LT5578IUH#TRPBF [Linear]
LT5578 - 0.4GHz to 2.7GHz High Linearity Upconverting Mixer; Package: QFN; Pins: 24; Temperature Range: -40°C to 85°C;
| 型号： | LT5578IUH#TRPBF |
| 厂家： | 
Linear |
| 描述： | LT5578 - 0.4GHz to 2.7GHz High Linearity Upconverting Mixer; Package: QFN; Pins: 24; Temperature Range: -40°C to 85°C 电信 电信集成电路 |
| 文件： | 总16页 (文件大小：207K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
LT5578
0.4GHz to 2.7GHz
High Linearity
Upconverting Mixer
FEATURES
DESCRIPTION
The LT®5578 mixer is a high performance upconverting
mixer optimized for frequencies in the 0.4GHz to 2.7GHz
range. The single-ended LO input and RF output ports
simplify board layout and reduce system cost. The mixer
needs only –1dBm of LO power and the balanced design
results in low LO signal leakage to the RF output. At
1.95GHz operation, the LT5578 provides conversion gain
of –0.7dB, high OIP3 of 24.3dBm and a low noise floor of
–158dBm/Hz at a –5dBm RF output signal level.
n
High Output IP3: 27dBm at 0.9GHz
24.3dBm at 1.95GHz
n
Low Noise Floor: –158dBm/Hz (P
= –5dBm)
OUT
n
n
n
n
n
n
n
High Conversion Gain: 1.4dB at 0.9GHz
Noise Figure: 8.6dB
Low LO-RF Leakage: –43dBm
Single-Ended RF and LO Ports
Low LO Drive Level: –1dBm
Single 3.3V Supply
5mm × 5mm QFN24 Package
(Pin Compatible with LT5579)
The LT5578 offers a high performance alternative to pas-
sivemixers.Unlikepassivemixers,whichhaveconversion
loss and require high LO drive levels, the LT5578 delivers
conversion gain at significantly lower LO input levels and
is less sensitive to LO power level variations. The lower
LO drive level requirements, combined with the excellent
LO leakage performance, translate into lower LO signal
contamination of the output signal.
APPLICATIONS
n
GSM 900PCS/1800PCS and W-CDMA Infrastructure
n
LTE and WiMAX Basestations
n
Wireless Repeaters
Public Safety Radios
n
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear
Technology Corporation. All other trademarks are the property of their respective owners.
TYPICAL APPLICATION
Frequency Upconversion in LTE Transmitter
LO INPUT
–1dBm
Gain, NF and OIP3 vs
RF Output Frequency
2.7pF
6.8pF
30
OIP3
LO
LT5578
25
GND
RF
13.7Ω
100nH
20
15
T
= 25°C
A
BIAS
f
f
= 140MHz
IF
RF
= f – f
LO RF IF
IF
700MHz
TO 950MHz
TC4-1W+
4:1
220pF
220pF
140MHz
22nH
2pF
13nH
2.7pF
+
–
IF
SSB NF
GAIN
10
5
39pF
IF
100nH
13.7Ω
0
V
CC
5579 TA01a
850
950 1000
650 700 750 800
900
V
CC
3.3V
RF OUTPUT FREQUENCY (MHz)
10μF
100μF
1nF
5578 TA01b
5578f
1
LT5578
ABSOLUTE MAXIMUM RATINGS
PIN CONFIGURATION
TOP VIEW
(Note 1)
Supply Voltage............................................................4V
LO Input Power....................................................10dBm
LO Input DC Current ..............................................30mA
RF Output DC Current ............................................45mA
IF Input Power (Differential).................................18dBm
24 23 22 21 20 19
GND
GND
1
2
3
4
5
6
18 GND
GND
GND
17
16
+
IF
+
–
IF , IF DC Currents ...............................................45mA
.................................................................... 150°C
25
–
IF
15 RF
T
JMAX
GND
GND
14 GND
13 GND
Operating Temperature Range.................. –40°C to 85°C
Storage Temperature Range................... –65°C to 150°C
7
8
9 10 11 12
UH PACKAGE
24-LEAD (5mm s 5mm) PLASTIC QFN
T
= 150°C, θ = 34°C/W
JA
JMAX
EXPOSED PAD (PIN 25) IS GND, MUST BE SOLDERED TO PCB
ORDER INFORMATION
LEAD FREE FINISH
TAPE AND REEL
PART MARKING
PACKAGE DESCRIPTION
24-Lead (5mm × 5mm) Plastic QFN
TEMPERATURE RANGE
–40°C to 85°C
LT5578IUH#PBF
LT5578IUH#TRPBF
5578
Consult LTC Marketing for parts specified with wider operating temperature ranges.
Consult LTC Marketing for information on non-standard lead based finish parts.
For more information on lead free part marking, go to: http://www.linear.com/leadfree/
For more information on tape and reel specifications, go to: http://www.linear.com/tapeandreel/
VCC = 3.3V, TA = 25°C (Note 3), unless otherwise noted.
DC ELECTRICAL CHARACTERISTICS
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
Power Supply Requirements (V
Supply Voltage
)
CC
3.1
3.3
3.5
V
DC
Supply Current
V
CC
V
CC
= 3.3V, P = –1dBm
152
159
170
mA
mA
LO
= 3.5V, P = –1dBm
LO
Input Common Mode Voltage (V
)
CM
Internally Regulated
565
mV
(Notes 2, 3)
AC ELECTRICAL CHARACTERISTICS
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
MHz
IF Input Frequency Range (Note 4)
LO Input Frequency Range (Note 4)
RF Output Frequency Range (Note 4)
Requires Matching
LF to 600
Requires Matching Below 1.5GHz
Requires Matching
400 to 3000
400 to 2700
MHz
MHz
5578f
2
LT5578
V
CC = 3.3V, TA = 25°C, Test circuits are shown in Figure 1. (Notes 2, 3)
AC ELECTRICAL CHARACTERISTICS
PARAMETER
CONDITIONS
Z = 50Ω, External Match
MIN
TYP
15
MAX
UNITS
dB
IF Input Return Loss
LO Input Return Loss
RF Output Return Loss
LO Input Power
O
Z = 50Ω, External Match
>9
dB
O
Z = 50Ω, External Match
>10
dB
O
–5 to 2
dBm
VCC = 3.3V, TA = 25°C, PIF = –5dBm (–5dBm/tone for 2-tone tests, Δf = 1MHz), PLO = –1dBm, unless otherwise noted.
Low side LO for 900MHz. High side LO for 740MHz and 1950MHz. (Notes 2, 3, 4)
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
Conversion Gain
f
f
f
= 740MHz, f = 140MHz
0.8
1.4
–0.7
dB
dB
dB
RF
RF
RF
IF
= 900MHz, f = 140MHz
IF
= 1950MHz, f = 240MHz
IF
Conversion Gain vs Temperature
A
f
f
f
= 740MHz, f = 140MHz
–0.020
–0.018
–0.021
dB/°C
dB/°C
dB/°C
RF
RF
RF
IF
(T = –40°C to 85°C)
= 900MHz, f = 140MHz
IF
= 1950MHz, f = 240MHz
IF
Output 3rd Order Intercept
f
RF
f
RF
f
RF
= 740MHz, f = 140MHz
26.5
27.0
24.3
dBm
dBm
dBm
IF
= 900MHz, f = 140MHz
IF
= 1950MHz, f = 240MHz
IF
Output 2nd Order Intercept (LO 2IF)
Single Sideband Noise Figure
f
f
f
= 740MHz, f = 140MHz
62
52
58
8.6
8.6
10.5
dBm
dBm
dBm
dB
dB
dB
RF
RF
RF
IF
= 900MHz, f = 140MHz
IF
= 1950MHz, f = 240MHz
IF
f
RF
f
RF
f
RF
= 740MHz, f = 140MHz
IF
= 900MHz, f = 140MHz
IF
= 1950MHz, f = 240MHz
IF
Output Noise: P
Output Noise: P
Output Noise: P
= –5dBm
= 0dBm
= 5dBm
f
f
f
f
f
f
f
f
f
= 740MHz, f = 140MHz
–161
–160.5
–158
–158
–157.5
–154
–154
–153
–149.5
dBm/Hz
dBm/Hz
dBm/Hz
dBm/Hz
dBm/Hz
dBm/Hz
dBm/Hz
dBm/Hz
dBm/Hz
OUT
OUT
OUT
RF
RF
RF
IF
= 900MHz, f = 140MHz
IF
= 1950MHz, f = 240MHz
IF
= 740MHz, f = 140MHz
RF
RF
RF
IF
= 900MHz, f = 140MHz
IF
= 1950MHz, f = 240MHz
IF
= 740MHz, f = 140MHz
RF
RF
RF
IF
= 900MHz, f = 140MHz
IF
= 1950MHz, f = 240MHz
IF
Output 1dB Compression
IF to LO Isolation
f
f
f
= 740MHz, f = 140MHz
11.6
12
dBm
dBm
dBm
dB
dB
dB
RF
RF
RF
IF
= 900MHz, f = 140MHz
IF
= 1950MHz, f = 240MHz
10
IF
f
f
f
= 740MHz, f = 140MHz
80
75
60
RF
RF
RF
IF
= 900MHz, f = 140MHz
IF
= 1950MHz, f = 240MHz
IF
LO to IF Leakage
f
f
f
= 740MHz, f = 140MHz
–31
–40
–22
dBm
dBm
dBm
RF
RF
RF
IF
= 900MHz, f = 140MHz
IF
= 1950MHz, f = 240MHz
IF
LO to RF Leakage
f
f
f
= 740MHz, f = 140MHz
–43
–43
–46
dBm
dBm
dBm
RF
RF
RF
IF
= 900MHz, f = 140MHz
IF
= 1950MHz, f = 240MHz
IF
Note 1: Stresses beyond those listed under Absolute Maximum Ratings
may cause permanent damage to the device. Exposure to any Absolute
Maximum Rating condition for extended periods may affect device
reliability and lifetime.
Note 3: The LT5578 is guaranteed functional over the operating
temperature range from –40°C to 85°C.
Note 4: SSB noise figure measurements performed with a small-signal
noise source and bandpass filter on LO signal generator. No other IF signal
applied.
Note 2: Each set of frequency conditions requires appropriate matching
(see Figure 1).
5578f
3
LT5578
(Test Circuit Shown in Figure 1)
TYPICAL DC PERFORMANCE CHARACTERISTICS
Supply Current vs Supply Voltage
180
170
160
150
140
85°C
25°C
–40°C
130
120
3.0
3.2
3.3
3.4
3.5
3.6
3.1
SUPPLY VOLTAGE (V)
5578 G01
TYPICAL AC PERFORMANCE CHARACTERISTICS 900MHz Application:
VCC = 3.3V, TA = 25°C, fIF = 140MHz, PIF = –5dBm (–5dBm/tone for 2-tone tests, Δf = 1MHz), low side LO, PLO = –1dBm,
output measured at 900MHz, unless otherwise noted. (Test circuit shown in Figure 1)
SSB Noise Figure Distribution at
900MHz
Gain Distribution at 900MHz
OIP3 Distribution at 900MHz
45
40
35
30
25
20
15
10
5
25
20
15
10
60
50
T
T
T
= 90°C
T
A
T
A
T
A
= 90°C
= 25°C
= –45°C
T
T
T
= 90°C
A
A
A
A
A
A
= 25°C
= 25°C
= –45°C
= –45°C
40
30
20
10
0
5
0
0
–0.5
1.5
0.5 1.0
GAIN (dB)
0
2.0 2.5 3.0 3.5
23
25
26
27
28
29
6
7
8
9
10
11
24
OIP3 (dBm)
NOISE FIGURE (dB)
5578 G02
5578 G03
5578 G04
5578f
4
LT5578
TYPICAL AC PERFORMANCE CHARACTERISTICS
output measured at 740MHz, unless otherwise noted. (Test circuit shown in Figure 1)
740MHz Application:
VCC = 3.3V, TA = 25°C, fIF = 140MHz, PIF = –5dBm (–5dBm/tone for 2-tone tests, Δf = 1MHz), high side LO, PLO = –1dBm,
Conversion Gain and OIP3
vs RF Output Frequency
SSB Noise Figure
LO-RF Leakage
vs RF Output Frequency
vs RF Output Frequency
0
–10
–20
–30
–40
–50
–60
16
12
8
30
26
22
18
14
10
18
16
OIP3
14
12
10
8
85°C
25°C
–40°C
4
GAIN
6
0
85°C
25°C
–40°C
85°C
25°C
–40°C
4
2
–4
680 700
740 760 780 800
660 680 700
720 740 760 780 800
660 680 700 720 740 760 780 800
RF FREQUENCY (MHz)
660
720
RF FREQUENCY (MHz)
RF FREQUENCY (MHz)
5578 G07
5578 G05
5578 G06
Conversion Gain and OIP3
vs LO Input Power
SSB Noise Figure
vs LO Input Power
Conversion Gain and OIP3
vs Supply Voltage
30
30
26
22
18
14
16
16
12
8
18
16
14
12
10
8
OIP3
OIP3
GAIN
26
22
18
14
10
12
8
85°C
25°C
–40°C
85°C
25°C
–40°C
4
4
GAIN
6
0
0
85°C
4
2
25°C
–40°C
10
–4
–4
–17
–13
–9
–5
–1
3
–9
–13
LO INPUT POWER (dBm)
3.0
3.2
3.3
3.4
3.5
–17
–5
–1
3
3.1
SUPPLY VOLTAGE (V)
LO INPUT POWER (dBm)
5578 G08
5578 G10
5578 G09
IM3 Level
vs RF Output Power (2-Tone)
IM2 Level
vs RF Output Power (1-Tone)
SSB Noise Figure
vs Supply Voltage
18
0
0
16
14
12
10
8
–20
–20
–40
–40
–60
–80
–60
–80
6
85°C
85°C
25°C
–40°C
85°C
4
25°C
25°C
–40°C
–40°C
2
3.0
–100
–100
3.1
3.2
SUPPLY VOLTAGE (V)
3.4
2
4
6
–12 –10 –8 –6 –4 –2
2
4
6
3.3
3.5
–12 –10 –8 –6 –4 –2
0
0
RF OUTPUT POWER (dBm/TONE)
RF OUTPUT POWER (dBm)
5578 G13
5578 G11
5578 G12
5578f
5
LT5578
TYPICAL AC PERFORMANCE CHARACTERISTICS 900MHz Application:
VCC = 3.3V, TA = 25°C, fIF = 140MHz, PIF = –5dBm (–5dBm/tone for 2-tone tests, Δf = 1MHz), low side LO, PLO = –1dBm,
output measured at 900MHz, unless otherwise noted. (Test circuit shown in Figure 1)
Conversion Gain and OIP3
vs RF Output Frequency
SSB Noise Figure
LO-RF Leakage
vs RF Output Frequency
vs RF Output Frequency
0
–10
–20
–30
–40
–50
–60
16
12
8
30
26
22
18
14
10
18
16
14
12
OIP3
85°C
25°C
–40°C
10
8
4
GAIN
6
4
2
0
85°C
25°C
–40°C
85°C
25°C
–40°C
–4
830
870 890 910 930 950 970
RF FREQUENCY (MHz)
850 870
910
970
850
830
930 950 970
830 850 870 890
910
RF FREQUENCY (MHz)
930 950
890
RF FREQUENCY (MHz)
5578 G14
5578 G15
5578 G16
Conversion Gain and OIP3
vs LO Input Power
SSB Noise Figure
vs LO Input Power
Conversion Gain and OIP3
vs Supply Voltage
16
12
8
30
26
22
18
14
10
16
30
26
22
18
14
10
18
16
14
12
10
8
OIP3
OIP3
GAIN
12
8
85°C
25°C
–40°C
85°C
25°C
–40°C
4
4
GAIN
6
0
0
85°C
4
25°C
–40°C
–4
–4
2
3.0
3.2
3.3
3.4
3.5
–17
–13
–9
–5
–1
3
3.1
–9
–13
LO INPUT POWER (dBm)
–17
–5
–1
3
SUPPLY VOLTAGE (V)
LO INPUT POWER (dBm)
5578 G19
5578 G17
5578 G18
IM3 Level
vs RF Output Power (2-Tone)
IM2 Level
vs RF Output Power (1-Tone)
SSB Noise Figure
vs Supply Voltage
0
–20
0
18
16
14
12
–20
–40
–40
10
8
–60
–60
–80
6
4
2
–80
85°C
25°C
–40°C
85°C
25°C
–40°C
85°C
25°C
–40°C
–100
–100
3.1
3.2
SUPPLY VOLTAGE (V)
3.4
–12 –10 –8 –6 –4 –2
0
2
4
6
–12 –10 –8 –6 –4 –2
0
2
4
6
3.0
3.3
3.5
RF OUTPUT POWER (dBm/TONE)
RF OUTPUT POWER (dBm)
5578 G22
5578 G20
5578 G21
5578f
6
LT5578
TYPICAL PERFORMANCE CHARACTERISTICS 1950MHz Application:
VCC = 3.3V, TA = 25°C, fIF = 240MHz, PIF = –5dBm (–5dBm/tone for 2-tone tests, Δf = 1MHz), high side LO, PLO = –1dBm,
output measured at 1950MHz, unless otherwise noted. (Test circuit shown in Figure 1)
Conversion Gain and OIP3
vs RF Output Frequency
SSB Noise Figure
LO-RF Leakage
vs RF Output Frequency
vs RF Output Frequency
0
–10
–20
–30
–40
–50
–60
16
12
8
28
24
20
16
12
8
18
16
14
12
10
8
OIP3
85°C
25°C
–40°C
4
GAIN
6
0
85°C
25°C
–40°C
85°C
25°C
–40°C
4
–4
2
1900 2000 2100
1600 1700 1800
RF FREQUENCY (MHz)
1900
1600 1700 1800
1900 2000 2100 2200 2300
1600 1700 1800
2000 2100 2200
2200
RF FREQUENCY (MHz)
RF FREQUENCY (MHz)
5578 G25
5578 G23
5578 G24
Conversion Gain and OIP3
vs LO Input Power
SSB Noise Figure
vs LO Input Power
Conversion Gain and OIP3
vs Supply Voltage
16
12
8
28
24
20
16
12
16
12
8
28
24
20
16
12
8
18
16
14
12
10
8
OIP3
OIP3
85°C
25°C
–40°C
85°C
25°C
–40°C
4
4
GAIN
GAIN
6
0
0
85°C
4
25°C
–40°C
–4
8
–4
2
–13
–9
–5
–1
3
–17
–13
–9
LO INPUT POWER (dBm)
–5
–1
3
3.0
3.1
3.2
3.3
3.4
3.5
–17
SUPPLY VOLTAGE (V)
LO INPUT POWER (dBm)
5578 G28
5578 G26
5578 G27
IM3 Level
vs RF Output Power (2-Tone)
IM2 Level
vs RF Output Power (1-Tone)
SSB Noise Figure
vs Supply Voltage
0
18
0
16
14
12
10
8
–20
–40
–20
–40
–60
–80
–60
–80
6
85°C
85°C
85°C
25°C
–40°C
4
25°C
25°C
–40°C
–40°C
–100
–100
2
3.2
SUPPLY VOLTAGE (V)
3.0
3.1
3.3
3.4
3.5
–6
RF OUTPUT POWER (dBm/TONE)
–14 –12 –10 –8
–4 –2
0
2
4
–6
RF OUTPUT POWER (dBm)
–14 –12 –10 –8
–4 –2
0
2
4
5578 G31
5578 G29
5578 G30
5578f
7
LT5578
PIN FUNCTIONS
GND (Pins 1, 2, 5-7, 12-14, 16-21, 23, 24): Ground
Connections. These pins are internally connected to the
exposed pad and should be soldered to a low impedance
RF ground on the printed circuit board.
RF (Pin 15): Single-Ended RF Output. This pin is con-
nected to an internal transformer winding. The opposite
end of the winding is grounded internally. An impedance
transformation may be required to match the output and a
DC decoupling capacitor is required if the following stage
has a DC bias voltage present.
+
–
IF , IF (Pins 3, 4): Differential IF Input. The common
mode voltage on these pins is set internally to 565mV. The
DC current from each pin is determined by the value of
an external resistor to ground. The maximum DC current
through each pin is 45mA.
LO(Pin22):Single-EndedLocalOscillatorInput.Aninternal
series capacitor acts as a DC block to this pin.
Exposed Pad (Pin 25): PGND. Electrical and thermal
ground connection for the entire IC. This pad must be
soldered to a low impedance RF ground on the printed
circuit board. This ground must also provide a path for
thermal dissipation.
V
(Pins 8-11): Power Supply Pins for the IC. These
CC
pins are connected together internally. Typical current
consumption is 152mA. These pins should be connected
together on the circuit board with external bypass capaci-
tors of 1000pF, 100pF and 10pF located as close to the
pins as possible.
BLOCK DIAGRAM
25
15
RF
EXPOSED
PAD
V
CC
V
CC
V
CC
V
CC
11
10
9
LO
22
DOUBLE
BALANCED
MIXER
LO BUFFER
V
CC2
BIAS
8
V
CC2
V
CM
CTRL
+
–
IF
IF
3
4
5578 BD
GND PINS ARE NOT SHOWN
5578f
8
LT5578
TEST CIRCUIT
LO INPUT
C13
Z1
C12
R1
L1
24 23 22 21 20 19
1
2
3
4
5
6
18
17
16
15
14
13
T1
4:1
GND
GND
GND
C1
C2
TL1
TL2
GND
GND
RF
RF
OUTPUT
+
IF
INPUT
IF
L3
TL3
C14
C9
C3
GND
–
IF
C8
GND
GND
GND
GND
L2
R2
7
8
9
10 11 12
V
CC
C4
C5
C6
C7
5578 F01
f
= 740MHz
= 140MHz
= 880MHz
f
= 900MHz
= 140MHz
= 760MHz
220pF
–
f
f
= 1950MHz
= 240MHz
= 2190MHz
RF
IF
LO
RF
IF
RF
IF
LO
f
f
f
REF DES
C1, C2
C3
f
f
SIZE
COMMENTS
AVX
LO
220pF
–
82pF
4.7pF
100pF
10pF
1nF
0402
0402
0402
0402
0402
0603
0402
0402
0402
0402
0402
0603
0402
0603
AVX
C4
100pF
10pF
1nF
1μF
100pF
10pF
1nF
AVX
C5
AVX
C6
AVX
C7
1μF
1μF
Taiyo Yuden LMK107BJ105MA
C8
3.3pF
39pF
–
1.8pF
39pF
–
–
AVX ACCU-P
AVX
C9
33pF
–
C12
C13
C14
L1, L2
L3
–
2.7pF
–
–
–
1.2pF
100nH
1.8nH
100nH
18nH
100nH
12nH
Coilcraft 0603CS
Toko LL1005-FHL
R1, R2
T1
13.7, 0.1%
4:1
13.7, 0.1%
4:1
13.7, 0.1%
4:1
IRC PFC-W0603LF-02-13R7-B
Mini-Circuits TC4-1W+
AT224-1
TL1, TL2*
TL3
–
–
1.9mm
1.3mm
0Ω
–
–
Z = 70Ω
O
2.3mm
2.6pF
2.3mm
6.8pF
Z = 70Ω
O
Z1
0402
AVX/0Ω Jumper
*Center-to-center spacing between C9 and C3. Center of C9 is 3.0mm from the edge of the package.
Figure 1. Test Circuit Schematic and Component Values
5578f
9
LT5578
APPLICATIONS INFORMATION
The LT5578 uses a high performance LO buffer amplifier
drivingadouble-balancedmixercoretoachievefrequency
conversion with high linearity. Internal baluns are used to
provide single-ended LO input and RF output ports. The
IF input is differential. The LT5578 is intended for opera-
tion in the 0.4GHz to 2.7GHz frequency range, though
operation outside this range is possible with reduced
performance.
L1 and L2 should connect to the signal lines as close to
the package as possible. This location will be at the lowest
impedancepoint, whichwillminimizethesensitivityofthe
performance to the loading of the shunt L-R branches.
Capacitors C1 and C2 are used to cancel out the parasitic
series inductance of the IF transformer. They also provide
DCisolationbetweentheIFportstopreventunwantedinter-
actions that can affect the LO to RF leakage performance.
IF Input Interface
The differential input resistance to the mixer is approxi-
mately 10Ω, as indicated in Table 1. The package and
external inductances (TL1 and TL2) are used along with
C9 to step the impedance up to about 12.5Ω. At lower
frequencies additional series inductance may be required
between the IF ports and C9. The position of C9 may vary
withtheIFfrequencyduetothedifferentseriesinductance
requirements. The 4:1 impedance ratio of transformer T1
completes the transformation to 50Ω. Table 1 lists the
differentialIFinputimpedancesandreflectioncoefficients
for several frequencies.
TheIFinputsaretiedtotheemittersofthedouble-balanced
mixer transistors, as shown in Figure 2. These pins are
internally biased to a common mode voltage of 565mV.
TheoptimumDCcurrentinthemixercoreisapproximately
40mA per side, and is set by the external resistors, R1 and
R2. The inductors and resistors must be able to handle
the anticipated current and power dissipation. For best
LO leakage performance the board layout must be sym-
metrical and the input resistors should be well matched
(0.1% tolerance is recommended).
Table 1. IF Input Differential Impedance
REFLECTION COEFFICIENT
The purpose of the inductors (L1 and L2) is to reduce the
loading effects of R1 and R2. The impedances of L1 and
L2shouldbeatleastseveraltimesgreaterthantheIFinput
impedance at the desired IF frequency. The self-resonant
frequency of the inductors should also be at least several
times the IF frequency. Note that the DC resistances of L1
and L2 will affect the DC current and should be accounted
for in the selection of R1 and R2.
FREQUENCY
(MHz)
IF INPUT
IMPEDANCE
MAG
0.666
0.661
0.705
0.705
0.705
0.704
0.705
0.683
0.685
ANGLE
177.4
176.5
175.7
175.2
174.0
170.9
169.3
162.0
155.9
70
140
170
190
240
380
450
750
1000
10.0 + j1.1
10.2 + j1.5
8.7 + j1.8
8.7 + j2.0
8.7 + j2.5
8.7 + j3.9
8.7 + j4.5
9.6 + j7.6
9.8 + j10.3
R1
LT5578
IF
L1
40mA
C1
C2
INPUT T1
4:1
TL1
+
IF
3
4
The purpose of capacitor C3 is to improve the LO-RF
leakage in some applications. This relatively small-valued
capacitor has little effect on the impedance match in most
cases. This capacitor should typically be located close to
the IC, however, there may be cases where re-positioning
the capacitor will improve performance.
565mV
2k
2k
V
CC
C9
TL2
C3
–
IF
565mV
40mA
L2
The measured return loss of the IF input is shown in
Figure 3 for application frequencies of 70MHz, 140MHz
and 240MHz. Component values are listed in Table 2. All
of the applications use L1 = L2 = 100nH, R1 = R2 =13.7Ω
5578 F02
R2
Figure 2. IF Input with External Matching
5578f
10
LT5578
APPLICATIONS INFORMATION
and T1 = TC4-1W+. The 70MHz match was not used for
140MHz characterization because it requires the addition
of two inductors.
EXTERNAL
MATCHING
LO
INPUT
Z1
LO
22
C13
C12
Table 2. IF Input Component Values
V
BIAS
FREQUENCY C1, C2
C9
C3
TL1, TL2 MATCH BW
(MHz)
(pF)
560
220
82
(pF)
(pF)
(nH)
3.3
–
(at 12dB RL)
5578 F04
70
82
39
33
–
–
50-215
Figure 4. LO Input Circuit
140
240
98-187
4.7
–
175-295
0
–5
SEE FIGURES 1 AND 8 FOR
COMPONENT VALUES
0
–5
–10
–15
–10
–15
–20
–25
–30
d
–20
–25
b
c
b
a
a
c
0
1000 1500 2000 2500 3000
FREQUENCY (MHz)
500
50
150
200
250
300
350
100
5578 F05
FREQUENCY (MHz)
Figure 5. LO Input Return Loss with 520MHz (a),
760MHz (b), 880MHz (c) and >1.5GHz (d) Matching
5578 F03
Figure 3. IF Input Return Loss with 70MHz (a),
140MHz (b) and 240MHz (c) Matching
Table 3 lists the input impedance and reflection coefficient
vs frequency for the LO input for use in such cases.
LO Input Interface
Thesimplifiedschematicforthesingle-endedLOinputport
is shown in Figure 4. An internal transformer provides a
broadband impedance match and performs single-ended
todifferentialconversion.Theprimarywindingisinternally
grounded, thus an external DC block may be necessary
in some applications. The transformer secondary feeds
the differential limiting amplifier stages that drive the
mixer core.
Table 3. Single-Ended LO Input Impedance
(at Pin 22, No External Match)
REFLECTION COEFFICIENT
FREQUENCY
(MHz)
LO INPUT
IMPEDANCE
MAG
0.747
0.657
0.558
0.456
0.353
0.247
0.158
0.097
0.111
0.159
ANGLE
142.8
105.5
67.6
300
600
41.7||j20.3
95.0||j42.7
126||j84.2
127||j239
900
1200
1500
1800
2100
2400
2700
3000
27.6
104||–j686
74.0||–j188
52.5||–j162
42.3||–j459
44.4||j249
52.4||j161
–10.8
–48.3
–90.0
–152.0
127.5
90.6
The measured return loss of the LO input port is shown in
Figure 5 for different application frequencies. The imped-
ance match is acceptable from about 1.5GHz to beyond
3GHz, with a minimum return loss across this range of
about 9dB. Below 1.5GHz, external components are used
to tune the impedance match to the desired frequency.
5578f
11
LT5578
APPLICATIONS INFORMATION
RF Output Interface
the board. As many vias as possible should connect the
topside ground to other ground layers to aid in thermal
dissipation and reduce inductance.
The RF output interface is shown in Figure 6. An internal
RF transformer reduces the mixer core output impedance
to simplify matching of the RF output pin. A center tap in
the transformer provides the DC connection to the mixer
core and the transformer provides DC isolation to the RF
output. The RF pin is internally grounded through the
secondary winding of the transformer, thus a DC voltage
should not be applied to this pin.
Table 4. Single-Ended RF Output Impedance
(at Pin 15, No External Matching)
REFLECTION COEFFICIENT
FREQUENCY
(MHz)
RF OUTPUT
IMPEDANCE
MAG
0.741
0.614
0.507
0.330
0.225
0.273
0.384
ANGLE
117.6
32.6
400
800
10.1 + j29.3
90.8 + j96.6
69.7 – j66.6
32.8 – j22.5
32.3 – j5.4
28.6 + j0.3
22.5 + j4.4
1200
1600
2000
2400
2800
–44.4
–112.3
–159.3
179.0
167.3
While the LT5578 performs best at frequencies above
700MHz, the part can be used down to 400MHz. The low
inductance of the internal transformer limits the perfor-
manceatlowerfrequencies.TheimpedancedatafortheRF
output, listed in Table 4, can be used to develop matching
networks for different frequencies or load impedances.
Figure 7 illustrates the output return loss performance
for several applications. The component values and ap-
proximate matching bandwidths are listed in Table 5.
Table 5. RF Output Component Values
FREQUENCY
MATCH BW
(at 12dB RL)
(MHz)
C8 (pF) L3 (nH) C14 (pF)
450
9.0
3.3
1.8
–
18
18
–
–
430-505
740
680-768
DC and RF Grounding
900
12
–
835-970
The LT5578 relies on the back side ground for both RF
and thermal performance. The Exposed Pad must be
soldered to the low impedance topside ground plane of
1950
2600
1.8
0Ω
1.2
0.8
1765-2305
2150-2990
–
0
–5
LT5578
RF
50Ω
L3
15
–10
–15
C8
C14
5578 F06
8
9
10
11
–20
–25
d
b
a
V
CC
c
e
0
1000 1500 2000 2500 3000
FREQUENCY (MHz)
500
Figure 6. RF Output Circuit
5578 F07
Figure 7. RF Output Return Loss with 450MHz (a), 740MHz (b),
900MHz (c), 1950MHz (d) and 2600MHz (e) Matching
5578f
12
LT5578
TYPICAL APPLICATIONS
The following examples illustrate the implementation and Figure 9 shows measured conversion gain, noise figure
performance of the LT5578 in some selected applications. andOIP3asafunctionofRFoutputfrequency.At450MHz,
These circuits were evaluated using the board layout the gain is –2.1dB with a NF of 9.3dB and an OIP3 of
shown in Figure 12.
23.8dBm.
12
10
8
32
30
28
26
24
22
20
18
16
450MHz Application
SSB NF
In this case, the LT5578 was evaluated for an application
with an IF input at 70MHz, an RF output of 450MHz and
a high side LO. The LO port is tuned for high side LO in-
jection at 520MHz. The matching networks for the three
ports are shown in Figure 8.
6
4
OIP3
GAIN
T
IF
P
= 25°C
2
A
f
= 70MHz
= –5dBm/TONE
0
IF
At the IF input, the 560pF capacitors are used mainly as
DC blocks, but also help tune out the parasitic inductance
of the transformer. The 82pF differential capacitor and
3.3nH chip inductors provide an impedance transforma-
tion between the IF input pins and the transformer. The
relatively low input frequency requires the use of chip
inductors instead of the short transmission lines that are
shown in Figure 2. The measured IF port return loss is
included in Figure 3.
–2
–4
460
RF OUTPUT FREQUENCY (MHz)
420
440
480
500
5578 F09
Figure 9. Gain, Noise Figure and OIP3 vs RF Frequency
in the 450MHz Application
2600MHz Application
TheRFportimpedancematchisrealizedwithashunt12pF
capacitor and a series 18nH inductor. The return loss with
this configuration is better than 12dB from about 430MHz
to 505MHz and is plotted in Figure 7.
For this application, the impedance match of the RF port is
optimized at 2600MHz and has a good return loss over the
rangeof2200MHzto2900MHz.Thecomponentvaluesare
listed in Table 5 and typical output return loss is shown in
Figure 7. The IF input is matched at 240MHz as described
in Table 2. The LO port requires no external matching for
this band as its return loss is good for frequencies above
1.5GHz.
To tune the LO port, a series 6.8pF and shunt 4.7pF ca-
pacitor are used as shown. This combination provides a
10dB, or better, return loss from 435MHz to 580MHz as
shown in Figure 5. The series capacitor also provides DC
decoupling for the internal transformer at the LO input.
LO
520MHz
6.8pF
4.7pF
13.7Ω
100nH
TC4-1W+
4:1
560pF
560pF
3.3nH
3.3nH
RF
450MHz
18nH
IF
82pF
70MHz
12pF
5578 F08
100nH
13.7Ω
Figure 8. Schematic for 450MHz RF Application with 70MHz IF and 520MHz LO
5578f
13
LT5578
TYPICAL APPLICATIONS
The measured room temperature performance is plotted
in Figure 10 for both low side and high side LO drive. At
2600MHz, the gain is approximately –2.8dB with a noise
figure of 11.2dB and OIP3 of about 22.2dBm. Low side
LO yields slightly better overall performance than high
side LO.
width to be extended to cover the range from 700MHz to
950MHz. Figure 11 compares the broadband return loss
to the typical 740MHz and 900MHz return loss perfor-
mance.
The swept gain, noise figure and OIP3 results are plotted
on page 1 for an IF of 140MHz and a low side LO. The
conversiongainisgreaterthan0.7dBacrossthebandwith
OIP3 better than 25.5dBm. The single side-band noise
figure is less than 8.8dB across the band.
700 to 950 MHz Output Matching
The application shown on page 1 has a wider bandwidth
than the 740MHz and 900MHz configurations. Using two
additional components at the RF output allows the band-
0
12
10
8
32
30
28
26
24
22
20
18
16
–5
SSB NF
OIP3
–10
c
LS LO
HS LO
6
–15
4
2
–20
a
b
0
GAIN
–25
600
–2
–4
700
800
900
1000
1100
FREQUENCY (MHz)
5578 F11
2400
2300
RF OUTPUT FREQUENCY (MHz)
2200
2500
2600
2700
Figure 11. Return Loss Comparison: 740MHz (a),
900MHz (b) and 700MHz to 950MHz (c)
5578 F09
Figure 10. Gain, Noise Figure and OIP3 vs RF Frequency
for the 2600MHz Application
Figure 12. LT5578 Evaluation Board (DC1545A)
5578f
14
LT5578
PACKAGE DESCRIPTION
UH Package
24-Lead Plastic QFN (5mm × 5mm)
(Reference LTC DWG # 05-08-1747 Rev A)
0.75 p0.05
5.40 p0.05
3.90 p0.05
3.20 p 0.05
3.25 REF
3.20 p 0.05
PACKAGE OUTLINE
0.30 p 0.05
0.65 BSC
PIN 1 NOTCH
R = 0.30 TYP
OR 0.35 s 45o
CHAMFER
RECOMMENDED SOLDER PAD LAYOUT
APPLY SOLDER MASK TO AREAS THAT ARE NOT SOLDERED
BOTTOM VIEW—EXPOSED PAD
R = 0.150
R = 0.05
TYP
0.75 p 0.05
5.00 p 0.10
TYP
23 24
0.00 – 0.05
0.55 p 0.10
PIN 1
TOP MARK
(NOTE 6)
1
2
3.20 p 0.10
5.00 p 0.10
3.25 REF
3.20 p 0.10
(UH24) QFN 0708 REV A
0.200 REF
0.30 p 0.05
0.65 BSC
NOTE:
1. DRAWING IS NOT A JEDEC PACKAGE OUTLINE
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 0.20mm 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
5578f
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 representa-
tion that the interconnection of its circuits as described herein will not infringe on existing patent rights.
15
LT5578
RELATED PARTS
PART NUMBER
Infrastructure
LT5514
DESCRIPTION
COMMENTS
Ultralow Distortion, IF Amplifier/ADC Driver
with Digitally Controlled Gain
40MHz to 900MHz Quadrature Demodulator
1.5GHz to 2.4GHz High Linearity Direct
Quadrature Modulator
850MHz Bandwidth, 47dBm OIP3 at 100MHz, 10.5dB to 33dB Gain Control Range
21dBm IIP3, Integrated LO Quadrature Generator
LT5517
LT5518
22.8dBm OIP3 at 2GHz, –158.2dBm/Hz Noise Floor, 50Ω Single-Ended RF and LO
Ports, 4-Channel W-CDMA ACPR = –64dBc at 2.14GHz
LT5519
LT5520
LT5521
LT5522
LT5526
LT5527
LT5528
LT5557
LT5558
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
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
24.2dBm IIP3 at 1.95GHz, NF = 12.5dB, 3.15V to 5.25V Supply, Single-Ended LO
Port Operation
10MHz to 3700MHz High Linearity
Upconverting Mixer
400MHz 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
High Linearity, Low Power Downconverting
Mixer
400MHz to 3.7GHz High Signal Level
Downconverting Mixer
1.5GHz to 2.4GHz High Linearity Direct
Quadrature Modulator
3V to 5.3V Supply, 16.5dBm IIP3, 100kHz to 2GHz RF, NF = 11dB, I = 28mA,
CC
–65dBm LO-RF Leakage
IIP3 = 23.5dBm and NF = 12.5dBm at 1900MHz, 4.5V to 5.25V Supply, I = 78mA,
CC
Conversion Gain = 2dB
21.8dBm OIP3 at 2GHz, –159.3dBm/Hz Noise Floor, 50Ω, 0.5V Baseband
DC
Interface, 4-Channel W-CDMA ACPR = –66dBc at 2.14GHz
400MHz to 3.8GHz 3.3V Downconverting Mixer IIP3 = 23.5dBm at 3.6GHz, NF = 15.4dB, Conversion Gain = 1.7dB, 3.3V Supply at
82mA, Single-Ended RF and LO Inputs
600MHz to 1100MHz High Linearity Direct
Quadrature Modulator
22.4dBm OIP3 at 900MHz, –158dBm/Hz Noise Floor, 3kΩ, 2.1V Baseband
DC
Interface, 3-Ch CDMA2000 ACPR = –70.4dBc at 900MHz
LT5560
LT5568
Ultra-Low Power Active Mixer
700MHz to 1050MHz High Linearity Direct
Quadrature Modulator
10mA Supply Current, 10dBm IIP3, 10dB NF, Usable as Up- or Down-Converter.
22.9dBm OIP3 at 850MHz, –160.3dBm/Hz Noise Floor, 50Ω, 0.5V Baseband
DC
Interface, 3-Ch CDMA2000 ACPR = –71.4dBc at 850MHz
LT5572
LT5575
LT5579
1.5GHz to 2.5GHz High Linearity Direct
Quadrature Modulator
700MHz to 2.7GHz Direct Conversion I/Q
Demodulator
1.5GHz to 3.8GHz High Linearity Upconverting 27.3dBm OIP3 at 2.14GHz, NF = 9.9dB, 3.3V Supply, Single-Ended LO and RF Ports
Mixer
21.6dBm OIP3 at 2GHz, –158.6dBm/Hz Noise Floor, High-Ohmic 0.5V Baseband
DC
Interface, 4-Ch W-CDMA ACPR = –67.7dBc at 2.14GHz
Integrated Baluns, 28dBm IIP3, 13dBm P1dB, 0.03dB I/Q Amplitude Match,
0.4° Phase Match
RF Power Detectors
LTC®5505
LTC5507
LTC5508
LTC5509
RF Power Detectors with >40dB Dynamic Range 300MHz to 3GHz, Temperature Compensated, 2.7V to 6V Supply
100kHz to 1000MHz RF Power Detector
300MHz to 7GHz RF Power Detector
300MHz to 3GHz RF Power Detector
100kHz to 1GHz, Temperature Compensated, 2.7V to 6V Supply
44dB Dynamic Range, Temperature Compensated, SC70 Package
36dB Dynamic Range, Low Power Consumption, SC70 Package
LTC5530
LTC5531
LTC5532
300MHz to 7GHz Precision RF Power Detector Precision V
300MHz to 7GHz Precision RF Power Detector Precision V
300MHz to 7GHz Precision RF Power Detector Precision V
Offset Control, Shutdown, Adjustable Gain
Offset Control, Shutdown, Adjustable Offset
Offset Control, Adjustable Gain and Offset
OUT
OUT
OUT
LT5534
50MHz to 3GHz Log RF Power Detector with
60dB Dynamic Range
1dB Output Variation over Temperature, 38ns Response Time, Log Linear
Response
LTC5536
Precision 600MHz to 7GHz RF Power Detector 25ns Response Time, Comparator Reference Input, Latch Enable Input,
with Fast Comparator Output
–26dBm to +12dBm Input Range
LT5537
LT5570
Wide Dynamic Range Log RF/IF Detector
2.7GHz Mean-Squared Detector
Low Frequency to 1GHz, 83dB Log Linear Dynamic Range
0.5dB Accuracy Over Temperature and >50dB Dynamic Range, Fast 500ns
Rise Time
LT5581
6GHz Low Power RMS Detector
40dB Dynamic Range, 1dB Accuracy Over Temperature, 1.5mA Supply Current
5578f
LT 0709 • PRINTED IN USA
LinearTechnology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
16
●
●
© LINEAR TECHNOLOGY CORPORATION 2009
(408) 432-1900 FAX: (408) 434-0507 www.linear.com
相关型号：
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LT5579 - 1.5GHz to 3.8GHz High Linearity Upconverting Mixer; Package: QFN; Pins: 24; Temperature Range: -40°C to 85°C
Linear
LT5579IUH#TRPBF
LT5579 - 1.5GHz to 3.8GHz High Linearity Upconverting Mixer; Package: QFN; Pins: 24; Temperature Range: -40°C to 85°C
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