Introduction
The ISL281x6EVAL1Z evaluation board is a design platform
containing all the circuitry needed to characterize critical
performance parameters of the ISL281x6 operational
amplifiers, using a variety of user defined test circuits.
The ISL28136 and ISL28146 high-speed operational
amplifiers feature low power consumption, while ISL28156
and ISL28166 operational amplifiers feature ultra-low power
consumption. All op amps have rail-to-rail output drive
capability and are designed to operate with a single lithium
cell or two Ni_Cd batteries.
Reference Documents
• ISL28136 Data Sheet, FN6153
• ISL28146 Data Sheet, FN6321
• ISL28156 Data Sheet, FN6154
• ISL28166 Data Sheet, FN6155
Evaluation Board Key Features
The ISL281x6EVAL1Z is designed to enable the IC to
operate from a single supply, +2.4VDC to +5.5VDC or from
split supplies, ±1.2VDC to ±2.75V. The board is configured
for a single op amp connected for differential input with a
closed loop gain of 10. It also contains a single external
reference voltage (VREF) pin and provisions for a
user-selectable voltage divider (filter are included).
Power Supplies (
External power connections are made through the V+, V-
and Ground connections on the evaluation board. For single
supply operation, the V- and Ground pins are tied together to
the power supply negative terminal. For split supplies V+
VCM
IN-
IN+
VREF
Figure 1
®
VREF
GND
IN+
1
IN -
)
ISL281x6EVAL1Z Evaluation Board User’s Guide
Application Note
FIGURE 2. BASIC AMPLIFIER CONFIGURATION
0Ω
10kΩ
10kΩ
RIN-
RIN+
1-888-INTERSIL or 1-888-468-3774
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
RREF+
100kΩ
10kΩ
IN-
IN+
+
-
and V- terminals connect to their respective power supply
terminals. De-coupling capacitors C
ground through R
R
additional power supply filtering, or to reduce the voltage
rate-of-rise to less than ±1V/µs. Two additional capacitors,
C
frequency noise. Anti-reverse diodes D
circuit in the case of accidental polarity reversal.
Amplifier Configuration (
The schematic of the op amp with the components supplied
is shown in Figure 2. The circuit implements a differential
input amp with a closed loop gain of 10. The circuit can
operate from a single supply or from dual supplies. The
VREF pin can be connected to ground to establish a ground
referenced input for split supply operation, or can be
externally set to any reference level for single supply
operation.
100kΩ
RF
24
3
and C
are 0Ω but can be changed by the user to provide
0.1µF
August 17, 2007
C4
VP
V+
V-
VM
V-
All other trademarks mentioned are the property of their respective owners.
4
|
are connected close to the part to filter out high
Intersil (and design) is a registered trademark of Intersil Americas Inc.
FIGURE 1. POWER SUPPLY CIRCUIT
VM
4.7µF
C2
1
+
and R
ISL281x6
Copyright Intersil Americas Inc. 2007. All Rights Reserved
D2
R21
0Ω
0
21
0Ω resistors. Resistors R
R1
0
10kΩ
Figure 2
RL
1
D1
and C
1
4.7µF
and D
C1
+
2
connect to
)
VOUT
2
AN1351.0
VP
protect the
V+
0.1µF
C3
20
and