200 MHz to 6 GHz
35 dB TruPwr™ Detector
Data Sheet
ADL5903
Rev. B Document Feedback
Information furnished by Analog Devices is believed to be accurate and reliable. However, no
responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other
rights of third parties that may result from its use. Specifications subject to change without notice. No
license is granted by implication or otherwise under any patent or patent rights of Analog Devices.
Trademarks and registered trademarks are the property of their respective owners.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781.329.4700 ©2013–2015 Analog Devices, Inc. All rights reserved.
Technical Support www.analog.com
FEATURES
Accurate rms-to-dc conversion from 200 MHz to 6 GHz
Measurement dynamic range of 35 dB
Ripple-free transfer function
Single-ended input, 50 Ω source compatible
No external matching required
Waveform and modulation independent, such as
GSM/CDMA/W-CDMA/TD-SCDMA/LTE
Linear in decibels output, scaled 35.5 mV/dB at 900 MHz
Excellent temperature stability
Operates from 3.0 V to 5.0 V from −55°C to +125°C
Low power consumption: 3 mA at 3.0 V to 5.0 V supply
8-lead, 2 mm × 2 mm LFCSP package
APPLICATIONS
Power amplifier linearization/control loops
Transmitter power controls
Transmitter signal strength indication (TSSI)
RF instrumentation
Wireless repeaters
FUNCTIONAL BLOCK DIAGRAM
Figure 1.
GENERAL DESCRIPTION
The ADL5903 is a true rms responding power detector that has
a 35 dB measurement range. It features low power consumption
and an intrinsically ripple-free error transfer function.
The ADL5903 provides a solution in a variety of high frequency
systems requiring an accurate measurement of signal power.
Requiring only a single supply of 3.0 V to 5.0 V and a few
capacitors, it is easy to use and capable of being driven single-
ended or with a balun for differential input drive. An on-chip
matching network provides good return loss over the specified
frequency range of the device. The ADL5903 can operate from
200 MHz to 6 GHz and can accept inputs from −30 dBm to
+20 dBm.
The ADL5903 can be used to determine the true power of a
high frequency signal with a complex modulation envelope
including large crest factor signals such as GSM, CDMA,
W-CDMA, TD-SCDMA, and LTE modulated signals. The
output is then proportional to the logarithm of the rms value
of the input. In other words, the reading is presented directly
in decibels and is scaled about 35.5 mV/dB at 900 MHz.
The ADL5903 has low power consumption when operational
and a disable mode that further reduces the power consumption.
Power consumption is less than 100 µA when the ADL5903
enters power-down mode through a logic low at Pin ENBL.
The ADL5903 is supplied in a 2 mm × 2 mm, 8-lead LFCSP for
operation over the wide temperature range of −55°C to +125°C.
11769-001
5
1
6
ADL5903
RFIN
ENBL
RMS CORE
INTERNAL
FILTERING
BUFFER
630pF
1kΩ
100Ω
4pF
VPOS
2
GND 8
NIC EP
4
CREG
3CRMS
7VRMS
ADL5903 Data Sheet
Rev. B | Page 2 of 20
TABLE OF CONTENTS
Features .............................................................................................. 1
Applications ....................................................................................... 1
Functional Block Diagram .............................................................. 1
General Description ......................................................................... 1
Revision History ............................................................................... 2
Specifications ..................................................................................... 3
Absolute Maximum Ratings ............................................................ 6
ESD Caution .................................................................................. 6
Pin Configuration and Function Descriptions ............................. 7
Typical Performance Characteristics ............................................. 8
Measurement Setups ...................................................................... 14
Theory of Operation ...................................................................... 15
RF Input Interface ...................................................................... 15
Basic Connections ...................................................................... 15
Choosing a Value for CRMS ......................................................... 16
Device Calibration and Error Calculation .............................. 17
Evaluation Board Schematic and Configuration Options ........ 19
Outline Dimensions ....................................................................... 20
Ordering Guide .......................................................................... 20
REVISION HISTORY
5/15—Rev. A to Rev. B
Changes to Figure 49 ...................................................................... 19
2/15—Rev. 0 to Rev. A
Added ADL5903ACPZN Operating Temperature Range of
−40°C to +85°C; Table 2 .................................................................. 6
Changes to Ordering Guide .......................................................... 20
10/13—Revision 0: Initial Version
Data Sheet ADL5903
Rev. B | Page 3 of 20
SPECIFICATIONS
VPOS = 5.0 V, T A = 25°C, ZO = 50 Ω, Capacitor CRMS = 10 nF, unless otherwise noted.
Table 1.
Parameter Test Conditions/Comments Min Typ Max Unit
OVERALL FUNCTION
Frequency Range 200 to 6000 MHz
RF INPUT INTERFACE Pin RFIN
Nominal Input Impedance
1
Single-ended drive
Ω
OUTPUT INTERFACE Pin VRMS
DC Output Resistance 100 Ω
Rise Time PIN = off to 0 dBm, 10% to 90%, CRMS = 10 nF 3.5 µs
PIN = off to 0 dBm, 10% to 90%, CRMS = 100 nF 34 µs
Fall Time PIN = 0 dBm to off, 90% to 10%, CRMS = 10 nF 32 µs
PIN = 0 dBm to off, 90% to 10%, CRMS = 100 nF 330 µs
f = 300 MHz
±1.0 dB Dynamic Range Continuous wave (CW) input, TA = 25°C, VPOS = 5.0 V 37 dB
CW input, TA = 25°C, VPOS = 3.0 V 34 dB
Maximum Input Level, ±1.0 dB Three-point calibration at −16 dBm, −4 dBm, and +12 dBm 13 dBm
Minimum Input Level, ±1.0 dB Three-point calibration at −16 dBm, −4 dBm, and +12 dBm −24 dBm
Deviation vs. Temperature Deviation from output at 25°C
−40°C < TA < +85°C; PIN = 10 dBm −0.2/+0.032 dB
−55°C < TA < +125°C; PIN = 10 dBm −0.25/+0.052 dB
−40°C < TA < +85°C; PIN = −10 dBm −0.2/+0.152 dB
−55°C < TA < +125°C; PIN = −10 dBm −0.25/+0.22 dB
Logarithmic Slope Calibration at −16 dBm and +4 dBm 36.3 mV/dB
Logarithmic Intercept Calibration at −16 dBm and +4 dBm (X-intercept) −39 dBm
f = 700 MHz
±1.0 dB Dynamic Range
CW input, T
A
= 25°C, VPOS = 5.0 V
dB
CW input, TA = 25°C, VPOS = 3.0 V 34 dB
Maximum Input Level, ±1.0 dB Three-point calibration at −16 dBm, −3 dBm, and +13 dBm 14 dBm
Minimum Input Level, ±1.0 dB Three-point calibration at −16 dBm, −3 dBm, and +13 dBm −23 dBm
Deviation vs. Temperature Deviation from output at 25°C
−40°C < T
A
< +85°C; P
IN
= 10 dBm
dB
−55°C < TA < +125°C; PIN = 10 dBm −0.16 dB
−40°C < TA < +85°C; PIN = −10 dBm −0.15/+0.12 dB
−55°C < TA < +125°C; PIN = −10 dBm −0.2/+0.22 dB
Logarithmic Slope Calibration at −16 dBm and +4 dBm 36.4 mV/dB
Logarithmic Intercept Calibration at −16 dBm and +4 dBm (X-intercept) −38 dBm
f = 900 MHz
±1.0 dB Dynamic Range CW input, TA = 25°C, VPOS = 5.0 V 37 dB
CW input, TA = 25°C, VPOS = 3.0 V 33 dB
Maximum Input Level, ±1.0 dB
Three-point calibration at −16 dBm, −3 dBm, and +13 dBm
dBm
Minimum Input Level, ±1.0 dB Three-point calibration at −16 dBm, −3 dBm, and +13 dBm −23 dBm
Deviation vs. Temperature Deviation from output at 25°C
−40°C < TA < +85°C; PIN = 10 dBm −0.12 dB
−55°C < TA < +125°C; PIN = 10 dBm −0.15/+0.022 dB
−40°C < T
A
< +85°C; P
IN
= −10 dBm
2
dB
−55°C < TA < +125°C; PIN = −10 dBm −0.1/+0.12 dB
Logarithmic Slope Calibration at −16 dBm and +4 dBm 35.5 mV/dB
Logarithmic Intercept Calibration at −16 dBm and +4 dBm (X-intercept) −38 dBm
ADL5903 Data Sheet
Rev. B | Page 4 of 20
Parameter Test Conditions/Comments Min Typ Max Unit
f = 1900 MHz
±1.0 dB Dynamic Range CW input, TA = 25°C, VPOS = 5.0 V 37 dB
CW input, TA = 25°C, VPOS = 3.0 V 33 dB
Maximum Input Level, ±1.0 dB Three-point calibration at −15 dBm, −3 dBm, and +13 dBm 15 dBm
Minimum Input Level, ±1.0 dB
Three-point calibration at −15 dBm, −3 dBm, and +13 dBm
dBm
Deviation vs. Temperature Deviation from output at 25°C
−40°C < TA < +85°C; PIN = 10 dBm −0.15 dB
−55°C < TA < +125°C; PIN = 10 dBm −0.15 dB
−40°C < TA < +85°C; PIN = −10 dBm −0.3/+0.22 dB
−55°C < TA < +125°C; PIN = −10 dBm −0.35/+0.252 dB
Logarithmic Slope Calibration at −16 dBm and +4 dBm 37.2 mV/dB
Logarithmic Intercept Calibration at −16 dBm and +4 dBm (X-intercept) −35.5 dBm
f = 2140 MHz
±1.0 dB Dynamic Range
CW input, T
A
= 25°C, VPOS = 5.0 V
dB
CW input, TA = 25°C, VPOS = 3.0 V 32 dB
Maximum Input Level, ±1.0 dB Three-point calibration at −15 dBm, −3 dBm, and +13 dBm 15 dBm
Minimum Input Level, ±1.0 dB Three-point calibration at −15 dBm, −3 dBm, and +13 dBm −20 dBm
Deviation vs. Temperature Deviation from output at 25°C
−40°C < T
A
< +85°C; P
IN
= 10 dBm
dB
−55°C < TA < +125°C; PIN = 10 dBm −0.2 dB
−40°C < TA < +85°C; PIN = −10 dBm −0.4/+0.22 dB
−55°C < TA < +125°C; PIN = −10 dBm −0.5/+0.32 dB
Logarithmic Slope Calibration at −16 dBm and +4 dBm 37.4 mV/dB
Logarithmic Intercept Calibration at −16 dBm and +4 dBm (X-intercept) −35 dBm
f = 2600 MHz
±1.0 dB Dynamic Range CW input, TA = 25°C, VPOS = 5.0 V 34 dB
CW input, TA = 25°C, VPOS = 3.0 V 32 dB
Maximum Input Level, ±1.0 dB Three-point calibration at −14 dBm, −2 dBm, and +14 dBm 15 dBm
Minimum Input Level, ±1.0 dB Three-point calibration at −14 dBm, −2 dBm, and +14 dBm −19 dBm
Deviation vs. Temperature Deviation from output at 25°C
−40°C < TA < +85°C; PIN = 10 dBm −0.2 dB
−55°C < TA < +125°C; PIN = 10 dBm −0.25 dB
−40°C < T
A
< +85°C; P
IN
= −10 dBm
2
dB
−55°C < TA < +125°C; PIN = −10 dBm −0.6/+0.32 dB
Logarithmic Slope Calibration at −16 dBm and +4 dBm 37.7 mV/dB
Logarithmic Intercept Calibration at −16 dBm and +4 dBm (X-intercept) −34 dBm
f = 3500 MHz
±1.0 dB Dynamic Range CW input, TA = 25°C, VPOS = 5.0 V 33 dB
CW input, TA = 25°C, VPOS = 3.0 V 31 dB
Maximum Input Level, ±1.0 dB Three-point calibration at −12 dBm, 0 dBm, and +14 dBm 16 dBm
Minimum Input Level, ±1.0 dB Three-point calibration at −12 dBm, 0 dBm, and +14 dBm −17 dBm
Deviation vs. Temperature Deviation from output at 25°C
−40°C < TA < +85°C; PIN = 10 dBm −0.2 dB
−55°C < TA < +125°C; PIN = 10 dBm −0.25 dB
−40°C < TA < +85°C; PIN = −10 dBm −0.6/+0.32 dB
−55°C < TA < +125°C; PIN = −10 dBm −0.75/+0.42 dB
Logarithmic Slope
Calibration at −12 dBm and +8 dBm
mV/dB
Logarithmic Intercept Calibration at −12 dBm and +8 dBm (X-intercept) −31.5 dBm
Data Sheet ADL5903
Rev. B | Page 5 of 20
Parameter Test Conditions/Comments Min Typ Max Unit
f = 5800 MHz
±1.0 dB Dynamic Range CW input, TA = 25°C, VPOS = 5.0 V 35 dB
CW input, TA = 25°C, VPOS = 3.0 V 32 dB
Maximum Input Level, ±1.0 dB Three-point calibration at −12 dBm, −2 dBm, and +12 dBm 19 dBm
Minimum Input Level, ±1.0 dB
Three-point calibration at −12 dBm, −2 dBm, and +12 dBm
dBm
Deviation vs. Temperature Deviation from output at 25°C
−40°C < TA < +85°C; PIN = 10 dBm −0.6/+0.32 dB
−55°C < TA < +125°C; PIN = 10 dBm −0.7/+0.42 dB
−40°C < TA < +85°C; PIN = −10 dBm −1.1/+0.72 dB
−55°C < TA < +125°C; PIN = −10 dBm −1.4/+1.12 dB
Logarithmic Slope Calibration at −12 dBm and +8 dBm 40 mV/dB
Logarithmic Intercept Calibration at −12 dBm and +8 dBm (X-intercept) −27 dBm
POWER-DOWN INTERFACE Pin ENBL
Voltage Level to Enable
2
VPOS
V
Voltage Level to Disable 0 0.6 V
Input Bias Current VENBL = 2.2 V <20 nA
POWER SUPPLY INTERFACE Pin VPOS
Supply Voltage 3.0 5.25 V
Quiescent Current TA = 25°C, no signal at RFIN, VPOS = 5.0 V 3 mA
TA = 125°C, no signal at RFIN, VPOS = 5.0 V 3.6 mA
Power-Down Current ENBL input low condition <100 µA
1 Refer to Figure 12, input return loss, S11 (dB).
2 The slash indicates a range. For example, −0.2/+0.03 means −0.2 to +0.03.
ADL5903 Data Sheet
Rev. B | Page 6 of 20
ABSOLUTE MAXIMUM RATINGS
Table 2.
Parameter Rating
Supply Voltage, VPOS 5.5 V
Input Average RF Power1, 2 20 dBm
Equivalent Voltage, Sine Wave Input 3.16 V peak
Internal Power Dissipation 200 mW
θJC3 3.95°C/W
θJA3 78.5°C/W
Maximum Junction Temperature 150°C
Operating Temperature Range
(ADL5903ACPZN)
−40°C to +85°C
Operating Temperature Range
(ADL5903SCPZN)
−55°C to +125°C
Storage Temperature Range −65°C to +150°C
Lead Temperature (Soldering, 60 sec) 300°C
1 This is for long durations. Excursions above this level, with durations much
less than 1 second, are possible without damage.
2 Driven from a 50 Ω source.
3 No airflow with the exposed pad soldered to a 4-layer JEDEC board.
Stresses at or above those listed under Absolute Maximum
Ratings may cause permanent damage to the product. This is a
stress rating only; functional operation of the product at these
or any other conditions above those indicated in the operational
section of this specification is not implied. Operation beyond
the maximum operating conditions for extended periods may
affect product reliability.
ESD CAUTION
Data Sheet ADL5903
Rev. B | Page 7 of 20
PIN CONFIGURATION AND FUNCTION DESCRIPTIONS
Figure 2. Pin Configuration
Table 3. Pin Function Descriptions
Pin No. Mnemonic Description
1 RFIN
Signal Input. This pin is internally ac-coupled with a broadband matching network. See the RF Input Interface
section for broadband matching options.
2 GND Device Ground. Connect GND to system ground using a low impedance path.
3 CRMS
RMS Averaging Pin. Connect a capacitor between the CREG and CRMS pins for rms averaging. See the
Choosing a Value for CRMS section for choosing the correct CRMS capacitor value.
4 CREG
Bypass Capacitor Connection for On-Chip Regulator. Bypass this pin to ground using a capacitor and a series
resistor. See Basic Connections section for more information.
5 VPOS Supply Voltage. The operational range is 3.0 V to 5.25 V.
6 ENBL
Enable. Connect the ENBL pin to a logic high (2 V to VPOS) to enable the device. Connect the ENBL pin to a
logic low (0 V to 0.6 V) to disable the device.
7 VRMS
Signal Output. The output from the VRMS pin is proportional to the logarithm of the rms value at the input
level.
8 NIC No Internal Connection. Do not connect to this pin. This pin is not internally connected.
0 EP Exposed Pad. The exposed pad is internally connected to GND and requires a good thermal and electrical
connection to the ground of the printed circuit board (PCB).
11769-002
3CRMS
4CREG
1RFIN
2GND
6 ENBL
5 VPOS
8NIC
7VRMS
ADL5903
TOP VI EW
(Not to Scale)
NOTES
1. NIC = NO INT E RNAL CO NNE CTI ON.
2
.TH E E XPOS E D P AD IS I NTER NAL LY CONNE CT E D TO GND
AND REQUIRES A GOOD THERMAL AND ELECTRICAL
CONNECTI ON TO THE GROUND OF THE PRINTED
CIRC UI T BO ARD ( P CB) .
ADL5903 Data Sheet
Rev. B | Page 8 of 20
TYPICAL PERFORMANCE CHARACTERISTICS
VPOS = 5.0 V, CRMS = 10 n F, TA = −55°C (light blue), TA = −40°C (blue), +25°C (green), +85°C (red), +125°C (orange) where appropriate.
Input levels referred to 50 Ω source. Input RF signal is a sine wave (CW), unless otherwise indicated.
Figure 3. Typical VRMS vs. Input Level vs. Frequency
(300 MHz to 5.80 GHz) at 25°C
Figure 4. Error from CW Linear Reference vs. Input Level and Signal
Modulation (QPSK, 16 QAM, 64 QAM), Frequency = 900 MHz, CRMS = 1 µF
Figure 5. Error from CW Linear Reference vs. Input Level and Signal
Modulation (One-Carrier W-CDMA, Four-Carrier W-CDMA),
Frequency = 2.14 GHz, CRMS = 1 µF
Figure 6. Typical VRMS vs. Frequency for Four Input Levels
Figure 7. Error from CW Linear Reference vs. Input Level and Signal
Modulation (QPSK, 16 QAM, 64 QAM), Frequency = 2.14 GHz, CRMS = 1 µF
Figure 8. Error from CW Linear Reference vs. Input Level and Signal
Modulation (LTE TM1 One-Carrier, 20 MHz),
Frequency = 2.14 GHz, CRMS = 1 µF
20151050–5–10–15–20–25–30–35–40
2.0
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0.0
P
IN
(d Bm)
OUTPUT VOLTAGE (V)
300MHz
700MHz
900MHz
1.90GHz
2.14GHz
2.60GHz
3.50GHz
5.80GHz
11769-003
11769-004
1050–5–10–15–20–30
2.4
2.2
2.0
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0
P
IN
(d Bm)
OUTPUT VOLTAGE (V)
CW
16 QAM P E P = 6. 34dB
64 QAM P E P = 7. 17dB
QPSK PEP = 3.8dB
6
5
4
3
2
1
0
–1
–2
–3
–4
–5
–6
ERROR (dB)
CALIBRATIONAT –16dBm, –3dBm, AND +8dBm
–25
11769-005
2.4
2.2
2.0
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0
6
5
4
3
2
1
0
–1
–2
–3
–4
–5
–6
P
IN
(d Bm)
OUTPUT VOLTAGE (V)
ERROR (dB)
CW
4-CARRIER W-CDMA PEP = 12.08dBm
1-CARRIER W-CDMA PEP = 10.56dB
1050–5–10–15–20–25–30
CALIBRATIONAT –15dBm, –3dBm, AND +8dBm
1G 6G100M
2.0
1.5
1.0
0.5
0
FREQUENCY (Hz)
OUTPUT VOLTAGE (V)
–20dBm
–10dBm
0dBm
10dBm
11769-006
11769-007
1050–5–10–15–20–25–30
2.4
2.2
2.0
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0
P
IN
(d Bm)
OUTPUT VOLTAGE (V)
6
5
4
3
2
1
0
–1
–2
–3
–4
–5
–6
ERROR (dB)
CW
16 QAM P E P = 6. 34dB
64 QAM P E P = 7. 17dB
QPSK PEP = 3.8dB
CALIBRATIONAT –15dBm, –3dBm, AND +8dBm
1050–5–10–15–20–25–30
2.4
2.2
2.0
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0
6
5
4
3
2
1
0
–1
–2
–3
–4
–5
–6
P
IN
(d Bm)
OUTPUT VOLTAGE (V)
ERROR (dB)
CW
LT E TM1 1-CARRIER 20M Hz P EP = 11.58dB
11769-008
CALIBRATIONAT –15dBm, –3dBm, AND +8dBm
Data Sheet ADL5903
Rev. B | Page 9 of 20
Figure 9. Output Voltage vs. Input Level and Supply Voltage at 900 MHz
Figure 10. Output Response to RF Burst Input, Carrier Frequency = 900 MHz,
CRMS = 100 nF (see Figure 36 in the Measurement Setups Section)
Figure 11. Output Response to Gating on ENBL Pin for Various RF Input
Levels, Carrier Frequency = 900 MHz, CRMS = 100 nF (see Figure 38 in the
Measurement Setups Section)
Figure 12. Input Return Loss vs. RF Frequency
Figure 13. Output Response to RF Burst Input, Carrier Frequency = 900 MHz,
CRMS = 10 nF (see Figure 36 in the Measurement Setups Section)
Figure 14. Output Response to Gating on Power Supply for Various RF Input
Levels, Carrier Frequency = 900 MHz, CRMS = 100 nF, 5.0 V Supply
(see Figure 37, in the Measurement Setups Section))
0
0.5
1.0
1.5
2.0
2.5
–40 –30 –20 –10 010 20
OUTPUT VOLTAGE (V)
P
IN
(d Bm)
3.00V
3.40V
3.80V
4.00V
4.25V
4.50V
5.00V
11769-009
4.00V TO 5.00V FOLLOW SAME PLOT
0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
–0.4 –0.2 00.2 0.4 0.6 0.8 1.0 1.2
VOUT (V)
TIME (ms)
RF BURST PULSE
+5dBm
0dBm
–5dBm
–15dBm
11769-010
0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
–0.2 –0.1 00.1 0.2 0.3 0.4 1.5 0.6
OUTPUT (V)
TIME (ms)
11769-016
ENABLE PULSE
+5 dBm
0 dBm
–5 dBm
–15 dBm
–25
–20
–15
–10
–5
0
0123456
RET URN LOS S , S
11
(d B)
FREQUENCY (GHz)
11769-012
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
–0.2 00.2 0.4 0.6 0.8
OUTPUT (V)
TIME (ms)
+5dBm
0dBm
–5dBm
–15dBm
RF BURST PULSE
11769-011
0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
–0.2 –0.1 00.1 0.2 0.3 0.4 0.5 0.6
OUTPUT (V)
TIME (ms)
SUPPLY VOLTAGE PULSE
+5dBm
0dBm
–5dBm
–15dBm
11769-015
ADL5903 Data Sheet
Rev. B | Page 10 of 20
Figure 15. VRMS and Log Conformance Error vs. Input Level and Temperature
at 300 MHz
Figure 16. VRMS and Log Conformance Error vs. Input Level and Temperature
at 700 MHz
Figure 17. VRMS and Log Conformance Error vs. Input Level and Temperature
at 900 MHz
Figure 18. Distribution of Log Conformance Error with Respect to Calibration
at 25°C vs. Input Level and Temperature at 300 MHz
Figure 19. Distribution of Log Conformance Error with Respect to Calibration
at 25°C vs. Input Level and Temperature at 700 MHz
Figure 20. Distribution of Log Conformance Error with Respect to Calibration
at 25°C vs. Input Level and Temperature at 900 MHz
20
15
105
0
–5
–10
–15
–20–25
–30
–35–40
2.4
2.2
2.0
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0
6
5
4
3
2
1
0
–1
–2
–3
–4
–5
–6
P
IN
(d Bm)
OUTPUT VOLTAGE (V)
ERROR (dB)
–55°C
–40°C
+25°C
+85°C
+125°C
11769-017
CALIBRATIONAT –16dBm, –4dBm, AND +12dBm
20
15
105
0
–5
–10
–15
–20–25
–30–35–40
2.4
2.2
2.0
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0
6
5
4
3
2
1
0
–1
–2
–3
–4
–5
–6
P
IN
(d Bm)
OUTPUT VOLTAGE (V)
ERROR (dB)
–55°C
–40°C
+25°C
+85°C
+125°C
11769-021
CALIBRATIONAT –16dBm, –3dBm, AND +13dBm
20
15
105
0
–5
–10
–15
–20–25–30–35–40
2.4
2.2
2.0
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0
6
5
4
3
2
1
0
–1
–2
–3
–4
–5
–6
P
IN
(d Bm)
OUTPUT VOLTAGE (V)
ERROR (dB)
–55°C
–40°C
+25°C
+85°C
+125°C
11769-022
CALIBRATIONAT –16dBm, –3dBm, AND +13dBm
20
1510
5
0–5
–10
–15–20
–25
–30
–35
–40
2.4
2.2
2.0
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0
6
5
4
3
2
1
0
–1
–2
–3
–4
–5
–6
PIN (dBm)
OUTPUT VOLTAGE (V)
ERROR (dB)
–55°C
–40°C
+25°C
+85°C
+125°C
11769-020
20151050–5–10–15–20–25–30–35–40
2.4
2.2
2.0
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0
6
5
4
3
2
1
0
–1
–2
–3
–4
–5
–6
PIN (dBm)
OUTPUT VOLTAGE (V)
ERROR (dB)
11769-024
–55°C
–40°C
+25°C
+85°C
+125°C
2.4
2.2
2.0
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0
6
5
4
3
2
1
0
–1
–2
–3
–4
–5
–6
OUTPUT VOLTAGE (V)
ERROR (dB)
–55°C
–40°C
+25°C
+85°C
+125°C
20151050–5–10–15–20–25–30–35–40 PIN (dBm)
11769-025
Data Sheet ADL5903
Rev. B | Page 11 of 20
Figure 21. VRMS and Log Conformance Error vs. Input Level and Temperature
at 1.9 GHz
Figure 22. VRMS and Log Conformance Error vs. Input Level and Temperature
at 2.14 GHz
Figure 23. VRMS and Log Conformance Error vs. Input Level and Temperature
at 2.6 GHz
Figure 24. Distribution of Log Conformance Error with Respect to Calibration
at 25°C vs. Input Level and Temperature at 1.9 GHz
Figure 25. Distribution of Log Conformance Error with Respect to Calibration
at 25°C vs. Input Level and Temperature at 2.14 GHz
Figure 26. Distribution of Log Conformance Error with Respect to Calibration
at 25°C vs. Input Level and Temperature at 2.6 GHz
20151050–5–10–15–20–25–30–35–40
2.4
2.2
2.0
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0
6
5
4
3
2
1
0
–1
–2
–3
–4
–5
–6
P
IN
(d Bm)
OUTPUT VOLTAGE (V)
ERROR (dB)
–55°C
–40°C
+25°C
+85°C
+125°C
11769-023
CALIBRATIONAT –15dBm, –3dBm, AND +13dBm
2.4
2.2
2.0
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0
6
5
4
3
2
1
0
–1
–2
–3
–4
–5
–6
OUTPUT VOLTAGE (V)
20151050–5–10–15–20–25–30–35–40 PIN (dBm)
ERROR (dB)
–55°C
–40°C
+25°C
+85°C
+125°C
11769-027
CALIBRATIONAT –15dBm, –3dBm, AND +13dBm
2.4
2.2
2.0
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0
6
5
4
3
2
1
0
–1
–2
–3
–4
–5
–6
OUTPUT VOLTAGE (V)
20151050–5–10–15–20–25–30–35–40 P
IN
(d Bm)
ERROR (dB)
2015
–55°C
–40°C
+25°C
+85°C
+125°C
11769-028
CALIBRATIONAT –14dBm, –2dBm, AND +14dBm
2.4
2.2
2.0
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0
6
5
4
3
2
1
0
–1
–2
–3
–4
–5
–6
OUTPUT VOLTAGE (V)
ERROR (dB)
20151050–5–10–15–20–25–30–35–40 P
IN
(d Bm)
11769-026
–55°C
–40°C
+25°C
+85°C
+125°C
2.4
2.2
2.0
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0
6
5
4
3
2
1
0
–1
–2
–3
–4
–5
–6
OUTPUT VOLTAGE (V)
ERROR (dB)
20151050–5–10–15–20–25–30–35–40 PIN (dBm)
11769-030
–55°C
–40°C
+25°C
+85°C
+125°C
2.4
2.2
2.0
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0
6
5
4
3
2
1
0
–1
–2
–3
–4
–5
–6
OUTPUT VOLTAGE (V)
ERROR (dB)
–55°C
–40°C
+25°C
+85°C
+125°C
20151050–5–10–15–20–25–30–35–40 P
IN
(d Bm)
11769-031
ADL5903 Data Sheet
Rev. B | Page 12 of 20
Figure 27. VRMS and Log Conformance Error vs. Input Level and Temperature
at 3.5 GHz
Figure 28. VRMS and Log Conformance Error vs. Input Level and Temperature
at 5.8 GHz
Figure 29. Distribution of VRMS, PIN = 8 dBm, 900 MHz
Figure 30. Distribution of Log Conformance Error with Respect to Calibration
at 25°C vs. Input Level and Temperature at 3.5 GHz
Figure 31. Distribution of Log Conformance Error with Respect to Calibration
at 25°C vs. Input Level and Temperature at 5.8 GHz
Figure 32. Distribution of VRMS, PIN = −16 dBm, 900 MHz
2.4
2.2
2.0
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0
6
5
4
3
2
1
0
–1
–2
–3
–4
–5
–6
OUTPUT VOLTAGE (V)
20151050–5–10–15–20–25–30–35–40 P
IN
(d Bm)
ERROR (dB)
2015
–55°C
–40°C
+25°C
+85°C
+125°C
11769-029
CALIBRATIONAT –12dBm, 0Bm, AND +14d Bm
2.4
2.2
2.0
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0
6
5
4
3
2
1
0
–1
–2
–3
–4
–5
–6
OUTPUT VOLTAGE (V)
20151050–5–10–15–20–25–30–35–40 P
IN
(d Bm)
ERROR (dB)
–55°C
–40°C
+25°C
+85°C
+125°C
11769-033
CALIBRATIONAT –12dBm, –2dBm, AND +12dBm
1.50 1.55 1.60 1.65 1.70 1.75
0
200
400
600
800
1000
1200
1400
V
RMS
(V)
COUNT
11769-034
REPRESENTS MORE
THAN 8000 PARTS
2.4
2.2
2.0
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0
6
5
4
3
2
1
0
–1
–2
–3
–4
–5
–6
OUTPUT VOLTAGE (V)
ERROR (dB)
–55°C
–40°C
+25°C
+85°C
+125°C
11769-032
20151050–5–10–15–20–25–30–35–40 P
IN
(d Bm)
2.4
2.2
2.0
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0
6
5
4
3
2
1
0
–1
–2
–3
–4
–5
–6
OUTPUT VOLTAGE (V)
ERROR (dB)
–55°C
–40°C
+25°C
+85°C
+125°C
11769-036
20
15
10
50
–5
–10–15–20
–25–30
–35
–40 PIN (dBm)
0.60 0.65 0.70 0.75 0.80 0.85
0
200
400
600
800
1000
1200
1400
V
RMS
(V)
COUNT
11769-037
REPRESENTS MORE
THAN 8000 PARTS
Data Sheet ADL5903
Rev. B | Page 13 of 20
Figure 33. Distribution of Intercept at 900 MHz
Figure 34. Supply Current vs. Input Level
(at −55°C, −40°C, +25°C, +85°C, +125°C)
Figure 35. Distribution of Slope at 900 MHz
–44 –42 –40 –38 –36 –34 –32
0
200
400
600
800
1000
1200
1400
INTERCEP T (d Bm)
COUNT
11769-038
REPRESENTS MORE
THAN 8000 PARTS
CALIBRATION BETWEEN
–16dBm AND –4dBm
20100–10–20–30–40
30
25
20
15
10
5
0
P
IN
(d Bm)
SUPPLY CURRENT (mA)
–55°C
–40°C
+25°C
+85°C
+125°C
11769-014
30 32 34 36 38 40
0
200
400
600
800
1000
1200
SLOPE (mV/dB)
COUNT
11769-035
REPRESENTS MORE
THAN 8000 PARTS
CALIBRATION BETWEEN
–16dBm AND –4dBm
ADL5903 Data Sheet
Rev. B | Page 14 of 20
MEASUREMENT SETUPS
Figure 36. Hardware Configuration for Output Response to RF Burst Input
Measurements
Figure 37. Hardware Configuration for Output Response to Power Supply
Gating Measurements
Figure 38. Hardware Configuration for Output Response to ENBL Pin Gating
Measurements
ROHDE & S CHWARZ
SIGNAL GENERATOR
SMR 40
ADL5903
EVALUATION
BOARD
PULSE IN
RF OUT RFIN
VPOS ENBL
1MΩ
TRIGGER
VRMS
HP E3631A
POWER
SUPPLY
AGI LENT 33522A
FUNCTION/ARBITRATRY
WAV E FORM GENERATO R
CH2
CH1
TEKTRONIX
DIGITAL PHOSPHOR
OSCILLOSCOPE
TDS5104
11769-013
AD8019
EVALUATION
BOARD
+1
11769-018
ROHDE & S CHWARZ
SIGNAL GENERATOR
SMR 40
ADL5903
EVALUATION
BOARD
PULSE IN
RF OUT RFIN
1MΩ
TRIGGER
VRMS
AGI LENT 33522A
FUNCTION/ARBITRATRY
WAV E FORM GENERATO R
CH2
CH1
TEKTRONIX
DIGITAL PHOSPHOR
OSCILLOSCOPE
TDS5104
VPOS ENBL
11769-019
ROHDE & S CHWARZ
SIGNAL GENERATOR
SMR 40
ADL5903
EVALUATION
BOARD
PULSE IN
RF OUT RFIN
VPOS ENBL
1MΩ
TRIGGER
VRMS
HP E3631A
POWER
SUPPLY
AGI LENT 33522A
FUNCTION/ARBITRATRY
WAV E FORM GENERATO R
CH2
CH1
TEKTRONIX
DIGITAL PHOSPHOR
OSCILLOSCOPE
TDS5104
Data Sheet ADL5903
Rev. B | Page 15 of 20
THEORY OF OPERATION
The ADL5903 is a true rms detector with a 35 dB measurement
range at 2.14 GHz with useable range up to 6 GHz. It features
no error ripple over its range, low temperature drift, and very
low power consumption. Temperature stability of the rms
output measurements provides ≤±0.5 dB error typical over the
temperature range of −40°C to +85°C up to 3.5 GHz. The
measurement output voltage scales linearly in decibels with a
slope of approximately 36 mV/dB.
The ADL5903 operates from a nominal supply voltage of 3.0 V
to 5.0 V. The rms core is internally regulated to 3.6 V, that is, the
full measurement range is available for supply voltages between
3.8 V and 5.0 V. Below 3.8 V, the high end of the measurement
range degrades gradually whereas the low end shows no noticeable
change in error characteristics or calibration requirements. At
2.14 GHz, the measurement range extends to 14 dBm for 3.8 V
and above, and to 12 dBm at a supply voltage of 3.0 V. The low
end of the ADL5903 measurement range is limited by internal
device offsets that vary from device to device but tracks well
over temperature. See the Device Calibration and Error
Calculation section for more information.
The core rms processing of the ADL5903 uses a proprietary
technique that provides accuracy for complex modulation
signals irrespective of the crest factor of the input signal. An
integrating filter capacitor at Pin CRMS performs the square
domain averaging.
An RF input matching network allows the device to be driven
with a 50 Ω source with reasonable input return loss. The
measurement intercept varies with frequency, as shown in
Table 1 and the Typical Performance Characteristics section.
Figure 39. Simplified Architecture
RF INPUT INTERFACE
A single-ended input at the RFIN pin drives the ADL5903, and
a 50 Ω source can drive it directly without any external
components. Figure 40 shows the simplified RF input interface.
An on-chip matching network presents 133  of shunt
resistance to ground and ac coupling to the rms core. The ESD
protection circuitry is designed to allow voltage swings as high
as ±2 V at the input.
As shown in Figure 12 (input return loss, S11), the device offers
excellent input return loss over most of the operating range but
rises to around −9 dB near its minimum operating frequency of
200 MHz. Add an external shunt resistance of 127 Ω, if desired,
when operating at low frequencies to improve input return loss
over the range of 200 MHz to 1.7 GHz. Figure 41 shows a
comparison of the input return loss, with and without the
external shunt resistor.
Figure 40. Simplified RF Input Interface
Figure 41. Return Loss with and Without External Shunt Termination
BASIC CONNECTIONS
The ADL5903 requires a single supply of 3.0 V to 5.0 V. The
supply is connected to the VPOS supply pin. This pin is
decoupled using two capacitors with values equal or similar
to those shown in Figure 44. Place these capacitors as near the
VPOS pin as possible.
The CREG pin provides a bypass capacitor connection for an
on-chip regulator. The CREG pin is connected to ground with a
4.02 Ω resistor and a 0.1 µF capacitor. The CRMS pin provides
an averaging function for the rms computation and is
referenced to Pin 4 (CREG). A filter capacitor can be placed
between the CRMS and CREG pins. More information on
choosing the CRMS capacitor is provided in the Choosing a Value
for CRMS section. Using smaller values for CRMS allows quicker
response times to a pulsed waveform. Higher values of CRMS are
required for correct rms computation as the peak to average
ratio of modulated signals increases and the bandwidth of the
modulated signals decreases.
11769-039
5
1
6
ADL5903
RFIN
ENBL
RMS CORE
INTERNAL
FILTERING
BUFFER
630pF
1kΩ
100Ω
4pF
V
POS
2
GND
8
NIC EP
4
CRE
G
3CRMS
7VRMS
ESD
VPOS
MATCHING
NETWORK
GND
133Ω
4pF
OPTIONAL
127Ω
ESD
11769-040
–25
–20
–15
–10
–5
0
0123456
FREQUENCY (GHz)
RETURN LOSS, S
11
(dB)
EXTERNAL 127ΩSHUNT TERM
NO SHUNT TERM
11769-041
ADL5903 Data Sheet
Rev. B | Page 16 of 20
The ENBL pin configures the device enable interface.
Connecting the ENBL pin to a logic high signal (2 V to 5.0 V)
enables the device, and connecting the pin to a logic low signal
(0 V to 0.6 V) disables the device. The exposed pad is internally
connected to GND and must be soldered to a low impedance
ground plane.
The output buffer of the ADL5903 features a PMOS common
source drive transistor and a resistive pull-down load. Under
typical operating conditions, the internal measurement range of
the device limits the output signal range to ≤2.2 V. Place a
100 Ω resistor on chip in series with the output to allow
additional filtering, if desired.
CHOOSING A VALUE FOR CRMS
CRMS provides the averaging function for the internal rms
computation. Using the minimum value for CRMS allows the
quickest response time to a pulsed waveform but leaves signifi-
cant output noise on the output voltage signal. However, a large
filter capacitor reduces output noise and improves the rms
measurement accuracy but at the expense of the response time.
In applications where the response time is not critical, place a
relatively large capacitor on the CRMS pin. In Figure 44, a value
of 0.1 µF is used. For most signal modulation schemes, this value
ensures excellent rms measurement compliance and low residual
output noise. There is no maximum capacitance limit for CRMS.
Figure 42 and Figure 43 show how output noise varies with CRMS
when the ADL5903 is driven by a single carrier W-CDMA
(Test Model TM1-64, peak envelope power = 10.56 dB, bandwidth
= 3.84 MHz) and an LTE signal (Test Model TM1-20, peak
envelope power = 11.58 dB, bandwidth = 20 MHz), respectively.
Figure 42 and Figure 43 also show how the value of CRMS affects
the response time. This is measured by applying an RF burst at
2.14 GHz at 0 dBm to the ADL5903. The 10% to 90% rise time
and 90% to 10% fall time are then measured.
Figure 42. Output Noise, Rise/Fall Times vs. CRMS Capacitance,
Single Carrier W-CDMA (Test Model TM1-64) at 2.14 GHz with PIN = 0 dBm
Figure 43. Output Noise, Rise/Fall Times vs. CRMS Capacitance,
Single Carrier LTE (Test Model TM1-20) at 2.14 GHz with PIN = 0 dBm
Figure 44. Basic Connections
0.1
1
10
100
1k
10k
100k
1M
0
100
200
300
400
500
600
700
0.1 110 100 1000
RISE/FALL TIME (µs)
OUTPUT NOISE (mV p-p)
C
RMS
CAPACITANCE (n F)
OUTPUT NOISE (mV p-p)
10% TO 90% RISE TIME (µs)
90% to 10% FALL TIME (µs)
11769-042
0.1
1
10
100
1k
10k
100k
1M
10M
100M
0
50
100
150
200
250
300
350
400
450
0.1 110 100 1000
RISE/FALL TIME (µs)
OUTPUT NOISE (mV p-p)
CFLT4 (nF)
OUTPUT NOISE (mV p-p)
10% TO 90% RISE TIME (µs)
90% to 10% FALL TIME (µs)
11769-043
RFIN
VPOS
VRMS
GND
ADL5903
INTERNAL
FILTERING
CRMS
ENBL
RMS CORE
BUFFER
100Ω
1kΩ
CREG
NIC
630pF
EP
4pF
0.1μF
4.02Ω
0.1μF
VPOS
RFINVRMS
VENBL
0.1μF
100pF
6
5 4
3
7
1
2 8
11769-044
Data Sheet ADL5903
Rev. B | Page 17 of 20
Table 4. Recommended Minimum CRMS Values for Various Modulation Schemes
Modulation/Standard
Peak Envelope
Power Ratio (dB)
Carrier
Bandwidth (MHz) CRMSMIN (nF)
Output Noise
(mV p-p)
Rise/Fall
Times (μs)
QPSK, 5 MSPS (SQR COS Filter, = 0.35) 4.0 5 10 140 3.5/32
QPSK ,15 MSPS (SQR COS Filter, = 0.35) 4.1 15 10 80 3.5/32
64 QAM, 1 MSPS (SQR COS Filter, = 0.35) 7.4 1 1000 60 280/2600
64 QAM, 5 MSPS (SQR COS Filter, = 0.35) 7.4 5 100 50 34/330
64 QAM, 13 MSPS (SQR COS Filter, = 0.35) 7.4 13 100 50 34/330
W-CDMA, One-Carrier, TM1-64 10.56 3.84 100 80 34/330
W-CDMA Four-Carrier, TM1-64, TM1-32, TM1-16, TM1-8 12.08 18.84 100 96 34/330
LTE, TM1, One-Carrier, 20 MHz (2048 QPSK Subcarriers) 11.58 20 100 76 34/330
Table 4 shows the recommended minimum values of CRMS for
popular modulation schemes. The output response time and
noise performance are also shown. Using lower capacitor values
results in faster response times but can result in degraded rms
measurement accuracy. If the output noise shown in Table 4 is
unacceptably high, it can be reduced by increasing CRMS or by
implementing an averaging algorithm after the output voltage of
the ADL5903 has been sampled by an analog-to-digital
converter (ADC).
The values in Table 4 were experimentally determined to be the
minimum capacitance that ensures good rms accuracy for that
particular signal type. This test was initially performed with a
large capacitance value on the CRMS pin (for example, 10 μF).
The value of VRMS was noted for a fixed input level (for example,
−10 dBm). The value of CRMS was then progressively reduced (this
can be accomplished with press-down capacitors) until the
value of VRMS started to deviate from its original value (this
indicates that the accuracy of the rms computation is degrading
and that CRMS is becoming too small).
In general, the minimum CRMS required increases as the peak-to-
average ratio of the carrier increases. The minimum required CRMS
also tends to increase as the bandwidth of the carrier decreases.
With narrow-band carriers, the noise spectrum of the VRMS
output tends to have a correspondingly narrow profile. The
relatively narrow spectral profile demands a larger value of CRMS
that reduces the low-pass corner frequency of the averaging
function and ensures a valid rms computation.
DEVICE CALIBRATION AND ERROR CALCULATION
The measured transfer function of the ADL5903 at 2.14 GHz is
shown in Figure 45, which contains plots of both output voltage
and log conformance error vs. input level for one device. As the
input level varies from −30 dBm to +14 dBm, the output voltage
varies from near 0 V to 1.9 V.
Figure 45. 2.14 GHz VRMS and Log Conformance Error at +25°C, −40°C, −55°C,
+85°C, and +125°C
Board level calibration must be performed to achieve high
accuracy because the slope and intercept vary from device to
device. For a two-point calibration, write the equation for the
idealized output voltage as
VRMS(IDEAL) = Slope × (PIN − Intercept) (1)
where:
Slope is the change in output voltage divided by the change in
input level (dBm).
PIN is the input level.
Intercept is the calculated input level at which the output voltage
is equal to 0 V (note that Intercept is an extrapolated theoretical
value and not a measured value).
In general, calibration is performed during equipment
manufacture by applying two or more known signal levels to the
input of the ADL5903 and measuring the corresponding output
voltages. The calibration points must be within the linear
operating range of the device.
With a two-point calibration, calculate the slope and intercept
as follows:
Slope = (VRMS1 − VRMS2)/(PIN1 − PIN2) (2)
Intercept = PIN1 − (VRMS1/Slope) (3)
20151050–5–10–15–20–25–30–35–40
2.4
2.2
2.0
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0
6
5
4
3
2
1
0
–1
–2
–3
–4
–5
–6
P
IN
(dBm)
OUTPUT VOLTAGE (V)
ERRO R ( dB)
–55°C
–40°C
+25°C
+85°C
+125°C
11769-045
CAL IBR ATION AT –10d Bm AND +10dBm
ADL5903 Data Sheet
Rev. B | Page 18 of 20
After the slope and intercept are calculated (and stored in some
form) an equation can be used to calculate an unknown input
level based on the output voltage of the detector.
PIN (Unknown) = (VRMS(MEASURED)/Slope) + Intercept (4)
The log conformance error is the difference between this
straight line and the actual performance of the detector.
Error (dB) = (VRMS(MEASURED) − VRMS(IDEAL))/Slope (5)
Figure 45 shows the log conformance error at five temperatures,
ranging from −55°C to +125°C, when using a two-point
calibration (calibration points are +10 dBm and −10 dBm)
measured at one temperature, 25°C. The error at the two
calibration points passes through 0 dB for the 25°C curve by
definition.
Multipoint calibration can be used to further extend the
measurement dynamic range. In this case, the transfer function
is segmented, with each segment having its own slope and
intercept. Figure 46 shows the error plot of the same device with
calibration points at −16 dBm, −4 dBm, and+12 dBm. The
three-point, dual-slope calibration results in tighter error
bounds over the high end of the range and extends the lower
measurement range to better than −20 dBm for ±1 dB error.
Figure 46. 2.14 GHz VRMS and Log Conformance Error at +25°C, −40°C, −55°C,
+85°C, and +125°C
For the example shown in Figure 46, the error drift with tempera-
ture is very small over the upper 20 dB of the measurement
range, varying ±0.3 dB, but widens at lower power levels, from
−20 dBm to −5 dBm to as high as ±0.9 dB. This is typical
performance, although some devices may perform better.
Figure 47. 2.14 GHz VRMS and Log Conformance Error for Second Device at
+25°C, −40°C, −55°C, +85°C, and +125°C
For comparison, the three-point calibration of a different device
is shown in Figure 47 for the same frequency and calibration
points. For this example, note that the device has greater
dynamic range, and the temperature dependence of error at
lower power levels is inverted.
Finally, Figure 48 shows the log conformance error at 2.14 GHz
for a collection of four devices at +25°C, −40°C, and +85°C with
three-point calibration (−16 dBm, −4 dBm, and+12 dBm). The
error plots at each temperature are calculated with respect to
the slope and intercept measurements from the 25°C line for
each device. This is consistent with a typical production
environment where calibration at one temperature is required.
Figure 48 illustrates the various error scenarios possible at low
input levels. The dynamic range of the three-point calibrated
devices extends to below −20 dBm for ±1.0 dB error.
Figure 48. 2.14 GHz VRMS and Log Conformance +25°C, −40°C, and +85°C for
Multiple Devices
20
15
105
0
–5
–10
–15
–20–25–30–35–40
2.4
2.2
2.0
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0
6
5
4
3
2
1
0
–1
–2
–3
–4
–5
–6
P
IN
(d Bm)
OUTPUT VOLTAGE (V)
ERROR (dB)
–55°C
–40°C
+25°C
+85°C
+125°C
11769-046
CALIBRATIONAT –16dBm, –4dBm, AND +12dBm
20
15
105
0
–5
–10
–15
–20–25–30–35–40
2.4
2.2
2.0
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0
6
5
4
3
2
1
0
–1
–2
–3
–4
–5
–6
P
IN
(d Bm)
OUTPUT VOLTAGE (V)
ERROR (dB)
–55°C
–40°C
+25°C
+85°C
+125°C
11769-047
CALIBRATIONAT –16dBm, –4dBm, AND +12dBm
20
15
10
5
0
–5
–10
–15
–20–25–30–35–40
2.4
2.2
2.0
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0
6
5
4
3
2
1
0
–1
–2
–3
–4
–5
–6
P
IN
(d Bm)
OUTPUT VOLTAGE (V)
ERROR (dB)
–40°C
+25°C
+85°C
11769-048
CALIBRATIONAT –16dBm, –4dBm, AND +12dBm
Data Sheet ADL5903
Rev. B | Page 19 of 20
EVALUATION BOARD SCHEMATIC AND CONFIGURATION OPTIONS
Figure 49. Evaluation Board Schematic
Table 5. Evaluation Board Configuration Options
Component Description Default Value
RFIN, R208 RF input. R208 is a shunt input termination to optimize low frequency input
return loss.
RFIN = SMA connector,
R208 = DNI1
R205, R206, S201 Device enable interface. Header S201 configures the enable network. Pin 2
and Pin 3 of S201 enable the resistive divider network. R205 and R206 form a
resistive divider network to step down the voltage provided by VPOS for an
optimal enable setpoint condition.
R205 = 100 kΩ,
R206 = 100 kΩ,
S201 = Jumper Pin 2 and
Jumper Pin 3
C201, C202 Power supply decoupling. The nominal supply decoupling consists of a
100 pF and a 0.1 μF capacitor placed near the device.
C201 = 100 pF,
C202 = 0.1 µF
C209 RMS averaging capacitor. C209 is the capacitor (CRMS) interfacing CREG and
CRMS for rms averaging. Set the value of the rms averaging capacitor on the
peak-to-average ratio of the input signal and based on the desired output
response time and residual output noise. See the Choosing a Value for CRMS
section for more information.
C209 = 0.1 µF
R202, C203A Bypass capacitor connection for on-chip regulator. R202 and C203A are
connected to the CREG pin to provide decoupling for the internal regulator.
R202 = 4.02 Ω, C203A = 0.1 µF
R204, C210 RMS output. R204 and C210 provide options for output filtering and to mimic
system load conditions.
R204 = 0 Ω, C210 = DNI1
C203, C204, C204A, C205,
C205A, R203, R207, R209
Test header interface. C203, C204, C204A, C205, C205A,
R203, R207, R208, R209 = DNI1
EP Exposed pad. The exposed pad is soldered to a ground pad, which provides
both a thermal ground and an electrical ground.
1 DNI = do not install.
VOUT
RFIN 1
2
3
4
COMM
RFIN
ADL5903
8
7
6
5
CRMS
CREG
VRMS
NIC
VPOS
ENBL
VPOS
VPOS
C201
100pF C202
0.1μF
4.02Ω
DNI
ENBL
R208
DNI
R207
DNI
R202
R206
100kΩ
R205
100kΩ
R209
DNI
R204
0Ω
OUT C210
DNI
C203
DNI
C203A
0.1μF
COMM
EP
P201 (24- P IN TE S T HEADER)
1 2
S201 3
1
2
3 4 5 6 7 8 9 10 11 12
1 2 3 4 5 6 7 8 9 10 11 12
B
A
C205A
DNI
TO P201
R203
DNI TO P201
TO P201
C205
DNI
C204A
DNI C204
DNI
TO P201
0.1μF
C209
11769-049
ADL5903 Data Sheet
Rev. B | Page 20 of 20
OUTLINE DIMENSIONS
Figure 50. 8-Lead Lead Frame Chip Scale Package [LFCSP_UD]
2.00 mm × 2.00 mm Body, Ultra Thin, Dual Lead
(CP-8-10)
Dimensions shown in millimeters
ORDERING GUIDE
Model1 Temperature Range Package Description Package Option Branding Ordering Quantity
ADL5903ACPZN-R7 −40°C to +85°C 8-Lead LFCSP_UD, 7’’ Tape and Reel CP-8-10 BS 3,000
ADL5903SCPZN-R7 −55°C to +125°C 8-Lead LFCSP_UD, 7’’ Tape and Reel CP-8-10 CJ 3,000
ADL5903-EVALZ Evaluation Board
1 Z = RoHS Compliant Part.
1.70
1.60
1.50
0.425
0.350
0.275
TOP VIEW
8
1
5
4
0.30
0.25
0.20
BOTTOM VIEW
PI N 1 INDEX
AREA
SEATING
PLANE
0.60
0.55
0.50
1.10
1.00
0.90
0.20 REF
0.15 REF
0.05 MAX
0.02 NOM
0.50 BSC
EXPOSED
PAD
PIN 1
INDICATOR
(R 0.15)
FOR P ROPE R CONNEC TI ON OF
THE EXPOSED PAD, REFER TO
THE PIN CONFI GURAT ION AND
FUNCTION DESCRIPTIONS
SECTION O F THIS DATA SHEET.
01-14-2013-
C
2.10
2.00 SQ
1.90
©2013–2015 Analog Devices, Inc. All rights reserved. Trademarks and
registered trademarks are the property of their respective owners.
D11769-0-5/15(B)
Mouser Electronics
Authorized Distributor
Click to View Pricing, Inventory, Delivery & Lifecycle Information:
Analog Devices Inc.:
ADL5903SCPZN-R7 ADL5903-EVALZ