FEATURES
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LTC5585
Wideband IQ Demodulator
with IIP2 and DC Offset
Control
DESCRIPTION
The
LTC
®
5585
is a direct conversion quadrature demodu-
lator optimized for high linearity receiver applications in
the 400MHz to 4GHz frequency range. It is suitable for
communications receivers where an RF signal is directly
converted into I and Q baseband signals with bandwidth
of 530MHz or higher. The LTC5585 incorporates balanced
I and Q mixers, LO buffer amplifiers and a precision, high
frequency quadrature phase shifter. The integrated on-chip
broadband transformer provides a single-ended interface
at the RF input with simple off-chip L-C matching. In ad-
dition, the LTC5585 provides four analog control voltage
interface pins for IIP2 and DC offset correction, greatly
simplifying system calibration.
The high linearity of the LTC5585 provides excellent spur-
free dynamic range for the receiver. This direct conversion
demodulator can eliminate the need for intermediate fre-
quency (IF) signal processing, as well as the corresponding
requirements for image filtering and IF filtering. These
I/Q outputs can interface directly to channel-select filters
(LPFs) or to baseband amplifiers.
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.
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400MHz to 4GHz Operating Frequency
High IIP3: 28.7dBm at 700MHz, 25.7dBm at 1.95GHz
High IIP2: 70dBm at 700MHz, 60dBm at 1.95GHz
User Adjustable IIP2 Up to 80dBm
User Adjustable DC Offset Null
High Input P1dB: 16dBm at 1950MHz
I/Q Bandwidth of 530MHz or Higher
Image Rejection: 43dB at 1950MHz
Noise Figure: 13.5dB at 700MHz
12.7dB at 1.95GHz
Conversion Gain: 2.0dB at 700MHz
2.4dB at 1.95GHz
Single-Ended RF with On-Chip Transformer
Shutdown Mode
Operating Temperature Range (T
C
): –40°C to 105°C
24-Lead 4mm
×
4mm QFN Package
APPLICATIONS
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LTE/W-CDMA/TD-SCDMA Base Station Receivers
Wideband DPD Receivers
Point-To-Point Broadband Radios
High Linearity Direct Conversion I/Q Receivers
Image Rejection Receivers
TYPICAL APPLICATION
Direct Conversion Receiver with IIP2 and DC Offset Calibration
5V
BPF
LNA
BPF
RF
INPUT RF
V
CC
I
+
I
–
LPF
VGA
A/D
IIP2 vs IP2I, IP2Q Trim Voltage
120
110
100
I, –40°C
I, 25°C
I, 85°C
I, 105°C
Q, –40°C
Q, 25°C
Q, 85°C
Q, 105°C
f
RF
= 700MHz
IP2 AND DC
OFFSET CAL
LO
0°
90°
LTC5585
IP2 ADJUST
DC OFFSET
D/A
D/A
IIP2 (dBm)
90
80
70
60
LO INPUT
IP2 AND DC
OFFSET CAL
DC OFFSET
IP2 ADJUST
D/A
D/A
Q
+
Q
–
LPF
VGA
A/D
5585 TA01a
50
40
0
0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0
IP2I, IP2Q (V)
5585 G09
ENABLE
EN
5585fb
For more information
www.linear.com/LTC5585
1
LTC5585
ABSOLUTE MAXIMUM RATINGS
(Note 1)
PIN CONFIGURATION
TOP VIEW
24 23 22 21 20 19
IP2Q 1
DCOQ 2
DCOI 3
IP2I 4
RF 5
GND 6
7
EN
8
GND
9 10 11 12
V
BIAS
EDC
EIP2
V
CC
25
GND
18 CMQ
17 V
CAP
16 LO
–
15 LO
+
14 GND
13 GND
CMI
REF
Q
+
Q
–
I
+
I
–
V
CC
Supply Voltage ................................... –0.3V to 5.5V
V
CAP
Voltage .................................................V
CC
±0.05V
I
–
, I
+
, Q
+
, Q
–
, CMI, CMQ Voltage ........2.5V to V
CC
+ 0.3V
Voltage on Any Other Pin .................–0.3V to V
CC
+ 0.3V
LO
+
, LO
–
, RF Input Power ....................................20dBm
RF Input DC Voltage ............................................... ±0.1V
Maximum Junction Temperature (T
JMAX
) ............. 150°C
Operating Temperature Range (T
C
) ........ –40°C to 105°C
Storage Temperature Range .................. –65°C to 150°C
UF PACKAGE
24-LEAD (4mm
×
4mm) PLASTIC QFN
T
JMAX
= 150°C,
θ
JC
= 7°C/W
EXPOSED PAD (PIN 25) IS GND, MUST BE SOLDERED TO PCB
ORDER INFORMATION
LEAD FREE FINISH
LTC5585IUF#PBF
TAPE AND REEL
LTC5585IUF#TRPBF
PART MARKING
5585
PACKAGE DESCRIPTION
24-Lead (4mm x 4mm) Plastic QFN
TEMPERATURE RANGE
–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/
ELECTRICAL CHARACTERISTICS
SYMBOL
f
RF(RANGE)
f
LO(RANGE)
P
LO(RANGE)
f
RF(MATCH)
f
LO(MATCH)
G
V
NF
NF
BLOCKING
IIP3
IIP2
IIP2
OPT
P1dB
PARAMETER
RF Input Frequency Range
LO Input Frequency Range
LO Input Power Range
RF Input Frequency Range
LO Input Frequency Range
Voltage Conversion Gain
Noise Figure
Noise Figure Under Blocking Conditions
Input 3rd Order Intercept
Input 2nd Order Intercept
Optimized Input 2nd Order Intercept
Input 1dB Compression
T
C
= 25°C, V
CC
= 5V, EN = 5V, EDC = EIP2 = 0V, REF = IP2I = IP2Q = DCOI =
DCOQ = 0.5V, P
RF
= –5dBm (–5dBm/tone for 2-tone IIP2 and IIP3 tests), P
LO
= 6dBm, unless otherwise noted. (Notes 2, 3, 5, 6, 9)
CONDITIONS
(Note 12)
(Note 12)
(Note 12)
Return Loss > 10dB
Return Loss > 10dB
Loaded with 100Ω Pull-Up (Note 8)
Double-Side Band (Note 4)
Double-Side Band, P
RF
= 0dBm (Note 7)
Unadjusted, EIP2 = 0V
EIP2 = 5V, IP2I, IP2Q Adjusted for Minimum IM2
MIN
TYP
0.4 to 4.0
0.4 to 4.0
0 to 10
680 to 870
690 to 820
2.0
13.5
15.5
28.7
70
80
16
MAX
UNITS
GHz
GHz
dBm
MHz
MHz
dB
dB
dB
dBm
dBm
dBm
dBm
5585fb
f
RF1
= 700MHz, f
RF2
= 701MHz, f
LO
= 690MHz, L6 = 2.7pF, C19 = 1.0pF, L5 = 12nH, C14 = 5.6pF
2
For more information
www.linear.com/LTC5585
LTC5585
ELECTRICAL CHARACTERISTICS
SYMBOL
DC
OFFSET
∆G
∆φ
IRR
LO-RF
RF-LO
f
RF(MATCH)
f
LO(MATCH)
G
V
NF
IIP3
IIP2
IIP2
OPT
P1dB
DC
OFFSET
∆G
∆φ
IRR
LO-RF
RF-LO
f
RF(MATCH)
f
LO(MATCH)
G
V
NF
NF
BLOCKING
IIP3
IIP2
IIP2
OPT
P1dB
DC
OFFSET
∆G
∆φ
IRR
LO-RF
RF-LO
f
RF(MATCH)
f
LO(MATCH)
G
V
PARAMETER
DC Offset at I/Q Outputs
I/Q Gain Mismatch
I/Q Phase Mismatch
Image Rejection Ratio
LO to RF Leakage
RF to LO Isolation
RF Input Frequency Range
LO Input Frequency Range
Voltage Conversion Gain
Noise Figure
Input 3rd Order Intercept
Input 2nd Order Intercept
Optimized Input 2nd Order Intercept
Input 1dB Compression
DC Offset at I/Q Outputs
I/Q Gain Mismatch
I/Q Phase Mismatch
Image Rejection Ratio
LO to RF Leakage
RF to LO Isolation
RF Input Frequency Range
LO Input Frequency Range
Voltage Conversion Gain
Noise Figure
Noise Figure Under Blocking Conditions
Input 3rd Order Intercept
Input 2nd Order Intercept
Optimized Input 2nd Order Intercept
Input 1dB Compression
DC Offset at I/Q Outputs
I/Q Gain Mismatch
I/Q Phase Mismatch
Image Rejection Ratio
LO to RF Leakage
RF to LO Isolation
RF Input Frequency Range
LO Input Frequency Range
Voltage Conversion Gain
Return Loss > 10dB
Return Loss > 10dB
Loaded with 100Ω Pull-Up (Note 8)
(Note 10)
Unadjusted, EDC = 0V (Note 13)
Unadjusted, EIP2 = 0V
EIP2 = 5V, IP2I, IP2Q Adjusted for Minimum IM2
Return Loss > 10dB
Return Loss > 10dB
Loaded with 100Ω Pull-Up (Note 8)
Double-Side Band (Note 4)
Double-Side Band, P
RF
= 0dBm (Note 7)
(Note 10)
Unadjusted, EDC = 0V (Note 13)
Unadjusted, EIP2 = 0V
EIP2 = 5V, IP2I, IP2Q Adjusted for Minimum IM2
Return Loss > 10dB
Return Loss > 10dB
Loaded with 100Ω Pull-Up (Note 8)
Double-Side Band (Note 4)
(Note 10)
T
C
= 25°C, V
CC
= 5V, EN = 5V, EDC = EIP2 = 0V, REF = IP2I = IP2Q = DCOI =
DCOQ = 0.5V, P
RF
= –5dBm (–5dBm/tone for 2-tone IIP2 and IIP3 tests), P
LO
= 6dBm, unless otherwise noted. (Notes 2, 3, 5, 6, 9)
CONDITIONS
Unadjusted, EDC = 0V (Note 13)
MIN
TYP
4
0.05
0.3
48
–64
60
1.6 to 2.1
1.85 to 2.05
2.4
12.7
25.7
60
80
16
7
0.05
0.7
43
–49
58
2.03 to 2.36
2.05 to 2.18
2.3
13.0
14.6
25.9
56
80
15
6
0.05
1.0
40
–50
60
2.35 to 3.1
2.47 to 2.65
2.3
MAX
UNITS
mV
dB
Deg
dB
dBm
dB
GHz
GHz
dB
dB
dBm
dBm
dBm
dBm
mV
dB
Deg
dB
dBm
dB
GHz
GHz
dB
dB
dB
dBm
dBm
dBm
dBm
mV
dB
Deg
dB
dBm
dB
GHz
GHz
dB
5585fb
f
RF1
= 1950MHz, f
RF2
= 1951MHz, f
LO
= 1940MHz, L6 = 1.2pF, C19 = 5.1nH, L5 = 1.0pF, C13 = 5.1nH
f
RF1
= 2150MHz, f
RF2
= 2151MHz, f
LO
= 2140MHz, C17 = 1.5pF, L6 = 4.7nH, C19 = 0.5pF, L5 = 5.1nH, C14 = 0.7pF
f
RF1
= 2600MHz, f
RF2
= 2601MHz, f
LO
= 2590MHz, C17 = 0.5pF, L6 = 2.7nH, L5 = 1.2nH, C14 = 1pF
For more information
www.linear.com/LTC5585
3
LTC5585
ELECTRICAL CHARACTERISTICS
SYMBOL
NF
NF
BLOCKING
IIP3
IIP2
IIP2
OPT
P1dB
DC
OFFSET
∆G
∆φ
IRR
LO-RF
RF-LO
f
RF(MATCH)
f
LO(MATCH)
G
V
NF
IIP3
IIP2
IIP2
OPT
P1dB
DC
OFFSET
∆G
∆φ
IRR
LO-RF
RF-LO
V
CC
I
CC
I
CC(LOW)
I
CC(OFF)
t
ON
t
OFF
V
EH
V
EL
I
ENH
I
EDCH
PARAMETER
Noise Figure
Noise Figure Under Blocking Conditions
Input 3rd Order Intercept
Input 2nd Order Intercept
Minimum Input 2nd Order Intercept
Input 1dB Compression
DC Offset at I/Q Outputs
I/Q Gain Mismatch
I/Q Phase Mismatch
Image Rejection Ratio
LO to RF Leakage
RF to LO Isolation
RF Input Frequency Range
LO Input Frequency Range
Voltage Conversion Gain
Noise Figure
Input 3rd Order Intercept
Input 2nd Order Intercept
Minimum Input 2nd Order Intercept
Input 1dB Compression
DC Offset at I/Q Outputs
I/Q Gain Mismatch
I/Q Phase Mismatch
Image Rejection Ratio
LO to RF Leakage
RF to LO Isolation
Supply Voltage
Supply Current
Supply Current
Shutdown Current
Turn-On Time
Turn-Off Time
EN, EDC, EIP2 Input High Voltage (On)
EN, EDC, EIP2 Input Low Voltage (Off)
EN Pin Input Current
EDC Pin Input Current
EN = 5.0V
EDC = 5.0V
52
33
EDC = EIP2 = 5V
EDC = EIP2 = 0V
EN < 0.3V
EN Transition from Logic Low to High (Note 14)
EN Transition from Logic High to Low (Note 15)
2.0
0.3
4.75
180
170
(Note 10)
Unadjusted, EDC = 0V (Note 13)
Unadjusted, EIP2 = 0V
EIP2 = 5V, IP2I, IP2Q Adjusted for Minimum IM2
Return Loss > 10dB
Return Loss > 10dB
Loaded with 100Ω Pull-Up (Note 8)
Double-Side Band (Note 4)
(Note 10)
Unadjusted, EDC = 0V (Note 13)
Unadjusted, EIP2 = 0V
EIP2 = 5V, IP2I, IP2Q Adjusted for Minimum IM2
T
C
= 25°C, V
CC
= 5V, EN = 5V, EDC = EIP2 = 0V, REF = IP2I = IP2Q = DCOI =
DCOQ = 0.5V, P
RF
= –5dBm (–5dBm/tone for 2-tone IIP2 and IIP3 tests), P
LO
= 6dBm, unless otherwise noted. (Notes 2, 3, 5, 6, 9)
CONDITIONS
Double-Side Band (Note 4)
Double-Side Band, P
RF
= 0dBm (Note 7)
MIN
TYP
13.6
15.2
27.5
60
80
15.5
8
0.05
1.0
40
–46
55
2.88 to 3.97
2.97 to 3.96
0.3
17.1
28.1
52.5
65.9
17.1
16.5
0.04
1.8
36
–34.7
44.5
5.0
200
190
11
0.2
0.8
5.25
220
210
900
MAX
UNITS
dB
dB
dBm
dBm
dBm
dBm
mV
dB
Deg
dB
dBm
dB
GHz
GHz
dB
dB
dBm
dBm
dBm
dBm
mV
dB
Deg
dB
dBm
dB
V
mA
mA
μA
µs
µs
V
V
μA
μA
f
RF1
= 3500MHz, f
RF2
= 3501MHz, f
LO
= 3490MHz, C17 = 0.6pF, L6 = 1.0nH, C13 = 0.7pF, L5 = Short, C14 = Open, Single-Ended LO (See Figure 14)
Power Supply and Other Parameters
5585fb
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For more information
www.linear.com/LTC5585
LTC5585
ELECTRICAL CHARACTERISTICS
SYMBOL
I
EIP2H
V
REF
V
REF(RANGE)
Z
REF
PARAMETER
EIP2 Pin Input Current
REF Pin Voltage
REF Pin Voltage Range
REF Input Impedance
DCOI, DCOQ, IP2I, IP2Q Pin Voltage
DCOI, DCOQ, IP2I, IP2Q Voltage Range
DCOI, DCOQ, IP2I, IP2Q Impedance
DCOI, DCOQ, IP2I, IP2Q Settling Time
DC Offset Adjustment Range
DC Offset Drift Over Temperature
V
CM
Z
OUT
BW
BB
I
+
, I
–
, Q
+
, Q
–
Common Mode Voltage
I
+
, I
–
, Q
+
, Q
–
Output Impedance
I
+
, I
–
, Q
+
, Q
–
Output Bandwidth
Single Ended
100Ω External Pull-Up, –3dB Corner Frequency
CONDITIONS
EIP2 = 5.0V
With REF Pin Unloaded
When Driven with External Source
(Note 11)
Unloaded
When Driven with External Source
(Note 11)
For Step Input, Output with 90% of Final Value
DCOI, DCOQ Swept from 0V to 1V, EDC = 5V
Unadjusted, EDC = 0V
MIN
TYP
50
0.5
0.4 to 0.7
2||1
0.5
0 to 2V
REF
8||1
20
±20
20
V
CC
– 1.5
100||6
530
MAX
UNITS
μA
V
V
kΩ||pF
V
V
kΩ||pF
ns
mV
μV/°C
V
Ω||pF
MHz
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:
Tests are performed with the test circuit of Figure 1.
Note 3:
The LTC5585 is guaranteed to be functional over the –40°C to
105°C case temperature operating range.
Note 4:
DSB noise figure is measured at the baseband frequency of 15MHz
with a small-signal noise source without any filtering on the RF input and
no other RF signal applied.
Note 5:
Performance at the RF frequencies listed is measured with external
RF and LO impedance matching, as shown in the table of Figure 1.
Note 6:
The complementary outputs (I
+
, I
–
and Q
+
, Q
–
) are combined
using a 180° phase-shift combiner.
Note 7:
Noise figure under blocking conditions (NF
BLOCKING
) is measured
at an output frequency of 60MHz with RF input signal at f
LO
+ 1MHz. Both
RF and LO input signals are appropriately filtered, as well as the baseband
output. NF
BLOCKING
measured at 840MHz, 2140MHz and 2500MHz only.
Note 8:
Voltage conversion gain is calculated from the average measured
power conversion gain of the I and Q outputs using the test circuit shown
in Figure 1. Power conversion gain is measured with a 100Ω differential
load impedance on the I and Q outputs.
Note 9:
Baseband outputs have a 100Ω external pull-up resistor to V
CC
as
shown in the test circuit shown in Figure 1.
Note 10:
Image rejection is calculated from the measured gain error and
phase error using the method listed in the appendix.
Note 11:
The DCOI, DCOQ, IP2I, IP2Q pins have an 8k internal resistor to
ground. The REF pin has a 2k internal resistor to ground. If unconnected,
these pins will float up to 500mV through internal current sources. A low
output resistance voltage source is recommended for driving these pins.
Note 12:
This is the recommended operating range, operation outside the
listed range is possible with degraded performance to some parameters.
Note 13:
DC offset measured differentially between I
+
and I
–
and between
Q
+
and Q
–
. The reported value is the mean of the absolute values of the
characterization data distribution.
Note 14:
Baseband amplitude is within 10% of final value.
Note 15:
Baseband amplitude is at least 30dB down from its on state.
5585fb
For more information
www.linear.com/LTC5585
5
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