OMO ElectronicOMO Electronic
Expand menu
Hello, Sign inMy Account
0 Cart

LTC5551IUF#PBF

P1-P3P4-P6P7-P9P10-P12P13-P15P16-P18P19-P21P22-P24
LTC5551
13
5551fa
For more information www.linear.com/LTC5551
TesT circuiT
Figure 1. Standard Downmixer Test Circuit Schematic (153MHz IF)
RF
GND
GND
BIAS
TBD
BOARD
STACK-UP
(NELCO N4000-13)
0.015"
0.015"
0.062"
T1
4:1
IF
OUT
153MHz
50Ω
C8
C9
L2L1
R2R1
C5C4
17
GND
LTC5551
1
6
13141516
LO
IN
50Ω
11
12
10
9
C2
C7
ISEL
0V TO 3.3V
C6
5 7 8
4
V
CC
3.1V TO 3.5V
EN
0V TO 3.3V
3
RF
IN
50Ω
V
CC
X2
2
IFBIAS IF
+
IF
–
LO
GND
TEMP
GND
EN V
CC
V
CC
ISEL
GND
GND
RF
CT
GND
5551 F01
C1
C3
X1
APPLICATION RF MATCH LO MATCH IF TRANSFORMER
RF (MHz) LO X1 C1 X2 C2 C3 T1 VENDOR
300 to 650 HS 15nH 15pF 15pF 15pF 8.2pF TC4-1W-7ALN+ Mini-Circuits
500 to 1100 HS 13nH 6.8pF 4.7pF 8.2pF 2.2pF WBC4-6TLB Coilcraft
1100 to 2700 LS, HS 7.5nH 2.2pF – 3.9pF – TC4-1W-7ALN+ Mini-Circuits
2300 to 3500 LS, HS 1.2pF 22pF 2.2nH 3.9pF – TC4-1W-7ALN+ Mini-Circuits
REF DES VALUE SIZE VENDOR REF DES VALUE SIZE VENDOR
C4, C6 0.56µF 0603 Murata R1, R2 475Ω, 1% 0402 Vishay
C5, C7 22pF 0402 AVX L1, L2 470nH, 2% 0603 Coilcraft 0603LS
C8, C9 1nF 0402 AVX
LTC5551
14
5551fa
For more information www.linear.com/LTC5551
Introduction
The LTC5551 consists of a high linearity double-balanced
mixer core, IF buffer amplifier, LO buffer amplifier and
bias/enable circuits. See the Block Diagram section for a
description of each pin function. The RF and LO inputs
are single-ended. The IF output is differential. Low side or
high side LO injection can be used. 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.
applicaTions inForMaTion
Figure 2. Evaluation Board Layout
For the RF input to be matched, the LO input must be
driven. Using components listed in Figure 1, the RF input
can be matched from 300MHz to 3.5GHz. The measured
RF input return loss is shown in Figure 4 for LO frequen
-
cies of
0.5GHz, 1.0GHz. 1.8GHz and 2.8GHz. These LO
frequencies correspond to the lower, middle and upper
values of the LO range.
The RF input impedance and input reflection coefficient,
versus RF frequency, is listed in Table 1. The reference
plane for this data is Pin 2 of the IC, with no external
matching, and the LO is driven at 1.8GHz.
Figure 3. RF Input Schematic
Figure 4. RF Input Return Loss
LTC5551
RF
IN
CT
RF
TO MIXER
2
3
5551 F03
C1
X2X1
RF FREQUENCY (GHz)
0.3
35
RF PORT RETURN LOSS (dB)
30
25
15
20
0
0.6
5551 F04
5
10
3.60.9 1.2 1.5 1.8 2.1 2.4 2.7 3.0 3.3
LO = 0.5GHz
LO = 1.0GHz
LO = 1.8GHz
LO = 2.8GHz
300MHz to 650MHz
MATCHING
500MHz to
1100MHz
MATCHING
1100MHz to
2700MHz
MATCHING
2300MHz to
3500MHz
MATCHING
RF Input
The mixer’s RF input, shown in Figure 3, is connected
to the primary winding of an integrated transformer. A
50Ω match can be realized with a π-network as shown in
Figures 1 and 3. The primary side of the RF transformer
is DC-grounded internally and the DC resistance of the
primary is approximately 4Ω. A DC blocking capacitor is
needed if the RF source has DC voltage present.
The secondary winding of the RF transformer is inter
-
nally connected to the mixer core. The center-tap of the
transformer secondary is connected to Pin 3 (CT). Pin 3
needs to be connected to ground with a minimum parasitic
resistance and inductance.
LTC5551
15
5551fa
For more information www.linear.com/LTC5551
applicaTions inForMaTion
Table 1. RF Input Impedance and S11
(at Pin 2, No External Matching, LO Input Driven at 1.8GHz)
FREQUENCY
(GHz)
INPUT
IMPEDANCE
S11
MAG
ANGLE
0.3 7.6 + j8.4 0.74 160.4
0.7 11.7 + j15.2 0.65 144.5
1.1 17.7 + j 22.2 0.55 127.4
1.5 29.3 + j27.8 0.41 107.4
1.9 46.7 + j21.8 0.22 85.8
2.3 49.6 – j1.3 0.01 –106.3
2.7 31.1 – j9.0 0.26 –148.2
3.1 18.2 – j1.8 0.47 –175.2
3.5 11.8 + j8.4 0.63 159.8
LO Input
The mixer’s LO input circuit, shown in Figure 5, consists
of a balun transformer and a two-stage high speed limiting
differential amplifier to drive the mixer core. The LTC5551’s
LO amplifiers are optimized for the 200MHz to 3.5GHz
LO frequency range. LO frequencies above or below this
frequency range may be used with degraded performance.
The mixer’s LO input is directly connected to the primary
winding of an integrated transformer. The LO is 50Ω
matched from 1GHz to 3.5GHz with a single 3.9pF series
Figure 5. LO Input Schematic
capacitor on the input. Matching to LO frequencies below
1GHz is easily accomplished by adding shunt capacitor
C3 shown in Figure 5. Measured LO input return loss is
shown in Figure 6.
The nominal LO input level is 0dBm although the limiting
amplifiers will deliver excellent performance over a ±6dB
input power range. LO input power of –9dBm may be
used
with slightly degraded performance.
The LO input impedance and input reflection coefficient,
versus frequency, is shown in Table 2.
Table 2. LO Input Impedance vs Frequency
(at Pin 10, No External Matching)
FREQUENCY
(GHz)
INPUT
IMPEDANCE
S11
MAG
ANGLE
0.3 4.8 + j12.0 0.84 152.7
0.7 13.4 + j28.1 0.67 118.5
1.1 32.7 + j39.1 0.47 88.6
1.5 56.8 + j31.1 0.29 61.5
1.9 62.8 + j9.3 0.14 31.4
2.3 54.1 – j1.4 0.04 –18.3
2.7 45.1 – j1.4 0.05 –163.6
3.1 39.8 + j3.6 0.12 158.6
3.5 37.2 + j10.4 0.19 134.1
Figure 6. LO Input Return Loss
LO
IN
V
CC
V
CC
LO BUFFER
TO
MIXER
LTC5551
LO
EN
5551 F05
10
7
6
5
C2
C3
4mA
BIAS
LO FREQUENCY (GHz)
0.3
25
20
LO PORT RETURN LOSS (dB)
15
0
0.6 0.9
5551 F06
5
10
3.61.2 1.5 1.8 2.1 2.4 2.7 3.0 3.3
C2 = 15pF, C3 = 8.2pF
C2 = 8.2pF, C3 = 2.2pF
C2 = 3.9pF, C3 OPEN
P1-P3P4-P6P7-P9P10-P12P13-P15P16-P18P19-P21P22-P24

LTC5551IUF#PBF

Mfr. #:
Buy LTC5551IUF#PBF
Manufacturer:
Analog Devices Inc.
Description:
RF Mixer 300MHz - 3.5GHz Ultra-High Dynamic Range Downconverting Mixer
Lifecycle:
New from this manufacturer.
Delivery:
DHL FedEx Ups TNT EMS
Payment:
T/T Paypal Visa MoneyGram Western Union

Products related to this Datasheet