AD8347ARU Analog Devices Inc, AD8347ARU Datasheet - Page 6

• Manufacturer Part Number: AD8347ARU
• Description: Quadrature Dmod 65MHz 28-Pin TSSOP
• Manufacturer: Analog Devices Inc

Specifications of AD8347ARU

• Package: 28TSSOP
• Device Type: Demodulator
• Maximum I/q Frequency: 65(Typ) MHz
• Modulation Type: Quadrature
• Typical Noise Figure: 11 dB
• Maximum Conversion Gain: 39.5(Typ) dB
• Rohs Status: RoHS non-compliant
• Function: Demodulator
• Lo Frequency: 800MHz ~ 2.7GHz
• Rf Frequency: 800MHz ~ 2.7GHz
• P1db: -30dBm
• Gain: 39.5dB
• Noise Figure: 11dB
• Current - Supply: 80mA
• Voltage - Supply: 2.7 V ~ 5.5 V
• Package / Case: 28-TSSOP

AD8347
PIN CONFIGURATION AND FUNCTION DESCRIPTIONS
Table 3. Pin Function Descriptions
Pin No.
1, 28
2
3, 4
5
6
7, 23
8, 22
9
10, 11
12
13, 16
14
15
17
Mnemonic
LOIN, LOIP
VPS1
IOPN, IOPP
VCMO
IAIN
COM3
IMXO, QMXO
COM2
RFIN, RFIP
VPS2
IOFS, QOFS
VREF
ENBL
VGIN
Equiv.
Circuit
A
B
C
D
B
E
F
G
H
C
Description
LO Input. For optimum performance, these inputs are differentially driven. Typical input drive level is
equal to −8 dBm. To improve the match to a 50 Ω source, connect a 200 Ω shunt resistor between LOIP
and LOIN. A single-ended drive is possible, but slightly increases LO leakage.
Positive Supply for LO Section. Decouple VPS1 with 0.1 μF and 100 pF capacitors.
I-Channel Differential Baseband Output. Typical output swing is equal to 760 mV p-p differential in
AGC mode. The common-mode level on these pins is programmed by the voltage on VCMO.
Baseband Amplifier Common-Mode Voltage. The voltage applied to this pin sets the output common-
mode level of the baseband amplifiers. This pin can either be connected to VREF (Pin 14) or to a
reference voltage from another device (typically an ADC).
I-Channel Baseband Amplifier Input. This pin, which has a high input impedance, should be biased to
VREF (approximately 1 V). If IAIN is connected directly to IMXO, biasing is provided by IMXO. If an ac-
coupled filter is placed between IMXO and IAIN, this pin can be biased from VREF through a 1 kΩ
resistor. The gain from IAIN to the differential outputs IOPN/IOPP is 30 dB.
Ground for Biasing and Baseband Sections.
I-Channel and Q-Channel Baseband Mixer/VGA Outputs. Low impedance outputs with bias levels equal to
VREF. IMXO and QMXO are typically connected to IAIN and QAIN, respectively, either directly or through
filters. These outputs have a maximum current limit of about 1.5 mA. This allows for a 600 mV p-p swing into
a 200 Ω load. This corresponds to an input level of −40 dBm @ a maximum gain of 39.5 dB. At lower output
levels, IMXO and QMXO can drive a lower load resistance, subject to the same current limit.
RF Section Ground.
RF Input. RFIN must be ac-coupled to ground. The RF input signal should be ac-coupled into RFIP. For
a broadband 50 Ω input impedance, connect a 200 Ω resistor from the signal side of the RFIP coupling
capacitor to ground. Note that RFIN and RFIP are not interchangeable differential inputs. RFIN is the
ground reference for the input system.
Positive Supply for RF Section. Decouple VPS2 with 0.1 μF and 100 pF capacitors.
I-Channel and Q-Channel Offset Nulling Inputs. To null the dc offset on the I-channel and Q-channel
mixer outputs (IMXO, QMXO), connect a 0.1 μF capacitor from these pins to ground. Alternately, a
forced voltage of approximately 1 V on these pins disables the offset compensation circuit.
Reference Voltage Output. This output voltage (1 V) is the main bias level for the device and can be
used to externally bias the inputs and outputs of the baseband amplifiers. The VREF pin should be
decoupled with a 0.1 μF capacitor to ground.
Chip Enable Input. Active high.
Gain Control Input. The voltage on this pin controls the gain on the RF and baseband VGAs. The gain
control is applied in parallel to all VGAs. The gain control voltage range is from 0.2 V to 1.2 V and
corresponds to a gain range from +39.5 dB to −30 dB. This is the gain to the output of the baseband
VGAs (that is, QMXO and IMXO). There is an additional 30 dB of gain in the baseband amplifiers. Note
that the gain control function has a negative sense (that is, increasing control voltage decreases gain).
In AGC mode, connect this pin directly to VAGC.
VCMO
COM3
COM2
Figure 2. 28-Lead TSSOP Pin Configuration
VREF
VPS1
IMXO
VPS2
IOPN
LOIN
IOPP
RFIN
IOFS
RFIP
IAIN
10
11
12
13
14
1
2
3
4
5
6
7
8
9
Rev. A | Page 6 of 28
(Not to Scale)
AD8347
TOP VIEW
28
27
26
25
24
23
22
21
20
19
18
17
16
15
LOIP
COM1
QOPN
QOPP
QAIN
COM3
QMXO
VPS3
VDT1
VAGC
VDT2
V GIN
QOFS
ENBL