AD8556ARZ Analog Devices Inc, AD8556ARZ Datasheet - Page 23

• 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

3.
4.
5.
Determining Optimal Gain and Offset Codes
First, determine the desired gain:
1.
2.
Next, set the second stage gain:
1.
2.
3.
Set VSS to 0 V and VDD to 5.25 V ( ± 0.25 V). Power
supplies should be capable of supplying 250 mA at the
required voltage and properly bypassed as described
in the Programming Mode section. Use program mode to
permanently enter the desired codes for the first stage gain,
second stage gain, and output offset. Blow the parity bit
fuse if necessary (see Parity Error Detection section). Blow
the master fuse to allow the AD8556 to read data from the
fuses and to prevent further programming.
Set VDD and VSS to the desired values in the application.
Use read mode with low sense current followed by high
sense current to verify programmed codes.
Measure gain and offset to verify correct functionality.
Determine the desired gain, G
obtained from the simulation).
Use Table 6 to determine G
that (4.00 × 1.04) < (G
first and last codes for the first stage gain are not used,
thereby allowing enough first stage gain codes within each
second stage gain range to adjust for the 3% accuracy.
Important: Once a programming attempt is made for any
fuse, there should be no further attempt to blow that fuse.
If a fuse does not program to the expected state, discard
the unit. The expected incidence rate of attempted but
unblown fuses is very small when following the proper
programming procedure and conditions.
Use the simulation mode to set the second stage gain to G
Set the output offset to allow the AD8556 gain to be
measured, for example, use Code 128 to set it to
midsupply.
Use Table 5 or Equation 1 to set the first stage gain code
C
G1
, so the first stage gain is nominally G
A
/G
2
) < (6.4/1.04). This ensures the
2
, the second stage gain, such
A
(using the measurements
A
/G
2
.
2
Rev. A | Page 23 of 28
.
4.
5.
6.
7.
8.
9.
10. Calculate the error (in the number of the first stage gain
11. Set the first stage gain code to C
Finally, determine the desired output offset:
1.
2.
3.
4.
5.
6.
7.
8.
9.
10. Set the output offset code to C
Determine the desired output offset O
measurements obtained from the simulation).
Use Equation 2 to set the output offset code C
the output offset is nominally O
Measure the output offset, O
3% of O
Calculate the error (in relative terms) E
Calculate the error (in the number of the output offset
codes) C
Set the output offset code to C
Measure the output offset, O
than to O
Calculate the error (in relative terms) E
Calculate the error (in the number of the output offset
codes) C
resulting offset should be within one code of O
Measure the resulting gain, G
3% of G
Calculate the first stage gain error (in relative terms)
E
Calculate the error (in the number of the first stage gain
codes) C
Set the first stage gain code to C
Measure the gain, G
Calculate the error (in relative terms) E
codes) C
resulting gain should be within one code of G
G1
= G
B
A
A
/G
B
EO1
EO2
EG1
EG2
.
.
B
.
B
A
= E
= E
= E
= E
− 1.
O1
O2
G1
G2
/0.00392.
/0.00392.
/0.00370.
/0.00370.
C
. G
C
should be closer to G
B
C
. O
B
. O
B
O1
O1
. G
B
A
G1
G1
B
− C
C
− C
.
B
B
should be within
should be closer to O
B
− C
− C
should be within
EO1
EO1
EG1
EG1
A
.
O1
O2
G2
− C
(using the
.
− C
= O
= O
= G
EO2
A
EG2
B
C
C
A
O1
. The
than to G
/O
B
/O
/G
.
A
AD8556
. The
.
such that
A
A
A
− 1.
− 1.
− 1.
B
A
.
B