AD8556ARZ Analog Devices Inc, AD8556ARZ Datasheet - Page 24

• Manufacturer Part Number: AD8556ARZ
• Description: IC AMP CHOPPER 2MHZ 10MA 8SOIC
• Manufacturer: Analog Devices Inc
• Series: DigiTrim®r
• Type: Instrumentation Amplifierr

Specifications of AD8556ARZ

• Operating Temperature: -40°C ~ 140°C
• Amplifier Type: Chopper (Zero-Drift)
• Number Of Circuits: 1
• Slew Rate: 1.2 V/µs
• Gain Bandwidth Product: 2MHz
• Current - Input Bias: 49nA
• Voltage - Input Offset: 2µV
• Current - Supply: 2mA
• Current - Output / Channel: 10mA
• Voltage - Supply, Single/dual (±): 4.5 V ~ 5.5 V
• Mounting Type: Surface Mount
• Package / Case: 8-SOIC (3.9mm Width)
• No. Of Amplifiers: 1
• Bandwidth: 700kHz
• Rail To Rail I/o Type: Rail-Rail I/O
• No. Of Channels: 1
• Supply Voltage Range: 2.7V To 5.5V
• Amplifier Case Style: SOIC
• No. Of Pins: 8
• Number Of Channels: 1
• Number Of Elements: 5
• Power Supply Requirement: Single
• Common Mode Rejection Ratio: 80dB
• Unity Gain Bandwidth Product (typ): 8MHz
• Single Supply Voltage (typ): 5V
• Dual Supply Voltage (typ): Not RequiredV
• Power Supply Rejection Ratio: 109dB
• Rail/rail I/o Type: Rail to Rail Input/Output
• Single Supply Voltage (min): 4.5V
• Single Supply Voltage (max): 5.5V
• Dual Supply Voltage (min): Not RequiredV
• Dual Supply Voltage (max): Not RequiredV
• Operating Temp Range: -40C to 140C
• Operating Temperature Classification: Automotive
• Mounting: Surface Mount
• Pin Count: 8
• Package Type: SOIC N
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Output Type: -
• -3db Bandwidth: -
• Lead Free Status / Rohs Status: Compliant

AD8556
EMI/RFI PERFORMANCE
Real-world applications must work with ever increasing
radio/magnetic frequency interference (RFI and EMI). In
situations where signal strength is low and transmission lines
are long, instrumentation amplifiers, such as the AD8556, are
needed to extract weak, small differential signals riding on
common-mode noise and interference. Additionally, wires and
PCB traces act as antennas and pick up high frequency EMI
signals. The longer the wire, the larger the voltage it picks up.
The amount of voltages picked up is dependent on the impedances
at the wires, as well as the EMI frequency. These high frequency
voltages are then passed into the in-amp through its pins. All
instrumentation amplifiers can rectify high frequency out-of-
band signals. Unfortunately, the EMI/RFI rectification occurs
because amplifiers do not have any significant common-mode
rejection above 100 kHz. Once these high frequency signals are
rectified, they appear as dc offset errors at the output.
VPOS
VNEG
FILTER
FILTER
EMI
EMI
FILTER
VSS
EMI
LOGIC
DIGIN
2
1
2
1
+IN
–IN
+IN
–IN
VDD
VSS
VDD
VSS
A2
A1
Figure 51. Block Diagram Showing EMI/RFI Built-In Filters
OUT
OUT
3
3
R2
R3
R1
P2
P1
Rev. A | Page 24 of 28
R5
DAC
R4
AD8556
P3
P4
2
1
+IN
–IN
R5
The AD8556 features internal EMI filters on the VNEG, VPOS,
FILT, and VCLAMP pins. These built-in filters on the pins limit
the interference bandwidth and provide good RFI suppression
without reducing performance within the pass-band of the
instrumentation amplifier. A functional diagram of the
AD8556 along with its EMI/RFI filters is shown in Figure 51.
The AD8556 has built-in filters on its inputs, VCLAMP, and
filter pins. The first-order, low-pass filters inside the AD8556
are useful to reject high frequency EMI signals picked up by
wires and PCB traces outside the AD8556. The most sensitive
pin of any amplifier to RFI/EMI signal is the noninverting pin.
Signals present at this pin appear as common-mode signals and
create problems.
The filters built at the input of the AD8556 have two different
bandwidths: common mode and differential mode. The common-
mode bandwidth defines what a common-mode RF signal sees
between the two inputs tied together and ground. The EMI
filters placed on the input pins of the AD8556 reject EMI/RFI
suppressions that appear as common-mode signals.
A3
VCLAMP
R7
VDD
OUT
VSS
3
FILTER
FILT/DIGOUT
EMI
RF
FILTER
EMI
1
2
+IN
–IN
A5
VDD
OUT
VSS
2
1
+IN
–IN
3
VDD
VSS
A4
OUT
3
V
OUT