The DC426B demo circuit board is intended to demonstrate the capabilities of the LT5511 high
signal level upconverting mixer IC for 1900MHz infrastructure applications.
The LT5511 mixer IC is designed to meet the high linearity requirements of cable TV
infrastructure downstream transmitters and wireless infrastructure transmit systems. The IC
includes a differential LO buffer amplifier driving a double-balanced mixer. The LO, RF and IF
ports can be easily matched to a broad range of frequencies for different applications. The high
performance capability of the LO buffer allows the use of a single-ended source, thus eliminating
the need for an LO balun.
The LT5511 mixer delivers +17dBm typical input 3rd order intercept at 950MHz, and +15.5dBm
IIP3 at 1900MHz, with IF input signal levels of –5dBm. The input 1dB compression point is
typically +6dBm.
The DC426B demo board is optimized to upconvert a 50MHz IF input to 1900MHz RF output
with the LO injected from the high-side at 1950MHz.
:
GND
GND
VCCBIAS
LO- LO+
NC
IF+
IF-
1
2
3
4
5
6
7
8 9
GND
BIAS
GND
(BACKSIDE)
16
BUFFER
17
Figure 1. LT5511 IC Block Diagram
LO
NC
15
14
13
12
11
10
VCCLO
GND
RF+
RF-
GND
EN
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Page 2
LT5511 Upconverting Mixer Single-Tone Measurements for 1900MHz Band.
1. Connect all test equipment as shown in Figure 2.
2. Set the Power Supply output voltage to 5V, and set the current limit to 100mA.
3. Set the dipswitch SW1 (Enable) to 1. Mixer is in ENABLE mode.
4. Set the Signal Generator #1 to provide a 1950MHz, -10dBm, CW signal to the demo board
LOin port.
5. Set the Signal Generator #2 to provide a 50MHz, -5dBm, CW signal to the demo board IFin
port.
6. Set the Spectrum Analyzer’s center frequency to 1900MHz. Perform mixer conversion gain,
and 1dB compression measurements.
7. Set the Spectrum Analyzer’s center frequency to 1950MHz. Perform mixer LO to RF
suppression measurement.
8. Set the Spectrum Analyzer’s center frequency to 1850MHz and 2050MHz. Perform input 2nd
order distortion measurement. (IIP2 = 2 * P1 – P2 – Gc, where P1 is the power level of the
desired output at 1900MHz, P2 is the largest 2nd order product at either 1850MHz or
2050MHz, and Gc is conversion gain. P1 and P2 are in units of dBm, and Gc is in dB.)
SPECTRUM
ANALYZER
SIGNAL
GENERATOR 1
POWER SUPPLY
SIGNAL
GENERATOR 2
Figure 2. Test Set-Up for Mixer Single-Tone Measurements
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LT5511 Upconverting Mixer Two-Tone Measurements for 1900MHz Band.
∑
1. Connect all test equipment as shown in Figure 3.
Note: 1). A high quality combiner that provides 50-ohm termination on all ports and has
good port-to-port isolation should be used.
2). The two 3dB attenuators on the inputs of the combiner are used to further improve
source isolation.
2. Set the Power Supply output voltage to 5V, and set the current limit to 100mA.
3. Set the dipswitch SW1 (Enable) to 1. Mixer is in ENABLE mode.
4. Set the Signal Generator #1 to provide a 1950MHz, -10dBm, CW signal to the demo board
LOin port.
5. Set the Signal Generator #2 and #3 to provide two -5dBm CW signals to the demo board IFin
port—one at 50MHz, and the other at 51MHz.
6. Set the Spectrum Analyzer’s center frequency to 1899.5MHz. Perform input 3rd order
distortion measurement. (IIP3 = P1 + (P1 – P3) / 2 – Gc, where P1 is the lowest power level
of the two desired output tones at either 1899MHz or 1900MHz, P3 is the largest 3rd order
product at either 1898MHz or 1901MHz, and Gc is conversion gain. P1 and P3 are in units
of dBm, and Gc is in dB.)
SIGNAL
GENERATOR 1
SIGNAL
GENERATOR 2
3dB PAD 3dB PAD
SPECTRUM
ANALYZER
POWER SUPPLY
SIGNAL
GENERATOR 3
Figure 3. Test Set-Up for Mixer Two-Tone Measurements
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APPROVED VENDOR LIST
VENDOR PHONE NUMBER PART TYPE WEBSITE ADDRESS
AAC (was TAD) (800) 508-1521 CHIP RESISTORS
AAC (was TAD) (714) 255-9186
AAVID (714) 556-2665 HEAT SINKS
ALLEN BRADLEY (800) 592-4888 CARBON RESISTORS
AMP (717) 564-0100 PC MOUNT BNC
APEM (718) 246-1007 SMD TOGGLE/PB SWITCH
API DELEVAN (716) 652-3600 INDUCTORS
AVX (843) 946-0362 CHIP CAPS
AVX (843) 946-0524 CHIP RESISTORS
AVX (207) 282-5111 TANTALUM CAPS
AVX (843) 946-0323 HIGH VOLTAGE CAPS
BERG (800) 237-2374 CONNECTORS
BH ELECTRONICS (952) 894-9590 INDUCTORS
BI TECHNOLOGIES (714) 447-2656 TRANSFORMERS
BI TECHNOLOGIES (714) 447-2345 RES./RES. NETWORKS
BOURNS (801) 750-7253 POTENTIOMETERS, SIPS
CADDOCK ELECTRONICS (541) 496-0700 HIPO. RES., SIPS, DIPS
CENTRAL SEMI (631) 435-1110 SMALL SIGNAL DISCRETES
CHICAGO MINIAT. LAMP (201) 489-8989 LEDS
COILCRAFT (847) 639-6400 INDUCTORS
COMM CON (626) 301-4200 HEADERS, SHUNTS
CONNEX (805) 378-6464 BNC CONNECTORS
COOPER ELECT. TECH. (561) 752-5000 INDUCTORS
CORNELL DUBILIER (508) 996-8561 CAPACITORS
CTS (219) 293-7511 RESISTOR ARRAYS
CUI-STACK (503) 643-4899 POWER CONNECTORS
DALE (see Vishay) (605) 665-1627 INDUCTORS
DALE (see Vishay) (605) 665-9301 SENSE RESISTORS
DATA DISPLAY PRODUCT (800) 421-6815 LEDS
DIODES INC. (805) 446-4800 DIODES
ELECTRONIC CONCEPTS (908) 542-7880 400V FILM CAPACITORS
EPSON (310) 787-6300 CRYSTALS
FAIRCHILD (207) 775-4502 LOGIC
FAIRCHILD (408) 822-2126 MOSFETS
FAIRCHILD (888) 522-5372 CRG (CUST. RESPONSE)
FCI (717) 767-8005 HOT PLUG CONNECTORS
FUKUSHIMA (818) 765-8300 MPC RESISTORS
FUJI (201) 712-0555 SCHOTTKY DIODES