ANALOG DEVICES ADL5372 Service Manual
1500 MHz to 2500 MHz
FEATURES
Output frequency range: 1500 MHz to 2500 MHz
Modulation bandwidth: >500 MHz (3 dB)
1 dB output compression: 14 dBm @ 1900 MHz
Noise floor: −158 dBm/Hz
Sideband suppression: −45 dBc @ 1900 MHz
Carrier feedthrough: −45 dBm @ 1900 MHz
Single supply: 4.75 V to 5.25 V
24-lead LFCSP_VQ
APPLICATIONS
Cellular communication systems
CDMA2000/GSM/WCDMA
WiMAX/broadband wireless access systems
Satellite modems
GENERAL DESCRIPTION
The ADL5372 is a member of the fixed-gain quadrature modulator
(F-MOD) family designed for use from 1500 MHz to 2500 MHz.
Its excellent phase accuracy and amplitude balance enable high
performance intermediate frequency or direct radio frequency
modulation for communication systems.
The ADL5372 provides a >500 MHz, 3 dB baseband bandwidth,
making it ideally suited for use in broadband zero IF or low
IF-to-RF applications and in broadband digital predistortion
transmitters.
Quadrature Modulator
ADL5372
FUNCTIONAL BLOCK DIAGRAM
IBBP
IBBN
LOIP
LOIN
QBBN
QBBP
The ADL5372 accepts two differential baseband inputs and a
single-ended, local oscillator (LO) and generates a singleended output.
The ADL5372 is fabricated using the Analog Devices, Inc.
advanced silicon-germanium bipolar process. It is available in
a 24-lead, exposed-paddle, Pb-free, LFCSP. Performance is
specified over a −40°C to +85°C temperature range. A Pb-free
evaluation board is available.
QUADRATURE
PHASE
SPLITTER
Figure 1.
VOUT
06511-001
Rev. 0
Information furnished by Analog Devices is believed to be accurate and reliable. However, no
responsibility is assumed by Anal og Devices for its use, nor for any infringements of patents or ot her
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 www.analog.com
Fax: 781.461.3113 ©2006 Analog Devices, Inc. All rights reserved.
ADL5372
TABLE OF CONTENTS
Features.............................................................................................. 1
Applications....................................................................................... 1
Functional Block Diagram .............................................................. 1
General Description ......................................................................... 1
Revision History ............................................................................... 2
Specifications..................................................................................... 3
Absolute Maximum Ratings............................................................ 5
ESD Caution.................................................................................. 5
Pin Configuration and Function Descriptions............................. 6
Typical Performance Characteristics ............................................. 7
Theory of Operation ...................................................................... 11
Circuit Description..................................................................... 11
Basic Connections ..........................................................................12
Optimization............................................................................... 13
Applications Information .............................................................. 14
DAC Modulator Interfacing ..................................................... 14
Limiting the AC Swing .............................................................. 14
Filtering........................................................................................ 14
Using the AD9779 Auxiliary DAC for Carrier Feedthrough
Nulling ......................................................................................... 15
GSM Operation .......................................................................... 15
WCDMA Operation.................................................................. 16
WiMAX Operation .................................................................... 16
LO Generation Using PLLs....................................................... 16
Transmit DAC Options ............................................................. 17
Modulator/Demodulator Options ........................................... 17
Evaluation Board............................................................................ 18
Characterization Setup .................................................................. 19
Outline Dimensions....................................................................... 21
Ordering Guide .......................................................................... 21
REVISION HISTORY
12/06—Revision 0: Initial Version
Rev. 0 | Page 2 of 24
ADL5372
SPECIFICATIONS
VS = 5 V; TA = 25°C; LO = 0 dBm1 single-ended; baseband I/Q amplitude = 1.4 V p-p differential sine waves in quadrature with a 500 mV
dc bias; baseband I/Q frequency (f
Table 1.
Parameter Conditions Min Typ Max Unit
OPERATING FREQUENCY RANGE Low frequency 1500 MHz
High frequency 2500 MHz
LO = 1900 MHz
Output Power VIQ = 1.4 V p-p differential 7.1 dBm
Output P1dB 14.2 dBm
Carrier Feedthrough −45 dBm
Sideband Suppression −45 dBc
Quadrature Error 0.21 Degrees
I/Q Amplitude Balance 0.09 dB
Second Harmonic P
Third Harmonic P
Output IP2 f1BB = 3.5 MHz, f2BB = 4.5 MHz, P
Output IP3 f1BB = 3.5 MHz, f2BB = 4.5 MHz, P
Noise Floor
GSM 6 MHz carrier offset, P
WCDMA
LO = 2150 MHz
Output Power VIQ = 1.4 V p-p differential 7.2 dBm
OutputP1dB 14 dBm
Carrier Feedthrough −41 dBm
Sideband Suppression −44 dBc
Quadrature Error 0.27 Degrees
I/Q Amplitude Balance 0.12 dB
Second Harmonic P
Third Harmonic P
Output IP2 f1BB = 3.5 MHz, f2BB = 4.5 MHz, P
Output IP3 f1BB = 3.5 MHz, f2BB = 4.5 MHz, P
Noise Floor
WCDMA
LO = 2400 MHz
Output Power VIQ = 1.4 V p-p differential 5.6 dBm
OutputP1dB 12.4 dBm
Carrier Feedthrough −36 dBm
Sideband Suppression −40 dBc
Quadrature Error 0.6 Degrees
I/Q Amplitude Balance 0.13 dB
Second Harmonic P
Third Harmonic P
Output IP2 f1BB = 3.5 MHz, f2BB = 4.5 MHz, P
Output IP3 f1BB = 3.5 MHz, f2BB = 4.5 MHz, P
Noise Floor
WiMAX
) = 1 MHz, unless otherwise noted.
BB
− (fLO + (2 × fBB)), P
OUT
− (fLO + (3 × fBB)), P
OUT
= 6.2 dBm −50 dBc
OUT
= 6.2 dBm −47 dBc
OUT
= 1 dBm per tone 54 dBm
OUT
= 1 dBm per tone 27 dBm
OUT
I/Q inputs = 0 V differential with a 500 mV common-mode bias,
20 MHz carrier offset; LO = 1960 MHz
= 5 dBm, PLO = 6 dBm; LO = 1960 MHz −158 dBc/Hz
OUT
Single carrier, 20 MHz carrier offset, P
P
= 0 dBm; LO = 1966 MHz
LO
− (fLO + (2 × fBB)), P
OUT
− (fLO + (3 × fBB)), P
OUT
= 6.2 dBm −59 dBc
OUT
= 6.2 dBm −48 dBc
OUT
OUT
OUT
= −10 dBm,
OUT
= 1 dBm per tone 65 dBm
= 1 dBm per tone 26.5 dBm
I/Q inputs = 0 V differential with a 500 mV common-mode bias,
20 MHz carrier offset
Single carrier, 20 MHz carrier offset, P
= −10 dBm, PLO = 0 dBm;
OUT
LO = 2140 MHz
− (fLO + (2 × fBB)), P
OUT
− (fLO + (3 × fBB)), P
OUT
= 6.2 dBm −54 dBc
OUT
= 6.2 dBm −48 dBc
OUT
= 1 dBm per tone 57 dBm
OUT
= 1 dBm per tone 24.5 dBm
OUT
I/Q inputs = 0 V differential with a 500 mV common-mode bias,
20 MHz carrier offset; LO = 2350 MHz
10 MHz carrier bandwidth (256 subcarriers), 64 QAM signal,
70 MHz carrier offset, P
= −10 dBm, PLO = 0 dBm; LO = 2350 MHz
OUT
−158 dBm/Hz
−157.6 dBm/Hz
−158 dBm/Hz
−157.5 dBm/Hz
−158.5 dBm/Hz
−158 dBm/Hz
Rev. 0 | Page 3 of 24
ADL5372
Parameter Conditions Min Typ Max Unit
LO INPUTS
LO Drive Level
Input Return Loss See Figure 9 for a plot of return loss vs. frequency −12 dB
BASEBAND INPUTS Pin IBBP, Pin IBBN, Pin QBBP, Pin QBBN
I and Q Input Bias Level 500 mV
Input Bias Current Current sourcing from each baseband input with a bias of 500 mV dc2 45 μA
Input Offset Current 0.1 μA
Differential Input Impedance 2900 kΩ
Bandwidth (0.1 dB) LO = 1900 MHz, baseband input = 700 mV p-p sine wave on 500 mV dc 70 MHz
Bandwidth (1 dB) LO = 1900 MHz, baseband input = 700 mV p-p sine wave on 500 mV dc 350 MHz
POWER SUPPLIES Pin VPS1 and Pin VPS2
Voltage 4.75 5.25 V
Supply Current 165 mA
1
High LO drive reduces noise at a 6 MHz carrier offset in GSM applications.
2
See V-to-I Converter section for architecture information.
1
Characterization performed at typical level −6 0 +6 dBm
Rev. 0 | Page 4 of 24
ADL5372
ABSOLUTE MAXIMUM RATINGS
Table 2.
Parameter Rating
Supply Voltage VPOS 5.5 V
IBBP, IBBN, QBBP, QBBN 0 V to 2 V
LOIP and LOIN 13 dBm
Internal Power Dissipation 1100 mW
θJA (Exposed Paddle Soldered Down) 54°C/W
Maximum Junction Temperature 150°C
Operating Temperature Range −40°C to +85°C
Storage Temperature Range −65°C to +150°C
Stresses above those listed under Absolute Maximum Ratings
may cause permanent damage to the device. This is a stress
rating only; functional operation of the device at these or any
other conditions above those indicated in the operational
section of this specification is not implied. Exposure to absolute
maximum rating conditions for extended periods may affect
device reliability.
ESD CAUTION
Rev. 0 | Page 5 of 24
ADL5372
PIN CONFIGURATION AND FUNCTION DESCRIPTIONS
QBBP
COM4
QBBN
COM4
IBBN
IBBP
2422232120
19
COM1
COM1
VPS1
VPS1
VPS1
VPS1
1
2
3
4
5
6
F-MOD
TOP VIEW
(Not to Scale)
798
101112
LOIP
LOIN
COM2
COM2
COM3
VPS5
18
VPS4
17
VPS3
16
VPS2
15
VPS2
14
VOUT
13
COM3
06511-002
Figure 2. Pin Configuration
Table 3. Pin Function Descriptions
Pin No. Mnemonic Description
1, 2, 7, 10 to 12,
COM1 to COM4 Input Common Pins. Connect to ground plane via a low impedance path.
21, 22
3 to 6, 14 to 18 VPS1 to VPS5
Positive Supply Voltage Pins. All pins should be connected to the same supply (V
adequate external bypassing, connect 0.1 μF capacitors between each pin and ground.
Adjacent power supply pins of the same name can share one capacitor (see Figure 25).
8, 9 LOIP, LOIN
50 Ω Single-Ended Local Oscillator Input. Internally dc-biased. Pins must be ac-coupled.
AC-couple LOIN to ground and drive LO through LOIP.
13 VOUT
Device Output. Single-ended RF output. Pin should be ac-coupled to the load. The output
is ground referenced.
19, 20, 23, 24 IBBP, IBBN, QBBN, QBBP
Differential In-Phase and Quadrature Baseband Inputs. These high impedance inputs
must be dc-biased to 500 mV dc and must be driven from a low impedance source.
Nominal characterized ac signal swing is 700 mV p-p on each pin. This results in a differential
drive of 1.4 V p-p with a 500 mV dc bias. These inputs are not self-biased and must be
externally biased.
Exposed Paddle Connect to ground plane via a low impedance path.
). To ensure
S
Rev. 0 | Page 6 of 24
ADL5372
TYPICAL PERFORMANCE CHARACTERISTICS
VS = 5 V; TA = 25°C; LO = 0 dBm single-ended; baseband I/Q amplitude = 1.4 V p-p differential sine waves in quadrature with a 500 mV
dc bias; baseband I/Q frequency (f
9
8
7
6
5
4
3
SSB OUTPUT P OWER (d Bm)
2
1
0
1500 1600 1700 1800 1900 2000 2100 2200 2300 2400 2500
9
8
7
6
5
4
3
SSB OUTPUT POWER (d Bm)
2
1
0
1500 1600 1700 1800 1900 2000 2100 2200 2300 2400 2500
TA = –40°C
TA = +85°C
LO FREQUENCY (MHz)
Figure 3. Single Sideband (SSB) Output Power (P
LO Frequency (f
VS = 5V
VS = 5.25V
LO FREQUENCY (MHz)
Figure 4. Single Sideband (SSB) Output Power (P
LO Frequency (f
5
) = 1 MHz, unless otherwise noted.
BB
TA = +25°C
) vs.
) and Temperature
LO
) and Supply
LO
OUT
VS = 4.75V
) vs.
OUT
16
TA = –40°C
14
12
10
TA = +85°C
8
6
OUTPUT P1dB (dBm)
4
2
0
1500 1600 1700 1800 1900 2000 2100 2200 2300 2400 2500
06511-003
Figure 6. SSB Output P1dB Compression Point (OP1dB) vs. f
16
14
12
10
8
6
OUTPUT P1d B (dBm)
4
2
0
1500 1600 1700 1800 1900 2000 2100 2200 2300 2400 2500
06511-004
Figure 7. SSB Output P1dB Compression Point (OP1dB) vs. f
150
VS = 5V
120
S11 OF LOIP
S22 OF OUTPUT
TA = +25°C
LO FREQUENCY (MHz)
VS = 5.25V
LO FREQUENCY (MHz)
90
1500MHz
and Temperature
LO
VS = 4.75V
and Supply
LO
60
30
06511-006
06511-007
0
OUTPUT PO WER VARIANCE (d B)
–5
1 10 100 1000
BASEBAND FREQUENCY (M Hz)
Figure 5. I and Q Input Bandwidth Normalized to
Gain @ 1 MHz (f
= 1900 MHz)
LO
06511-005
Rev. 0 | Page 7 of 24
2500MHz
210
240
1500MHz
270
2500MHz
300
Figure 8. Smith Chart of LOIP S11 and VOUT S22
(f
from 1600 MHz to 2500 MHz)
LO
330
0180
06511-043
ADL5372
–
0
0
–5
–10
–15
RETURN LOSS ( dB)
–20
–25
1500 1600 1700 1800 1900 2000 2100 2200 2300 2400 2500
LO FREQ UENCY (MHz)
Figure 9. Return Loss (S11) of LOIP
0
–10
–20
TA = –40°C
–30
–40
–50
–60
CARRIER FEEDTHRO UGH (dBm)
–70
–80
1500 1600 1700 1800 1900 2000 2100 2200 2300 2400 2500
Figure 10. Carrier Feedthrough vs. f
TA = +25°C
TA = +85°C
LO FREQUENCY (MHz)
and Temperature
LO
Multiple Devices Shown
–10
–20
–30
–40
SIDEBAND SUPPRESSI ON (dBc)
–50
–60
1500 1600 1700 1800 1900 2000 2100 2200 2300 24 00 2500
6511-009
TA = +25°C
Figure 12. Sideband Suppression vs. f
TA = –40°C
LO FREQUENCY (MHz)
LO
TA = +85°C
and Temperature
06511-012
Multiple Devices Shown
0
–10
–20
–30
–40
–50
–60
–70
SIDEBAND SUPPRESSION (dBc)
–80
–90
1500 1600 1700 1800 1900 2000 2100 2200 2300 2400 2500
06511-010
Figure 13. Sideband Suppression vs. f
TA = +85°C
TA = –40°C
LO FREQUENCY (MHz)
TA = +25°C
and Temperature after Nulling at 25°C
LO
06511-041
Multiple Devices Shown
0
–10
–20
–30
–40
–50
–60
–70
CARRIER FEEDTHROUG H (dBm)
–80
–90
1500 1600 1700 1800 1900 2000 2100 2200 2300 2400 2500
Figure 11. Carrier Feedthrough vs. f
TA = +85°C
LO FREQUENCY (MHz)
and Temperature after Nulling at 25°C
LO
TA = +25°C
Multiple Devices Shown
TA = –40°C
6511-040
20
–30
–40
–50
–60
SIDEBAND SUPPRESSI ON
–70
DISTORT ION, CARRIER F EEDTHROUG H,
SECOND-ORDER DI STORTI ON, THI RD-ORDER
–80
CARRIER
FEEDTHROUGH (dBm)
THIRD ORDER (d Bc)
0.20.61.01.41.82.22.63.03.4
SSB OUTPUT POWER (d Bm)
SIDEBAND SUPPRESSION (dBc)
SECOND ORDER (d Bc)
BASEBAND INPUT VO LTAGE (V p–p)
Figure 14. Second- and Third-Order Distortion, Carrier Feedthrough,
Sideband Suppression, and SSB P
vs. Baseband Differential Input Level
OUT
(f
= 1900 MHz)
LO
15
10
5
0
–5
–10
–15
SSB OUTPUT POWER (dBm)
06511-014
Rev. 0 | Page 8 of 24
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