LT5521EUF [Linear]
Very High Linearity Active Mixer; 极高的线性度有源混频器
| 型号： | LT5521EUF |
| 厂家： | 
Linear |
| 描述： | Very High Linearity Active Mixer |
| 文件： | 总16页 (文件大小：270K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
LT5521
Very High Linearity
Active Mixer
U
FEATURES
DESCRIPTIO
The LT®5521 is a very high linearity mixer optimized for
low distortion and low LO leakage applications. The chip
includes a high speed LO buffer with single-ended input
and a double-balanced active mixer. The LT5521 requires
only –5dBm LO input power to achieve excellent distor-
tion and noise performance, while reducing external drive
circuit requirements. The LO buffer is internally 50Ω
matched for wideband operation.
■
Wideband Output Frequency Range to 3.7GHz
■
+24.2dBm IIP3 at 1.95GHz RF Output
■
Low LO Leakage: –42dBm
■
Integrated LO Buffer: Low LO Drive Level
■
Single-Ended LO Drive
■
Wide Single Supply Range: 3.15V to 5.25V
■
Double-Balanced Active Mixer
Shutdown Function
■
■
16-Lead (4mm × 4mm) QFN Package
With a 250MHz input, a 1.7GHz LO and a 1.95GHz output
frequency, the mixer has a typical IIP3 of +24.2dBm,
–0.5dB conversion gain and a 12.5dB noise figure.
U
APPLICATIO S
The LT5521 offers exceptional LO-RF isolation, greatly
reducing the need for output filtering to meet LO suppres-
sion requirements.
■
Cellular, W-CDMA, PHS and UMTS Infrastructure
■
Cable Downlink Infrastructure
■
Wireless Infrastructure
■
Fixed Wireless Access Equipment
Thedeviceisdesignedtoworkoverasupplyvoltagerange
from 3.15V to 5.25V.
■
High Linearity Mixer Applications
, LTC and LT are registered trademarks of Linear Technology Corporation.
U
TYPICAL APPLICATIO
Fundamental, 3rd Order
Intermodulation Distortion
vs Input Power
LO INPUT
–5dBm
6.8pF
20
0
LO
GND
110Ω
4:1
82pF
82pF
P
FUND
BPF
1nF
2.7nH
2.7nH
+
–
+
–
IN
OUT
OUT
IF
INPUT
–20
–40
1:1
6.8pF
BPF
10pF
1nF
IN
RF
OUTPUT
PA
IM3
110Ω
–60
–80
BIAS
EN
f
f
f
= 250MHz
1nF
5V DC
IF
= 1.7GHz
LO
RF
V
V
V
CC CC CC
= 1.95GHz
= –5dBm
P
A
LO
= 25°C
T
1µF
–100
–14 –12 –10 –8 –6 –4 –2
(dBm)
0
2
4
6
5521 TA01
P
IN
5521 TA02
5521f
1
LT5521
W W
U W
U
W U
ABSOLUTE MAXIMUM RATINGS
PACKAGE/ORDER INFORMATION
(Note 1)
Power Supply Voltage ........................................... 5.5V
Enable Voltage ............................... –0.2V to VCC + 0.2V
LO Input Power ................................................ +10dBm
LO Input DC Voltage ..................................... 0V to 1.5V
IF Input Power ................................................. +10dBm
Difference Voltage Across Output Pins ................ ±1.5V
Maximum Pin 2 or Pin 3 Current ......................... 34mA
Operating Ambient Temperature Range.. – 40°C to 85°C
Storage Temperature Range ................. –65°C to 125°C
Maximum Junction Temperature .......................... 125°C
ORDER PART
TOP VIEW
NUMBER
16 15 14 13
LT5521EUF
+
GND
1
2
3
4
12 OUT
11 GND
+
IN
17
–
IN
GND
10
9
–
GND
OUT
UF PART
MARKING
5
6
7
8
UF PACKAGE
16-LEAD (4mm × 4mm) PLASTIC QFN
5521
TJMAX = 125°C, θJA = 37°C/W
EXPOSED PAD (PIN 17) IS GND
MUST BE SOLDERED TO PCB
Consult LTC Marketing for parts specified with wider operating temperature ranges.
VCC = 5V, EN = 2.9V, TA = 25°C unless otherwise noted.
DC ELECTRICAL CHARACTERISTICS
Test circuit shown in Figure 1. (Note 2)
PARAMETER
CONDITIONS
MIN
TYP
MAX
5.25
98
UNITS
V
Supply Voltage
3.15
Supply Current
82
20
mA
µA
Shutdown Current
Enable (EN) Low = Off, High = On
Enable Mode
EN = 0.2V
100
EN = High
EN = Low
EN = 5V
2.9
V
V
Disable Mode
0.2
Enable Current
137
0.1
µA
µA
ns
ns
V
Shutdown Enable Current
Turn-On Time (Note 3)
Turn-Off Time (Note 4)
LO Voltage (Pin 15)
Input Voltage (Pins 2, 3)
EN = 0.2V
200
200
0.96
Internally Biased
V
V
= 5V, Internally Biased
= 3.3V, Internally Biased
2.20
0.46
V
V
CC
CC
VCC = 5V, EN = 2.9V, TA = 25°C unless otherwise noted.
AC ELECTRICAL CHARACTERISTICS
Test circuit shown in Figure 1. (Note 2)
PARAMETER
CONDITIONS
MIN
TYP
10 to 4000
10 to 3000
10 to 3700
–5
MAX
UNITS
MHz
MHz
MHz
dBm
dB
LO Frequency Range
Input Frequency Range
Output Frequency Range
LO Input Power
1
LO Return Loss
Z = 50Ω, f = 1700MHz
12
O
LO
Output Return Loss
Input Return Loss (Pins 2, 3)
Requires Matching
Requires Matching
12
dB
15
dB
5521f
2
LT5521
VCC = 5V, EN = 2.9V, fIF = 250MHz, PIF = –7dBm, fLO = 1700MHz,
AC ELECTRICAL CHARACTERISTICS
PLO = –5dBm, fRF = 1950MHz, TA = 25°C. Test circuit shown in Figure 1.
PARAMETER
CONDITIONS
MIN
TYP
–0.5
MAX
UNITS
dB
Conversion Gain
Conversion Gain Variation vs Temperature
Input P1dB
–0.009
+10
dB/°C
dBm
dB
Single-Side Band Noise Figure
IIP3
12.5
Two Tones, ∆f = 5MHz, P = –7dBm/Tone
+24.2
+49
dBm
dBm
IF
IF
IIP2 (Note 6)
Two Tones, ∆f = 5MHz, P = –7dBm/Tone,
IF IF
f
+ f + f
IF1 IF2
LO
LO-RF Leakage
LO-IF Leakage
–42
–40
dBm
dBm
VCC = 5V, EN = 2.9V, fIF = 44MHz, PIF = –7dBm, fLO = 1001MHz, PLO = –5dBm, fRF = 1045MHz, TA = 25°C.
PARAMETER
CONDITIONS
MIN
TYP
–0.5
MAX
UNITS
dB
Conversion Gain
Conversion Gain Variation vs Temperature
Input P1dB
–0.012
+10
dB/°C
dBm
dB
Single-Side Band Noise Figure
IIP3
12.8
Two Tones, ∆f = 5MHz, P = –7dBm/Tone
+24.5
+49
dBm
dBm
IF
IF
IIP2 (Note 6)
Two Tones, ∆f = 5MHz, P = –7dBm/Tone,
IF IF
f
+ f + f
IF1 IF2
LO
LO-RF Leakage
LO-IF Leakage
–38
–59
dBm
dBm
VCC = 3.3V, EN = 2.9V, fIF = 250MHz, PIF = –7dBm, fLO = 1700MHz, PLO = –5dBm, fRF = 1950MHz, TA = 25°C. (Note 5)
PARAMETER
CONDITIONS
MIN
TYP
–0.5
MAX
UNITS
dB
Conversion Gain
Conversion Gain Variation vs Temperature
Input P1dB
–0.013
+11
dB/°C
dBm
dB
Single-Side Band Noise Figure
IIP3
13.5
Two Tones, ∆f = 5MHz, P = –7dBm/Tone
+25.8
+50
dBm
dBm
IF
IF
IIP2 (Note 6)
Two Tones, ∆f = 5MHz, P = –7dBm/Tone,
IF IF
f
+ f + f
IF1 IF2
LO
LO-RF Leakage
LO-IF Leakage
–36
–60
dBm
dBm
Note 1: Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.
Note 4: Interval from the falling edge of the Enable signal to a 20dB drop
in the RF output power.
Note 2: Specifications over the –40°C to 85°C temperature range are
assured by design, characterization and correlation with statistical process
controls.
Note 5: R1 = R7 = 22.6Ω, Z1 = Z7 = 100nH.
Note 6: Second harmonic distortion measured at f + f + f .
IF2
LO
IF1
Note 3: Interval from the rising edge of the Enable input to the time when
the RF output is within 1dB of its steady-state output.
5521f
3
LT5521
TYPICAL DC PERFOR A CE CHARACTERISTICS
W U
Test circuit shown in Figure 1.
Supply Current vs Supply Voltage
(5V Application)
Supply Current vs Supply Voltage
(3.3V Application)
110
100
90
100
95
85°C
25°C
85°C
25°C
90
85
80
80
75
–40°C
70
–40°C
70
65
60
60
50
3.4
3.1
3.2
3.3
(V)
3.5
4.8
4.9
5.1
4.7
5.2
5.3
5.0
(V)
V
V
CC
CC
5521 G02
5521 G01
W U
TYPICAL AC PERFOR A CE CHARACTERISTICS
fLO = 1700MHz, fIF = 250MHz, fRF = 1950MHz, PLO = –5dBm, VCC = 5V, EN = 2.9V, TA = 25°C, unless otherwise noted. Test circuit
shown in Figure 1 is tuned for 1.95GHz output frequency and VCC = 5V.
Fundamental, 2nd and 3rd Order
Conversion Gain and IIP3
vs RF Frequency
Intermodulation Distortion
vs Input Power
Conversion Gain vs Input Power
20
0
10
8
25
24
23
1.0
0.5
85°C
25°C
P
FUND
–40°C
–40°C
IIP3
6
0
IM3
IM2
–20
–40
25°C
85°C
4
2
22
21
20
19
18
–0.5
–1.0
–1.5
–2.0
85°C
25°C
–40°C
G
C
–60
–80
0
IM2
IM3
–2
–4
–100
–2.5
1850
1950
(MHz)
2150
1750
2050
–14 –12 –10 –8 –6 –4 –2
(dBm)
0
2
4
6
–15 –10 –5
0
15
–25 –20
5
10
P
RF
OUT
IN
P
(dBm)
IN
5521 G05
5521 G03
5521 G04
5521f
4
LT5521
W U
fLO = 1700MHz, fIF = 250MHz, fRF = 1950MHz,
PLO = –5dBm, VCC = 5V, EN = 2.9V, TA = 25°C, unless otherwise noted. Test circuit shown in Figure 1 is tuned for 1.95GHz output
TYPICAL AC PERFOR A CE CHARACTERISTICS
frequency and VCC = 5V.
Conversion Gain, IIP3 and Noise
Figure vs Supply Voltage
Conversion Gain and IIP3
vs LO Power
LO-RF Leakage vs LO Frequency
–36
–38
–40
–42
–44
–46
–48
10
8
30
25
20
15
10
5
10
8
25
24
IIP3
IIP3
–40°C
85°C
6
4
23
22
21
20
19
85°C
25°C
–40°C
6
85°C
25°C
–40°C
4
NF
2
G
C
25°C
2
0
G
C
0
–2
–2
0
–4
18
1750 1800
5.1 5.2
1500 1550 1600 1650 1700
1850 1900
4.6 4.7 4.8 4.9 5.0
(V)
5.3 5.4
–5
LO POWER (dBm)
5
10
–25 –20 –15 –10
0
LO FREQUENCY (MHz)
V
CC
5521 G06
5521 G07
5521 G08
LO-RF Leakage vs LO Power
LO-RF Leakage vs Supply Voltage
Noise Figure vs LO Power
20
19
18
17
16
15
14
13
12
11
10
–32
–34
–36
–38
–40
–42
–44
–46
–48
–34
–36
–38
–40
–40°C
85°C
25°C
–40°C
85°C
85°C
25°C
–42
–44
25°C
–40°C
–46
–48
–50
–50
–20
–15
–10
–5
0
5
4.8
4.9
5.1
4.7
5.2
5.3
5.0
(V)
–25 –20 –15 –10
LO POWER (dBm)
10
–5
0
5
LO POWER (dBm)
V
CC
5521 G11
5521 G10
5521 G09
Low Side LO (LS) and High Side
LO (HS) Comparison: Conversion
Gain and IIP3 vs RF Frequency
Low Side LO (LS) and High Side
LO (HS) Comparison: Noise Figure
vs RF Frequency
10
8
26
24
22
13.5
13.3
13.1
12.9
12.7
12.5
12.3
12.1
11.9
11.7
11.5
LS: R1 = R7 = 110Ω
HS: R1 = R7 = 121Ω
LS
IIP3
f
= 250MHz
IF
HS
6
LS: R1 = R7 = 110Ω
HS: R1 = R7 = 121Ω
4
2
20
18
16
14
12
f
= 250MHz
IF
HS
LS
0
G
C
LS
HS
–2
–4
1850
1950
(MHz)
2150
1750
2050
1700
1900
2000 2050
2100
1750 1800 1850
1950
RF
RF
OUT
(MHz)
OUT
5521 G13
5521 G14
5521f
5
LT5521
W U
fLO = 1001MHz, fIF = 44MHz, fRF = 1045MHz,
TYPICAL AC PERFOR A CE CHARACTERISTICS
PLO = –5dBm, VCC = 5V, EN = 2.9V, TA = 25°C, unless otherwise noted. Test circuit shown in Figure 1 is tuned for 1.045GHz output
frequency.
Fundamental, 2nd and 3rd Order
Intermodulation Distortion
vs Input Power
Conversion Gain and IIP3
vs RF Frequency, Fixed IF
Conversion Gain vs Input Power
1.0
0.5
20
0
10
8
25
24
23
22
21
20
19
18
P
–40°C
25°C
85°C
FUND
IIP3
IM3
IM2
–20
0
6
85°C
25°C
–40°C
–0.5
–1.0
–1.5
–2.0
–2.5
–40
–60
4
2
IM2
IM3
G
C
–80
0
85°C
–100
–2
–4
25°C
–40°C
–120
–15 –10 –5
0
15
–25 –20
5
10
–14
–8
–4 –2
0
2
4
6
–12 –10
–6
970
1020
RF
1070
1170
920
1120
INPUT POWER (dBm)
P
(dBm)
(MHz)
IN
OUT
5521 G16
5521 G15
5521 G17
Conversion Gain, IIP3 and Noise
Figure vs Supply Voltage
Conversion Gain and IIP3
vs LO Power
LO-RF Leakage vs LO Frequency
10
8
25
10
8
26
22
18
14
10
6
–32
–33
–34
–35
–36
–37
–38
–39
–40
–41
–42
IIP3
IIP3
24
85°C
25°C
–40°C
6
4
23
22
21
20
19
6
–40°C
25°C
85°C
25°C
–40°C
NF
4
2
G
C
2
0
G
C
0
–2
85°C
–2
2
–4
18
5.1 5.2
4.6 4.7 4.8 4.9 5.0
(V)
5.3 5.4
–5
LO POWER (dBm)
5
10
–25 –20 –15 –10
0
850
900
1000 1050 1100 1150
950
LO FREQUENCY (MHz)
V
CC
5521 G19
5521 G20
5521 G18
LO-RF Leakage vs LO Power
LO-RF Leakage vs Supply Voltage
–30
–32
–30
–32
–34
–36
–34
–40°C
25°C
85°C
–40°C
–36
–38
–40
–42
25°C
85°C
–38
–40
–42
–44
4.8 4.9 5.0 5.1
(V)
5.4
–5
LO POWER (dBm)
5
10
4.6
4.7
5.2 5.3
–25 –20 –15 –10
0
V
CC
5521 G22
5521 G21
5521f
6
LT5521
W U
fLO = 1001MHz, fIF = 44MHz, fRF = 1045MHz,
PLO = –5dBm, VCC = 5V, EN = 2.9V, TA = 25°C, unless otherwise noted. Test circuit shown in Figure 1 is tuned for 1.045GHz output
TYPICAL AC PERFOR A CE CHARACTERISTICS
frequency.
Low Side LO (LS) and High Side
LO (HS) Comparison: Conversion
Gain and IIP3 vs RF Frequency
Low Side LO (LS) and High Side
LO (HS) Comparison: Noise Figure
vs RF Frequency
Noise Figure vs LO Power
20
19
18
17
16
15
14
13
12
11
10
14.0
13.5
4
3
25
24
f
= 44MHz
f
= 44MHz
IF
IF
LS
IIP3
HS
13.0
12.5
2
1
23
22
HS
LS
85°C
25°C
12.0
11.5
11.0
0
–1
–2
21
20
19
LS
G
C
–40°C
HS
–20
–15
–10
–5
0
5
945
985
1025
RF
1065
(MHz)
1105
1145
940
990
1040
(MHz)
1090
1140
LO POWER (dBm)
RF
OUT
OUT
5521 G23
5521 G24
5521 G34
fLO = 1.7GHz, fIF = 250MHz, fRF = 1.95GHz, PLO = –5dBm, VCC = 3.3V, EN = 2.9V, TA = 25°C, unless otherwise noted. Test circuit
shown in Figure 1 is tuned for 1.95GHz output frequency and VCC = 3.3V.
Conversion Gain and IIP3
vs RF Frequency
POUT, IM3 and IM2 vs Input Power
Conversion Gain vs Input Power
10
8
27
25
20
0
0.5
0
–40°C
P
OUT
IIP3
6
23
IM3
–20
–40
–60
–80
–100
–0.5
–1.0
25°C
85°C
4
2
85°C
25°C
–40°C
21
19
17
15
IM2
G
C
–1.5
–2.0
–2.5
0
IM2
IM3
85°C
25°C
–40°C
–2
–4
13
1850 1900 1950 2000
2150
1750 1800
2050 2100
–14
–8
–4 –2
(dBm)
0
2
4
6
–12 –10
–6
P
0
10
–20 –15 –10
–5
(dBm)
5
RF
(MHz)
P
IN
IN
OUT
5521 G27
5521 G25
5521 G26
5521f
7
LT5521
W U
fLO = 1.7GHz, fIF = 250MHz, fRF = 1.95GHz, PLO
TYPICAL AC PERFOR A CE CHARACTERISTICS
= –5dBm, VCC = 3.3V, EN = 2.9V, TA = 25°C, unless otherwise noted. Test circuit shown in Figure 1 is tuned for 1.95GHz output
frequency and VCC = 3.3V.
Conversion Gain, IIP3 and Noise
Figure vs Supply Voltage
Conversion Gain and IIP3
vs LO Power
LO-RF Leakage vs LO Frequency
10
8
27
25
–32
–33
–34
–35
–36
–37
–38
–39
–40
85°C
25°C
–40°C
8
6
24
20
16
12
8
IIP3
IIP3
6
23
85°C
25°C
–40°C
NF
4
85°C
25°C
–40°C
21
19
17
15
4
2
2
G
C
0
G
C
0
–2
–4
–2
4
13
3.35 3.40
–15 –10 –5
LO POWER (dBm)
10
3.10 3.15 3.20 3.25 3.30
3.45 3.50
–25 –20
0
5
1700 1750
1500 1550 1600 1650
1800 1850 1900
V
(V)
CC
LO FREQUENCY (MHz)
5521 G31
5521 G29
5521 G28
LO Leakage vs Supply Voltage
LO-RF Leakage vs LO Power
Noise Figure vs LO Power
22
20
–20
–23
–26
–29
–32
–35
–38
–41
–44
–47
–50
–30
–32
85°C
–34
–36
–38
–40
–42
18
16
85°C
25°C
–40°C
–40°C
85°C
25°C
25°C
14
12
10
–40°C
–44
–20
–15
–10
–5
0
5
3.0
3.1
3.3
(V)
3.4
3.5
3.6
3.2
–5
5
10
–25 –20 –15 –10
0
LO POWER (dBm)
V
LO POWER (dBm)
CC
5521 G32
5521 G33
5521 G30
U
U
U
PI FU CTIO S
GND (Pins 1, 4, 10, 11, 13, 14, 16): Ground. These pins
are internally connected to the Exposed Pad for improved
isolation. They should be connected to RF ground on the
printed circuit board, and are not intended to replace the
primary grounding through the backside of the package.
IN+, IN– (Pins 2, 3): Differential Input Pins. Each pin
requires a resistive DC path to ground. See Applications
Informationforchoosingtheresistorvalue.Externalmatch-
ing is required.
VCC (Pins 6, 7, 8): Power Supply Pins. Total current draw
for these three pins is 40mA.
OUT+,OUT– (Pins12,9):RFOutputPins.Thesepinsmust
have a DC connection to the supply voltage (see Applica-
tions Information). These pins draw 20mA each. External
matching is required.
LO (Pin 15): Local Oscillator Input. This input is internally
DC biased to 0.96V. Input signal must be AC coupled.
Exposed Pad (Pin 17): Circuit Ground Return for the
Entire IC. For best performance, this pin must be soldered
to the printed circuit board.
EN (Pin 5): Enable Input Pin. The enable voltage should be
at least 2.9V to turn the chip on and less than 0.2V to turn
the chip off.
5521f
8
LT5521
W
BLOCK DIAGRA
17
16
15
LO
14
GND
13
GND
EXPOSED GND
PAD
+
GND
OUT
1
2
3
4
12
11
10
9
+
IN
IN
GND
GND
–
–
GND
OUT
BIAS
EN
V
V
CC
V
CC
CC
5
6
7
8
5521 BD
TEST CIRCUITS
C1
16
RF
GND
ε = 4.4
0.017"
0.062"
0.017"
r
LO
IN
50Ω
DC
Z1
OPT
GND
15
14
13
T2
C3
GND L0 GND GND
+
L1
R1
C2
1
2
3
4
12
11
10
9
RF
OUT
50Ω
Z3
GND
+
OUT
GND
GND
IF
IN
50Ω
T1
LT5521
IN
C4
L2
Z14
C13
R7
–
EXPOSED
PAD (17)
C12
IN
–
GND
EN
5
OUT
C6
V
V
V
CC
6
CC
7
CC
8
Z7
OPT
V
CC
R8
C11
5521 F01
EN
Figure 1. Demonstration Board Schematic
Table 1. Demonstration Board Bill of Materials1, 2
f
IF
= 250MHz, f = 1.95GHz
LO
f
IF
f
= 44MHz, f = 1.045GHz
LO
f
= 250MHz, f = 1.95GHz
RF
RF
IF
RF
REF
R1, R7
Z14
f
= 1.7GHz, V = 5V
CC
= 1.001GHz, V = 5V
CC
f
= 1.7GHz, V = 3.3V
LO CC
110Ω, 1%
10pF
110Ω, 1%
120nH
22.6Ω, 1%
10pF
Z3
0Ω
150pF
0Ω
L1, L2
T1
2.7nH
10nH
3
2.7nH
3
3
M/A-COM MABACT0010
M/A-COM MABACT0010
M/A-COM MABACT0010
T2
M/A-COM ETC1.6-4-2-3
M/A-COM ETC1.6-4-2-3
M/A-COM ETC1.6-4-2-3
C1, C13
C3
6.8pF
82pF
82pF
1nF
27pF
3.9pF
1nF
6.8pF
82pF
82pF
1nF
C12
C2, C4, C6
C11
1nF
1µF
1µF
0Ω
1µF
Z1, Z7
0Ω
100nH
THIS COMPONENT CAN BE REPLACED BY PCB TRACE ON FINAL APPLICATION
10k 10k 10k
R8
Note 1: Tabulated values are used for characterization measurements.
Note 2: Components shown on the schematic are included for consistency with the demo board.
If no value is shown for the component, the site is unpopulated.
Note 3: T1 also M/A-COM ETC1-1-13 and Sprague Goodman GLSW4M202. These alternative transformers
have been measured and have similar performance.
5521f
9
LT5521
W U U
U
APPLICATIO S I FOR ATIO
The LT5521 is a high linearity double-balanced active
mixer. The chip consists of a double-balanced mixer core,
a high performance LO buffer and associated bias and
enable circuitry. The chip is designed to operate with a
supply voltage ranging from 3.15V to 5.25V.
0
–5
–10
–15
–20
–25
Table 2. Port Impedance
FREQUENCY
(MHz)
DIFFERENTIAL
INPUT
DIFFERENTIAL SINGLE-ENDED
OUTPUT
282.2 – j8.4
282.3 – j20.8
262.3 – j55.1
231.4 – j67.0
215.0 – j124.5
109.5 – j158.0
52.9 – j92.1
61.6 – j74.2
14.2 – j27.5
27.9 – j4.4
LO
–30
–35
–40
50
19.8 + j0.7
20.1 + j2.0
49.9 + j0.1
49.8 + j0.3
49.2 + j0.9
47.7 + j2.0
45.3 + j2.8
43.3 + j2.8
43.0 + j3.3
43.4 + j4.6
44.6 + j14.0
42.4 + j17.9
38.6 + j22.8
100
150
200
300
100
350
400
250
300
18.2 + j5.3
FREQUENCY (MHz)
600
15.2 + j16.8
14.5 + j28.1
20.5 + j42.3
48.2 + j26.8
18.2 + j29.4
22.4 + j125.1
5521 F03
1000
1500
2000
2300
3200
3500
4000
Figure 3. IF Input Return Loss
For input frequencies above 100MHz, a broadband im-
pedance matching tranformer with a 1:1 impedance ratio
is recommended. Table 3 provides the component values
necessary to match various IF frequencies using the M/A-
COM CT0010 transformer (T1, Figure 1).
42.8 – j16.0
Table 3. Component Values for Input Matching Using the
M/A-COM CT0010
Signal Input Interface
IF
C2
Z14
120nH
33pF
Z3
150pF
27nH
18nH
10nH
6.8nH
0Ω
Figure 2 shows the signal inputs of the LT5521. The signal
input pins are connected to the common emitter nodes of
the mixer quad differential pairs. The real part of the
differential IN+/IN– impedance is 20Ω. The mixer core
currentissetbyexternalresistorsR1andR7. Settingtheir
values at 110Ω, the nominal DC voltage at the inputs is
2.2V with VCC = 5V. Figure 3 shows the input return loss
for a matched input at 250MHz.
44MHz
95MHz
120MHz
150MHz
170MHz
250MHz
300MHz
435MHz
520MHz
1000pF
820pF
1000pF
330pF
330pF
82pF
27pF
22pF
18pF
10pF
15pF
3.9pF
0.5pF
Unused
0Ω
8.2pF
6.8pF
0Ω
0Ω
Z1
OPT
LT5521
Below 100MHz, the Mini-Circuits TCM2-1T or the Pulse
CX2045 are better choices for a wider input match. This
configuration is shown in Figure 4. The series 1nF capaci-
tors maintain differential symmetry while providing DC
isolation between the inputs. This helps to improve LO
suppression.
R1
C2
+
Z3
IN
IF
IN
2
3
50Ω
T1
1:1
C13
Z14
V
CC
–
IN
C6
1nF
R7
Shunt capacitor C13 (Figure 2) is an optional capacitor
across the input pins that significantly improves LO sup-
pression. Although this capacitor is optional, it is impor-
tant to regulate LO suppression, mitigating part-to-part
5521 F02
Z7
OPT
variation. This capacitor should be optimized depending
Figure 2. Signal Input with External Matching
5521f
10
LT5521
W U U
APPLICATIO S I FOR ATIO
U
Operation at Reduced Supply Voltage
LT5521
R1
C2
1nF
+
IN
IF
IN
50Ω
External resistors R1 and R7 (Figure 2) set the current
through the mixer core. For best distortion performance,
these resistors should be chosen to maintain a total of
40mA through the mixer core (20mA per side). At 5V
supply, R1 and R7 should be 110Ω. Table 5 shows
recommended values for R1 and R7 at various supply
voltages.Caution:Usingvaluesbelowtherecommended
resistancecanadverselyaffectoperationordamagethe
part.
T1
2:1
2
C13
1nF
V
CC
–
IN
3
R7
5521 F04
Figure 4. Low Frequency Signal Input
Table 5. Minimum External Resistor Values vs Supply Voltage
on the IF input frequency and the LO frequency. Smaller
C13 values have reduced impact on the LO output sup-
pression; larger values will degrade the conversion gain.
V
CC
(V)
R1, R7 (Ω)
5
110
4.5
4
82.5
54.9
A single-ended 50Ω source can also be matched to the
differential signal inputs of the LT5521 without an input
transformer. Figure 5 shows an example topology for a
discrete balun, and Table 4 lists component values for
several frequencies. The discrete input match is intrinsi-
cally narrowband. LO suppression to the output is de-
graded and noise figure degrades by 4dB for input
frequencies greater than 200MHz. Noise figure degrada-
tion is worse at lower input frequencies.
3.5
3.3
38.3
23.2
Excessive mismatch between the external resistors R1
and R7 will degrade performance, particularly LO sup-
pression. Resistors with 1% mismatch are recommended
for optimum performance.
Figure 2 shows RF chokes in series with R1 and R7. These
inductors are optional. In general, the chokes improve the
conversiongainandnoisefigureby2dBat3.3V(i.e., atthe
minimum values of R1 and R7). The DC resistance varia-
tionoftheRFchokesmustbeconsideredinthe1%source
resistance mismatch suggested for maintaining LO sup-
pression performance.
R1
C16
L4
LT5521
110Ω
C2
82pF
+
IN
2
3
IF
IN
C13
50Ω
–
C14
IN
Figure 6 indicates the typical performance of the LT5521
as the external source resistance (R1, R7) is varied while
keeping the supply current constant. Figure 6 data was
taken without the benefit of input chokes, and shows the
gradual gain degradation for smaller values of the input
resistors R1 and R7. Figure 7 shows the typical behavior
when the supply voltage is fixed and the core current is
varied by adjusting values of the external resistors R1 and
R7. Decreasing the core current decreases the power
consumption and improves noise figure but degrades
distortion performance. Figure 8 demonstrates the im-
pact of the RF chokes in series with the source resistance
at 3.3V. There is a 2dB improvement in conversion gain
and noise figure and a corresponding decrease in IIP3.
R7
L3
110Ω
5521 F05
1nF
Figure 5. Alternative Transformerless Input Circuit
Using Low Cost Discrete Components
Table 4. Component Values for Discrete Bridge Balun Signal
Input Matching
IF (MHz)
220
C14, C16 (pF)
L3, L4 (nH)
22
18
22
18
250
640
4.7
4.7
5521f
11
LT5521
APPLICATIO S I FOR ATIO
W U U
U
3.5
2.5
1.5
0.5
30
25
20
15
The user can tailor the biasing of the LT5521 to meet
individual system requirements. It is recommended to
choose a source resistance as large as possible to mini-
mize sensitivity to power supply variation.
IIP3
T
= 25°C
A
f
f
f
= 250MHz
IF
LO
RF
= 1.7GHz
= 1.95GHz
Output Interface
NF
–0.5
–1.5
–2.5
10
5
ADCconnectiontoVCC mustbeprovidedonthePCBtothe
output pins. These pins will draw approximately 20mA
each from the power supply. On-chip, there is a nominal
300Ω differential resistance between the output pins.
Figure9showsatypicalmatchingcircuitusinganexternal
balun to provide differential to single-ended conversion.
G
C
0
80
R1 AND R7 (Ω)
120 140
0
20
40
60
100
5521 F06
Figure 6. IIP3, GC and Noise Figure vs External Resistance,
Constant Core Current (Variable Supply Voltage)
LO suppression and 2xLO suppression are influenced by
the symmetry of the external output matching circuitry.
PCB design must maintain the trace layout symmetry of
the output pins as much as possible to minimize these
signals.
1.8
1.2
30
25
20
15
10
5
T
= 25°C
A
f
f
f
= 250MHz
IF
= 1.7GHz
LO
RF
V
IIP3
NF
= 1.95GHz
= 4V
CC
0.6
The M/A-COM ETC1.6-4-2-3 4:1 transformer (T2, Fig-
ure 9) is suitable for applications with output frequencies
between 500MHz and 2700MHz. Output matching at vari-
ous frequencies is achieved by adding inductors in series
with the output (L1, L2) and DC blocking capacitor C3, as
shown in Figure 9. Table 6 specifies center frequency and
bandwidth of the output match for different matching
configurations. Figure 10 shows the typical output return
lossvsfrequencyfor1GHzand2GHzapplications.Capaci-
tor C12 provides a solid AC ground at the RF output
frequency.
0
–0.6
–1.2
–1.8
G
C
0
15
25
30
35
40
45
20
CORE CURRENT (mA)
5521 F07
Figure 7. IIP3, GC and Noise Figure vs Core Current,
Constant Supply Voltage
9
7
30
25
20
15
10
5
IIP3
LT5521
RFC
+
L1
OUT
T2
4:1
T
= 25°C
f
= 1.95GHz
CC
A
IF
RF
12
5
f
f
= 250MHz
V
= 3.3V
C3
NF
= 1.7GHz
LO
OUT
3
RFC
300Ω
V
CC
V
CC
1
G
C
RFC
–1
–3
–
L2
OUT
C12
9
5521 F09
0
25
35
40
45
50
55
30
CORE CURRENT (mA)
5521 F08
Figure 9. Simplified Output Circuit
with External Matching Components
Figure 8. Comparison of 3.3V Performance With
and Without Input RF Choke
5521f
12
LT5521
W U U
U
APPLICATIO S I FOR ATIO
Table 6. Matching Values Using M/A-COM ETC1.6-4-2-3
Output Transformer
Johanson Technology supplies the 3700BL15B100S hy-
brid balun for use between 3.4GHz and 4GHz. With addi-
tional matching, this transformer can be used for
applicationsbetween3.3GHzand3.7GHz.ExampleLT5521
performance is shown in Figure 11.
f
L1, L2
0nH
C3
C12
82pF
82pF
82pF
82pF
82pF
1nF
∆f (10dB RL)
450MHz
430MHz
400MHz
400MHz
400MHz
500MHz
OUT
2.4GHz
2.2GHz
2.0GHz
1.7GHz
1.3GHz
1.0GHz
82pF
82pF
82pF
82pF
82pF
3.9pF
1nH
2.7nH
4.7nH
10nH
10nH
10
22
20
18
16
14
12
10
8
LS
8
HS
IIP3
NF
6
T
IF
= 25°C
A
5
0
f
= 300MHz
4
HS
LS
2
1GHz
2GHz
–5
0
G
C
–10
–15
–20
–25
–30
LS
–2
–4
HS
3.6
FREQUENCY (GHz)
3.8
3.2
3.3
3.4
3.5
3.7
5521 F11
Figure 11. LT5521 Performance for an Application Tuned to
3.5GHz with Low Side (LS) and High Side (HS) LO Injection
1.2
1.7
0.7
2.2
FREQUENCY (GHz)
LO Interface
5521 F10
Figure 10. Output Return Loss vs Frequency
The LO input pin is internally matched to 50Ω. It has an
internal DC bias of 960mV. External AC coupling is re-
quired. Figure 12 shows a simplified schematic of the LO
input. Overdriving the LO input will dramatically reduce
the performance of the mixer. The LO input power should
notexceed+1dBmfornormaloperation. SelectC1(Figure
12) only large enough to achieve the desired LO input
return loss. This reduces external low frequency signal
amplification through the LO buffer.
For applications with LO and output frequencies below
1GHz, the M/A-COM MABAES0054 is recommended for
the output component T2. This transformer maintains
better low frequency output symmetry. Table 7 lists com-
ponents necessary for a 750MHz output match using the
M/A-COM MABAES0054.
Table 7. Matching Values Using M/A-COM MABAES0054
Output Transformer
For applications with LO frequency in the range of 2.1GHz
to 2.4GHz, the LT5521 achieves improved distortion and
f
L1, L2
C3
C12
∆f (10dB RL)
OUT
750MHz
33nH
82pF
1nF
500MHz
LT5521
Hybrid baluns provide a low cost alternative for differen-
tial to single-ended conversion. The critical performance
parameters of conversion gain, IIP3, noise figure and LO
suppression are largely unaffected by these transform-
ers. However, their limited bandwidth and reduced sym-
metry outside the frequency of operation degrades the
suppression of higher order LO harmonics, particularly
2xLO. Murata LBD21 series hybrid balun transformers,
for example, can be used for output frequencies as low as
840MHz and as high as 2.4GHz.
60Ω
60Ω
V
CC
C1
8Ω
LO
IN
15
50Ω
5521 F12
Figure 12. Simplified LO Input Circuit
5521f
13
LT5521
W U U
U
APPLICATIO S I FOR ATIO
0
0Ω resistor. If the shutdown function is not required, then
theENpinshouldbewireddirectlytotheVCC powersupply
on the PCB.
–5
–10
C1 = 6.8pF
–15
Supply Decoupling
–20
The power supply decoupling shown in the schematic of
Figure 1 is recommended to minimize spurious signal
coupling into the output through the power supply.
C1 = 2.7pF
–25
–30
–35
1000 1500 2000 2500
4000
3000 3500
0
500
ACPR Performance
FREQUENCY (MHz)
5521 F13
Becauseofitshighlinearityandlownoise,theLT5521offers
outstandingACPRperformanceinavarietyofapplications.
For example, Figures 15 and 16 show ACPR and Alternate
Channel measurements for single channel and 4-channel
64 DPCH W-CDMA signals at 1.95GHz output frequency.
Figure 13. LO Port Return Loss
noise performance with slightly reduced current through
the mixer core. Accordingly, in a 5V application operating
within this LO frequency range, the recommended source
resistor value (R1 and R7) is increased to 121Ω.
–30
–130
T
= 25°C
A
f
f
f
= 1.95GHz
= 70MHz
RF
IF
LO
–40
–135
= 1.88GHz
Enable Interface
–50
–60
–140
–145
–150
–155
–160
–165
Figure 14 shows a simplified schematic of the EN pin
interface. The voltage necessary to turn on the LT5521 is
2.9V.Todisablethechip,theenablevoltagemustbebelow
0.2V. If the EN pin is not connected, the chip is disabled.
It is not recommended, however, that any pins be left
floating for normal operation.
–70
ACPR
–80
–90
30MHz OFFSET NOISE
–100
–30
–20
–10
10
–40
0
It is important that the voltage at the EN pin never exceed
VCC, the power supply voltage, by more than 0.2V. If this
shouldoccur,thesupplycurrentcouldbesourcedthrough
the EN pin ESD protection diodes, potentially damaging
the IC. The resistor R8 (Figure 1) in series with the EN pin
on the demo board is populated with a 10kΩ resistor to
protect the EN pin to avoid inadvertant damage to the IC.
For timing measurements, this resistor is replaced with a
OUTPUT CHANNEL POWER (dBm)
5521 F15
Figure 15. Single Channel W-CDMA ACPR
and 30MHz Offset Noise Performance
–50
–55
–60
–65
–70
–75
–80
–135
–140
–145
–150
–155
–160
–165
ACPR
LT5521
T
= 25°C
A
AltCPR
f
f
f
= 1.95GHz
= 70MHz
RF
IF
LO
= 1.88GHz
V
CC
30MHz OFFSET NOISE
–30 –25 –20
–40
–15
–35
OUTPUT CHANNEL POWER, EACH CHANNEL (dBm)
1635 G24
EN
5
Figure 16. 4-Channel W-CDMA ACPR,
AltCPR and 30MHz Offset Noise Floor
5521 F14
Figure 14. Enable Input Circuit
5521f
14
LT5521
W U U
APPLICATIO S I FOR ATIO
U
Figure 17. Top View of Demo Board
U
PACKAGE DESCRIPTIO
UF Package
16-Lead Plastic QFN (4mm × 4mm)
(Reference LTC DWG # 05-08-1692)
BOTTOM VIEW—EXPOSED PAD
0.75 ± 0.05
R = 0.115
TYP
0.55 ± 0.20
4.00 ± 0.10
(4 SIDES)
15
16
0.72 ±0.05
PIN 1
TOP MARK
(NOTE 6)
1
2
4.35 ± 0.05 2.15 ± 0.05
2.15 ± 0.10
(4-SIDES)
(4 SIDES)
2.90 ± 0.05
PACKAGE
OUTLINE
(UF) QFN 1103
0.30 ± 0.05
0.65 BSC
0.200 REF
0.30 ±0.05
0.65 BSC
0.00 – 0.05
NOTE:
RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS
1. DRAWING CONFORMS TO JEDEC PACKAGE OUTLINE MO-220 VARIATION (WGGC)
2. DRAWING NOT TO SCALE
3. ALL DIMENSIONS ARE IN MILLIMETERS
4. DIMENSIONS OF EXPOSED PAD ON BOTTOM OF PACKAGE DO NOT INCLUDE
MOLD FLASH. MOLD FLASH, IF PRESENT, SHALL NOT EXCEED 0.15mm ON ANY SIDE
5. EXPOSED PAD SHALL BE SOLDER PLATED
6. SHADED AREA IS ONLY A REFERENCE FOR PIN 1 LOCATION
ON THE TOP AND BOTTOM OF PACKAGE
5521f
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 represen-
tationthattheinterconnectionofitscircuitsasdescribedhereinwillnotinfringeonexistingpatentrights.
15
LT5521
RELATED PARTS
PART NUMBER DESCRIPTION
COMMENTS
Infrastructure
LT5511
LT5512
LT5514
High Linearity Upconverting Mixer
RF Output to 3GHz, 17dBm IIP3, Integrated LO Buffer
DC to 3GHz, 21dBm IIP3, Integrated LO Buffer
DC-3GHz High Signal Level Downconverting Mixer
Ultralow Distortion, Wideband Digitally Controlled
Gain Amplifier/ADC Driver
BW = 850MHz, OIP3 = 47dBm at 100MHz, 22.5dB Gain Control Range
LT5515
LT5516
LT5517
LT5519
1.5GHz to 2.5GHz Direct Conversion Quadrature Demodulator 20dBm IIP3, Integrated LO Quadrature Generator
0.8GHz to 1.5GHz Direct Conversion Quadrature Demodulator 21.5dBm IIP3, Integrated LO Quadrature Generator
40MHz to 900MHz Quadrature Demodulator
21dBm IIP3, Integrated LO Quadrature Generator
0.7GHz to 1.4GHz High Linearity Upconverting Mixer
17.1dBm IIP3 at 1GHz, Integrated RF Output Transformer with 50Ω
Matching, Single-Ended LO and RF Ports Operation
LT5520
LT5522
1.3GHz to 2.3GHz High Linearity Upconverting Mixer
15.9dBm IIP3 at 1.9GHz, Integrated RF Output Transformer with 50Ω
Matching, Single-Ended LO and RF Ports Operation
600MHz to 2.7GHz High Signal Level Downconverting Mixer
4.5V to 5.25V Supply, 25dBm IIP3 at 900MHz, NF = 12.5dB,
50Ω Single-Ended RF and LO Ports
RF Power Detectors
LT5504
800MHz to 2.7GHz RF Measuring Receiver
80dB Dynamic Range, Temperature Compensated,
2.7V to 5.25V Supply
LTC®5505
LTC5507
LTC5508
LTC5509
LTC5530
LTC5531
LTC5532
LT5534
RF Power Detectors with >40dB Dynamic Range
100kHz to 1000MHz RF Power Detector
300MHz to 7GHz RF Power Detector
300MHz to 3GHz, Temperature Compensated, 2.7V to 6V Supply
100kHz to 1GHz, Temperature Compensated, 2.7V to 6V Supply
44dB Dynamic Range, Temperature Compensated, SC70 Package
36dB Linear Dynamic Range, Low Power Consumption, SC70 Package
300MHz to 3GHz RF Power Detector
300MHz to 7GHz Precision RF Power Detector
300MHz to 7GHz Precision RF Power Detector
300MHz to 7GHz Precision RF Power Detector
50MHz to 3GHz RF Power Detector
Precision V
Precision V
Precision V
Offset Control, Shutdown, Adjustable Gain
Offset Control, Shutdown, Adjustable Offset
Offset Control, Adjustable Gain and Offset
OUT
OUT
OUT
60dB Dynamic Range, Temperature Compensated, SC70 Package
Low Voltage RF Building Blocks
LT5500
LT5502
1.8GHz to 2.7GHz Receiver Front End
1.8V to 5.25V Supply, Dual-Gain LNA, Mixer, LO Buffer
400MHz Quadrature IF Demodulator with RSSI
1.8V to 5.25V Supply, 70MHz to 400MHz IF, 84dB Limiting Gain,
90dB RSSI Range
LT5503
LT5506
LT5546
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
500MHz Quadrature IF Demodulator with VGA
1.8V to 5.25V Supply, 40MHz to 500MHz IF, –4dB to 57dB
Linear Power Gain, 8.8MHz Baseband Bandwidth
500MHz Ouadrature IF Demodulator with
VGA and 17MHz Baseband Bandwidth
17MHz Baseband Bandwidth, 40MHz to 500MHz IF, 1.8V to 5.25V
Supply, –7dB to 56dB Linear Power Gain
RF Power Controllers
LTC1757A
LTC1758
LTC1957
LTC4400
RF Power Controller
Multiband GSM/DCS/GPRS Mobile Phones
Multiband GSM/DCS/GPRS Mobile Phones
Multiband GSM/DCS/GPRS Mobile Phones
RF Power Controller
RF Power Controller
SOT-23 RF PA Controller
Multiband GSM/DCS/GPRS Phones, 45dB Dynamic Range,
450kHz Loop BW
LTC4401
LTC4403
SOT-23 RF PA Controller
Multiband GSM/DCS/GPRS Phones, 45dB Dynamic Range,
250kHz Loop BW
RF Power Controller for EDGE/TDMA
Multiband GSM/GPRS/EDGE Mobile Phones
5521f
LT/TP 0604 1K • PRINTED IN THE USA
LinearTechnology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
16
●
●
(408) 432-1900 FAX: (408) 434-0507 www.linear.com
LINEAR TECHNOLOGY CORPORATION 2004
相关型号：
LT5521EUF#PBF
LT5521 - Very High Linearity Active Mixer; Package: QFN; Pins: 16; Temperature Range: -40°C to 85°C
Linear
LT5521EUF#TR
LT5521 - Very High Linearity Active Mixer; Package: QFN; Pins: 16; Temperature Range: -40°C to 85°C
Linear
LT5522EUF#TR
LT5522 - 600MHz to 2.7GHz High Signal Level Downconverting Mixer; Package: QFN; Pins: 16; Temperature Range: -40°C to 85°C
Linear
LT5525EUF#PBF
LT5525 - High Linearity, Low Power Downconverting Mixer; Package: QFN; Pins: 16; Temperature Range: -40°C to 85°C
Linear
LT5525EUF#TR
LT5525 - High Linearity, Low Power Downconverting Mixer; Package: QFN; Pins: 16; Temperature Range: -40°C to 85°C
Linear
©2020 ICPDF网 联系我们和版权申明