LT5511 - High Signal Level Upconverting Mixer

LT5511
High Signal Level
Upconverting Mixer
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FEATURES
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DESCRIPTIO
The LT®5511 mixer is designed to meet the high linearity
requirements of cable TV infrastructure downstream transmitters and wireless infrastructure transmit systems. The
IC includes a differential LO buffer amplifier driving a
double-balanced mixer. The LO, RF and IF ports can be
easily matched to a broad range of frequencies for different applications. The high performance capability of the
LO buffer allows the use of a single-ended source, thus
eliminating the need for an LO balun.
Wide RF Output Frequency Range to 3000MHz
Broadband RF and IF Operation
+17dBm Typical Input IP3 (at 950MHz)
+6dBm IF Input for 1dB RF Output Compression
Integrated LO Buffer: –10dBm Drive Level
Single-Ended or Differential LO Input
Double-Balanced Mixer
Enable Function
Single 4.0V – 5.25V Supply Voltage Range
16-Pin TSSOP Exposed Pad Package
The LT5511 mixer delivers +17dBm typical input 3rd
order intercept point at 950MHz, and +15.5dBm IIP3 at
1900MHz, with IF input signal levels of – 5dBm. The input
1dB compression point is typically +6dBm.
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APPLICATIO S
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CATV Downlink Infrastructure
Wireless Infrastructure
High Linearity Mixer Applications
, LTC and LT are registered trademarks of Linear Technology Corporation.
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TYPICAL APPLICATIO
VCC
5V
ENABLE
RF Output Power
and 3rd Order Intermodulation
vs Input Power (Two Input Tones)
LT5511
EN
VCCBIAS
VCCLO
BIAS
MOD
IF+
0
TO
DOWNMIXER
RF –
IF–
10
950MHz
RF +
–10
POUT, IM3 (dBm/TONE)
44MHz
GND
–20
–30
–40
–50
LO–
–70
–90
5511 F01a
LO INPUT
994MHz
–10dBm
IM3
–60
–80
LO+
POUT
–100
–20
PLO = –10dBm
fRF1 = 950MHz
fRF2 = 949MHz
TA = 25°C
–15
–5
0
–10
IF INPUT POWER (dBm/TONE)
5
5511 F01b
Figure 1. High Signal Level Upmixer for CATV Downlink Infrastructure.
5511i
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LT5511
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ABSOLUTE
AXI U RATI GS
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PACKAGE/ORDER I FOR ATIO
(Note 1)
Supply Voltage ....................................................... 5.5V
Enable Voltage ................................ –0.3V to VCC + 0.3V
LO Input Power (Differential) .............................. 10dBm
IF Input Power (Differential) ............................... 10dBm
IF+, IF– DC Currents .............................................. 25mA
Operating Temperature Range .................–40°C to 85°C
Storage Temperature Range ..................–65°C to 150°C
Lead Temperature (Soldering, 10sec)................... 300°C
ORDER PART
NUMBER
TOP VIEW
LO–
1
16 LO
NC
2
15 VCCLO
GND
3
14 GND
+
IF+
4
13
IF–
5
12 RF –
GND
6
11 GND
VCCBIAS
7
10 EN
GND
8
9
LT5511EFE
RF+
FE PART MARKING
NC
5511EFE
FE PACKAGE
16-LEAD PLASTIC TSSOP
TJMAX = 150°C, θJA = 38°C/W
EXPOSED PAD IS GROUND
(MUST BE SOLDERED TO
PRINTED CIRCUIT BOARD)
Consult LTC Marketing for parts specified with wider operating temperature ranges.
ELECTRICAL CHARACTERISTICS
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
VCC = 5VDC, EN = High, TA = 25°C
IF Input Frequency Range (Note 6)
1 to 300
MHz
LO Input Frequency Range (Note 6)
30 to 2700
MHz
RF Output Frequency Range (Note 6)
10 to 3000
MHz
950MHz Application: (Test Circuit Shown in Figure 2) VCC = 5VDC, EN = High, TA = 25°C, IF Input = 50MHz at –5dBm, LO Input = 1GHz at –10dBm,
RF Output Measured at 950MHz, unless otherwise noted. (Notes 2, 3)
IF Input Return Loss
With External Matching, ZO = 50Ω
LO Input Power
14
–15 to –5
dB
dBm
LO Input Return Loss
With External Matching, ZO = 50Ω
14
dB
RF Output Return Loss
With External Matching, ZO = 50Ω
17
dB
Conversion Gain
0
LO to RF Leakage
–46
dBm
dB
Input 1dB Compression
5.9
dBm
Input 3rd Order Intercept
Two-Tone, –5dBm/Tone, ∆f = 1MHz
17
dBm
Input 2nd Order Intercept
Single-Tone, –5dBm
52
dBm
15
dB
SSB Noise Figure
5511f
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LT5511
ELECTRICAL CHARACTERISTICS
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
1.9GHz Application: (Test Circuit Shown in Figure 3) VCC = 5VDC, EN = High, TA = 25°C, IF Input = 50MHz at –5dBm, LO Input = 1.95GHz at –10dBm,
RF Output Measured at 1900MHz, unless otherwise noted. (Notes 3, 4)
IF Input Return Loss
With External Matching, ZO = 50Ω
14
LO Input Power
dB
–15 to –5
dBm
LO Input Return Loss
With External Matching, ZO = 50Ω
11.5
dB
RF Output Return Loss
With External Matching, ZO = 50Ω
11.5
dB
Conversion Gain
–0.7
dB
LO to RF Leakage
–47
dBm
Input 1dB Compression
5.2
dBm
15.5
dBm
51
dBm
14
dB
Supply Voltage
4.0 to 5.25
VDC
Supply Current
56
65
1
30
Input 3rd Order Intercept
Two-Tone, –5dBm/Tone, ∆f = 1MHz
Input 2nd Order Intercept
Single-Tone, –5dBm
SSB Noise Figure
Power Supply Requirements: VCC = 5VDC, EN = High, TA = 25°C, unless otherwise noted.
Shutdown Current (Chip Disabled)
EN = Low
Enable Mode Threshold
EN = High
Disable Mode Threshold
EN = Low
3
mA
µA
VDC
0.5
VDC
Turn ON Time (Note 5)
2
µs
Turn OFF Time (Note 5)
6
µs
1
µA
Enable Input Current
EN = 5V
Note 1: Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.
Note 2: External components on the final test circuit are optimized for
operation at f RF = 950MHz, f LO = 1GHz and f IF = 50MHz (Figure 2).
Note 3: Specifications over the – 40°C to 85°C temperature range are
assured by design, characterization and correlation with statistical process
controls.
Note 4: External components on the final test circuit are optimized for
operation at f RF = 1900MHz, f LO = 1.95GHz and f IF = 50MHz (Figure 3).
Note 5: Turn On and Turn Off times are based on rise and fall times of RF
output envelope from full power to –40dBm with an IF input power of
–5dBm.
Note 6: Part can be used over a broader range of operating frequencies.
Consult factory for applications assistance.
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LT5511
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TYPICAL PERFOR A CE CHARACTERISTICS
(950MHz Application)
VCC = 5VDC, EN = High , TA = 25°C, IF Input = 50MHz at –5dBm, LO Input = 1GHz at –10dBm, RF Output Measured at 950MHz, unless
otherwise noted. For 2-Tone Measurements: 2nd IF Input = 51MHz at –5dBm. (Test Circuit Shown in Figure 2).
RF Output Power and 3rd Order
Intermodulation vs IF Input Power
(Two Input Tones)
0
–10
–20
TA = 25°C
–30
–40
TA = 85°C
TA = –40°C
–50
–20
2
–30
–40
TA = 85°C
TA = –40°C
–50
–70
–70
–80
–15
–80
–15
–5
–15
5
–10
0
–5
IF INPUT POWER (dBm)
IIP2 vs LO Power
LO to RF Leakage vs LO Power
–5
60
TA = –40°C
2
13
TA = –40°C
TA = 25°C
0
–10
–15
–15
TA = 25°C
40
–25
–35
TA = 85°C
9
–55
–20
0
–10
–15
LO POWER (dBm)
30
10
TA = 25°C
–5
TA = 85°C
20
TA = –40°C
–45
11
TA = 85°C
50
IIP2 (dBm)
15
IIP3 (dBm)
4
LO TO RF LEAKAGE (dBm)
17
TA = –40°C
TA = 85°C
GAIN (dB)
5
5511 G03
19
6
–2
–20
–10
0
–5
IF INPUT POWER (dBm)
5511 G02
TA = 25°C
GAIN
TA = 85°C
–4
Conversion Gain and IIP3
vs LO Power
IIP3
TA = 25°C
0
–1
–3
IM2
5511 G01
8
TA = –40°C
1
–2
TA = 25°C
–60
5
3
POUT
–60
–10
0
–5
IF INPUT POWER (dBm/TONE)
4
TA = 85°C
IM3
POUT, IM2 (dBm)
POUT, IM3 (dBm/TONE)
TA = 85°C
5
TA = –40°C
TA = 25°C
0
TA = –40°C
–10
10
POUT
TA = 25°C
Conversion Gain vs IF Input
Power (Single Input Tone)
GAIN (dB)
10
RF Output Power and 2nd Order
Intermodulation vs IF Input Power
(Single Input Tone)
–5
0
–20
0
–15
LO POWER (dBm)
–10
–5
LO POWER (dBm)
0
5511 G06
5511 G04
5511 G05
2
0
–4
–25
TA = –40°C
–35
–6
–45
LO LEAKAGE
TA = 25°C
–8
IF = 50MHz, LO SWEPT FROM
400MHz TO 1300MHz AT –10dBm
–10
300
500
700
900
1100
RF OUTPUT FREQUENCY (MHz)
–55
–65
1300
5511 G07
IIP3, IIP2 (dBm)
GAIN (dB)
TA = 85°C
TA = 85°C
LO TO RF LEAKAGE (dBm)
TA = 25°C
40
30
20
IIP2
18
TA = –40°C
TA = 25°C
IIP3
TA = 85°C
20
10
TA = 25°C
TA = 85°C
50
–15
GAIN
–2
60
–5
TA = –40°C
SSB Noise Figure vs
Output Frequency
IIP3 and IIP2
vs Output Frequency
NOISE FIGURE (dB)
Conversion Gain and LO to RF
Leakage vs Output Frequency
TA = 25°C
TA = –40°C
IF = 50MHz, LO SWEPT FROM
400MHz TO 1300MHz AT –10dBm
0
300
500
700
900
1100
RF OUTPUT FREQUENCY (MHz)
16
14
12
1300
5511 G08
IF = 50MHz, LO SWEPT FROM
400MHz TO 1300MHz AT –10dBm
10
300
500
700
900
1100
RF OUTPUT FREQUENCY (MHz)
1300
5511 G09
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LT5511
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TYPICAL PERFOR A CE CHARACTERISTICS
(950MHz Application)
VCC = 5VDC, EN = High , TA = 25°C, IF Input = 50MHz at –5dBm, LO Input = 1GHz at –10dBm, RF Output Measured at 950MHz, unless
otherwise noted. For 2-Tone Measurements: 2nd IF Input = 51MHz at –5dBm. (Test Circuit Shown in Figure 2).
Conversion Gain
vs Supply Voltage
LO and RF Port Return Loss
vs Frequency
IIP3 and IIP2
vs Supply Voltage
6
0
60
35
TA = 25°C
IIP2
4
30
LO PORT
–30
2
IIP3 (dBm)
GAIN (dB)
–20
TA = –40°C
TA = 25°C
0
TA = 85°C
–50
300
900
700
1100
FREQUENCY(MHz)
500
1300
TA = 85°C
25
20
IIP3
–2
–40
4.2
4.4 4.6 4.8 5.0 5.2
SUPPLY VOLTAGE (V)
4.2
4.4 4.6 4.8 5.0 5.2
SUPPLY VOLTAGE (V)
5511 G11
5511 G10
30
TA = –40°C
10
4.0
5.4 5.6
40
TA = 85°C
TA = 25°C
15
–4
4.0
50
TA = –40°C
RF PORT
IIP2 (dBm)
RETURN LOSS (dB)
–10
20
10
5.4 5.6
5511 G12
(1.9GHz Application)
VCC = 5VDC, EN = High , TA = 25°C, IF Input = 50MHz at –5dBm, LO Input = 1.95GHz at –10dBm, RF Output Measured at 1900MHz,
unless otherwise noted. For 2-Tone Measurements: 2nd IF Input = 51MHz at –5dBm. (Test Circuit Shown in Figure 3).
RF Output Power and 2nd Order
Intermodulation vs IF Input Power
(Single Input Tone)
RF Output Power and 3rd Order
Intermodulation vs IF Input
Power (Two Input Tones)
10
0
TA = 25°C
TA = 85°C
0
–10
IM3
–20
POUT, IM2 (dBm)
POUT, IM3 (dBm/TONE)
–10
POUT
TA = –40°C
–30
TA = –40°C
–40
–50
TA = 25°C
–70
–80
–15
TA = 85°C
5
5511 G13
4
3
TA = 85°C
2
–30
IM2
–40
–50
–70
–10
0
–5
IF INPUT POWER (dBm/TONE)
5
POUT
TA = –40°C
–20
–60
–60
TA = 25°C
GAIN (dB)
10
Conversion Gain vs IF Input
Power (Single Input Tone)
–80
–15
1
0
–1
–2
TA = –40°C
TA = –40°C
TA = 25°C
TA = 85°C
–3
TA = 85°C
–4
TA = 25°C
5
–10
0
–5
IF INPUT POWER (dBm)
5511 G14
–5
–15
–10
0
–5
IF INPUT POWER (dBm)
5
5511 G15
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LT5511
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TYPICAL PERFOR A CE CHARACTERISTICS
(1.9GHz Application)
VCC = 5VDC, EN = High , TA = 25 ºC, IF Input = 50MHz at –5dBm, LO Input = 1.95GHz at –10dBm. RF Output Measured at 1900MHz,
unless otherwise noted. For 2-Tone Measurements: 2nd IF Input = 51MHz at –5dBm. (Test Circuit Shown in Figure 3).
Conversion Gain and IIP3
vs LO Input Power
60
–5
50
–15
40
TA = 85°C
TA = 25°C
15
TA = 25°C
TA = –40°C
2
13
GAIN
TA = –40°C
11
0
IIP3 (dBm)
GAIN (dB)
4
IIP2 vs LO Input Power
5
TA = 25°C
–2
9
TA = 85°C
IIP2 (dBm)
IIP3
17
LO TO RF LEAKAGE (dBm)
6
LO to RF Leakage
vs LO Input Power
–25
TA = –40°C
–35
TA = 85°C
TA = –40°C
TA = 85°C
30
20
–45
10
TA = 25°C
–4
–25
–55
–25
7
–10
–15
–5
–20
LO INPUT POWER (dBm)
0
–10
–15
–5
–20
LO INPUT POWER (dBm)
5511 G16
TA = 85°C
–2
–4
–25
–35
TA = 25°C
LO LEAKAGE
TA = 85°C
–6
TA = –40°C –45
IF = 50MHz, LO SWEPT
FROM 1600MHz TO 2350MHz
–8
1500
1700
1900
2100
RF OUTPUT FREQUENCY (MHz)
50
IIP3, IIP2 (dBm)
–15
TA = 25°C
TA = –40°C
IIP3
TA = 25°C
20
TA = 85°C
14
IF = 50MHz, LO SWEPT
FROM 1600MHz TO 2350MHz
10
1500
1700
1900
2100
RF OUTPUT FREQUENCY (MHz)
IF = 50MHz, LO SWEPT
FROM 1600MHz TO 2350MHz
0
1500
16
12
TA = –40°C
10
–55
2300
TA = 25°C
TA = 25°C
18
40
30
20
IIP2
TA = 85°C
NOISE FIGURE (dB)
TA = –40°C
LO TO RF LEAKAGE (dBm)
GAIN (dB)
GAIN
SSB Noise Figure
vs Output Frequency
60
–5
1700
1900
2100
RF OUTPUT FREQUENCY (MHz)
2300
5511 G20
5511 G19
LO and RF Port Return Loss
vs Frequency
IIP3 and IIP2 vs Supply Voltage
4
30
2
25
60
IIP2
–5
TA = 85°C
IIP3 (dBm)
GAIN (dB)
RF PORT
–15
0
TA = –40°C
50
TA = –40°C
–10
TA = 25°C
TA = 85°C
–2
40
20
IIP3
15
TA = 85°C
TA = 25°C
–20
30
TA = –40°C
2100
1900
1700
FREQUENCY(MHz)
2300
5511 G22
–6
4.0
20
10
–4
–25
–30
1500
TA = 25°C
IIP2 (dBm)
RETURN LOSS (dB)
LO PORT
2300
5511 G21
Conversion Gain
vs Supply Voltage
0
0
5511 G18
IIP3 and IIP2 vs Output Frequency
2
–20
–15
–10
–5
LO INPUT POWER (dBm)
5511 G17
Conversion Gain and LO to RF
Leakage vs RF Output Frequency
0
0
–25
0
4.2
4.4 4.6 4.8 5.0 5.2
SUPPLY VOLTAGE (V)
5.4 5.6
5511 G23
5
4.0
4.2
4.4 4.6 4.8 5.0 5.2
SUPPLY VOLTAGE (V)
10
5.4 5.6
5511 G24
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LT5511
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TYPICAL PERFOR A CE CHARACTERISTICS
Table 1. Typical S-Parameters for the IF, RF and LO Ports (referenced to 50Ω). VCC = 5VDC, EN = High , TA = 25ºC.
For each Port Measurement, the other Ports are Terminated as Shown in Figure 2.
Frequency
Differential IF Port
Differential RF Port
Differential LO Port
Single LO Port
(MHz)
Mag.
Ang.
Mag.
Ang.
Mag.
Ang.
Mag.
Ang.
10
0.65
179.2
–
–
–
–
–
–
50
0.648
176.2
0.644
–0.8
0.814
–0.6
0.788
–1.0
100
0.645
173.3
0.643
–2.0
0.836
–0.8
0.808
–1.5
150
0.627
170.6
0.642
–3.0
0.804
–1.0
0.780
–2.1
200
0.626
168.5
0.642
–4.0
0.823
–1.6
0.789
–3.0
250
0.619
166.7
0.639
–5.0
0.803
–1.8
0.779
–3.7
300
0.617
165.0
0.635
–6.1
0.815
–2.5
0.773
–4.7
350
0.609
164.1
0.632
–7.2
0.806
–2.9
0.777
–5.9
400
0.597
162.7
0.629
–8.3
0.804
–3.8
0.760
–7.2
450
0.586
162.2
0.626
–9.5
0.805
–4.4
0.776
–8.9
500
0.567
161.3
0.623
–10.7
0.798
–5.2
0.749
–10.0
600
0.527
160.6
0.622
–13.0
0.797
–6.6
0.746
–12.9
700
0.484
160.0
0.620
–15.4
0.799
–7.8
0.750
–15.7
800
0.438
160.6
0.617
–18.0
0.804
–8.9
0.753
–18.0
900
0.451
167.8
0.615
–20.3
0.808
–9.6
0.756
–19.5
1000
0.554
162.3
0.613
–22.4
0.814
–10.2
0.763
–20.5
1100
0.581
150.0
0.611
–24.6
0.817
–10.7
0.765
–21.6
1200
0.574
141.4
0.607
–26.6
0.813
–11.2
0.755
–22.7
1300
0.567
137.2
0.602
–28.6
0.811
–12.2
0.751
–24.7
1400
0.557
135.1
0.594
–30.7
0.805
–13.7
0.743
–27.7
1500
0.540
135.6
0.585
–32.9
0.795
–15.6
0.731
–31.2
1600
0.520
136.5
0.576
–35.3
0.790
–18.0
0.727
–35.3
1700
0.495
136.9
0.567
–37.8
0.789
–20.6
0.726
–39.3
1800
0.462
135.3
0.557
–40.7
0.791
–22.9
0.728
–42.6
1900
0.432
131.0
0.548
–43.8
0.793
–24.8
0.728
–45.0
2000
0.405
124.4
0.540
–47.0
0.795
–26.2
0.728
–46.7
2100
0.390
116.1
0.529
–50.2
0.796
–27.3
0.724
–48.0
2200
0.366
108.1
0.521
–53.9
0.796
–28.4
0.718
–49.8
2300
0.310
110.2
0.513
–57.4
0.790
–29.8
0.703
–52.4
2400
0.417
127.5
0.503
–61.4
0.782
–31.8
0.687
–56.5
2500
0.489
121.5
0.495
–65.3
0.765
–34.8
0.668
–62.7
2600
0.491
122.0
0.486
–69.0
0.748
–38.8
0.656
–70.5
2700
0.472
126.7
0.479
–73.2
0.731
–43.3
0.652
–78.7
2800
0.445
132.0
0.472
–76.8
0.721
–48.3
0.663
–85.9
2900
0.412
138.9
0.468
–80.4
0.720
–52.5
0.680
–91.2
3000
0.375
142.4
0.463
–83.1
0.722
–55.9
0.701
–94.2
5511i
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LT5511
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PI FU CTIO S
LO–, LO+ (Pins 1, 16): Differential Inputs for the Local
Oscillator Signal. They can also be driven single-ended by
connecting one to an RF ground through a DC blocking
capacitor. For single-ended drive, use LO+ for the signal
input, as this results in less interference from unwanted
coupling of the LO signal to other pins. These pins are
internally biased to about 1.4V; thus, DC blocking capacitors are required. An impedance transformation is required to match the LO input to 50Ω (or 75Ω). At frequencies below 1.5GHz this input can be resistively matched
with a shunt resistor.
VCCBIAS (Pin 7): Supply Voltage for the LO Buffer Bias and
Enable Circuits. This pin should be connected to VCC and
have appropriate RF bypass capacitors. Care should be
taken to ensure that RF signal leakage to the VCC line is
minimized.
NC (Pins 2, 9): Not Connected Internally. Connect to
ground for improved isolation between pins.
RF –, RF+ (Pins 12, 13): Differential Outputs for the RF
Output Signal. An impedance transformation may be
required to match the outputs. These pins are also used to
connect the mixer to the DC supply through impedancematching inductors, RF chokes or transformer center-tap.
Care should be taken to ensure that the RF signal leakage
to VCCLO and VCCBIAS is minimized.
EN (Pin 10): Chip Enable/Disable. When the applied voltage is greater than 3V, the IC is enabled. When the applied
voltage is less than 0.5V, the IC is disabled and the DC
current drops to about 1µA. Under no conditions should
the voltage on this pin exceed VCC + 0.3V, even at power
on.
GND (Pins 3, 6, 8,11, 14): Internal Grounds. These pins
are used to improve isolation and are not intended as DC
or RF grounds for the IC. Connect these pins to ground for
best performance.
IF+, IF – (Pins 4, 5): Differential Inputs for the IF Signal. A
differential signal must be applied to these pins. These
pins are internally biased to about 1.2V, and thus require
DC blocking capacitors. These pins should be DC isolated
from each other for best LO suppression. Imbalances in
amplitude or phase between these two signals will degrade the linearity of the mixer.
VCCLO (Pin 15): Supply Voltage for the LO Buffer Amplifier. This pin should be connected to VCC and have appropriate RF bypass capacitors. Care should be taken to
ensure that RF signal leakage to the VCC line is minimized.
GROUND (Backside Contact) (Pin 17): DC and RF Ground
Return for the Entire IC. This contact must be connected
to a low impedance ground plane for proper operation.
W
BLOCK DIAGRA
NC
LO–
LO+
1
16
2
15 VCCLO
GND 3
14 GND
LO
BUFFER
IF+
4
IF –
5
12 RF –
BIAS
CIRCUITS
GND 6
VCCBIAS
13 RF+
11 GND
10 EN
7
8
GND
17
9
GND
NC
(BACKSIDE)
5511 BD
5511f
8
LT5511
TEST CIRCUIT
LO
R1
C1
VCC
VCC
C4
C5
C7
1
2
IF
T1
4
C8
4x
3
R2
C10
1x
5
3
C11
1
R3
C13
4
5
6
7
VCC
C17
8
LT5511
LO–
LO+
NC
VCCLO
GND
GND
16
15
RF+
IF –
12
RF –
GND
VCCBIAS
EN
GND
NC
L1
13
IF+
GND
T2
14
3
4
C12
C15
2
1
11
10
4x
1x
C9
RF
5
L2
C14
R5
EN
9
EXPOSED
PAD GND
5511F02
Component
Value
Comments
C1, C9, C11, C15
22pF
0402
C5, C7, C17
100pF
0402
C4
0.1µF
0402
C8
220pF
0402
C10, C12, C13
1000pF
0402
C14
1.5pF
0402
L1, L2
6.8nH
0402
62Ω
0402
75Ω, 0.1%
0603
R1
R2, R3
R5
10kΩ
0402
T1
4:1
Coilcraft TTWB-4-A
T2
4:1
M/A-Com ETC1.6-4-2-3
Figure 2. Test Circuit and Evaluation Board Schematic for 950MHz Application.
5511i
9
LT5511
TEST CIRCUIT
LO
C1
VCC
C2
L3
C7
1
2
IF
T1
4
C8
4x
5
3
3
C10
1x
R2
C11
1
C13
R3
4
5
6
7
VCC
C17
8
LT5511
LO–
NC
LO+
VCCLO
GND
GND
IF –
RF –
12
GND
EN
NC
T2
14
13
VCCBIAS
C4
15
RF+
GND
C5
16
IF+
GND
VCC
L1
3
4
C12
C15
2
1
11
10
4x
1x
5
RF
L2
EN
9
5511 F03
Value
Comments
C1, C9, C11, C15
22pF
0402
C5, C7, C17
100pF
0402
C4
0.1µF
0402
C8
220pF
0402
C10, C12, C13
1000pF
0402
C2
1.2pF
0402
L3
6.8nH
0402
L1, L2
4.7nH
0402
L4
1.8nH
0402
R2, R3
C9
R5
EXPOSED
PAD GND
Component
L4
75Ω, 0.1%
0603
R5
10kΩ
0402
T1
4:1
Coilcraft TTWB-4-A
T2
4:1
M/A-Com ETC1.6-4-2-3
Figure 3. Test Circuit and Evaluation Board Schematic for 1.9GHz Application.
5511f
10
LT5511
U
W
U
U
APPLICATIO S I FOR ATIO
The LT5511 consists of a double-balanced mixer driven by
a high-performance, differential, limiting LO buffer. The
mixer has been optimized for high linearity and high signal
level operation. The LT5511 is intended for applications
with LO frequencies of 0.4GHz to 2.7GHz and IF input
frequencies from 10MHz to 300MHz, but can be used at
other frequencies with excellent results. The LT5511 can
be used in applications using either a low side or high side
LO.
IF Input Port
The IF+ and IF– pins are the differential inputs to the mixer.
These inputs drive the emitters of the switching transistors, and thus have a low impedance. The DC current
through these transistors is set by external resistors from
each IF pin to ground. The typical internal voltage on the
emitters is 1.2V; thus, the current through each IF pin is
approximately:
IIF = 1.2/RIF
LO Input Port
The LO buffer on the LT5511 consists of differential high
speed amplifiers and limiters that are designed to drive the
mixer quad to achieve high linearity and performance at
high IF input signal levels. The LO+ and LO– pins are the
differential inputs to the LO buffer. Though the LO signal
can be applied differentially, the LO buffer performs well
with only one input driven, thus eliminating the need for a
balun. In this case, a capacitor should be connected
between the unused LO input pin and ground. The LO pins
are biased internally to about 1.4V, and thus must be DC
isolated from the external LO signal source.
The LO input should be matched to 50Ω. The impedance
match can be accomplished through the use of a reactive
impedance matching network. However, for lower LO
frequencies (below about 1.5GHz), an easier approach is
to use a shunt 62Ω resistor to resistively match the port.
(The resistor must be DC isolated from the LO input pin).
This method is broadband and requires LO power levels of
only –10dBm. At higher frequencies, a better match can be
realized with reactive components. Transmission lines
and parasitics should be considered when designing the
matching circuits. Typical S-parameter data for the LO
input is included in Table 1 to facilitate the design of the
matching network.
RIF is the value of the external resistors to ground. Best
performance is obtained when the IF inputs are perfectly
balanced and 0.1% tolerance resistors are recommended
here. The LT5511 has been characterized with 75Ω
resistors on each of the IF inputs.
The IF signal to the mixer must be differential. To realize
this, an RF balun transformer or lumped element balun can
be used. The RF transformer is recommended, as it is
easier to realize broadband operation, and also does not
have the component sensitivity issues of a lumped element balun.
The differential input impedance of the IF input is approximately 12.5Ω; therefore, a 4:1 impedance transformation
is required to match to 50Ω. Selecting a transformer with
this impedance ratio will reduce the amount of additional
components required, as the full impedance transformation is realized by the transformer. DC-isolating transformers or transmission-line transformers can be used,
as could lumped element transformation networks. Because the IF ports are internally biased, they must be DC
isolated from the IF source. Additionally, IF+ and IF– must
be DC isolated from each other in order to maintain good
LO suppression.
5511i
11
LT5511
U
W
U
U
APPLICATIO S I FOR ATIO
On the evaluation board (Figure 4), 1nF DC-blocking
capacitors are used on the IF input pins. A 220pF capacitor
on the 50Ω source side of the input balun is used to tune
out the excess inductance to improve the match at 50MHz.
To shift the match higher in frequency, this capacitor value
should be reduced.
optimum performance. These pins are biased at the
supply voltage, which can be applied through the center
tap of the output transformer. (The center tap should be RF
bypassed for best performance). A pair of series inductors
can be used to match RF+ and RF– to the high impedance
(200Ω) side of a 4:1 balun.
RF Output Port
The RF outputs, RF+ and RF–, are internally connected to
the collectors of the mixer switching transistors. These
differential output signals should be combined externally
through an RF balun transformer or 180° hybrid to achieve
The output balun has a significant impact on the performance of the mixer. A broadband balun provides better
rejection of the 2fLO spur. If the level of that spur is not
critical, a less expensive and smaller balun can be used.
The amplitude and phase balances of the balun will affect
the LO suppression.
(4a) Top Layer Silkscreen
(4b) Top Layer Metal
Figure 4. Evaluation Board Layout.
5511f
12
LT5511
U
U
W
U
APPLICATIO S I FOR ATIO
SPECTRUM
ANALYZER
POWER
SUPPLY
RFOUT
GND
10dB
PAD
LOIN
LO SIGNAL
GENERATOR 3
T2
E3
LT5511
IC
E2
T1
E1
IFIN
DMM
SW1
RF SIGNAL
GENERATOR 1
POWER
SUPPLY
+
RF SIGNAL
GENERATOR 2
(OR PULSE GENERATOR
FOR TURN-ON AND
TURN-OFF MEASUREMENTS)
5511 F05
Figure 5. Test Set-Up for Mixer Measurements
5511i
13
LT5511
U
TYPICAL APPLICATIO S
LO
C1
VCC
C11
L1
C7
1
2
C10
L6
IF +
(50Ω)
3
R2
C2
C13
L7
IF –
(50Ω)
R3
C18
NC
LO+
VCCLO
GND
GND
15
14
IF+
RF+
13
5
IF –
RF –
12
6
8
GND
GND
VCCBIAS
GND
EN
NC
C4
16
4
7
VCC
LT5511
LO–
VCC
C5
3
TL1
C12
11
10
9
C9
5
EN
R5
EXPOSED
PAD GND
Component
Value
5511 F06
Comments
C1, C9
22pF
0402
C5, C7, C18
100pF
0402
C4
0.1µF
0402
C2
12pF
0402
1000pF
0402
C11
1pF
0402
L1
5.2nH
0402
L6, L7
5.6nH
0402
R2, R3
75Ω, 0.1%
0603
C10, C12, C13
RF
1
2
4
TL2
T2
R5
10kΩ
0402
T2
1:1
MURATA LDB15C500A2400
ZO = 80Ω
L = 16° AT 2.4GHz
Transmission Lines
TL1, TL2
Figure 6. Test Circuit Schematic for 2.4GHz RF Application with 300MHz IF Input Frequency
5511f
14
LT5511
U
TYPICAL APPLICATIO S
IIP3 and IIP2 vs Output Frequency
(Figure 6)
Conversion Gain and LO to RF Leakage
vs Output Frequency (Figure 6)
–8
50
–1
–13
45
–2
–18
40
–23
GAIN (dB)
–3
–4
–5
–6
–28
fIF1 = 300MHz AT –8dBm
fIF2 = 301MHz AT –8dBm
PLO = –10dBm
fLO SWEPT FROM 1900MHz TO 2300MHz
–33
–38
–43
–7
–8
–48
LO LEAKAGE
–53
–9
–10
2200
2300
2500
2400
RF OUTPUT FREQUENCY (MHz)
–58
2600
IIP2
35
IIP3, IIP2 (dBm)
GAIN
LO TO RF LEAKAGE (–dBm)
0
30
25
20
fIF1 = 300MHz AT –8dBm
fIF2 = 301MHz AT –8dBm
PLO = –10dBm
fLO SWEPT FROM 1900MHz TO 2300MHz
IIP3
15
10
5
0
2200
2300
2500
2400
RF OUTPUT FREQUENCY (MHz)
5511 F06a
2600
5511 F06a
5511i
Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no representation that the interconnection of its circuits as described herein will not infringe on existing patent rights.
15
LT5511
U
PACKAGE DESCRIPTIO
FE Package
16-Lead Plastic TSSOP (4.4mm)
(Reference LTC DWG # 05-08-1663)
Exposed Pad Variation BA
4.90 – 5.10*
(.193 – .201)
2.74
(.108)
2.74
(.108)
16 1514 13 12 1110
6.60 ±0.10
9
2.74
(.108)
4.50 ±0.10
SEE NOTE 4
2.74 6.40
(.108) BSC
0.45 ±0.05
1.05 ±0.10
0.65 BSC
1 2 3 4 5 6 7 8
RECOMMENDED SOLDER PAD LAYOUT
1.10
(.0433)
MAX
4.30 – 4.50*
(.169 – .177)
0° – 8°
0.09 – 0.20
(.0036 – .0079)
0.65
(.0256)
BSC
0.45 – 0.75
(.018 – .030)
NOTE:
1. CONTROLLING DIMENSION: MILLIMETERS
MILLIMETERS
2. DIMENSIONS ARE IN
(INCHES)
3. DRAWING NOT TO SCALE
0.195 – 0.30
(.0077 – .0118)
0.05 – 0.15
(.002 – .006)
FE16 (BA) TSSOP 0203
4. RECOMMENDED MINIMUM PCB METAL SIZE
FOR EXPOSED PAD ATTACHMENT
*DIMENSIONS DO NOT INCLUDE MOLD FLASH. MOLD FLASH
SHALL NOT EXCEED 0.150mm (.006") PER SIDE
RELATED PARTS
PART NUMBER
DESCRIPTION
COMMENTS
LT5500
1.8GHz to 2.7GHz Receiver-Front End
1.8V to 5.25V Supply, Dual-Gain LNA, Mixer, LO Buffer
LT5502
400MHz Quadrature IF Demodulator with RSSI
1.8V to 5.25V Supply, 70MHz to 400MHz IF, 84dB Limiting Gain,
90db RSSI Range
LT5503
1.2GHz to 2.7GHz Direct IQ Modulator
and Upconverting Mixer
1.8V to 5.25V Supply, Four-Step RF Power Control,
120MHz Modulation Bandwidth
LT5504
800MHz to 2.7GHz Measuring Receiver
80dB Dynamic Range, Temperature Compensated, 2.7V to 5.5V Supply
LTC®5505
RF Power Detectors with >40dB Dynamic Range
300MHz to 3GHz, Temperature Compensated, 2.7V to 6V Supply
LT5506
500MHz Quadrature Demodulator with VGA
1.8V to 5.25V Supply, –4dB to 57dB Linear Power Gain
LT5507
100kHz to 1GHz RF Power Detector
48dB Dynamic Range, Temperature Compensated, 2.7V to 6V Supply
LTC5508
300MHz to 7GHz RF Power Detector
>40dB Dynamic Range, SC70 Package
LT5512
High Signal Level Down Converting Mixer
Up to 3GHz, 20dBm IIP3, Integrated LO Buffer
5511f
16
Linear Technology Corporation
LT/TP 0503 1K • PRINTED IN USA
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900 ● FAX: (408) 434-0507
●
www.linear.com
 LINEAR TECHNOLOGY CORPORATION 2001