DEMO MANUAL DC1710A-B
LTC5591
Dual 1.3GHz to 2.3GHz
High Dynamic Range
Downconverting Mixer
The LTC5591’s high conversion gain and high dynamic
range enable the use of lossy IF filters in high-selective
receiver designs, while minimizing the total solution cost,
board space and system-level variation.
High Dynamic Range Dual Downconverting Mixer Family
DEMO #
DC1710A-A
DC1710A-B
DC1710A-C
DC1710A-D
DESCRIPTION
Demonstration circuit 1710A-B is a dual 1.3GHz to 2.3GHz
high dynamic range downconverting mixer featuring the
LTC
®
5591. The LTC5591 is part of a family of dual-channel
high dynamic range, high gain downconverting mixers
covering the 600MHz to 4.5GHz frequency range.
The
demo circuit 1710A-B and the LTC5591 are 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 1.7GHz or 2.1GHz
RF input and low side LO.
The LTC5591 is designed for 3.3V operation, however the
IF amplifiers can be powered by 5V for the highest P1dB. A
low current mode is provided for power savings, and each
of the mixer channels has independent shutdown control.
IC PART #
LTC5590
LTC5591
LTC5592
LTC5593
RF RANGE
1.3GHz to 2.3GHz
1.6GHz to 2.7GHz
2.3GHz to 4.5GHz
LO RANGE
1.4GHz to 2.1GHz
1.7GHz to 2.5GHz
2.1GHz to 4.2GHz
600MHz to 1.7GHz 700MHz to 1.5GHz
Design files for this circuit board are available at
http://www.linear.com/demo
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.
PERFORMANCE SUMMARY
PARAMETER
VCC Supply Voltage Range
VCCIF Supply Voltage Range
Total Supply Current (VCC + VCCIF), Normal Power Mode
Total Supply Current (VCC + VCCIF), Low Power Mode
Total Supply Current During Shutdown
ENA, ENB Input High Voltage (Channel Enabled)
ENA, ENB Input Low Voltage (Channel Disabled)
ENA, ENB Input Current
ISEL Input High Voltage (Low Power Mode)
ISEL Input Low Voltage (Normal Power Mode)
ISEL Input Current
T
C
= 25°C, VCC = VCCIF = 3.3V, ENA = ENB = High, ISEL = Low, P
LO
= 0dBm,
P
RF
= –3dBm (Δf = 2MHz for two-tone IIP3 tests), unless otherwise noted. (Note 1)
CONDITIONS
VALUE
3.1 to 3.5
3.1 to 5.3
Both Mixer Channels Enabled
Both Mixer Channels Enabled, ISEL = High
ENA = ENB = Low
382
239
≤500
>2.5
<0.3
–0.3V to VCC + 0.3V
–20 to 30
>2.5
<0.3
–0.3V to VCC + 0.3V
–20 to 30
UNITS
V
V
mA
mA
μA
V
V
μA
V
V
μA
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DEMO MANUAL DC1710A-B
PERFORMANCE SUMMARY
PARAMETER
LO Input Frequency Range
LO Input Return Loss
LO Input Power Range
RF Input Frequency Range
RF Input Return Loss
IF Output Frequency
IF Output Return Loss
LO to RF Leakage
LO to IF Leakage
RF to LO Isolation
RF to IF Isolation
Channel-to-Channel Isolation
Conversion Gain
Z
0
= 50Ω, f
LO
= 1400MHz to 2100MHz
f
LO
= 1400MHz to 2100MHz
Low Side LO
High Side LO
Z
0
= 50Ω, f
RF
= 1300MHz to 2300MHz
Can be re-matched for other frequencies
Z
0
= 50Ω
f
LO
= 1400MHz to 2100MHz
f
LO
= 1400MHz to 2100MHz
f
RF
= 1300MHz to 2300MHz
f
RF
= 1300MHz to 2300MHz
f
RF
= 1750MHz to 2150MHz
RF = 1750MHz
RF = 1950MHz
RF = 2150MHz
RF = 1750MHz
RF = 1950MHz
RF = 2150MHz
RF = 1750MHz
RF = 1950MHz
RF = 2150MHz
f
RF
= 1950MHz, f
LO
= 1760MHz, f
BLOCK
= 2050MHz,
P
BLOCK
= 5dBm
P
BLOCK
= 10dBm
f
RF
= 1855MHz at –10dBm, f
LO
= 1760MHz,
f
IF
= 190MHz
f
RF
= 1823.33MHz at –10dBm, f
LO
= 1760MHz,
f
IF
= 190MHz
f
RF
= 1950MHz, VCCIF = 3.3V
f
RF
= 1950MHz, VCCIF = 5V
RF = 1950MHz
RF = 1950MHz
RF = 1950MHz
f
RF
= 1950MHz, VCCIF = 3.3V
f
RF
= 1950MHz, VCCIF = 5V
T
C
= 25°C, VCC = VCCIF = 3.3V, ENA = ENB = High, ISEL = Low, P
LO
= 0dBm,
P
RF
= –3dBm (Δf = 2MHz for two-tone IIP3 tests), unless otherwise noted. (Note 1)
CONDITIONS
VALUE
1400 to 2100
>12
–4 to 6
1600 to 2300
1300 to 1800
>12
190
>12
< –30
< –30
>45
>30
>47
8.7
8.5
8.0
26.9
26.2
26.2
9.4
9.9
10.8
15.5
20.2
–69
–74
10.7
13.9
7.2
21.4
10.3
10.7
11.7
UNITS
MHz
dB
dBm
MHz
MHz
dB
MHz
dB
dBm
dBm
dB
dB
dB
dB
dB
dB
dBm
dBm
dBm
dB
dB
dB
dB
dB
dBc
dBc
dBm
dBm
dB
dBm
dB
dBm
dBm
Low Side LO Downmixer Application: ISEL = Low, RF = 1700MHz to 2300MHz, IF = 190MHz, f
LO
= f
RF
– f
IF
Input 3rd Order Intercept
SSB Noise Figure
SSB Noise Figure Under Blocking
2RF – 2LO Output Spurious Product
(f
RF
= f
LO
+ f
IF
/2)
3RF – 3LO Output Spurious Product
(f
RF
= f
LO
+ f
IF
/3)
Input 1dB Compression
Low Power Mode, Low Side LO Downmixer Application: ISEL = High, RF = 1700MHz to 2300MHz, IF = 190MHz, f
LO
= f
RF
– f
IF
Conversion Gain
Input 3rd Order Intercept
SSB Noise Figure
Input 1dB Compression
dc1710abf
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DEMO MANUAL DC1710A-B
T
C
= 25°C, VCC = VCCIF = 3.3V, ENA = ENB = High, ISEL = Low, P
LO
= 0dBm,
P
RF
= –3dBm (Δf = 2MHz for two-tone IIP3 tests), unless otherwise noted. (Note 1)
PARAMETER
Conversion Gain
CONDITIONS
RF = 1450MHz
RF = 1600MHz
RF = 1750MHz
RF = 1450MHz
RF = 1600MHz
RF = 1750MHz
RF = 1450MHz
RF = 1600MHz
RF = 1750MHz
f
RF
= 1600MHz, f
LO
= 1790MHz, f
BLOCK
= 1500MHz,
P
BLOCK
= 5dBm
P
BLOCK
= 10dBm
f
RF
= 1695MHz at –10dBm, f
LO
= 1790MHz,
f
IF
= 190MHz
f
RF
= 1726.67MHz at –10dBm, f
LO
= 1790MHz,
f
IF
= 190MHz
f
RF
= 1600MHz, VCCIF = 3.3V
f
RF
= 1600MHz, VCCIF = 5V
VALUE
8.9
8.6
8.4
25.0
24.6
24.3
10.0
10.1
10.1
16.4
21.2
–64
–75
10.2
13.6
UNITS
dB
dB
dB
dBm
dBm
dBm
dB
dB
dB
dB
dB
dBc
dBc
dBm
dBm
PERFORMANCE SUMMARY
High Side LO Downmixer Application: ISEL = Low, RF = 1300MHz to 1800MHz, IF = 190MHz, f
LO
= f
RF
+ f
IF
Input 3rd Order Intercept
SSB Noise Figure
SSB Noise Figure Under Blocking
2LO – 2RF Output Spurious Product
(f
RF
= f
LO
– f
IF
/2)
3LO – 3RF Output Spurious Product
(f
RF
= f
LO
– f
IF
/3)
Input 1dB Compression
Note 1: Subject to change without notice. Refer to the latest LTC5591 data sheet for most-up-to-date specifications.
DETAILED DESCRIPTION
ABSOLUTE MAXIMUM RATINGS
NOTE.
Stresses beyond 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.
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
RFA, RFB Input Power (1GHz to 3GHz) ................15dBm
Operating Temperature Range (T
C
) ........ –40°C to 105°C
SUPPLY VOLTAGE RAMPING
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 volt-
age transient that exceeds the maximum rating. A supply
voltage ramp time of greater than 1ms is recommended.
Do not clip powered test leads directly onto the demon-
stration circuit’s VCC and VCCIF turrets.
Instead, make
all necessary connections with power supplies turned off,
then increase to operating voltage.
ENABLE FUNCTION
The LTC5591’s two mixer channels can be independently
enabled or disabled. When the Enable voltage (ENA or ENB)
is logic high (>2.5V), the corresponding mixer channel is
enabled. When the Enable voltage is logic low (<0.3V),
the mixer channel is disabled. The voltages at the enable
pins should never fall below –0.3V or exceed the power
supply voltage by more than 0.3V. The Enable pins must
be pulled high or low. If left floating, the on/off state of
the IC will be indeterminate. A logic table for the Enable
control (ENA, ENB) is shown in Table 1.
Table 1. Enable Control Logic Table
ENA, ENB
Low
High
MIXER CHANNEL STATE
Disabled
Enabled
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DEMO MANUAL DC1710A-B
DETAILED DESCRIPTION
LOW POWER MODE
The LTC5591 features a low power mode, which allows
the flexibility to choose a 37% total power saving when
lower RF performance is acceptable. When the ISEL volt-
age is logic low (<0.3V), both mixer channels operate at
nominal power and best performance. When the ISEL
voltage is logic high (>2.5V), both mixer channels are in
low power mode and operate with reduced performance.
The ISEL voltage should never fall below –0.3V or exceed
the power supply voltage by more than 0.3V. The ISEL pin
must be pulled low or high. If left floating, the operating
state of the IC will be indeterminate. A logic table for ISEL
is shown in Table 2.
Table 2. ISEL Logic Table
ISEL
Low
High
the channel B IF outputs are identical, and the impedance
matching is realized with a bandpass topology using IF
transformers as shown in Figure 1. Only channel A is
shown for clarity and simplicity.
OPERATING MODE
Normal power, best performance
Low power, reduced performance
Figure 1. IF Output with Bandpass Matching
RF INPUTS
Demonstration circuit 1710A-B’s RF inputs of channel
A and channel B are identical. For the RF inputs to be
matched, the appropriate LO signal must be applied. The
RF inputs’ impedance is dependent on LO frequency, but
the demonstration circuit 1710A-B are well matched to
50Ω from 1.3GHz to 2.3GHz, with better than 12dB return
loss, when a 1.4GHz to 2.1GHz LO signal is applied.
LO INPUT
The LTC5591’s LO amplifier is optimized for the 1.4GHz
to 2.1GHz LO frequency range. LO frequencies above and
below this frequency range may be used with degraded
performance. The LO input is always 50Ω-matched when
VCC is applied to the chip, even when one or both of the
channels is disabled. The nominal LO input level is 0dBm.
The LO input power range is between –4dBm and 6dBm.
IF OUTPUTS
Demonstration circuit 1710A-B features single-ended,
50Ω-matched IF outputs for 190MHz. The channel A and
Demonstration circuit 1710A-B can be easily reconfigured
for other IF frequencies by simply replacing inductors L1A,
L2A, L1B and L2B. Inductor values for several common
IF frequencies are presented in Table 3, and return losses
are plotted in Figure 2. An external load resistor, R2A, can
be used to improve impedance matching if desired.
Table 3. Inductor Values vs. IF Frequencies
IF FREQUENCY (MHz)
L1A, L2A, L1B, L2B (nH)
140
190
240
300
380
270
150
100
56
33
For IF frequencies below 90MHz, the values of the induc-
tors become unreasonably high, and the lowpass topology
shown in Figure 3 is preferred. See the LTC5591 datasheet
for details.
Demonstration circuit 1710A-B’s IF outputs can be easily
converted to lowpass matching. Follow the procedures
below, and refer to Figure 3 and Figure 4 to modify the
channel A IF output. Modifications for Channel B are similar.
dc1710abf
4
DEMO MANUAL DC1710A-B
DETAILED DESCRIPTION
a. Remove existing L1A, L2A, and C7A.
b. Cut the traces leading to the IF transformer close to
the pads of L1A and L2A.
c. Insert series inductors onto the cut traces.
d. Install a 0Ω jumper between the pads of C5A and
C7A.
e. Install resistor at location R2A.
f. Install C9A next to, or on top of, R2A.
Figure 3. IF Output with Lowpass Matching
Figure 2. IF Output Return Loss with Bandpass Matching
Figure 4. IF Output with Lowpass Matching
MEASUREMENT EQUIPMENT AND SETUP
The LTC5591 is a dual high dynamic range downconverting
mixer IC with very high input 3rd order intercept. Accuracy
of its performance measurement is highly dependent on
equipment setup and measurement technique. The recom-
mended measurement setups are presented in Figure 5,
Figure 6, and Figure 7. The following precautions should
be observed:
1. Use high performance signal generators with low har-
monic output and low phase noise, such as the Rohde &
Schwarz SME06. Filters at the signal generators’ outputs
may also be used to suppress higher-order harmonics.
2. A high quality RF power combiner that provide broad-
band 50Ω-termination on all ports and have good
port-to-port isolation should be used, such as the MCLI
PS2-17.
3. Use high performance amplifiers with high IP3 and high
reverse isolation, such as the Mini-Circuits ZHL-1042J,
on the outputs of the RF signal generators to improve
source isolation to prevent the sources from modulating
each other and generating intermodulation products.
dc1710abf
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