Transcript
LTC5591 Dual 1.3GHz to 2.3GHz High Dynamic Range Downconverting Mixer DESCRIPTION
FEATURES n n n n n n n n n n n n n n
Conversion Gain: 8.5dB at 1950MHz IIP3: 26.2dBm at 1950MHz Noise Figure: 9.9dB at 1950MHz 15.5dB NF Under 5dBm Blocking High Input P1dB 47dB Channel-to-Channel Isolation 1.25W Power Consumption at 3.3V Low Power Mode: <800mW Consumption Independent Channel Shutdown Control 50Ω Single-Ended RF and LO Inputs LO Input Matched In All Modes 0dBm LO Drive Level Small Package and Solution Size –40°C to 105°C Operation
The LTC®5591 is part of a family of dual-channel high dynamic range, high gain downconverting mixers covering the 600MHz to 4.5GHz RF frequency range. The LTC5591 is optimized for 1.3GHz to 2.3GHz RF applications. The LO frequency must fall within the 1.4GHz to 2.1GHz range for optimum performance. A typical application is a LTE or W-CDMA multichannel or diversity receiver with a 1.7GHz to 2.2GHz RF input and low side LO. The LTC5591’s high conversion gain and high dynamic range enable the use of lossy IF filters in high selectivity receiver designs, while minimizing the total solution cost, board space and system-level variation. A low current mode is provided for additional power savings and each of the mixer channels has independent shutdown control. High Dynamic Range Dual Downconverting Mixer Family
APPLICATIONS n
n n
PART NUMBER
RF RANGE
LO RANGE
LTC5590
600MHz to 1.7GHz
700MHz to 1.5GHz
LTC5591
1.3GHz to 2.3GHz
1.4GHz to 2.1GHz
LTC5592
1.6GHz to 2.7GHz
1.7GHz to 2.5GHz
LTC5593
2.3GHz to 4.5GHz
2.1GHz to 4.2GHz
3G/4G Wireless Infrastructure Diversity Receivers (LTE, W-CDMA, TD-SCDMA, UMTS, GSM1800) Remote Radio Unit MIMO Multichannel Receivers
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 Wideband Receiver 190MHz SAW
VCCIF 3.3V or 5V
1µF
22pF
150nH
IFA+
22pF
LO AMP
4.7pF
9.5
LO 1760MHz
LO
SYNTH
IFB+
BIAS IFB–
150nH
6.0 160
VCCB 22pF
150nH 1nF 190MHz SAW
22pF
1nF
8.0
6.5
VCC
VCCIF
8.5
24 22 20 18
GC
16 14 12
7.0
ENB (0V/3.3V)
ENB IF AMP
9.0
26
IIP3 LO = 1760MHz PLO = 0dBm RF = 1950 ±30MHz TEST CIRCUIT IN FIGURE 1
7.5
LO AMP
RFB
LNA
10.5
ENA (0V/3.3V)
ENA
28
11.0
IIP3 (dBm), SSB NF (dB)
BIAS
IMAGE BPF 2.7pF
VCC 3.3V
1µF
10.0
RFA
LNA
RF 1920MHz TO 1980MHz
ADC
VCCA
IFA– IF AMP
IMAGE BPF 2.7pF
RF 1920MHz TO 1980MHz
IF AMP
1nF 150nH
Wideband Conversion Gain, IIP3 and NF vs IF Frequency (Mixer Only, Measured on Evaluation Board)
190MHz BPF
GC (dB)
1nF
NF
10
210 180 170 200 190 IF OUTPUT FREQUENCY (MHz)
8 220
5591 TA01b
190MHz BPF IF AMP
ADC 5591 TA01a
5591f
1
LTC5591 ABSOLUTE MAXIMUM RATINGS
PIN CONFIGURATION
(Note 1)
Supply Voltage (VCC) ...............................................4.0V IF Supply Voltage (VCCIF) .........................................5.5V Enable Voltage (ENA, ENB) ..............–0.3V to VCC + 0.3V Bias Adjust Voltage (IFBA, IFBB) .........–0.3V to VCC + 0.3V Power Select Voltage (ISEL) .............–0.3V to VCC + 0.3V LO Input Power (1GHz to 3GHz) .............................9dBm LO Input DC Voltage............................................... ±0.1V RFA, RFB Input Power (1GHz to 3GHz) ................15dBm RFA, RFB Input DC Voltage .................................... ±0.1V Operating Temperature Range (TC) ........ –40°C to 105°C Storage Temperature Range .................. –65°C to 150°C Junction Temperature (TJ) .................................... 150°C
VCCA
IFBA
IFA–
IFA+
IFGNDA
GND
TOP VIEW
24 23 22 21 20 19 RFA 1
18 ISEL
CTA 2
17 ENA
GND 3
16 LO
25 GND
GND 4
15 GND 13 GND
IFBB
VCCB
9 10 11 12 IFB–
8
IFB+
7 GND
14 ENB
RFB 6
IFGNDB
CTB 5
UH PACKAGE 24-LEAD (5mm × 5mm) PLASTIC QFN TJMAX = 150°C, θJC = 7°C/W EXPOSED PAD (PIN 25) IS GND, MUST BE SOLDERED TO PCB
ORDER INFORMATION LEAD FREE FINISH
TAPE AND REEL
PART MARKING
PACKAGE DESCRIPTION
TEMPERATURE RANGE
LTC5591IUH#PBF
LTC5591IUH#TRPBF
5591
24-Lead (5mm × 5mm) Plastic QFN
–40°C to 105°C
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/
DC ELECTRICAL CHARACTERISTICS unless otherwise noted. Test circuit shown in Figure 1. (Note 2) PARAMETER
VCC = 3.3V, VCCIF = 3.3V, ENA = ENB = High, ISEL = Low, TC = 25°C,
CONDITIONS
MIN
TYP
MAX
UNITS
VCCA, VCCB Supply Voltage (Pins 12, 19)
3.1
3.3
3.5
V
VCCIFA, VCCIFB Supply Voltage (Pins 9, 10, 21, 22)
3.1
3.3
5.3
V
Power Supply Requirements (VCCA, VCCB, VCCIFA, VCCIFB)
Mixer Supply Current (Pins 12, 19)
Both Channels Enabled
182
218
mA
IF Amplifier Supply Current (Pins 9, 10, 21, 22)
Both Channels Enabled
200
240
mA
Total Supply Current (Pins 9, 10, 12, 19, 21, 22)
Both Channels Enabled
382
458
mA
Total Supply Current – Shutdown
ENA = ENB = Low
500
µA
Enable Logic Input (ENA, ENB) High = On, Low = Off ENA, ENB Input High Voltage (On)
2.5
V
ENA, ENB Input Low Voltage (Off) ENA, ENB Input Current
–0.3V to VCC + 0.3V
–20
0.3
V
30
µA
Turn On Time
0.9
µs
Turn Off Time
1
µs 5591f
2
LTC5591 DC ELECTRICAL CHARACTERISTICS unless otherwise noted. Test circuit shown in Figure 1. (Note 2) PARAMETER
VCC = 3.3V, VCCIF = 3.3V, ENA = ENB = High, ISEL = Low, TC = 25°C,
CONDITIONS
MIN
TYP
MAX
UNITS
Low Current Mode Logic Input (ISEL) High = Low Power, Low = Normal Power Mode ISEL Input High Voltage
2.5
V
ISEL Input Low Voltage ISEL Input Current
–0.3V to VCC + 0.3V
–20
0.3
V
30
µA
Low Current Mode Current Consumption (ISEL = High) Mixer Supply Current (Pins 12, 19)
Both Channels Enabled
119
143
mA
IF Amplifier Supply Current (Pins 9, 10, 21, 22)
Both Channels Enabled
120
144
mA
Total Supply Current (Pins 9, 10, 12, 19, 21, 22)
Both Channels Enabled
239
287
mA
AC ELECTRICAL CHARACTERISTICS
VCC = 3.3V, VCCIF = 3.3V, ENA = ENB = High, ISEL = Low, TC = 25°C, PLO = 0dBm, PRF = –3dBm (∆f = 2MHz for two tone IIP3 tests), unless otherwise noted. Test circuit shown in Figure 1. (Notes 2, 3, 4)
PARAMETER
CONDITIONS
MIN
LO Input Frequency Range
TYP
MAX
UNITS
1400 to 2100
MHz
1600 to 2300 1300 to 1800
MHz MHz
5 to 500
MHz
RF Input Frequency Range
Low Side LO High Side LO
IF Output Frequency Range
Requires External Matching
RF Input Return Loss
ZO = 50Ω, 1300MHz to 2300MHz
>12
dB
LO Input Return Loss
ZO = 50Ω, 1400MHz to 2100MHz
>12
dB
IF Output Impedance
Differential at 190MHz
300Ω||2.3pF
R||C
LO Input Power
fLO = 1400MHz to 2100MHz
–4
0
6
dBm
LO to RF Leakage
fLO = 1400MHz to 2100MHz
<–30
dBm
LO to IF Leakage
fLO = 1400MHz to 2100MHz
<–30
dBm
RF to LO Isolation
fRF = 1300MHz to 2300MHz
>45
dB
RF to IF Isolation
fRF = 1300MHz to 2300MHz
>30
dB
Channel-to-Channel Isolation
fRF = 1750MHz to 2150MHz
>47
dB
Low Side LO Downmixer Application: ISEL = Low, RF = 1700MHz to 2300MHz, IF = 190MHz, fLO = fRF – fIF PARAMETER
CONDITIONS
MIN
TYP
Conversion Gain
RF = 1750MHz RF = 1950MHz RF = 2150MHz
7.0
8.7 8.5 8.0
dB dB dB
RF = 1950 ±30MHz, LO = 1760MHz, IF = 190 ±30MHz
±0.25
dB
Conversion Gain vs Temperature
TC = –40ºC to 105ºC, RF = 1950MHz
–0.006
dB/°C
Input 3rd Order Intercept
RF = 1750MHz RF = 1950MHz RF = 2150MHz
26.9 26.2 26.2
dBm dBm dBm
9.4 9.9 10.8
dB dB dB
Conversion Gain Flatness
SSB Noise Figure
RF = 1750MHz RF = 1950MHz RF = 2150MHz
24.0
MAX
UNITS
5591f
3
LTC5591 AC ELECTRICAL CHARACTERISTICS
VCC = 3.3V, VCCIF = 3.3V, ENA = ENB = High, TC = 25°C, PLO = 0dBm, PRF = –3dBm (∆f = 2MHz for two tone IIP3 tests), unless otherwise noted. Test circuit shown in Figure 1. (Notes 2, 3) Low Side LO Downmixer Application: ISEL = Low, RF = 1700MHz to 2300MHz, IF = 190MHz, fLO = fRF – fIF PARAMETER
CONDITIONS
MIN
SSB Noise Figure Under Blocking
fRF =1950MHz, fLO = 1760MHz, fBLOCK = 2050MHz, PBLOCK = 5dBm PBLOCK = 10dBm
TYP
MAX
UNITS
15.5 20.2
dB dB
2RF-2LO Output Spurious Product (fRF = fLO + fIF/2)
fRF = 1855MHz at –10dBm, fLO = 1760MHz, fIF = 190MHz
–69
dBc
3RF-3LO Output Spurious Product (fRF = fLO + fIF/3)
fRF = 1823.33MHz at –10dBm, fLO = 1760MHz, fIF = 190MHz
–74
dBc
Input 1dB Compression
fRF = 1950MHz, VCCIF = 3.3V fRF = 1950MHz, VCCIF = 5V
10.7 13.9
dBm dBm
Low Power Mode, Low Side LO Downmixer Application: ISEL = High, RF = 1700MHz to 2300MHz, IF = 190MHz, fLO = fRF – fIF PARAMETER
CONDITIONS
Conversion Gain
RF = 1950MHz
MIN
TYP 7.2
MAX
UNITS dB
Input 3rd Order Intercept
RF = 1950MHz
21.4
dBm
SSB Noise Figure
RF = 1950MHz
10.3
dB
Input 1dB Compression
RF = 1950MHz, VCCIF = 3.3V RF = 1950MHz, VCCIF = 5V
10.7 11.7
dBm dBm
High Side LO Downmixer Application: ISEL = Low, RF = 1300MHz to 1800MHz, IF = 190MHz, fLO = fRF + fIF PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
Conversion Gain
RF = 1450MHz RF = 1600MHz RF = 1750MHz
8.9 8.6 8.4
dB dB dB
Conversion Gain Flatness
RF = 1600 ±30MHz, LO = 1790MHz, IF = 190 ±30MHz
±0.1
dB
Conversion Gain vs Temperature
TC = –40ºC to 105ºC, RF = 1600MHz
–0.007
dB/°C
Input 3rd Order Intercept
RF = 1450MHz RF = 1600MHz RF = 1750MHz
25.0 24.6 24.3
dBm dBm dBm
SSB Noise Figure
RF = 1450MHz RF = 1600MHz RF = 1750MHz
10.0 10.1 10.1
dB dB dB
SSB Noise Figure Under Blocking
fRF = 1600MHz, fLO = 1790MHz, fBLOCK = 1500MHz, PBLOCK = 5dBm PBLOCK = 10dBm
16.4 21.2
dB dB
2LO-2RF Output Spurious Product (fRF = fLO – fIF/2)
fRF = 1695MHz at –10dBm, fLO = 1790MHz, fIF = 190MHz
–64
dBc
3LO-3RF Output Spurious Product (fRF = fLO – fIF/3)
fRF = 1726.67MHz at –10dBm, fLO = 1790MHz, fIF = 190MHz
–75
dBc
Input 1dB Compression
RF = 1600MHz, VCCIF = 3.3V RF = 1600MHz, VCCIF = 5V
10.2 13.6
dBm dBm
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 2: The LTC5591 is guaranteed functional over the case operating temperature range of –40°C to 105°C. (θJC = 7°C/W)
Note 3: SSB Noise Figure measured with a small-signal noise source, bandpass filter and 6dB matching pad on RF input, bandpass filter and 6dB matching pad on the LO input, and no other RF signals applied. Note 4: Channel A to channel B isolation is measured as the relative IF output power of channel B to channel A, with the RF input signal applied to channel A. The RF input of channel B is 50Ω terminated and both mixers are enabled. 5591f
4
LTC5591 TYPICAL AC PERFORMANCE CHARACTERISTICS
Low Side LO VCC = 3.3V, VCCIF = 3.3V, ENA = ENB = High, ISEL = Low, TC = 25°C, PLO = 0dBm, PRF = –3dBm (–3dBm/tone for two-tone IIP3 tests, ∆f = 2MHz), IF = 190MHz, unless otherwise noted. Test circuit shown in Figure 1. Conversion Gain and IIP3 vs RF Frequency 16
21 GC 19
2.3
1.7 1.8 1.9 2 2.1 2.2 RF FREQUENCY (GHz)
50
12
10
8
8
6 2.4
6
2.3
1.7 1.8 1.9 2 2.1 2.2 RF FREQUENCY (GHz)
27
20
27
25
18
25
–40°C 16 25°C 85°C 14
23
–40°C 16 25°C 85°C 14
23
15
8
13
6 GC
9 7
–6
–4
2 –2 0 LO INPUT POWER (dBm)
6
4
21 19
10
15
8
13
6
11
2
9
0
7
GC
–6
–4
2 –2 0 LO INPUT POWER (dBm)
6
4
Conversion Gain, IIP3 and NF vs Supply Voltage (Single Supply)
9 –40°C 7 25°C 85°C 5
4
11
2
9
0
7
25
–40°C 18 25°C 85°C 16
23
10
13
8
9 7
3
3.1 3.4 3.2 3.3 3.5 VCC, VCCIF SUPPLY VOLTAGE (V)
19
18 16 14
17
12
NF
15
10
13
8
11
4
9
2 3.6
7
5591 G07
RF = 1950MHz VCC = 3.3V
21
6
GC
–40°C 25°C 85°C
6
GC
3
3.3
4
3.6 3.9 4.2 4.5 4.8 5.1 VCCIF SUPPLY VOLTAGE (V)
2 5.4
5591 G08
SSB NF (dB)
12
15
SSB NF (dB)
14
IIP3
GC (dB), IIP3 (dBm), P1dB (dBm)
27
20
GC (dB), IIP3 (dBm)
22
11
–6
–4
3
2 –2 0 LO INPUT POWER (dBm)
4
6
1
Conversion Gain, IIP3 and RF Input P1dB vs Temperature
27
NF
GC
5591 G06
25
17
11
13
Conversion Gain, IIP3 and NF vs IF Supply Voltage (Dual Supply)
19
13
NF
15
22
RF = 1950MHz VCC = VCCIF
15
19
20
21
17
17
27 IIP3
19
IIP3
21
25 23
21
5591 G05
5591 G04
GC (dB), IIP3 (dB)
12
NF
17
4
2.4
SSB NF (dB)
10
IIP3
SSB NF (dB)
12
NF
17
GC (dB), IIP3 (dB)
21
2.3
1.8 1.9 2.1 2.2 2 RF FREQUENCY (GHz)
2150MHz Conversion Gain, IIP3 and NF vs LO Power
18
SSB NF (dB)
GC (dB), IIP3(dB)
23
1.6 1.7
5591 G03
20 IIP3
11
2.4
1950MHz Conversion Gain, IIP3 and NF vs LO Power
27
–40°C 25°C 85°C 105°C
5591 G02
1750MHz Conversion Gain, IIP3 and NF vs LO Power
19
40
30
1.6
5591 G01
25
45
35
GC (dB), IIP3 (dB)
1.6
SSB NF (dB)
12 –40°C 25°C 85°C 10 105°C
55
–40°C 25°C 85°C 105°C
14
GC (dB)
IIP3 (dBm)
14
IIP3
23
17
16
ISOLATION (dB)
27
25
Channel Isolation vs RF Frequency
SSB NF vs RF Frequency
IIP3
23 RF = 1950MHz VCCIF = 5V VCCIF = 3.3V
21 19 17 15 13
P1dB
11 9
GC
7 –40 –25 –10 5 20 35 50 65 80 95 110 CASE TEMPERATURE (°C) 5591 G09
5591f
5
LTC5591 TYPICAL AC PERFORMANCE CHARACTERISTICS
Low Side LO (continued) VCC = 3.3V, VCCIF = 3.3V, ENA = ENB = High, ISEL = Low, TC = 25°C, PLO = 0dBm, PRF = –3dBm (–3dBm/tone for two-tone IIP3 tests, ∆f = 2MHz), IF = 190MHz, unless otherwise noted. Test circuit shown in Figure 1. Single-Tone IF Output Power, 2 × 2 and 3 × 3 Spurs vs RF Input Power
20
20
10
10
IFOUT
–20 –30 –40 –50
IM3
–60
–10 (LO = 1760MHz)
–20 –30
3RF-3LO (RF = 1823.33MHz)
–40 –50
2RF-2LO (RF = 1855MHz)
–60 IM5
–70 –80 –12
–60
IFOUT (RF = 1950MHz)
0
RF1 = 1949MHz RF2 = 1951MHz LO = 1760MHz
2 × 2 and 3 × 3 Spurs vs LO Power
RELATIVE SPUR LEVEL (dBc)
0 –10
OUTPUT POWER (dBm)
OUTPUT POWER/TONE (dBm)
2-Tone IF Output Power, IM3 and IM5 vs RF Input Power
–65 2RF-2LO (RF = 1855MHz) –70
–80 3 –15 –12 –9 –6 –3 0 6 RF INPUT POWER (dBm)
6 5591 G10
9
–80
12
–4
LO Leakage vs LO Frequency
RF Isolation vs RF Frequency RF-LO 50
LO LEAKAGE (dBm)
18 PLO = –3dBm 16 PLO = 0dBm
12
ISOLATION (dB)
–30 LO-RF –40 LO-IF
45
40 RF-IF
–50
35
PLO = 3dBm –60
–15 –10 –5 0 5 RF BLOCKER POWER (dBm)
10
1.2
1.4
2 1.6 1.8 LO FREQUENCY (GHz)
Conversion Gain Distribution RF = 1950MHz
20
20 15 10
0 7.8
1.7 1.9 2.1 RF FREQUENCY (GHz)
2.3
2.5
–40°C 25°C 85°C
SSB Noise Figure Distribution 40
RF = 1950MHz
RF = 1950MHz
35
–40°C 25°C 85°C
30
15
10
25 20 15 10
5
5
1.5
5591 G15
IIP3 Distribution 25
DISTRIBUTION (%)
25
–40°C 25°C 85°C
1.3
5591 G14
5591 G13
30
30
2.2
DISTRIBUTION (%)
8 –25 –20
6
55
RF = 1950MHz LO = 1760MHz 20 BLOCKER = 2050MHz
10
–2 0 2 4 LO INPUT POWER (dBm)
5591 G12
–20
22
SSB NF (dB)
–6
5591 G11
SSB Noise Figure vs RF Blocker Power
DISTRIBUTION (%)
3RF-3LO (RF = 1823.33MHz)
–75
–70
–9 3 –6 –3 0 RF INPUT POWER (dBm/TONE)
14
RF = 1950MHz PRF = –10dBm LO = 1760MHz
5 8.0
8.2 8.4 8.6 8.8 CONVERSION GAIN (dB)
9.0 5591 G16
0 23.7 24 24.3 24.6 24.9 25.2 25.5 25.8 26.1 26.4 26.7 IIP3 (dBm) 5591 G17
0 8.5
8.9
9.3 9.7 10.1 10.5 10.9 11.3 11.7 SSB NOISE FIGURE (dB) 5591 G18
5591f
6
LTC5591 TYPICAL AC PERFORMANCE CHARACTERISTICS
Low Power Mode, Low Side LO VCC = 3.3V, VCCIF = 3.3V, ENA = ENB = High, ISEL = High, TC = 25°C, PLO = 0dBm, PRF = –3dBm (–3dBm/tone for two-tone IIP3 tests, ∆f = 2MHz), IF = 190MHz, unless otherwise noted. Test circuit shown in Figure 1. Conversion Gain and IIP3 vs RF Frequency
Channel Isolation vs RF Frequency
SSB NF vs RF Frequency
23
21
15
16
55
13
14
50
9
13
1.6 1.7
1.8 1.9 2 2.1 2.2 RF FREQUENCY (GHz)
10
7
8
5 2.3 2.4
6
15
ISOLATION (dB)
GC
12
–40°C 25°C 85°C 105°C 1.6
1.7
1.8 1.9 2 2.1 2.2 RF FREQUENCY (GHz)
2.3
1750MHz Conversion Gain, IIP3 and NF vs LO Power 22
18
22
16 –40°C 14 25°C 85°C 12
18
10
GC (dB), IIP3 (dBm)
NF
16
22
16 –40°C 14 25°C 85°C 12
20
16
18
14
14
10
12
8
10
6
12
4
8
4
8
2
6
2
6
0
4
0
4
–4
2 –2 0 LO INPUT POWER (dBm)
6
4
–6
–4
2 –2 0 LO INPUT POWER (dBm)
Conversion Gain, IIP3 and NF vs Supply Voltage (Single Supply)
IIP3
20
14 12
14
10
12
8
10 GC
8 6
3
–40°C 25°C 6 85°C 4
3.1 3.4 3.2 3.3 3.5 VCC, VCCIF SUPPLY VOLTAGE (V)
2 3.6 5591 G25
SSB NF (dB)
NF
16
22
16
IIP3
NF
16
18
14 12 10
14 12 10 GC
8 6
26 24
16 RF = 1950MHz VCC = 3.3V
18
20
3
3.3
–40°C 25°C 85°C
8 6 4
3.6 3.9 4.2 4.5 4.8 5.1 VCCIF SUPPLY VOLTAGE (V)
2 5.4
5591 G26
SSB NF (dB)
RF = 1950MHz VCC = VCCIF
18
GC (dB), IIP3 (dBm)
22
6
GC
4 2
–6
–4
2 –2 0 LO INPUT POWER (dBm)
6
4
0
Conversion Gain, IIP3 and RF Input P1dB vs Temperature
24
20
8
–40°C 25°C 85°C
5591 G24
Conversion Gain, IIP3 and NF vs IF Supply Voltage (Dual Supply)
24
18
12 10
5591 G23
5591 G22
20
6
4
NF
10
8
–6
18
14
8
GC
20 IIP3
16
6
4
GC (dB), IIP3 (dBm)
24
18
12
6
2.4
20
10
GC
2.3
5591 G21
GC (dB), IIP3 (dBm) P1dB (dBm)
GC (dB), IIP3 (dBm)
14
1.8 1.9 2 2.1 2.2 RF FREQUENCY (GHz)
2150MHz Conversion Gain, IIP3 and NF vs LO Power
IIP3
20
SSB NF (dB)
NF
1.6 1.7
SSB NF (dB)
24
16
30
2.4
SSB NF (dB)
20
18
–40°C 25°C 85°C 105°C
1950MHz Conversion Gain, IIP3 and NF vs LO Power
24 IIP3
40
5591 G20
5591 G19
20
45
35
GC (dB), IIP3 (dBm)
17
–40°C 25°C 85°C 105°C
SSB NF (dB)
11
19
GC (dB)
IIP3 (dBm)
IIP3
22
IIP3
20 RF = 1950MHz VCCIF = 5V VCCIF = 3.3V
18 16 14 12
P1dB
10 8
GC
6 –40 –25 –10 5 20 35 50 65 80 95 110 CASE TEMPERATURE (°C) 5591 G27
5591f
7
LTC5591 TYPICAL AC PERFORMANCE CHARACTERISTICS
High Side LO VCC = 3.3V, VCCIF = 3.3V, ENA = ENB = High, ISEL = Low, TC = 25°C, PLO = 0dBm, PRF = –3dBm (–3dBm/tone for two-tone IIP3 tests, ∆f = 2MHz), IF = 190MHz, unless otherwise noted. Test circuit shown in Figure 1. Conversion Gain and IIP3 vs RF Frequency
2-Tone IF Output Power, IM3 and IM5 vs RF Input Power
SSB NF vs RF Frequency 16
16
24
14
14
20
18
10
1.35
12
10
6 1.25
6 1.85
1.45 1.55 1.65 1.75 RF FREQUENCY (GHz)
–10 RF1 = 1599MHz RF2 = 1601MHz LO = 1790MHz
–20 –30 –40 –50
IM3
–60 –70
IM5
1.35
1.45 1.55 1.65 1.75 RF FREQUENCY (GHz)
–90 –12
1.85
0 –9 –6 0 –3 RF INPUT POWER (dBm/TONE)
3 5591 G30
5591 G29
1450MHz Conversion Gain, IIP3 and NF vs LO Power
1750MHz Conversion Gain, IIP3 and NF vs LO Power
1600MHz Conversion Gain, IIP3 and NF vs LO Power 20
26
20
26
20
18
24
18
24
18
16
22
14
20
20
8 –40°C 25°C 6 85°C 4
12 10 8 6
GC –6
–4
2 –2 0 LO INPUT POWER (dBm)
6
4
18
12
16
10
14
8 –40°C 25°C 6 85°C 4
NF
12 10
GC
8 6
26
23
24
NF
16 14 12
15
10
13
8 GC
9 7
3
RF = 1600MHz VCC = VCCIF
3.1 3.4 3.2 3.3 3.5 VCC, VCCIF SUPPLY VOLTAGE (V)
6 4 2 3.6
5591 G34
SSB NF (dB)
–40°C 25°C 85°C
GC (dB), IIP3 (dBm), P1dB (dBm)
20
2 –4
–6
2 –2 0 LO INPUT POWER (dBm)
6
4
0
Single-Tone IF Output Power, 2 × 2 and 3 × 3 Spurs vs RF Input Power 20 10
IIP3
22
0
20
RF = 1600MHz VCCIF = 5V VCCIF = 3.3V
18 16 14 12
P1dB
10 8
6 4
5591 G33
Conversion Gain, IIP3 and RF Input P1dB vs Temperature
IIP3
GC
5591 G32
18
11
6
4
–40°C 25°C 85°C
12
0
2 –2 0 LO INPUT POWER (dBm)
8
NF
10
2
25
17
14
6
Conversion Gain, IIP3 and NF vs Supply Voltage (Single Supply)
19
12 10
8 –4
16 14
18
0
–6
IIP3
16
2
5591 G31
21
20
OUTPUT POWER (dBm)
14
22
14
SSB NF (dB)
10
16
SSB NF (dB)
12
NF
SSB NF (dB)
18 16
IIP3
GC (dB), IIP3 (dBm)
IIP3
GC (dB), IIP3 (dBm)
26 24 22 GC (dB), IIP3 (dBm)
IFOUT
0
–80
5591 G28
GC (dB), IIP3 (dBm)
10
8
8
GC
16 1.25
SSB NF (dB)
12
–40°C 25°C 85°C 105°C
GC (dB)
IIP3 (dBm)
IIP3 22
20
–40°C 25°C 85°C 105°C
OUTPUT POWER TONE (dBm)
26
IFOUT (RF = 1600MHz)
–10
(LO = 1790MHz)
–20 –30 –40
2LO-2RF (RF = 1695MHz)
–50 –60 –70
GC
6 –40 –25 –10 5 20 35 50 65 80 95 110 CASE TEMPERATURE (°C) 5591 G35
–80 –12 –9
3LO-3RF (RF = 1726.67MHz) 6 9 –6 –3 0 3 RF INPUT POWER (dBm)
12
15
5591 G36
5591f
8
LTC5591 TYPICAL DC PERFORMANCE CHARACTERISTICS
ENA = ENB = High, test circuit shown in Figure 1.
ISEL = Low VCC Supply Current vs Supply Voltage (Mixer and LO Amplifier)
VCCIF Supply Current vs Supply Voltage (IF Amplifier)
192
Total Supply Current vs Temperature (VCC + VCCIF)
260
460 105°C
240 105°C
186 85°C 184 182
25°C
180 –40°C
3
3.1
220 25°C 200 180 –40°C 160
178 176
440 85°C
SUPPLY CURRENT (mA)
188
SUPPLY CURRENT (mA)
SUPPLY CURRENT (mA)
190
3.5 3.2 3.3 3.4 VCC SUPPLY VOLTAGE (V)
140
3.6
420
VCC = 3.3V, VCCIF = 5V (DUAL SUPPLY)
400 380 VCC = 3.3V, VCCIF = 3.3V (SINGLE SUPPLY)
360
3
3.3
3.6 3.9 4.2 4.5 4.8 5.1 VCCIF SUPPLY VOLTAGE (V)
5591 G37
340 –40 –25 –10 5 20 35 50 65 80 95 110 CASE TEMPERATURE (°C)
5.4
5591 G38
5591 G39
ISEL = High VCC Supply Current vs Supply Voltage (Mixer and LO Amplifier)
VCCIF Supply Current vs Supply Voltage (IF Amplifier)
Total Supply Current vs Temperature (VCC + VCCIF)
124
280 105°C
150 105°C 85°C
120
25°C
118
–40°C
85°C 130 25°C 110
116
114
SUPPLY CURRENT (mA)
SUPPLY CURRENT (mA)
SUPPLY CURRENT (mA)
122
260
VCC = 3.3V, VCCIF = 5V (DUAL SUPPLY)
240 VCC = VCCIF = 3.3V (SINGLE SUPPLY) 220
–40°C 90 3
3.1
3.4 3.5 3.2 3.3 VCC SUPPLY VOLTAGE (V)
3.6 5591 G40
3
3.3
3.6 3.9 4.2 4.5 4.8 VCCIF SUPPLY VOLTAGE (V)
5.1
5.4
5591 G41
200 –40 –20
60 80 0 20 40 CASE TEMPERATURE (°C)
100 5591 G42
5591f
9
LTC5591 PIN FUNCTIONS RFA, RFB (Pins 1, 6): Single-Ended RF Inputs for Channels A and B. These pins are internally connected to the primary sides of the RF input transformers, which have low DC resistance to ground. Series DC-blocking capacitors should be used to avoid damage to the integrated transformer when DC voltage is present at the RF inputs. The RF inputs are impedance matched when the LO input is driven with a 0±6dBm source between 1.4GHz and 2.1GHz and the channels are enabled. CTA, CTB (Pins 2, 5): RF Transformer Secondary CenterTap on Channels A and B. These pins may require bypass capacitors to ground to optimize IIP3 performance. Each pin has an internally generated bias voltage of 1.2V and must be DC-isolated from ground and VCC. GND (Pins 3, 4, 7, 13, 15, 24, Exposed Pad Pin 25): Ground. These pins must be soldered to the RF ground plane on the circuit board. The exposed pad metal of the package provides both electrical contact to ground and good thermal contact to the printed circuit board.
IFBB, IFBA (Pins 11, 20): Bias Adjust Pins for the IF Amplifiers. These pins allow independent adjustment of the internal IF buffer currents for channels B and A, respectively. The typical DC voltage on these pins is 2.2V. If not used, these pins must be DC isolated from ground and VCC. VCCB and VCCA (Pins 12, 19): Power Supply Pins for the LO Buffers and Bias Circuits. These pins must be connected to a regulated 3.3V supply with bypass capacitors located close to the pins. Typical current consumption is 91mA per pin. ENB, ENA (Pins 14, 17): Enable Pins. These pins allow Channels B and A, respectively, to be independently enabled. An applied voltage of greater than 2.5V activates the associated channel while a voltage of less than 0.3V disables the channel. Typical input current is less than 10μA. These pins must not be allowed to float.
IFGNDB, IFGNDA (Pins 8, 23): DC Ground Returns for the IF Amplifiers. These pins must be connected to ground to complete the DC current paths for the IF amplifiers. Chip inductors may be used to tune LO-IF and RF-IF leakage. Typical DC current is 100mA for each pin.
LO (Pin 16): Single-Ended Local Oscillator Input. This pin is internally connected to the primary side of the LO input transformer and has a low DC resistance to ground. Series DC-blocking capacitors should be used to avoid damage to the integrated transformer when DC voltage is present at the LO input. The LO input is internally matched to 50Ω for all states of ENA and ENB.
IFB+, IFB–, IFA–, IFA+ (Pins 9, 10, 21, 22): Open-Collector Differential Outputs for the IF Amplifiers of Channels B and A. These pins must be connected to a DC supply through impedance matching inductors, or transformer center-taps. Typical DC current consumption is 50mA into each pin.
ISEL (Pin 18): Low Current Select Pin. When this pin is pulled low (<0.3V), both mixer channels are biased at the normal current level for best RF performance. When greater than 2.5V is applied, both channels operate at reduced current, which provides reasonable performance at lower power consumption. This pin must not be allowed to float.
5591f
10
LTC5591 BLOCK DIAGRAM
24 GND
23 22 IFGNDA IFA+
21 IFA–
20 19 IFBA VCCA
IF AMP 1 2
BIAS
ISEL ENA
RFA LO AMP
CTA
LO
18 17
16
3 GND 4 GND CTB 5
6
GND 15 LO AMP
RFB
ENB IF AMP
14
BIAS GND 13
7
GND
IFB+
IFGNDB 8
9
IFB– 10
IFBB 11
VCCB 12
5591 BD
5591f
11
LTC5591 TEST CIRCUIT T1A 4:1
IFA 50Ω C7A
L1A VCCIF 3.3V TO 5V
RF
0.015”
L2A
GND
DC1710A EVALUATION BOARD BIAS STACK-UP GND (NELCO N4000-13)
0.062” C6
VCC 3.3V
C5A
24 C1A RFA 50Ω
23
GND IFGNDA
C3A
22
21
20
19
IFA+
IFA–
IFBA
VCCA
1 RFA
0.015”
C4
ISEL 18
ISEL (0V/3.3V)
ENA 17
ENA (0V/3.3V)
LTC5591 2 CTA C8A
C2 3 GND
LO 50Ω
LO 16 25 GND
C8B RFB 50Ω
4 GND
GND 15
5 CTB
ENB 14
ENB (0V/3.3V)
C1B 6 RFB
GND 13
GND IFGNDB 7
8
IFB+
IFB
9
10
–
IFBB
VCCB
11
12 5591 TC01
C3B C5B L2B
L1B
C7B
4:1 T1B
L1, L2 vs IF FREQUENCIES
IFB 50Ω
REF DES
VALUE
SIZE
VENDOR
2.7pF
0402
AVX
IF (MHz)
L1, L2 (nH)
140
270
C1A, C1B, C8A, C8B
190
150
C2
4.7pF
0402
AVX
240
100
22pF
0402
AVX
300
56
C3A, C3B C5A, C5B
380
33
C4, C6
1µF
0603
AVX
C7A, C7B
1000pF
0402
AVX
L1, L2
150nH
0603
Coilcraft
T1A, T1B
TC1-1W-7ALN+
Mini-Circuits
Figure 1. Standard Test Circuit Schematic (190MHz IF)
5591f
12
LTC5591 APPLICATIONS INFORMATION Introduction The LTC5591 consists of two identical mixer channels driven by a common LO input signal. Each high linearity mixer consists of a passive double-balanced mixer core, IF buffer amplifier, LO buffer amplifier and bias/enable circuits. See the Pin Functions and Block Diagram sections for a description of each pin. Each of the mixers can be shutdown independently to reduce power consumption and low current mode can be selected that allows a trade-off between performance and power consumption. The RF and LO inputs are single-ended and are internally matched to 50Ω. Low side or high side LO injection can be used. The IF outputs are differential. The evaluation circuit, shown in Figure 1, utilizes bandpass IF output matching and an IF transformer to realize a 50Ω single-ended IF output. The evaluation board layout is shown in Figure 2.
if the source has DC voltage present, since the primary side of the RF transformer is internally DC-grounded. The DC resistance of the primary is approximately 3.6Ω. The secondary winding of the RF transformer is internally connected to the channel A passive mixer core. The center-tap of the transformer secondary is connected to Pin 2 (CTA) to allow the connection of bypass capacitor, C8A. The value of C8A can be adjusted to improve the channel-to-channel isolation at specific RF operation frequency with minor impact to conversion gain, linearity and noise performance. The channel-to-channel isolation performance with different values of C8A is given in Figure 4. When used, it should be located within 2mm of Pin 2 for proper high frequency decoupling. The nominal DC voltage on the CTA pin is 1.2V. LTC5591
RFA
TO CHANNEL A MIXER
C1A 1
2
RFA
CTA
C8A
5591 F03
Figure 3. Channel A RF Input Schematic
5591 F02
Figure 2. Evaluation Board Layout
RF Inputs The RF inputs of channels A and B are identical. The RF input of channel A, shown in Figure 3, is connected to the primary winding of an integrated transformer. A 50Ω match is realized when a series external capacitor, C1A, is connected to the RF input. C1A is also needed for DC blocking
CHANNEL ISOLATION (dB)
55
50
45
40
35
30 1250 1450
C8 OPEN C8 = 2.2pF C8 = 2.7pF C8 = 3.3pF 1650 1850 2050 2250 RF FREQUENCY (MHz)
2450
5591 F04
Figure 4. Channel-to-Channel Isolation vs C8 Values 5591f
13
LTC5591 APPLICATIONS INFORMATION For the RF inputs to be properly matched, the appropriate LO signal must be applied to the LO input. A broadband input match is realized with C1A = 2.2pF. The measured input return loss is shown in Figure 4 for LO frequencies of 1.4GHz, 1.75GHz and 2GHz. These LO frequencies correspond to lower, middle and upper values in the LO range. As shown in Figure 5, the RF input impedance is dependent on LO frequency, although a single value of C1A is adequate to cover the 1.3GHz to 2.3GHz RF band.
LO Input The LO input, shown in Figure 6, is connected to the primary winding of an integrated transformer. A 50Ω impedance match is realized at the LO port by adding an external series capacitor, C2. This capacitor is also needed for DC blocking if the LO source has DC voltage present, since the primary side of the LO transformer is DC-grounded internally. The DC resistance of the primary is approximately 4.1Ω.
0
RF PORT RETURN LOSS (dB)
LTC5591 10
ISEL BIAS
18
20
ENA 30
C2
40
LO TO MIXER B
LO = 1.4GHz LO = 1.75GHz LO = 2GHz
50 60
17
TO MIXER A
1 1.2 1.4 1.6 1.8 2 2.2 2.4 2.6 2.8 RF FREQUENCY (GHz)
ENB
3
BIAS
LO
16
14
5591 F05
5591 F06
Figure 5. RF Port Return Loss
Figure 6. LO Input Schematic
The RF input impedance and input reflection coefficient, versus RF frequency, are listed in Table 1. The reference plane for this data is pin 1 of the IC, with no external matching, and the LO is driven at 1.75GHz. Table 1. RF Input Impedance and S11 (at Pin 1, No External Matching, fLO = 1.75GHz) S11
FREQUENCY (GHz)
RF INPUT IMPEDANCE
MAG
ANGLE
1.0
25.3 + j34.6
0.51
100.8
1.2
33.7 + j38.7
0.46
88.1
1.4
43.8 + j38.6
0.39
76.8
1.6
56.0 + j33.5
0.31
62.3
1.8
48.1 + j9.1
0.09
96.4
2.0
38.5 + j21.4
0.27
104.6
2.2
40.1 + j28.3
0.32
91.8
2.4
44.0 + j34.7
0.35
79.6
2.6
52.1 + j40.7
0.37
65.3
2.8
64.1 + j44.1
0.38
51.2
3.0
78.8 + j42.0
0.38
37.5
The secondary of the transformer drives a pair of high speed limiting differential amplifiers for channels A and B. The LTC5591’s LO amplifiers are optimized for the 1.4GHz to 2.1GHz LO frequency range; however, LO frequencies outside this frequency range may be used with degraded performance. The LO port is always 50Ω matched when VCC is applied, even when one or both of the channels is disabled. This helps to reduce frequency pulling of the LO source when
5591f
14
LTC5591 APPLICATIONS INFORMATION
LO1 PORT RETURN LOSS (dB)
the mixer is switched between different operating states. Figure 7 illustrates the LO port return loss for the different operating modes. 0 2 4 6 BOTH CHANNELS OFF 8 10 12 14 16 18 20 22 24 26 ONE 28 BOTH CHANNELS ON CHANNEL ON 30 0.8 1 1.2 1.4 1.6 1.8 2 2.2 2.4 2.6 2.8 LO FREQUENCY (GHz)
return pin (IFGNDA), and a pin for adjusting the internal bias (IFBA). The IF outputs must be biased at the supply voltage (VCCIFA), which is applied through matching inductors L1A and L2A. Alternatively, the IF outputs can be biased through the center tap of a transformer (T1A). The common node of L1A and L2A can be connected to the center tap of the transformer. Each IF output pin draws approximately 50mA of DC supply current (100mA total). An external load resistor, R2A, can be used to improve impedance matching if desired. IFGNDA (Pin 23) must be grounded or the amplifier will not draw DC current. Inductor L3A may improve LO-IF and RF-IF leakage performance in some applications, but is otherwise not necessary. Inductors should have small resistance for DC. High DC resistance in L3A will reduce the IF amplifier supply current, which will degrade RF performance.
5591 F07
Figure 7. LO Input Return Loss
The nominal LO input level is 0dBm, though the limiting amplifiers will deliver excellent performance over a ±6dBm input power range. Table 2 lists the LO input impedance and input reflection coefficient versus frequency.
T1A C7A L1A L3A (OR SHORT) 100mA
Table 2. LO Input Impedance vs Frequency (at Pin 16, No External Matching, ENA = ENB = High) S11
FREQUENCY (GHz)
INPUT IMPEDANCE
MAG
ANGLE
1.0
39.4 + j46.4
0.47
75.5
23
1.2
55.3 + j40.8
0.36
61.4
1.4
61.9 + j26.8
0.25
52.6
1.6
56.5 + j16.1
0.16
59.5
1.8
47.6 + j14.0
0.14
91.6
2.0
41.6 + j18.0
0.21
103.9
2.2
38.4 + j23.5
0.29
101.5
2.4
37.1 + j30.7
0.36
93.3
2.6
38.4 + j38.3
0.42
83.3
2.8
42.0 + j47.6
0.47
72.2
3.0
48.6 + j56.1
0.49
61.8
IF Outputs The IF amplifiers in channels A and B are identical. The IF amplifier for channel A, shown in Figure 8, has differential open collector outputs (IFA+ and IFA–), a DC ground
IFA 4:1
IGNDA
L2A R1A (OPTION TO REDUCE DC POWER)
VCCIFA C5A
22 IFA+
R2A LTC5591
21 20 IFBA IFA–
VCCA IF AMP 4mA BIAS
Figure 8. IF Amplifier Schematic with Bandpass Match
For optimum single-ended performance, the differential IF output must be combined through an external IF transformer or a discrete IF balun circuit. The evaluation board (see Figures 1 and 2) uses a 4:1 IF transformer for impedance transformation and differential to single-ended conversion. It is also possible to eliminate the IF transformer and drive differential filters or amplifiers directly. 5591f
15
LTC5591 APPLICATIONS INFORMATION
22
21
IFA+
IF A–
LTC5591 0.9nH
0.9nH RIF
Values of L1A and L2A are tabulated in Figure 1 for various IF frequencies. The measured IF output return loss for bandpass IF matching is plotted in Figure 10. 0 L1, L2 = 270nH 5 IF PORT RETURN LOSS (dB)
At IF frequencies, the IF output impedance can be modeled as 300Ω in parallel with 2.3pF. The equivalent small-signal model, including bondwire inductance, is shown in Figure 9. Frequency-dependent differential IF output impedance is listed in Table 3. This data is referenced to the package pins (with no external components) and includes the effects of IC and package parasitics.
10 15 L1, L2 = 150nH 20
L1, L2 = 100nH
25
CIF
L1, L2 = 56nH 30 50
100 150 200 250 300 350 400 450 IF FREQUENCY (MHz)
5591 F09
Figure 9. IF Output Small-Signal Model
5591 F10
Figure 10. IF Output Return Loss with Bandpass Matching
Lowpass IF Matching Bandpass IF Matching The bandpass IF matching configuration, shown in Figures 1 and 8, is best suited for IF frequencies in the 90MHz to 500MHz range. Resistor R2A may be used to reduce the IF output resistance for greater bandwidth and inductors L1A and L2A resonate with the internal IF output capacitance at the desired IF frequency. The value of L1A, L2A can be estimated as follows: L1A = L2A =
1 (2πfIF )
2•2•C
IF
For IF frequencies below 90MHz, the inductance values become unreasonably high and the lowpass topology shown in Figure 11 is preferred. This topology also can provide improved RF to IF and LO to IF isolation. VCCIFA is supplied through the center tap of the 4:1 transformer. A lowpass impedance transformation is realized by shunt elements R2A and C9A (in parallel with the internal RIF and CIF), and series inductors L1A and L2A. Resistor R2A is used to reduce the IF output resistance for greater bandwidth, or it can be deleted for the highest conversion gain. The final impedance transformation to 50Ω is realized by transformer T1A. The measured IF output return loss for
where CIF is the internal IF capacitance (listed in Table 3). Table 3. IF Output Impedance vs Frequency FREQUENCY (MHz)
DIFFERENTIAL OUTPUT IMPEDANCE (RIF || XIF (CIF))
90
321 || –j769 (2.3pF)
140
307 || –j494 (2.3pF)
190
300 || –j364 (2.3pF)
240
292 || –j286 (2.3pF)
300
285 || –j225 (2.4pF)
380
276 || –j177 (2.4pF)
500
264 || –j122 (2.6pF)
T1A
VCCIFA 3.1 TO 5.3V
IFA 50Ω
4:1 C6
C5A L1A
L2A R2A C9A
22
IFA+
21 LTC5591
IFA–
5591 F11
Figure 11. IF Output with Lowpass Matching 5591f
16
LTC5591 APPLICATIONS INFORMATION lowpass IF matching with R2A and C9A open is plotted in Figure 12. The LTC5591 demo board (see Figure 2) has been laid out to accommodate this matching topology with only minor modifications. L1, L2 = 180nH IF PORT RETURN LOSS (dB)
VCCIF (V) 3.3
0 5
Table 4. Performance Comparison with VCCIF = 3.3V and 5V (RF = 1950MHz, Low Side LO, IF = 190MHz, ENA = ENB = High)
5
R2A (Ω)
ICCIF (mA)
GC (dB)
P1dB (dBm)
IIP3 (dBm)
NF (dB)
Open
200
8.5
10.7
26.2
9.9
1k
200
7.4
11.5
26.5
9.9
Open
207
8.4
13.9
26.7
10.1
L1, L2 = 56nH
10 15 20 25 L1, L2 = 100nH 30 35 50
90
130 170 210 IF FREQUENCY (MHz)
250 5591 F12
Figure 12. IF Output Return Loss with Lowpass Matching
IF Amplifier Bias The IF amplifier delivers excellent performance with VCCIF = 3.3V, which allows a single supply to be used for VCC and VCCIF . At VCCIF = 3.3V, the RF input P1dB of the mixer is limited by the output voltage swing. For higher P1dB, in this case, resistor R2A (Figure 7) can be used to reduce the output impedance and thus the voltage swing, thus improving P1dB. The trade-off for improved P1dB will be lower conversion gain. With VCCIF increased to 5V the P1dB increases by over 3dB, at the expense of higher power consumption. Mixer P1dB performance at 1950MHz is tabulated in Table 4 for VCCIF values of 3.3V and 5V. For the highest conversion gain, high-Q wire-wound chip inductors are recommended for L1A and L2A, especially when using VCCIF = 3.3V. Low cost multilayer chip inductors may be substituted, with a slight reduction in conversion gain.
The IFBA pin (Pin 20) is available for reducing the DC current consumption of the IF amplifier, at the expense of IIP3. The nominal DC voltage at Pin 20 is 2.1V, and this pin should be left open-circuited for optimum performance. The internal bias circuit produces a 4mA reference for the IF amplifier, which causes the amplifier to draw approximately 100mA. If resistor R1A is connected to Pin 20 as shown in Figure 8, a portion of the reference current can be shunted to ground, resulting in reduced IF amplifier current. For example, R1A = 470Ω will shunt away 1.4mA from Pin 20 and the IF amplifier current will be reduced by 35% to approximately 65mA. Table 5 summarizes RF performance versus total IF amplifier current when both channels are enabled. Table 5. Mixer Performance with Reduced IF Amplifier Current RF = 1950MHz, Low Side LO, IF = 190MHz, VCC = VCCIF = 3.3V R1A, R1B
ICCIF (mA)
GC (dB)
IIP3 (dBm)
P1dB (dBm)
NF (dB)
Open
200
8.5
26.2
10.7
9.9
3.3kΩ
176
8.4
25.7
10.8
9.9
1.0kΩ
151
8.1
24.7
10.9
9.9
470Ω
130
7.9
23.7
10.9
9.9
RF = 1600MHz, High Side LO, IF = 190MHz, VCC = VCCIF = 3.3V R1A, R1B
ICCIF (mA)
GC (dB)
IIP3 (dBm)
P1dB (dBm)
NF (dB)
Open
200
8.6
24.6
10.2
10.2
3.3kΩ
176
8.4
24.3
10.4
10.3
1.0kΩ
151
8.1
23.5
10.6
10.3
470Ω
130
7.9
22.7
10.5
10.3
5591f
17
LTC5591 APPLICATIONS INFORMATION Low Current Mode
LTC5591
Both mixer channels can be set to low current mode using the ISEL pin. This allows flexibility to choose a reduced current mode of operation when lower RF performance is acceptable. Figure 13 shows a simplified schematic of the ISEL pin interface. When ISEL is set low (<0.3V), both channels operate at nominal DC current. When ISEL is set high (>2.5V), the DC currents in both channels are reduced, thus reducing power consumption. The performance in low power mode and normal power mode are compared in Table 6.
VCCA 19
ISEL
19 CLAMP ENA
500Ω
17
5591 F14
Figure 14. ENA Interface Schematic
The Enable pins must be pulled high or low. If left floating, the on/off state of the IC will be indeterminate. If a three-state condition can exist at the enable pins, then a pull-up or pull-down resistor must be used.
LTC5591
Supply Voltage Ramping
500Ω
18
VCCA
BIAS A
Fast ramping of the supply voltage can cause a current glitch in the internal ESD protection circuits. Depending on the supply inductance, this could result in a supply voltage transient that exceeds the maximum rating. A supply voltage ramp time of greater than 1ms is recommended.
VCCB BIAS B
5591 F13
Figure 13. ISEL Interface Schematic
Spurious Output Levels
Table 6. Performance Comparison Between Different Power Modes RF = 1950MHz, Low Side LO, IF = 190MHz, ENA = ENB = High ISEL
ITOTAL (mA)
GC (dB)
IIP3 (dBm)
P1dB (dBm)
NF (dB)
Low
382
8.5
26.2
10.7
9.9
High
239
7.2
21.4
10.7
10.3
Enable Interface Figure 14 shows a simplified schematic of the ENA pin interface (ENB is identical). To enable channel A, the ENA voltage must be greater than 2.5V. If the enable function is not required, the enable pin can be connected directly to VCC. The voltage at the enable pin should never exceed the power supply voltage (VCC) by more than 0.3V. If this should occur, the supply current could be sourced through the ESD diode, potentially damaging the IC.
Mixer spurious output levels versus harmonics of the RF and LO are tabulated in Table 7. The spur levels were measured on a standard evalution board using the test circuit shown in Figure 1. The spur frequencies can be calculated using the following equation: fSPUR = (M • fRF)–(N • fLO) Table 7. IF Output Spur Levels (dBc) RF = 1950MHz, PRF = –3dBm, PLO = 0dBm, PIF 190MHz, Low Side LO, VCC = 3.3V, VCCIF = 3.3V, ENA = ENB = High, ISEL = Low, TC = 25°C N 0 1 2 3 4 5 6 7 8 9 0 –41 –54 –64 –84 –66 –74 –75 –81 –84 1 –49 0 –56 –42 –68 –77 –75 –70 * –92 2 –82 –83 –70 –77 * * * * * * M * * * * * 3 * –88 * –71 * 4 * * * * * * * * * * 5 * * * * * * * * * * 6 * * * * * * * * * 7 * * * * * * –84 * *Less than –100dBc 5591f
18
LTC5591 PACKAGE DESCRIPTION UH Package 24-Lead Plastic QFN (5mm × 5mm)
× Rev A) (Reference LTC DWG # 05-08-1747
0.75 ±0.05
5.40 ±0.05 3.90 ±0.05
3.20 ± 0.05
3.25 REF 3.20 ± 0.05
PACKAGE OUTLINE
0.30 ± 0.05 0.65 BSC RECOMMENDED SOLDER PAD LAYOUT APPLY SOLDER MASK TO AREAS THAT ARE NOT SOLDERED 5.00 ± 0.10
R = 0.05 TYP
0.75 ± 0.05
BOTTOM VIEW—EXPOSED PAD R = 0.150 TYP
23
0.00 – 0.05
PIN 1 NOTCH R = 0.30 TYP OR 0.35 × 45° CHAMFER
24 0.55 ± 0.10
PIN 1 TOP MARK (NOTE 6)
1 2
5.00 ± 0.10
3.20 ± 0.10 3.25 REF
3.20 ± 0.10
(UH24) QFN 0708 REV A
0.200 REF 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
0.30 ± 0.05 0.65 BSC
5591f
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.
19
LTC5591 TYPICAL APPLICATION Lowpass IF Matching, Low Side LO, VCC = 3.3V, VCCIF = 3.3V, ENA = ENB = High, ISEL = Low, TC = 25°C, PLO = 0dBm, PRF = –3dBm (–3dBm/Tone for Two-Tone IIP3 Tests, ∆f = 2MHz), IF = 190MHz
T1A 4:1
Conversion Gain, IIP3 and SSB NF vs RF Frequency
IFA 50Ω
VCCIF 3.3V TO 5V
28 56nH
56nH VCC 3.3V
2.7pF RFA 50Ω
23
22
GND IFGNDA IFA+
22pF
21
20
19
IFA–
IFBA
VCCA
1 RFA
ISEL
ISEL 18
1µF
TO CHANNEL B
15 IIP3
24
13
20
12
18
10
14
9
12
8
2.7pF
LTC5591 CHANNEL A 3 GND
4.7pF LO 16
7
GC
8
ENA
ENA 17
11
NF
16
10 2 CTA
14
22
LO 50Ω
6 1.6
SSB NF (dB)
TO CHANNEL B 24
16
26
GC (dB), IIP3 (dBm)
22pF
1µF
6 1.7
1.8 1.9 2.0 2.1 2.2 RF FREQUENCY (GHz)
2.3
5 2.4
5591 TA02b
4 GND
GND 15 CHANNEL B NOT SHOWN
5591 TA02a
RELATED PARTS PART NUMBER DESCRIPTION COMMENTS Infrastructure LT5527 400MHz to 3.7GHz, 5V Downconverting Mixer 2.3dB Gain, 23.5dBm IIP3 and 12.5dB NF at 1900MHz, 5V/78mA Supply LT5557 400MHz to 3.8GHz, 3.3V Downconverting Mixer 2.9dB Gain, 24.7dBm IIP3 and 11.7dB NF at 1950MHz, 3.3V/82mA Supply LTC6416 2GHz 16-Bit ADC Buffer 40.25dBm OIP3 to 300MHz, Programmable Fast Recovery Output Clamping LTC6412 31dB Linear Analog VGA 35dBm OIP3 at 240MHz, Continuous Gain Range –14dB to 17dB LTC5540/LTC5541/ 600MHz to 4GHz Downconverting Mixer Family 8dB Gain, >25dBm IIP3, 10dB NF, 3.3V/200mA Supply LTC5542/LTC5543 LT5554 Ultralow Distort IF Digital VGA 48dBm OIP3 at 200MHz, 2dB to 18dB Gain Range, 0.125dB Gain Steps LT5578 400MHz to 2.7GHz Upconverting Mixer 27dBm OIP3 at 900MHz, 24.2dBm at 1.95GHz, Integrated RF Transformer LT5579 1.5GHz to 3.8GHz Upconverting Mixer 27.3dBm OIP3 at 2.14GHz, NF = 9.9dB, 3.3V Supply, Single-Ended LO and RF Ports RF Power Detectors LT5534 50MHz to 3GHz Log RF Power Detector with ±1dB Output Variation over Temperature, 38ns Response Time, Log Linear 60dB Dynamic Range Response LT5581 6GHz Low Power RMS Detector 40dB Dynamic Range, ±1dB Accuracy Over Temperature, 1.5mA Supply Current LTC5583 Dual 6GHz RMS Power Detector Measures 40MHz to 6GHz, Up to 60dB Dynamic Range, >40dB Channel-to-Channel VSWR Isolation, Difference Output for VSWR Measurement ADCs LTC2285 14-Bit, 125Msps Dual ADC 72.4dB SNR, >88dB SFDR, 790mW Power Consumption LTC2185 16-Bit, 125Msps Dual ADC Ultralow Power 76.8dB SNR, 185mW/Channel Power Consumption LTC2242-12 12-Bit, 250Msps ADC 65.4dB SNR, 78dB SFDR, 740mW Power Consumption 5591f
20 Linear Technology Corporation
LT 0311 • PRINTED IN USA
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900 ● FAX: (408) 434-0507
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LINEAR TECHNOLOGY CORPORATION 2011
