ISL282X7SOICEVAL2Z Datasheet, PDF (1/4 Pages) Intersil Corporation – Evaluation Board User’s Guide

Application Note 1509
ISL282X7SOICEVAL2Z Evaluation Board User’s Guide
Introduction
The ISL282X7SOICEVAL2Z evaluation board is a design
platform containing all the circuitry needed to
characterize critical performance parameters of the
ISL282X7 operational amplifiers in SOIC-8 package,
using a variety of user defined test circuits.
The ISL282X7 operational amplifiers feature low bias
current, low noise, and low offset and temperature drift.
but can be changed by the user to provide additional
power supply filtering, or to reduce the voltage rate-of-rise
to less than ±1V/µs. Two additional capacitors, C3 and C5
are connected close to the part to filter out high frequency
noise. Anti-reverse diode D1 protects the circuit in the
case of accidental polarity reversal.
J6
V- _J8
J11
V+ _J12
VREF
J13
J14
Reference Documents
• ISL28207 Data Sheet, FN6631
• ISL28217 Data Sheet, FN6632
C2
1µF
C4
1µF
• ISL28227 Data Sheet, FN6633
D1
Evaluation Board Key Features
C3
C5
The ISL282X7SOICEVAL2Z is designed to enable the IC
to operate from a single supply, +4.5VDC to +40VDC or
from split supplies, ±2.25VDC to ±20V. The board is
configured for a dual op amp connected for differential
input with a closed loop gain of 10. A single external
reference voltage (VREF) pin and provisions for a
user-selectable voltage divider - filter are included.
Power Supplies (Figure 1)
External power connections are made through the +V, -V,
VREF 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 and -V terminals connect to their
respective power supply terminals. De-coupling capacitors
C2 and C4 connect to their respective supplies through
R16 and R31 zero-ohm resistors. These resistors are 0Ω
0.01µF
0.01µF
FIGURE 1. POWER SUPPLY CIRCUIT
Amplifier Configuration (Figure 2)
The schematic of 1/2 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 must be connected to ground to
establish a ground referenced input for dual supply
operation, or can be externally set to any reference level for
single supply operation. VREF should not be left floating.
RF
IN-
IN+
IN -
RIN-
10kΩ
RIN+
100kΩ
VP
IN- _-
V+
V-
IN+ ₊
ISL282X7 (1/2)
0Ω
VOUT
VCM
IN +
10kΩ
VM
VREF
RREF+
100kΩ
RL
DNP
VREF GND
FIGURE 2. BASIC AMPLIFIER CONFIGURATION
November 6, 2009
AN1509.0
1
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
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