AD8592ARMZ Analog Devices Inc, AD8592ARMZ Datasheet - Page 12

• Manufacturer Part Number: AD8592ARMZ
• Description: OP AMP, +SHUTDOWN RRI/O, SMD, 8592
• Manufacturer: Analog Devices Inc

Specifications of AD8592ARMZ

• Op Amp Type: Low Input Bias
• No. Of Amplifiers: 2
• Bandwidth: 2.2MHz
• Slew Rate: 5V/µs
• Supply Voltage Range: 2.5V To 6V
• Amplifier Case Style: MSOP
• No. Of Pins: 10
• Operating Temperature Range: -40°C To
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

AD8591/AD8592/AD8594
SPICE Model for the AD8591/AD8592/AD8594 Amplifier
The SPICE model for the AD8591/AD8592/AD8594 amplifier is
one of the more realistic computer simulation macro-models
available, providing a high degree of realism with respect to char-
acteristics of the actual amplifier. This model, shown in Listing 1,
is based on typical values for the device and can be downloaded
from Analog Devices’ Internet site at www.analog.com.
The model uses a common source output stage to provide rail-
to-rail performance. This allows realistic simulation of open-
loop gain dependency on load resistance as well as maximum
output voltage versus output current. Two differential pairs are
used in the input stage of the model, simulating the rail-to-rail
input stage of the AD8591/AD8592/AD8594 amplifier.
The EOS voltage source establishes the input offset voltage and
is also used to simulate the common-mode rejection power
supply rejection, and input voltage noise characteristics for the
model. In addition, G2, R2 and CF are used to help set the
open-loop gain and gain-bandwidth product of the model.
–12–
A number of secondary characteristics are also accurately por-
trayed in the SPICE model. Flicker noise is accurately modeled
with the 1/f corner frequency set through the KF and AF terms
in the input stage transistors. C1 and C2 are used in the input
section to create secondary poles to achieve an accurate phase
margin characteristic for the model.
The AD8591/AD8592/AD8594 shutdown circuitry is included
in the model. Switches S1 through S7 deactivate the op amp
circuitry in shutdown mode. The logic threshold for the shut-
down circuitry is accurately modeled through the VSWITCH
model parameters near the end of the listing. The active supply
current versus supply voltage is also modeled through the volt-
age-controlled current source GSY.
Characteristics of this model are based on typical values for the
AD8591/AD8592/AD8594 amplifier at +27 C. The model’s
characteristics are optimized specifically at +27 C, and may lose
accuracy at different simulation temperatures.
REV. A