AD831AP [ADI]
Low Distortion Mixer; 低失真混频器
| 型号： | AD831AP |
| 厂家： | 
ADI |
| 描述： | Low Distortion Mixer |
| 文件： | 总16页 (文件大小：227K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
a
Low Distortion Mixer
AD831
FUNCTIO NAL BLO CK D IAGRAM
FEATURES
Doubly-Balanced Mixer
Low Distortion
3
2
1
20
50Ω
19
+24 dBm Third Order Intercept (IP3)
+10 dBm 1 dB Com pression Point
Low LO Drive Required: –10 dBm
Bandw idth
500 MHz RF and LO Input Bandw idths
250 MHz Differential Current IF Output
DC to >200 MHz Single-Ended Voltage IF Output
Single or Dual Supply Operation
DC Coupled Using Dual Supplies
All Ports May Be DC Coupled
No Low er Frequency Lim it—Operation to DC
User-Program m able Pow er Consum ption
50Ω
GND
VN
4
5
6
7
8
18
17
16
15
14
COM
VFB
OUT
VN
RFP
RFN
VN
AD831
BIAS
9
10
11
12
13
APPLICATIONS
High Perform ance RF/ IF Mixer
Direct to Baseband Conversion
Im age-Reject Mixers
filtering. When building a quadrature-amplitude modulator or
image reject mixer, the differential current outputs of two
AD831s may be summed by connecting them together.
I/ Q Modulators and Dem odulators
An integral low noise amplifier provides a single-ended voltage
output and can drive such low impedance loads as filters, 50 Ω
amplifier inputs, and A/D converters. Its small signal bandwidth
exceeds 200 MHz. A single resistor connected between pins
OUT and FB sets its gain. T he amplifier’s low dc offset allows
its use in such direct-coupled applications as direct-to-baseband
conversion and quadrature-amplitude demodulation.
P RO D UCT D ESCRIP TIO N
T he AD831 is a low distortion, wide dynamic range, monolithic
mixer for use in such applications as RF to IF down conversion
in HF and VHF receivers, the second mixer in DMR base sta-
tions, direct-to-baseband conversion, quadrature modula-
tion and demodulation, and doppler-shift detection in ultra-
sound imaging applications. T he mixer includes an LO driver
and a low-noise output amplifier and provides both user-pro-
grammable power consumption and 3rd-order intercept point.
T he mixer’s SSB noise figure is 10.3 dB at 70 MHz using its
output amplifier and optimum source impedance. Unlike pas-
sive mixers, the AD831 has no insertion loss and does not re-
quire an external diplexer or passive termination.
T he AD831 provides a +24 dBm third-order intercept point for
–10 dBm LO power, thus improving system performance and
reducing system cost compared to passive mixers, by eliminating
the need for a high power LO driver and its attendant shielding
and isolation problems.
A programmable-bias feature allows the user to reduce power
consumption, with a reduction in the 1 dB compression point
and third-order intercept. T his permits a tradeoff between dy-
namic range and power consumption. For example, the AD831
may be used as a second mixer in cellular and two-way radio
base stations at reduced power while still providing a substantial
performance improvement over passive solutions.
T he RF, IF, and LO ports may be dc or ac coupled when the
mixer is operating from ±5 V supplies or ac coupled when oper-
ating from a single supply of 9 V minimum. T he mixer operates
with RF and LO inputs as high as 500 MHz.
P RO D UCT H IGH LIGH TS
1. –10 dBm LO Drive for a +24 dBm Output Referred T hird
Order Intercept Point
T he mixer’s IF output is available as either a differential current
output or a single-ended voltage output. T he differential output
is from a pair of open collectors and may be ac coupled via a
transformer or capacitor to provide a 250 MHz output band-
width. In down-conversion applications, a single capacitor con-
nected across these outputs implements a low-pass filter to
reduce harmonics directly at the mixer core, simplifying output
2. Single-Ended Voltage Output
3. High Port-to-Port Isolation
4. No Insertion Loss
5. Single or Dual Supply Operation
6. 10.3 dB Noise Figure
REV. B
Inform ation furnished by Analog Devices is believed to be accurate and
reliable. However, no responsibility is assum ed by Analog Devices for its
use, nor for any infringem ents of patents or other rights of third parties
which m ay result from its use. No license is granted by im plication or
otherwise under any patent or patent rights of Analog Devices.
© Analog Devices, Inc., 1995
One Technology Way, P.O. Box 9106, Norw ood. MA 02062-9106, U.S.A.
Tel: 617/ 329-4700
Fax: 617/ 326-8703
(T = +25؇C and ؎V = ؎5 V unless otherwise noted;
A
S
AD831–SPECIFICATIONS all values in dBm assume 50 ⍀ load.)
P aram eter
Conditions
Min
Typ
Max
Units
RF INPUT
Bandwidth
–10 dBm Signal Level, IP3 ≥ +20 dBm
10.7 MHz IF and High Side Injection
See Figure 1
400
MHz
1 dB Compression Point
Common-Mode Range
Bias Current
DC Input Resistance
Capacitance
10
dBm
V
µA
kΩ
pF
±1
500
DC Coupled
Differential or Common Mode
160
1.3
2
IF OUT PUT
Bandwidth
Single-Ended Voltage Output, –3 dB
Level = 0 dBm, RL = 100 Ω
200
0
15
300
±1.4
75
MHz
dB
mV
V/µs
V
Conversion Gain
Output Offset Voltage
Slew Rate
Output Voltage Swing
Short Circuit Current
T erminals OUT and VFB Connected
DC Measurement; LO Input Switched ±1
–40
+40
RL = 100 Ω, Unity Gain
mA
LO INPUT
Bandwidth
–10 dBm Input Signal Level
400
MHz
10.7 MHz IF and High Side Injection
Maximum Input Level
Common-Mode Range
Minimum Switching Level
Bias Current
–1
–1
+1
+1
V
V
Differential Input Signal
DC Coupled
200
17
mV p-p
µA
50
Resistance
Capacitance
Differential or Common Mode
500
2
Ω
pF
ISOLAT ION BET WEEN PORT S
LO to RF
LO to IF
RF to IF
LO = 100 MHz, RS = 50 Ω, 10.7 MHz IF
LO = 100 MHz, RS = 50 Ω, 10.7 MHz IF
RF = 100 MHz, RS = 50 Ω, 10.7 MHz IF
70
30
45
dB
dB
dB
DIST ORT ION AND NOISE
3rd Order Intercept
2rd Order Intercept
1 dB Compression Point
Noise Figure, SSB
LO = –10 dBm, f = 100 MHz, IF = 10.7 MHz
Output Referred, ±100 mV LO Input
Output Referred, ±100 mV LO Input
RL = 100 Ω, RBIAS = ∞
Matched Input, RF = 70 MHz, IF = 10.7 MHz
Matched Input, RF = 150 MHz, IF = 10.7 MHz
24
62
10
10.3
14
dBm
dBm
dBm
dB
dB
POWER SUPPLIES
Recommended Supply Range
Dual Supply
Single Supply
For Best 3rd Order Intercept Point Performance
BIAS Pin Open Circuited
±4.5
9
±5.5
11
125
V
V
mA
Quiescent Current1
100
NOT ES
1Quiescent current is programmable.
Specifications subject to change without notice.
–2–
REV. B
AD831
ABSO LUTE MAXIMUM RATINGS1
Supply Voltage ±VS . . . . . . . . . . . . . . . . . . . . . . . . . . ±5.5 V
Input Voltages
P IN CO NFIGURATIO N
20-Lead P LCC
RFHI, RFLO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ±3 V
LOHI, LOLO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ±1 V
Internal Power Dissipation2 . . . . . . . . . . . . . . . . . . 1200 mW
Operating T emperature Range
AD831A . . . . . . . . . . . . . . . . . . . . . . . . . . . –40°C to +85°C
Storage T emperature Range . . . . . . . . . . . . –65°C to +150°C
3
2
1
20 19
18
17
16
GND
VN
4
5
6
7
8
COM
VFB
OUT
AD831
TOP VIEW
(Not to Scale)
RFP
RFN
VN
Lead T emperature Range (Soldering 60 sec) . . . . . . . . +300°C
NOT ES
15 VN
1Stresses above those listed under “Absolute Maximum Ratings” may cause
permanent damage to the device. T his is a stress rating only and 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.
2T hermal Characteristics:
14 BIAS
9
10
12 13
11
20-Pin PLCC Package: θJA = 110°C/Watt; θJC = 20°C/Watt.
Note that the θJA = 110°C/W value is for the package measured while suspended
in still air; mounted on a PC board, the typical value is θJA = 90°C/W due to the
conduction provided by the AD831’s package being in contact with the board,
which serves as a heat sink.
P IN D ESCRIP TIO N
P in
Mnem onic
D escription
O RD ERING GUID E
1
2
VP
Positive Supply Input
Mixer Current Output
Amplifier Negative Input
Ground
IFN
AN
Tem perature
Range
P ackage
D escription
P ackage
O ption
3
Model
4
GND
VN
AD831AP –40°C to +85°C 20-Lead PLCC
P-20A
5
Negative Supply Input
RF Input
6
RFP
RFN
VN
7
RF Input
8
Negative Supply Input
Positive Supply Input
Local Oscillator Input
Local Oscillator Input
Positive Supply Input
Ground
9
VP
10
11
12
13
14
15
16
17
18
19
20
LON
LOP
VP
GND
BIAS
VN
Bias Input
Negative Supply Input
Amplifier Output
OUT
VFB
COM
AP
Amplifier Feedback Input
Amplifier Output Common
Amplifier Positive Input
Mixer Current Output
IFP
CAUTIO N
ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily
accumulate on the human body and test equipment and can discharge without detection.
Although the AD831 features proprietary ESD protection circuitry, permanent damage may
occur on devices subjected to high energy electrostatic discharges. T herefore, proper ESD
precautions are recommended to avoid performance degradation or loss of functionality.
WARNING!
ESD SENSITIVE DEVICE
REV. B
–3–
AD831–Typical Characteristics
30
25
20
15
10
5
65
64
63
62
61
60
0
10
10
100
1000
100
1000
FREQUENCY – MHz
FREQUENCY – MHz
Figure 4. Second-Order Intercept vs. Frequency
Figure 1. Third-Order Intercept vs. Frequency,
IF Held Constant at 10.7 MHz
90
80
70
60
50
40
30
20
10
0
80
70
60
50
40
30
20
10
0
10
100
1000
10
100
1000
FREQUENCY – MHz
FREQUENCY – MHz
Figure 5. LO-to-RF Isolation vs. Frequency
Figure 2. IF-to-RF Isolation vs. Frequency
80
60
3 x RF-to-IF
2 x RF-to-IF
3 x RF-to-IF
2 x LO-to-IF
3 x LO-to-IF
70
60
50
40
30
20
10
0
50
40
30
20
2 x RF-to-IF
RF-to-IF
RF-to-IF
LO
10
0
10
100
1000
10
100
1000
FREQUENCY – MHz
FREQUENCY – MHz
Figure 6. RF-to-IF Isolation vs. Frequency
Figure 3. LO-to-IF Isolation vs. Frequency
–4–
REV. B
AD831
1.00
0.75
12
10
8
0.50
0.25
0.00
6
–0.25
–0.50
–0.75
–1.00
4
2
0
10
100
1000
10
100
1000
FREQUENCY – MHz
FREQUENCY – MHz
Figure 7. 1 dB Com pression Point vs. Frequency, Gain = 1
Figure 10. Gain Error vs. Frequency, Gain = 1
12
10
8
9
8
7
6
5
4
3
2
1
0
6
4
2
0
10
100
1000
10
100
1000
FREQUENCY – MHz
FREQUENCY – MHz
Figure 8. 1 dB Com pression Point vs. RF Input, Gain = 2
Figure 11. 1 dB Com pression Point vs. Frequency, Gain = 4
11
25
MIXER OUTPUT
TRANSFORMER
COUPLED PER FIGURE 18
V
= 9V
S
22
19
16
13
10
10
9
V
= 8V
S
MIXER PLUS AMPLIFIER,
G = 1
8
LO LEVEL = –10dBm
IF = 10.7MHz
7
0
100
200
300
400
500
600
100
150
200
250
300
350
FREQUENCY – MHz
FREQUENCY – MHz
Figure 12. Input 1 dB Com pression Point vs. Frequency,
Gain = 1, 9 V Single Supply
Figure 9. Third-Order Intercept vs. Frequency , LO Held
Constant at 241 MHz
REV. B
–5–
AD831–Typical Characteristics
30
1200
1000
800
600
400
200
0
INPUT RESISTANCE
INPUT CAPACITANCE
4.0
3.5
3.0
2.5
2.0
25
V
= 8V
S
20
15
V
= 9V
S
LO LEVEL = –10dBm
IF = 10.7MHz
∆f = 20kHz
0
50
100 150 200 250 300 350 400 450 500
FREQUENCY – MHz
50
100
150
200
250
FREQUENCY – MHz
Figure 13. Input Third Order Intercept, 9 V Single Supply
Figure 15. Input Im pedance vs. Frequency, ZIN = R ʈC
62.4
18
17
16
15
14
V
= 9V
S
62.2
62.0
61.8
61.6
V
= 8V
S
61.4
61.2
61.0
60.8
13
12
11
LO LEVEL = –10dBm
IF = 10.7MHz
∆f = 20kHz
10
9
60.6
60.4
60.2
8
50
0
50
100 150 200 250 300 350 400 450 500
FREQUENCY – MHz
100
150
200
250
FREQUENCY – MHz
Figure 14. Input Second Order Intercept,
9 V Single Supply
Figure 16. Noise Figure vs. Frequency,
Matched Input
–6–
REV. B
AD831
TH EO RY O F O P ERATIO N
T he AD831 consists of a mixer core, a limiting amplifier, a low
noise output amplifier, and a bias circuit (Figure 17).
When the integral output amplifier is used, pins IFN and IFP
are connected directly to pins AFN and AFP; the on-chip load
resistors convert the output current into a voltage that drives the
output amplifier. T he ratio of these load resistors to resistors
R1, R2 provides nominal unity gain (0 dB) from RF to IF. T he
expression for the gain, in decibels, is
T he mixer’s RF input is converted into differential currents by a
highly linear, Class A voltage-to-current converter, formed by
transistors Q1, Q2 and resistors R1, R2. T he resulting currents
drive the differential pairs Q3, Q4 and Q5, Q6. T he LO input is
through a high gain, low noise limiting amplifier that converts
the –10 dBm LO input into a square wave. T his square wave
drives the differential pairs Q3, Q4 and Q5, Q6 and produces a
high level output at IFP and IFN—consisting of the sum and
difference frequencies of the RF and LO inputs—and a series of
lower level outputs caused by odd harmonics of the LO fre-
quency mixing with the RF input.
4
1
2
π
GdB = 20 log10
Equation 1
π
2
where
4
is the amplitude of the fundamental component of a square wave
is the conversion loss
π
1
2
π
2
An on-chip network supplies the bias current to the RF and LO
inputs when these are ac coupled; this network is disabled when
the AD831 is dc coupled.
is the small signal dc gain of the AD831 when the LO input
is driven fully positive or negative.
VP
1
50Ω
20Ω
50Ω
20Ω
19
20
3
2
AP
AN
IFN
IFP
18mA TYP
18mA TYP
BIAS
A
16
OUT
O
11
10
Q3 Q4
Q6
LOP
LON
Q5
5kΩ
LOCAL
OSCILLATOR
INPUT
17 VFB
50Ω
50Ω
LIMITING
AMPLIFIER
R4
1kΩ
R5
1kΩ
18 COM
Q2
Q1
6
7
RFP
RFN
RF
INPUT
CURRENT
MIRROR
BIAS
5kΩ
R1
20Ω
R2
20Ω
VP
36Ω
BIAS
CURRENT
Q7
BIAS
R3
26Ω
VN
36mA TYP
27mA TYP
12mA TYP
Figure 17. Sim plified Schem atic Diagram
REV. B
–7–
AD831
T he mixer has two open-collector outputs (differential cur-
rents) at pins IFN and IFP. T hese currents may be used to pro-
vide nominal unity RF-to-IF gain by connecting a center-tapped
transformer (1:1 turns ratio) to pins IFN and IFP as shown in
Figure 18.
Low-P ass Filter ing
A simple low-pass filter may be added between the mixer and
the output amplifier by shunting the internal resistive loads (an
equivalent resistance of about 14 Ω with a tolerance of 20%)
with external capacitors; these attenuate the sum component in
a down-conversion application (Figure 20). T he corner fre-
quency of this one-pole low-pass filter (f = (2 π RCF)–1) should
be placed about an octave above the difference frequency IF.
T hus, for a 70 MHz IF, a –3 dB frequency of 140 MHz might
be chosen, using CF = (2 × π × 14 Ω × 140 MHz)–1 ≈ 82 pF, the
nearest standard value.
IF OUTPUT
MCLT4-1H
VP
VPOS
1
20
2
IFN
IFP
18mA TYP
18mA TYP
1
1
C
=
=
F
2 π f R
89.7 f
C
C
F
5kΩ
5kΩ
11
10
F
Q3 Q4
Q6
LOP
LON
Q5
LOCAL
OSCILLATOR
INPUT
2
20
3
1
19
AP
LIMITING
AMPLIFIER
R4
1kΩ
R5
1kΩ
AN
50Ω
IFN
VP
IFP
50Ω
Q2
Q1
6
7
COM
RFP
RFN
RF
INPUT
4
5
6
7
8
18
17
16
15
14
GND
R1
20Ω
R2
20Ω
VFB
OUT
VN
VP
RFP
BIAS
CURRENT
Q7
R3
BIAS
26Ω
VN
AD831
Top View
VN
RFN
VN
36mA TYP
BIAS
Figure 18. Connections for Transform er Coupling to the IF
Output
LON
10
LOP
11
GND
13
VP
9
VP
12
P r ogr am m ing the Bias Cur r ent
Because the AD831’s RF port is a Class-A circuit, the maxi-
mum RF input is proportional to the bias current. T his bias cur-
rent may be reduced by connecting a resistor from the BIAS pin
to the positive supply (Figure 19). For normal operation, the
BIAS pin is left unconnected. For lowest power consumption,
the BIAS pin is connected directly to the positive supply. T he
range of adjustment is 100 mA for normal operation to
45 mA total current at minimum power consumption.
Figure 20. Low-Pass Filtering Using External Capacitors
Using the O utput Am plifier
T he AD831’s output amplifier converts the mixer core’s dif-
ferential current output into a single-ended voltage and provides
an output as high as ±1 V peak into a 50 Ω load (+10 dBm).
For unity gain operation (Figure 21), the inputs AN and AP
connect to the open-collector outputs of the mixer’s core and
OUT connects to VFB.
2
20
3
1
19
2
20
3
1
19
AP
AN
50Ω
IFN
VP
IFP
50Ω
AP
COM
AN
50Ω
IFN
VP
IFP
50Ω
COM
4
5
6
7
8
18
17
16
15
14
GND
4
5
6
18
17
16
15
14
GND
VFB
OUT
VFB
OUT
VN
VN
RFP
RFP
IF
OUTPUT
VPOS
0.1µF
VN
AD831
Top View
7
8
RFN
VN
VN
AD831
Top View
RFN
VN
1.33kΩ
BIAS
BIAS
LON
10
LOP
11
GND
LON
10
VP
9
VP
12
LOP
11
NOTE ADDED
RESISTOR
GND
13
VP
9
VP
12
13
Figure 19. Program m ing the Quiescent Current
Figure 21. Output Am plifier Connected for Unity Gain
Operation
–8–
REV. B
AD831
For gains other than unity, the amplifier’s output at OUT is
connected via an attenuator network to VFB; this determines
the overall gain. Using resistors R1 and R2 (Figure 22), the gain
setting expression is
2
20
3
1
19
AP
AN
50Ω
IFN
VP
IFP
50Ω
COM
4
5
6
18
17
16
15
14
GND
R2
51.1Ω
VFB
OUT
R1 + R2
VN
GdB = 20 log10
Equation 2
R1
110Ω
R2
RFP
IF
BPF
OUTPUT
R
T
R
T
2
20
3
1
19
AP
7
8
VN
AD831
Top View
RFN
VN
AN
50Ω
IFN
VP
IFP
50Ω
COM
4
5
6
18
17
16
15
14
BIAS
GND
R2
R1
LON
10
LOP
11
GND
13
VP
9
VP
12
VFB
OUT
VN
RFP
IF
OUTPUT
Figure 23. Connections for Driving a Doubly-Term inated
Bandpass Filter
7
8
VN
AD831
Top View
RFN
VN
Higher gains can be achieved, using different resistor ratios, but
with concomitant reduction in the bandwidth of this amplifier
(Figure 24). Note also that the Johnson noise of these gain-set-
ting resistors, as well as that of the BPF terminating resistors, is
ultimately reflected back to the mixer’s input; thus they should
be as small as possible, consistent with the permissible loading
on the amplifier’s output.
BIAS
LON
10
LOP
11
GND
13
VP
9
VP
12
Figure 22. Output Am plifier Feedback Connections for
Increasing Gain
D r iving Filter s
12
T he output amplifier can be used for driving reverse-terminated
loads. When driving an IF bandpass filter (BPF), for example,
proper attention must be paid to providing the optimal source
and load terminations so as to achieve the specified filter re-
sponse. T he AD831’s wideband highly linear output amplifier
affords an opportunity to increase the RF-to-IF gain to compen-
sate for a filter’s insertion and termination losses.
G = 1
10
G = 2
8
G = 4
6
Figure 23 indicates how the output amplifier’s low impedance
(voltage source) output can drive a doubly-terminated bandpass
filter. T he typical 10 dB of loss (4 dB of insertion loss and 6 dB
due to the reverse-termination) be made up by the inclusion of a
feedback network that increases the gain of the amplifier by
10 dB (×3.162). When constructing a feedback circuit, the sig-
nal path between OUT and VFB should be as short as possible.
4
2
0
10
100
1000
FREQUENCY – MHz
Figure 24. Output Am plifier 1 dB Com pression Point for
Gains of 1, 2, and 4 (Gains of 0 dB, 6 dB, and 12 dB,
Respectively)
REV. B
–9–
AD831
AP P LICATIO NS
T he RF input to the AD831 is shown connected by an imped-
ance matching network for an assumed source impedance of
50 Ω. Figure 15 shows the input impedance of the AD831 plot-
ted vs. frequency. T he input circuit can be modeled as a resis-
tance in parallel with a capacitance. T he 82 pF capacitors (CF)
connected from IFN and IFP to VP provide a low-pass filter
with a cutoff frequency of approximately 140 MHz in down-
conversion applications (see the T heory of Operation section of
this data sheet for more details). T he LO input is connected
single-ended because the limiting amplifier provides a symmet-
ric drive to the mixer. T o minimize intermodulation distortion,
connect pins OUT and VFB by the shortest possible path. T he
connections shown are for unity-gain operation.
Careful component selection, circuit layout, power supply
decoupling, and shielding are needed to minimize the AD831’s
susceptibility to interference from radio and T V stations, etc. In
bench evaluation, we recommend placing all of the components
in a shielded box and using feedthrough decoupling networks
for the supply voltage.
Circuit layout and construction are also critical, since stray ca-
pacitances and lead inductances can form resonant circuits and
are a potential source of circuit peaking, oscillation, or both.
D ual-Supply O per ation
Figure 25 shows the connections for dual supply operation.
Supplies may be as low as ±4.5 V but should be no higher than
±5.5 V due to power dissipation.
At LO frequencies less than 100 MHz, the AD831’s LO power
may be as low as –20 dBm for satisfactory operation. Above
100 MHz, the specified LO power of –10 dBm must be used.
+5V
0.1µF
C
C
F
F
82pF
82pF
2
20
3
1
19
AP
AN
50Ω
IFN
VP
IFP
50Ω
COM
4
5
6
18
17
16
15
14
GND
51.1Ω
110Ω
0.1µF
VFB
OUT
VN
C1
C2
R
–5V
RFP
T
RF
INPUT
IF
BPF
OUTPUT
R
T
L1
7
8
–5V
0.1µF
VN
AD831
Top View
RFN
VN
0.1µF
BIAS
NC
LON
10
LOP
11
–5V
GND
13
VP
9
VP
12
0.1µF
51.1Ω
+5V
0.1µF
+5V
LO INPUT
–10 dBm
Figure 25. Connections for ±5 V Dual-Supply Operation Showing Im pedance
Matching Network and Gain of 2 for Driving Reverse-Term inated IF Filter
–10–
REV. B
AD831
Single Supply O per ation
In single supply operation, the COM terminal is the “ground”
reference for the output amplifier and must be biased to 1/2 the
supply voltage, which is done by resistors R1 and R2. T he OUT
pin must be ac-coupled to the load.
Figure 26 is similar to the dual supply circuit in Figure 19. Sup-
plies may be as low as 9 V but should not be higher than
11 V due to power dissipation. As in Figure 19, both the RF
and LO ports are driven single-ended and terminated.
+9V
0.1µF
82pF
IFN
82pF
+5V
2
20
3
1
19
R2
51.1Ω
5kΩ
5kΩ
AN
50Ω
VP
IFP
50Ω
AP
COM
4
5
6
18
17
16
15
14
GND
0.1µF
R1
110Ω
VFB
OUT
VN
C2
C
C
C1
R
T
RFP
RF
INPUT
IF
OUTPUT
0.1µF
L1
7
8
VN
AD831
Top View
RFN
VN
BIAS
NC
LON
10
LOP
11
GND
13
VP
9
VP
12
0.1µF
0.1µF
0.1µF
+9V
0.1µF
51.1Ω
+9V
LO INPUT
–10 dBm
Figure 26. Connections for +9 V Single-Supply Operation
REV. B
–11–
AD831
Connections Q uadr atur e D em odulation
(Q) outputs. T he mixers’ inputs may be connected in parallel
and a single termination resistor used if the mixers are located in
close proximity on the PC board.
T wo AD831 mixers may have their RF inputs connected in par-
allel and have their LO inputs driven in phase quadrature (Fig-
ure 27) to provide demodulated in-phase (I) and quadrature
+5V
0.1µF
C
C
F
F
2
20
3
1
19
AP
AN
50Ω
IFN
VP
IFP
50Ω
COM
4
5
6
7
8
18
17
16
15
14
GND
0.1µF
VFB
OUT
VN
–5V
DEMODULATED
QUADRATURE
OUTPUT
RFP
–5V
0.1µF
VN
AD831
Top View
RFN
VN
0.1µF
BIAS
NC
LON
10
LOP
11
–5V
GND
13
VP
9
VP
12
0.1µF
51.1Ω
+5V
0.1µF
+5V
LO INPUT
AT 90°
–10 dBm
IF
INPUT
+5V
51.1Ω
0.1µF
C
C
F
F
2
20
3
1
19
AP
AN
50Ω
IFN
VP
IFP
50Ω
COM
4
5
6
7
8
18
17
16
15
14
GND
0.1µF
VFB
OUT
VN
–5V
DEMODULATED
IN-PHASE
OUTPUT
RFP
–5V
0.1µF
VN
AD831
Top View
RFN
VN
0.1µF
BIAS
NC
LON
LOP
11
–5V
GND
13
VP
9
VP
12
10
51.1Ω
0.1µF
+5V
0.1µF
+5V
LO INPUT
AT 0°
–10 dBm
Figure 27. Connections for Quadrature Dem odulation
–12–
REV. B
AD831
Table I. AD 831 Mixer Table, ؎4.5 V Supplies, LO = –9 dBm
LO Level
RF Level
–9.0 dBm, LO Frequency 130.7 MHz, Data File imdT B10771
0.0 dBm, RF Frequency 120 MHz
T emperature Ambient
Dut Supply
VPOS Current
±4.50 V
90 mA
VNEG Current 91 mA
Intermodulation T able RF harmonics (rows) × LO harmonics (columns).
First row absolute value of nRF-mLO, and second row is the sum.
0
1
2
3
4
5
6
7
0
1
2
3
4
5
6
7
–32.7
–32.7
–35.7
–35.7
–21.1
–21.1
–11.6
–11.6
–19.2
–19.2
–35.1
–35.1
–41.9
–41.9
–31.6
–31.6
0.0
–28.5
–37.2
–26.7
–41.5
–28.0
–30.4
–27.2
–34.3
–33.2
–25.2
–34.3
–40.1
–44.8
–45.3
–45.3
–48.2
–42.4
–39.4
–49.4
–57.6
–42.5
–44.9
–51.1
–42.4
–46.2
–40.2
–58.1
–40.2
–61.6
–54.5
–54.5
–57.1
–65.5
–57.5
–46.0
–50.6
–63.7
–62.6
–60.6
–55.8
–69.6
–59.7
–72.7
–55.2
–73.5
–67.1
–67.1
–63.1
–53.6
–69.9
–72.9
–69.9
–71.2
–69.6
–70.1
–74.1
–72.6
–69.7
–73.5
–58.6
–72.7
–53.5
–53.5
–62.6
–68.4
–73.8
–70.8
–72.3
–72.8
–70.7
–73.4
–71.1
–73.2
–74.3
–73.3
–73.0
–72.5
–73.6
–73.6
–57.7
–73.5
–68.6
–72.7
–73.1
–73.5
–73.8
–73.6
–73.0
–73.1
–72.9
–72.4
–74.4
–73.7
–73.8
–73.8
–73.9
–73.8
–63.4
–73.2
–72.6
–73.8
–74.6
–72.6
–74.9
–73.7
–73.6
–73.5
–74.5
–72.9
Table II. AD 831 Mixer Table, ؎5 V Supplies, LO = –9 dBm
LO Level
RF Level
–9.0 dBm, LO Frequency 130.7 MHz, Data File imdT B13882
0.0 dBm, RF Frequency 120 MHz
T emperature Ambient
Dut Supply
VPOS Current
±5.00 V
102 mA
VNEG Current 102 mA
Intermodulation table RF harmonics (rows) × LO harmonics (columns).
First row absolute value of nRF-mLO, and second row is the sum.
0
1
2
3
4
5
6
7
0
1
2
3
4
5
6
7
–36.5
–36.5
–46.5
–46.5
–33.0
–33.0
–17.0
–17.0
–23.0
–23.0
–34.2
–34.2
–45.6
–45.6
–37.5
–37.5
0.0
–29.1
–41.2
–38.7
–41.1
–22.9
–38.5
–28.4
–29.0
–35.3
–31.7
–34.3
–47.4
–52.4
–45.9
–45.9
–45.2
–39.4
–47.6
–35.7
–61.5
–38.4
–53.7
–42.3
–43.5
–53.7
–41.5
–52.8
–41.8
–66.3
–46.4
–46.4
–53.0
–40.0
–67.0
–50.0
–43.0
–48.9
–60.9
–57.8
–47.9
–57.0
–50.7
–71.8
–41.0
–67.4
–45.1
–45.1
–56.0
–39.0
–48.7
–48.1
–64.6
–58.4
–53.5
–56.1
–55.7
–63.8
–53.5
–70.5
–51.1
–67.6
–35.2
–35.2
–45.3
–53.0
–54.1
–62.4
–54.1
–67.3
–53.7
–67.0
–57.9
–69.4
–66.6
–73.2
–64.3
–72.9
–63.4
–63.4
–41.1
–66.3
–53.6
–67.2
–66.5
–67.5
–58.8
–72.9
–63.3
–71.2
–61.7
–71.7
–71.4
–73.2
–67.3
–67.3
–65.8
–61.6
–37.8
–66.3
–54.6
–72.9
–62.5
–71.4
–71.7
–70.7
–55.2
–72.1
–57.1
–73.1
REV. B
–13–
AD831
Table III. AD 831 Mixer Table, ؎3.5 V Supplies, LO = –20 dBm
LO Level
RF Level
–20.0 dBm, LO Frequency 130.7 MHz, Data File G1T 1K 0771
0.0 dBm, RF Frequency 120 MHz
T emperature Ambient
Dut Supply
VPOS Current
±3.50 V
55 mA
VNEG Current 57 mA
Intermodulation T able RF harmonics (rows) × LO harmonics (columns).
First row absolute value of nRF-mLO, and second row is the sum.
0
1
2
3
4
5
6
7
0
1
2
3
4
5
6
7
–45.2
–45.2
–35.7
–35.7
–16.1
–16.1
–21.6
–21.6
–22.3
–22.3
–32.0
–32.0
–36.4
–36.4
–30.3
–30.3
0.0
–29.7
–33.7
–28.2
–47.9
–24.4
–37.5
–26.0
–33.8
–47.4
–32.0
–35.9
–45.2
–49.7
–50.3
–50.3
–49.4
–41.0
–47.4
–51.4
–49.9
–34.7
–48.8
–49.8
–38.5
–48.6
–40.7
–68.5
–51.0
–67.9
–48.4
–48.4
–55.7
–52.9
–58.2
–50.0
–45.0
–64.5
–57.0
–62.8
–68.4
–73.4
–55.5
–74.0
–47.7
–71.8
–66.7
–66.7
–59.7
–65.9
–67.2
–78.1
–62.8
–74.2
–58.2
–77.5
–71.5
–74.4
–72.9
–77.9
–63.5
–77.5
–66.9
–66.9
–71.5
–76.3
–73.6
–78.1
–77.6
–78.2
–70.8
–78.1
–70.2
–78.0
–75.8
–77.9
–78.1
–77.9
–78.0
–78.0
–69.7
–78.3
–76.7
–78.3
–78.6
–78.2
–78.8
–78.1
–75.4
–78.0
–78.1
–77.9
–79.0
–77.8
–78.4
–78.4
–78.5
–78.3
–76.9
–78.2
–78.7
–78.2
–79.0
–77.9
–79.1
–77.9
–78.6
–77.8
–78.9
–77.5
Table IV. AD 831 Mixer Table, ؎5 V Supplies, 1 k⍀ Bias Resistor, LO = –20 dBm
LO Level
RF Level
–20.0 dBm, LO Frequency 130.7 MHz, Data File G1T 1K 3881
0.0 dBm, RF Frequency 120 MHz
T emperature Ambient
Dut Supply
VPOS Current
±3.50 V
59 mA
VNEG Current 61 mA
Intermodulation table RF harmonics (rows) × LO harmonics (columns).
First row absolute value of nRF-mLO, and second row is the sum.
0
1
2
3
4
5
6
7
0
1
2
3
4
5
6
7
–60.6
–60.6
–52.3
–52.3
–16.6
–16.6
–12.8
–12.8
–26.0
–26.0
–45.0
–45.0
–38.8
–38.8
–34.1
–34.1
0.0
–27.3
–35.2
–28.7
–41.8
–20.7
–29.8
–32.9
–29.1
–39.2
–35.3
–38.2
–49.0
–47.8
–46.6
–46.6
–48.8
–37.8
–40.1
–47.6
–52.2
–41.7
–57.9
–54.2
–38.6
–50.4
–45.8
–64.1
–47.7
–64.9
–41.3
–41.3
–58.8
–47.9
–59.5
–65.2
–41.8
–62.5
–61.2
–64.2
–58.1
–73.8
–57.5
–72.3
–54.0
–72.6
–53.9
–53.9
–52.5
–61.4
–73.7
–70.6
–68.1
–76.9
–60.3
–76.8
–71.0
–78.6
–63.4
–78.3
–62.3
–78.1
–66.9
–66.9
–65.8
–69.7
–76.6
–72.9
–75.2
–77.4
–65.4
–77.7
–70.0
–78.5
–73.6
–78.4
–68.7
–78.2
–77.4
–77.4
–73.3
–78.6
–73.8
–78.7
–78.8
–78.6
–79.2
–78.6
–73.6
–78.4
–74.9
–78.2
–79.3
–78.2
–78.9
–78.9
–79.0
–78.8
–77.9
–78.7
–78.0
–78.6
–79.3
–78.3
–79.5
–78.3
–79.3
–78.1
–79.3
–78.0
–14–
REV. B
AD831
HP 6632A
HP 6632A
PROGRAMMABLE
POWER SUPPLY
PROGRAMMABLE
POWER SUPPLY
HP 8656B
SYNTHESIZED
SIGNAL GENERATOR
–5V
+5V
50Ω
HP 8561E
SPECTRUM
ANALYZER
AD831
MCL
ZFSC-2-1
COMBINER
PER
∑
FIGURE 25
LO
HP 8656A
SYNTHESIZED
SIGNAL GENERATOR
FLUKE 6082A
SYNTHESIZED
SIGNAL GENERATOR
HP 9920
IEEE CONTROLLER
HP 9121
DISK DRIVE
IEEE-488 BUS
Figure 28. Third-Order Intercept Characterization Setup
HP 6632A
HP 6632A
PROGRAMMABLE
POWER SUPPLY
PROGRAMMABLE
POWER SUPPLY
–5V
+5V
MCL
ZFSC-2-1
HP 8656B
SYNTHESIZED
SIGNAL GENERATOR
AD831
PER
FIGURE 25
RF
IF
HP 8656B
SYNTHESIZED
SIGNAL GENERATOR
50Ω
LO
50Ω
50Ω
MCL
ZFSC-2-1
USED FOR
IF TO RF, LO
LO TO RF
50Ω
MOVE SPECTRUM
ANALYZER FOR IF
MEASUREMENTS
HP 8561E
SPECTRUM
ANALYZER
HP 8656B
SYNTHESIZED
SIGNAL GENERATOR
Figure 29. IF to RF Isolation Characterization Setup
REV. B
–15–
AD831
O UTLINE D IMENSIO NS
D imensions shown in inches and (mm).
20-Lead P LCC (P -20A)
0.180 (4.57)
0.165 (4.19)
0.048 (1.21)
0.042 (1.07)
0.056 (1.42)
0.042 (1.07)
0.025 (0.63)
0.015 (0.38)
0.048 (1.21)
0.042 (1.07)
C1879a–10–6/95
3
19
18
0.021 (0.53)
0.013 (0.33)
0.330 (8.38)
0.290 (7.37)
0.032 (0.81)
PIN 1
IDENTIFIER
4
0.050
(1.27)
BSC
TOP VIEW
0.026 (0.66)
14
8
9
13
0.020
(0.50)
R
0.040 (1.01)
0.025 (0.64)
0.356 (9.04)
SQ
0.350 (8.89)
0.110 (2.79)
0.085 (2.16)
0.395 (10.02)
0.385 (9.78)
SQ
–16–
REV. B
相关型号：
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