AD8348ARUZ Analog Devices Inc, AD8348ARUZ Datasheet - Page 20

• Manufacturer Part Number: AD8348ARUZ
• Description: IC QUADRATURE DEMOD 28-TSSOP
• Manufacturer: Analog Devices Inc

Specifications of AD8348ARUZ

• Function: Demodulator
• Lo Frequency: 100MHz ~ 2GHz
• Rf Frequency: 50MHz ~ 1GHz
• P1db: -22dBm
• Gain: 25.5dB
• Noise Figure: 10.75dB
• Current - Supply: 58mA
• Voltage - Supply: 2.7 V ~ 5.5 V
• Package / Case: 28-TSSOP
• Frequency Range: 50MHz To 1GHz
• Rf Type: Quadrature
• Supply Voltage Range: 2.7V To 5.5V
• Rf Ic Case Style: TSSOP
• No. Of Pins: 28
• Operating Temperature Range: -40°C To +85°C
• Msl: MSL 1 - Unlimited
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

AD8348
APPLICATIONS
BASIC CONNECTIONS
Figure 49 shows the basic connections schematic for the AD8348.
IOPN
POWER SUPPLY
The voltage supply for the AD8348, between 2.7 V and 5 V, should
be provided to the +VPOSx pins, and ground should be connected
to the COMx pins. Each supply pin should be decoupled separately
using two capacitors whose recommended values are 100 pF and
0.1 μF (values close to these can also be used).
DEVICE ENABLE
To enable the device, the ENBL pin should be driven to V
Grounding the ENBL pin disables the device.
VGA ENABLE
Driving the voltage on the ENVG pin to V
this mode, the MX inputs are disabled and the IF inputs are
used. Grounding the ENVG pin disables the VGA and the IF
inputs. When the VGA is disabled, the MX inputs should be used.
GAIN CONTROL
When the VGA is enabled, the voltage applied to the VGIN pin sets
the gain. The gain control voltage range is between 0.2 V and 1.2 V.
This corresponds to a gain range between +25.5 dB and −18.5 dB.
LO INPUTS
For optimum performance, the local oscillator port should be
driven differentially through a balun. The recommended balun
is M/A-COM ETC1-1-13. The LO inputs to the device should
be ac-coupled, unless an ac-coupled transformer is being used.
For a broadband match to a 50 Ω source, a 60.4 Ω resistor
should be placed between the LOIP and LION pins.
IOPP
J3I
J2I
IFIP
+V
+V
S
S
57.6Ω
R31
0.1µF
0.1µF
C52
C54
174Ω
R32
1000pF
1000pF
100pF
C32
C31
100pF
C51
C53
Figure 49. Basic Connections Schematic
0.1µF
4.7µF
C11
V
C0l
REF
J21
LO
1000pF
C21
10
11
12
13
14
1
2
3
4
5
6
7
8
9
LOIP
VPOS1 COM1
IOPN
IOPP
VCMO
IAIN
COM3
IMXO
COM2 VPOS3
IFIN
IFIP
VPOS2
IOFS
VREF
AD8348
60.4Ω
4
3
R21
QMXO
5
1
QOPN
QOPP
COM3
ENVG
QOFS
ENBL
ETC1-1-13
QAIN
MXIN
MXIP
VGIN
LOIN
T21
C22
1000pF
28
27
26
25
24
23
22
21
20
19
18
17
16
15
C41
1µF
100pF
C55
0.1µF
C0Q
0.1µF
S
C56
VGIN
enables the VGA. In
+V
SW12
SW11
ENBL
DENBL
S
ETK4-2T
IF
MX
T41
1000pF
1000pF
C43
C42
+V
+V
S
S
R42
0Ω
S
.
QOPN
QOPP
MXIP
J2Q
J3Q
Rev. A | Page 20 of 28
Alternatively, the LO port can be driven from a single-ended source
without a balun (Figure 51). The LO signal is ac-coupled directly
into the LOIP pin via an ac-coupling capacitor, and the LOIN pin
is ac-coupled to ground. Driving the LO port from a single-
ended source results in an increase in both quadrature phase
error and LO leakage.
The recommended LO drive level is between −12 dBm and
0 dBm. The LO frequency at the input to the device should be
twice that of the desired LO frequency at the mixer core. The
applied LO frequency range is between 100 MHz and 2 GHz.
IF INPUTS
The IF inputs have an input impedance of 200 Ω. A broadband
50 Ω match can be presented to the driving source through the use
of a minimum-loss L pad. This minimum-loss pad introduces
an 11.46 dB loss in the input path and must be taken into account
when calculating metrics such as gain and noise figure. Figure 42
shows the S11 of the IF input with and without the L pad.
MX INPUTS
The mixer inputs, MXIP and MXIN, have a nominal impedance
of 200 Ω and should be driven differentially. When driven from
a differential source, the input should be ac-coupled to the
source via capacitors, as shown in Figure 53.
Figure 52. Minimum-Loss L Pad for 50 Ω IF Input
Figure 50. Differential LO Drive with Balun
IFIP
LO
1000pF
1000pF
Figure 51. Single-Ended LO Drive
LO
1
1
57.6Ω
LOIP
LOIP
60.4Ω
60.4Ω
4
3
174Ω
5
1
ETC1-1-13
LOIN
LOIN
1000pF
1000pF
28
28
1000pF
1000pF
10
11
IFIN
IFIP