LT5521
Very High Linearity
Active Mixer
FEATURES DESCRIPTIO
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Wideband Output Frequency Range to 3.7GHz The LT 5521 is a very high linearity mixer optimized for
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+24.2dBm IIP3 at 1.95GHz RF Output low distortion and low LO leakage applications. The chip
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Low LO Leakage: 42dBm includes a high speed LO buffer with single-ended input
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Integrated LO Buffer: Low LO Drive Level and a double-balanced active mixer. The LT5521 requires
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Single-Ended LO Drive only 5dBm LO input power to achieve excellent distor-
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Wide Single Supply Range: 3.15V to 5.25V tion and noise performance, while reducing external drive
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Double-Balanced Active Mixer circuit requirements. The LO buffer is internally 50W
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Shutdown Function matched for wideband operation.
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16-Lead (4mm 4mm) QFN Package
With a 250MHz input, a 1.7GHz LO and a 1.95GHz output
frequency, the mixer has a typical IIP3 of +24.2dBm,
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0.5dB conversion gain and a 12.5dB noise figure.
APPLICATIO S
The LT5521 offers exceptional LO-RF isolation, greatly
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Cellular, W-CDMA, PHS and UMTS Infrastructure
reducing the need for output filtering to meet LO suppres-
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Cable Downlink Infrastructure
sion requirements.
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Wireless Infrastructure
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Fixed Wireless Access Equipment
The device is designed to work over a supply voltage range
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High Linearity Mixer Applications
from 3.15V to 5.25V.
, LTC and LT are registered trademarks of Linear Technology Corporation.
TYPICAL APPLICATIO
Fundamental, 3rd Order
LO INPUT
Intermodulation Distortion
5dBm
vs Input Power
6.8pF
20
LO
GND
0
110
BPF 4:1 82pF P
1nF FUND
+ + 2.7nH
IN OUT
IF
20
1:1
INPUT
6.8pF
BPF
10pF
IN OUT 40
RF
PA
IM3
OUTPUT
2.7nH
1nF 82pF
110
60
BIAS
f = 250MHz
1nF IF
f = 1.7GHz
LO
V V V
EN
CC CC CC
80 f = 1.95GHz
RF
5V DC
P = 5dBm
LO
T = 25C
A
1F
100
14 12 10 8 6 4 2 0 2 4 6
5521 TA01
P (dBm)
IN
5521 TA02
5521f
1
OUTPUT POWER (dBm)
U
ULT5521
ABSOLUTE MAXIMUM RATINGS PACKAGE/ORDER INFORMATION
(Note 1)
Power Supply Voltage ........................................... 5.5V
TOP VIEW ORDER PART
Enable Voltage ............................... 0.2V to V + 0.2V NUMBER
CC
LO Input Power ................................................ +10dBm
16 15 14 13
LT5521EUF
+
LO Input DC Voltage ..................................... 0V to 1.5V GND 1 12 OUT
+
IN 2 11 GND
IF Input Power ................................................. +10dBm
17
IN 3 10 GND
Difference Voltage Across Output Pins ................ 1.5V
GND 4 9 OUT
Maximum Pin 2 or Pin 3 Current ......................... 34mA
UF PART
5 6 7 8
Operating Ambient Temperature Range .. 40 C to 85 C
MARKING
Storage Temperature Range ................. 65 C to 125 C
UF PACKAGE
16-LEAD (4mm 4mm) PLASTIC QFN
Maximum Junction Temperature .......................... 125 C
5521
T = 125 C, q = 37 C/W
JMAX JA
EXPOSED PAD (PIN 17) IS GND
MUST BE SOLDERED TO PCB
Consult LTC Marketing for parts specified with wider operating temperature ranges.
DC ELECTRICAL CHARACTERISTICS V = 5V, EN = 2.9V, T = 25 C unless otherwise noted.
CC A
Test circuit shown in Figure 1. (Note 2)
PARAMETER CONDITIONS MIN TYP MAX UNITS
Supply Voltage 3.15 5.25 V
Supply Current 82 98 mA
Shutdown Current EN = 0.2V 20 100 m A
Enable (EN) Low = Off, High = On
Enable Mode EN = High 2.9 V
Disable Mode EN = Low 0.2 V
Enable Current EN = 5V 137 m A
Shutdown Enable Current EN = 0.2V 0.1 m A
Turn-On Time (Note 3) 200 ns
Turn-Off Time (Note 4) 200 ns
LO Voltage (Pin 15) Internally Biased 0.96 V
Input Voltage (Pins 2, 3) V = 5V, Internally Biased 2.20 V
CC
V = 3.3V, Internally Biased 0.46 V
CC
AC ELECTRICAL CHARACTERISTICS V = 5V, EN = 2.9V, T = 25 C unless otherwise noted.
CC A
Test circuit shown in Figure 1. (Note 2)
PARAMETER CONDITIONS MIN TYP MAX UNITS
LO Frequency Range 10 to 4000 MHz
Input Frequency Range 10 to 3000 MHz
Output Frequency Range 10 to 3700 MHz
LO Input Power 5 1 dBm
LO Return Loss Z = 50W , f = 1700MHz 12 dB
O LO
Output Return Loss Requires Matching 12 dB
Input Return Loss (Pins 2, 3) Requires Matching 15 dB
5521f
2
EN GND
V LO
CC
V GND
CC
V GND
CC
U W U
U WWW