Power,
Modulated Waveforms, 3800MHz
Output Voltage, Linearity Error vs
RF Input Power, 5800MHz
Output Voltage Temperature
Variation from 25°C, 5800MHz
Linear Error vs RF Input Power,
Modulated Waveforms, 5800MHz
Output Voltage Temperature
Variation from 25°C, 2700MHz
Linear Error vs RF Input Power,
Modulated Waveforms, 2700MHz
RF INPUT POWER (dBm)
–65
VOUT VARIATION (dB)
3
2
0
–2
1
–1
–3 –25–45 –5
5582 G13
5–35–55 –15
TA = 85°C
TA = –40°C
Rt1 = 0
Rt2 = 1.6k
RF INPUT POWER (dBm)
–65
LINEARITY ERROR (dB)
3
2
0
–2
1
–1
–3 –25–45 –5
5582 G14
5–35–55 –15
TA = 25°C
CW
WiMAX
RF INPUT POWER (dBm)
–65
OUTPUT VOLTAGE (V)
2.8
2.4
1.6
0.8
2.0
1.2
0.4
LINEARITY ERROR (dB)
3
2
0
–2
1
–1
–3
–25–45 –5
5582 G15
5–35–55 –15
Rt1 = 0
Rt2 = 1.6k
TA = 85°C
TA = 25°C
TA = –40°C
RF INPUT POWER (dBm)
–65
VOUT VARIATION (dB)
3
2
0
–2
1
–1
–3 –25–45 –5
5582 G16
5–35–55 –15
TA = 85°C
TA = –40°C
Rt1 = 0
Rt2 = 1.6k
RF INPUT POWER (dBm)
–65
LINEARITY ERROR (dB)
3
2
0
–2
1
–1
–3 –25–45 –5
5582 G17
5–35–55 –15
TA = 25°C
CW
WiMAX
RF INPUT POWER (dBm)
–65
OUTPUT VOLTAGE (V)
2.8
2.4
1.6
0.8
2.0
1.2
0.4
LINEARITY ERROR (dB)
3
2
0
–2
1
–1
–3
–25–45 –5
5582 G18
5–35–55 –15
Rt1 = 0
Rt2 = 3k
TA = 85°C
TA = 25°C
TA = –40°C
RF INPUT POWER (dBm)
–65
VOUT VARIATION (dB)
3
2
0
–2
1
–1
–3 –25–45 –5
5582 G19
5–35–55 –15
TA = 85°C
TA = –40°C
Rt1 = 0
Rt2 = 3k
RF INPUT POWER (dBm)
–65
LINEARITY ERROR (dB)
3
2
0
–2
1
–1
–3 –25–45 –5
5582 G20
5–35–55 –15
TA = 25°C
CW
WiMAX
Output Voltage, Linearity Error vs
RF Input Power, 2700MHz
RF INPUT POWER (dBm)
–65
OUTPUT VOLTAGE (V)
2.8
2.4
1.6
0.8
2.0
1.2
0.4
LINEARITY ERROR (dB)
3
2
0
–2
1
–1
–3
–25–45 –5
5582 G12
5–35–55 –15
Rt1 = 0
Rt2 = 1.6k
TA = 85°C
TA = 25°C
TA = –40°C
LTC5582
7
5582f
VCC = 3.3V, EN = 3.3V, TA = 25°C unless otherwise
noted. Test circuits shown in Figure 1.
Typical perForMance characTerisTics
Logarithmic Intercept Distribution
vs Temperature, 2140MHz
Output Transient Response,
C3 = 8nF
Slope vs Frequency
Logarithmic Intercept vs
Frequency
Slope Distribution vs
Temperature, 2140MHz
TIME (µs)
0
OUTPUT VOLTAGE (V)
4.8
4.4
3.6
2.8
2.0
1.2
4.0
3.2
2.4
1.6
0.8
0.4 4 82 6
5582 G25
103 71 5 9
fRF = 100MHz
RF PULSE OFF
RF PULSE ON
RF PULSE OFF
PIN = 0dBm
PIN = –10dBm
PIN = –20dBm
PIN = –30dBm
PIN = –40dBm
PIN = –50dBm
SLOPE (mV/dB)
27.9
PERCENTAGE DISTRIBUTION (%)
35
30
20
10
25
15
5
028.5
5582 G23
30.329.729.1
TA = 85°C
TA = 25°C
TA = –40°C
LOGRITHMIC INTERCEPT (dBm)
–90
PERCENTAGE DISTRIBUTION (%)
25
20
10
15
5
0
5582 G24
–80–82–84–86–88
TA = 85°C
TA = 25°C
TA = –40°C
Output Voltage, Linearity Error vs
RF Input Power, 8GHz
RF INPUT POWER (dBm)
–45
OUTPUT VOLTAGE (V)
2.8
2.4
1.6
0.8
2.0
1.2
0.4
LINEARITY ERROR (dB)
3
2
0
–2
1
–1
–3
–25 –5
5582 G30
105–35 –15
TA = 85°C
TA = 25°C
TA = –40°C
Output Voltage Temperature
Variation from 25°C, 8GHz
Output Voltage Linearity Error vs
RF Input Power, 10GHz
RF INPUT POWER (dBm)
VOUT VARIATION (dB)
3
2
0
–2
1
–1
–3
5582 G31
TA = 85°C
TA = –40°C
–45 –25 –5 105–35 –15–45 –25 –5 105–35 –15
RF INPUT POWER (dBm)
OUTPUT VOLTAGE (V)
2.8
2.4
1.6
0.8
2.0
1.2
0.4
LINEARITY ERROR (dB)
3
2
0
–2
1
–1
–3
5582 G32
TA = 85°C
TA = 25°C
TA = –40°C
–45 –25 –5 105–35 –15
Output Voltage Temperature
Variation from 25°C, 10GHz
RF INPUT POWER (dBm)
VOUT VARIATION (dB)
3
2
0
–2
1
–1
5582 G33
TA = 85°C
TA = –40°C
–45 –25 –5 105–35 –15
LTC5582
8
5582f
pin FuncTions
VCC (Pin 1): Power Supply Pin. Typical current consump-
tion is 41.6mA at room temperature. This pin should be
externally bypassed with 1nF and 1µF 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 400Ω. The impedance
of each pin to the DEC pin is 200Ω.
DEC (Pin 3): Input Common Mode Decoupling Pin. This
pin is internally biased to 1.585V and connected to an on-
chip 50pF capacitor to ground. The impedance between
DEC and IN+ (or IN–) is 200Ω. 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 100Ω 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 (25°C) 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 reduc-
tion 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 100μA 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 Capaci-
tor C3. A minimum of 8nF capacitance is required for stable
AC average power measurement. This capacitor should
be connected to VCC.
VCC = 3.3V, EN = 3.3V, TA = 25°C unless otherwise
noted. Test circuits shown in Figure 1.
Typical perForMance characTerisTics
Supply Current vs RF Input Power
RF Input Return Loss vs
Frequency
RF INPUT POWER (dBm)
–65 –25–45 –5 5–35–55 –15
SUPPLY CURRENT (mA)
60
55
45
35
25
50
40
30
20
5582 G28
TA = 85°C
TA = 25°C
TA = –40°C
Output Transient Response,
C3 = 1µF
TIME (ms)
0
OUTPUT VOLTAGE (V)
4.8
4.4
3.6
2.8
2.0
1.2
4.0
3.2
2.4
1.6
0.8
0.4 0.4 0.80.2 0.6
5582 G26
1.00.3 0.70.1 0.5 0.9
fRF = 100MHz
RF PULSE OFF
RF PULSE ON
RF PULSE OFF
PIN = 0dBm
PIN = –10dBm
PIN = –20dBm
PIN = –30dBm
PIN = –40dBm
PIN = –50dBm
LTC5582
9
5582f
TesT circuiTs
Figure 2. Top Side of Evaluation Board
REF DES VALUE SIZE PART NUMBER
C1 1uF 0402 MURATA GRM155R60J105KE19
C2, C8 1nF 0402 MURATA GRM155R71H102KA01
C3 100nF 0402 TDK CID05X7R1C104K
C4 270pF 0402 MURATA GRM155CIH271JA01
C5 0.4pF 0402 MURATA GJM1555C1HR40BB01
C9 100pF 0402 AVX 0402YC101KAT
R1 1.5Ω 0603 VISHAY CRCW06031R50JNEA
R3 100KΩ 0402 VISHAY CRCW0402100KFKED
R4 68Ω 0402 VISHAY CRCW040268R1FKED
R5 2k 0402 VISHAY CRCW04022K00FKEA
R6 0 0402 VISHAY CRCW0402020000Z0ED
Figure 1. Test Schematic Optimized for 40MHz to 5500MHz in Single-Ended Input Configuration
R3
100k
C10
OPTIONAL
VCC
IN+
IN–
GND
FLTR
EN EN
J1
RF INPUT
OUT OUT
RT2
DECNC RT1
C3
100nF
C5
0.4pF
3.3V
5582 F01
LTC5582
C2
1nF
C1
1µF
C8
1nF
C9
100pF
1
2
3
4
5
10
9
8
7
6
C4
270pF
R4
68Ω
R1
1.5Ω
11
EXPOSED PAD
R5
2k
R6
0Ω
LTC5582
10
5582f
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 tem-
perature range from –40°C to 85°C. Its sensitivity can be
as low as –57dBm up to 2.7GHz even with single-ended
50Ω input termination.
RF Inputs
The differential RF inputs are internally biased at 1.585V.
The differential impedance is 400Ω. 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 68Ω resistor between the
IN+ and IN– Pins and coupling the non-signal side to ground
using a 1nF capacitor, broadband 50Ω 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.
Table 1. Single-Ended Input Impedance (DEC Floating)
FREQUENCY
(MHZ)
INPUT IMPEDANCE
(Ω)
S11
MAG ANGLE (˚)
40 220.7-j63.0 0.655 –7.0
100 195.2-j47.3 0.611 –7.1
200 175.1-j37.6 0.571 –7.3
400 200.9-j42.2 0.618 –6.3
600 159.8-j52.9 0.563 –11.5
800 154.8-j52.4 0.554 –12.2
1000 158.6-j57.1 0.568 –12.4
1200 164.1-j81.1 0.612 –14.7
1400 138.1-j110.5 0.650 –21.0
1600 102.7-j113.3 0.659 –28.5
1800 80.1-j103.1 0.647 –35.3
2000 67.1-j92.0 0.628 –41.3
2200 58.4-j82.3 0.607 –46.7
2400 52.9-j74.5 0.586 –52.0
2600 48.5-j67.6 0.566 –57.0
2800 44.8-j61.5 0.546 –62.0
3000 41.8-j56.1 0.526 –66.9
3200 41.8-j56.3 0.508 –72.0
3400 37.3-j47.0 0.490 –77.1
3600 35.4-j42.9 0.473 –80.2
3800 33.9-j39.1 0.457 –87.7
4000 32.4-j35.5 0.445 –93.1
4200 31.1-j32.3 0.429 –98.8
4400 29.9-j29.1 0.416 –104.7
4600 28.9-j26.2 0.405 –110.7
4800 27.9-j23.3 0.395 –117.0
5000 27.0-j20.5 0.388 –123.5
5200 26.2-j17.8 0.382 –130.2
5400 25.4-j15.2 0.376 –136.9
5600 24.7-j12.6 0.376 –144.1
5800 24.0-j10.0 0.377 –151.3
6000 23.3-j7.5 0.377 –158.4
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 50Ω, conversion to a dif-
ferential signal can be achieved using a 1:8 balun to match
the internal 400Ω input impedance to the 50Ω source.
This impedance transformation results in 9dB voltage
gain, thus 9dB improvement in sensitivity is obtained
Figure 3. Single-Ended Input Configuration
R4
68Ω
J1
RF INPUT
C5
C9
OPTIONAL
C8
1nF
IN–
4
IN+
VCC
5582 F03
200Ω
200Ω
LTC5582
2
C4
1nF
DEC
3
50pF
LTC5582
11
5582f
applicaTions inForMaTion
Figure 4. Differential Input Configuration
Figure 5. Single-Ended-to-Differential Conversion
Figure 7. Output Voltage vs RF Input Power
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.
J1
RF INPUT
IN–
4
IN+
VCC
T1
1:8
5582 F04
200Ω
200Ω
LTC5582
2
DEC
3
50pF
Figure 6. RF Input Return Loss
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).
C C fc R fc pF
S S
IN
1 2
9
1
50
2 25 10
= = =
π
. • ( )
LR
fc fc nH
MIN
= =
50
2
2 25 1010
π
. • ( )
where RIN is the differential input resistance (400Ω) 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.
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 50Ω input termination, the approximate RF input
power range of the LTC5582 is from –60dBm to 2dBm,
RF INPUT
CS1
6.8pF
CS2
6.8pF
TO IN–
TO IN+
5582 F05
MATCHING NETWORK
LM
66nH
FREQUENCY (MHz)
0
RETURN LOSS (dB)
0
–5
–10
–15
–20
–25
–30
5582 F06
1000900800700600500400300200100
RF INPUT POWER (dBm)
–75 –65 –25–45 –5
5582 F07
5–35–55 –15
SINGLE-ENDED-TO-
DIFFERENTIAL INPUTS
SINGLE-ENDED
OUTPUT VOLTAGE (V)
2.8
2.4
1.6
0.8
2.0
1.2
0.4
LTC5582
12
5582f
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 ap-
plication 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 ob-
served 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 imped-
ance is determined primarily by the 100Ω series resistor
applicaTions inForMaTion
Figure 8. Residual Ripple, Output Transient Times vs
Filtering Capacitor C3
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 5µs, 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.
100Ω RSS
OUT
INPUT
VCC
VOUT
CLOAD
5582 F09
LTC5582
FILTERNING CAPACITOR C3 (nF)
0
RIPPLE (mVP-P), FALL TIME (µs)
RISE TIME (µs)
1000200 400 600 800
0
500
450
400
350
300
250
200
150
100
50
0
50
45
40
35
30
25
20
15
10
5
5582 F08
RIPPLE
RISE TIME
FALL TIME
LTC5582
13
5582f
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 5μs), the
maximum value of CLOAD can be chosen as follows:
C mA allowable additional time
V
mA
LOAD ≤ =51 7
5
•.
•• .
.
0 25
1 7 735
µs
VpF=
Once CLOAD is determined, RSS can be chosen properly
to form a RC low-pass filter with a corner frequency of
1/[2π(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 tempera-
ture 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:
ΔVOUT = –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 refer-
ence 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
Figure 11. 1st-Order Temperature Compensation Coefficient
TC1 vs RT1 Value
Figure 10. Simplified Interface Circuit Schematic of the
Control Pins RT1 and RT2
TC2 are shown as functions of the tuning resistors RT1
and RT2 in Figures 11 and 12, respectively.
When Pins RT1 and RT2 are shorted to ground, the tem-
perature 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.
Table 2. Suggested RT1 and RT2 Values for Optimal Temperature
Performance vs RF Frequency
FREQUENCY (MHz) RT1 (kΩ) RT2 (kΩ)
450 12 2
880 12 2
2140 0 2
2700 0 1.6
3600 0 1.6
5800 0 3
250Ω
RT1 OR RT2
RT1 OR RT2
VCC
5582 F10
LTC5582
RT1 (kΩ)
5
TC1 (mV/°C)
detV1 (mV)
0.8
0.2
15 25 35 40302010
0
1.2
0.4
0.6
1.0 100
40
80
60
20
0
120
5582 F11
TC1
detV1
LTC5582
14
5582f
applicaTions inForMaTion
Figure 12. 2nd-Order Temperature Compensation Coefficient
TC2 vs RT2 Value
RT2 (kΩ)
0
TC2 (µV/°C)
detV2 (mV)
12
32 5 7 8641
0
20
4
8
16 160
40
80
120
0
200
5582 F12
TC2
detV2
Figure 13. Enable Pin Simplified Circuit
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 volt-
age 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 maxi-
mum 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., 1.5Ω) 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.
52k
VCC
5582 F13
52k
EN
LTC5582
15
5582f
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 representa-
tion that the interconnection of its circuits as described herein will not infringe on existing patent rights.
package DescripTion
3.00 p0.10
(4 SIDES)
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
0.40 p 0.10
BOTTOM VIEW—EXPOSED PAD
1.65 p 0.10
(2 SIDES)
0.75 p0.05
R = 0.125
TYP
2.38 p0.10
(2 SIDES)
15
106
PIN 1
TOP MARK
(SEE NOTE 6)
0.200 REF
0.00 – 0.05
(DD) DFN REV B 0309
0.25 p 0.05
2.38 p0.05
(2 SIDES)
RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS
1.65 p0.05
(2 SIDES)2.15 p0.05
0.50
BSC
0.70 p0.05
3.55 p0.05
PACKAGE
OUTLINE
0.25 p 0.05
0.50 BSC
DD Package
10-Lead Plastic DFN (3mm × 3mm)
(Reference LTC DWG # 05-08-1699 Rev B)
LTC5582
16
5582f
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com
LINEAR TECHNOLOGY CORPORATION 2010
LT 0510 • PRINTED IN USA
relaTeD parTs
Typical applicaTion
PART NUMBER DESCRIPTION COMMENTS
RF Power Detectors
LTC5505 RF Power Detectors with >40dB Dynamic Range 300MHz to 3GHz, Temperature Compensated, 2.7V to 6V Supply
LTC5507 100kHz to 1000MHz RF Power Detector 100kHz to 1GHz, Temperature Compensated, 2.7V to 6V Supply
LTC5508 300MHz to 7GHz RF Power Detector 44dB Dynamic Range, Temperature Compensated, SC70 Package
LTC5509 300MHz to 3GHz RF Power Detector 36dB Dynamic Range, Low Power Consumption, SC70 Package
LTC5530 300MHz to 7GHz Precision RF Power Detector Precision VOUT Offset Control, Shutdown, Adjustable Gain
LTC5531 300MHz to 7GHz Precision RF Power Detector Precision VOUT Offset Control, Shutdown, Adjustable Offset
LTC5532 300MHz to 7GHz Precision RF Power Detector Precision VOUT Offset Control, Adjustable Gain and Offset
LT5534 50MHz to 3GHz Log RF Power Detector with 60dB
Dynamic Range
±1dB Output Variation over Temperature, 38ns Response Time, Log Linear
Response
LTC5536 Precision 600MHz to 7GHz RF Power Detector
with Fast Comparator Output
25ns Response Time, Comparator Reference Input, Latch Enable Input,
–26dBm to +12dBm Input Range
LT5537 Wide Dynamic Range Log RF/IF Detector Low Frequency to 1GHz, 83dB Log Linear Dynamic Range
LT5538 75dB Dynamic Range 3.8GHz Log RF Power
Detector
±0.8dB Accuracy Over Temperature
LT5570 60dB Dynamic Range RMS Detector 40MHz to 2.7GHz, ±0.5dB Accuracy Over Temperature
LT5581 6GHz RMS Power Detector with 40dB Dynamic
Range
±1dB Accuracy Over Temperature, Log Linear Response, 1.4mA at 3.3V
Infrastructure
LTC5540/LTC5541/
LTC5542/LTC5543
600MHz to 4GHz High Dynamic Range
Downconverting Mixer
IIP3 = 26dBm, 8dB Conversion Gain, <10dB NF, 3.3V, 190mA Supply Operation
LT5579 1.5GHz to 3.8GHz High Linearity Upconverting
Mixer
27.3dBm OIP3 at 2.14GHz, 9.9dB NF, 2.6dB Conversion Gain, –35dBm LO
Leakage
LTC5598 5MHz to 1600MHz High Linearity Direct
Quadrature Modulator
27.7dBm OIP3 at 140MHz, –161.2dBm/Hz Noise Floor, 0.5VDC Baseband
Interface, –55dBm LO Leakage and 50.4dBc Image Rejection at 140MHz
1nF
VCC
IN+
IN–
GND
FLTR
EN
OUT OUT
RT2
DEC RT1
100nF
3.3V
RFIN
5582 TA02
LTC5582
1µF
1nF
1
2
3
4
5
10
9
8
7
6
270pF
68Ω
11
EXPOSED PAD
50Ω
ADC
PA
DIGITAL
POWER
CONTROL
DIRECTIONAL
COUPLER
40MHz to 6GHz Infrastructure Power Amplifier Level Control