an1352

Application Note 1352
ISL28194EVAL1Z, ISL28195EVAL1Z Evaluation
Board User’s Guide
Introduction
• ISL28194EVAL1Z
Reference Documents
C4
• ISL28194, ISL28195 Data Sheet, FN6236
J1
R21
R1
C1
+
4.7µF
0
0
+
4.7µF
D2
D1
V+
C3
0.1µF
0.1µF
Evaluation Board Key Features
VM
The ISL28194EVAL1Z, ISL28195EVAL1Z is designed to
enable the IC to operate from a single supply, +1.8VDC
to +5.5VDC or from split supplies, ±0.9VDC 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
R20
• ISL28195EVAL1Z
C2
0
V-
R24
Ordering Information
J2
The ISL28194 and ISL28195 micro-power operational
amplifiers feature ultra-low power consumption,
rail-to-rail input and output drive capability, and are
designed to operate with two 1.5V Alkaline batteries.
0
The ISL28194EVAL1Z, ISL28195EVAL1Z evaluation
board is a design platform containing all the circuitry
needed to characterize critical performance parameters
of the ISL28194 and ISL28195 operational amplifiers,
using a variety of user defined test circuits.
J3
supplies V+ and V- terminals connect to their respective
power supply terminals. De-coupling capacitors C1 and
C2 connect to ground through R1 and R21 0Ω resistors.
Resistors R20 and R24 are 0Ω 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 C4 are connected close to
the part to filter out high frequency noise. Anti-reverse
diodes D1 and D2 protect the circuit in the case of
accidental polarity reversal.
VP
FIGURE 1. POWER SUPPLY CIRCUIT
Amplifier Configuration
(Figure 2)
The schematic of the op amp with the components
supplied is shown in Figure 2.
(Figure 1)
External power connections are made through the V+, Vand 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
RF
10MΩ
IN RIN-
IN-
IN-
IN+
V+
IN+
VCM
0Ω
VOUT
V+
VM
1MΩ
IN+
VP
-
1MΩ
RIN+
ISL28194, ISL28195
RREF+
VREF
VREF
GND
0Ω
10MΩ
10kΩ
FIGURE 2. BASIC AMPLIFIER CONFIGURATION
May 26, 2010
AN1352.1
1
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
1-888-INTERSIL or 1-888-468-3774 | Intersil (and design) is a registered trademark of Intersil Americas Inc.
Copyright Intersil Americas Inc. 2007, 2010. All Rights Reserved
All other trademarks mentioned are the property of their respective owners.
Application Note 1352
User-Selectable Options
mode reference at the VREF input. The inverting and
non-inverting inputs have additional resistor placements
for adding input attenuation, or to establish input DC
offsets through the VREF pin.
(Figures 3 and 4)
Component pads are included to enable a variety of
user-selectable circuits to be added to the amplifier
inputs, the VREF input, outputs and the amplifier
feedback loops.
The output (Figure 4) has additional resistor and
capacitor placements for loading.
J4
A voltage divider and filter option (Figure 3) can be
added to establish a power supply-tracking common
J5 OUT
DNP
R27
DNP
R25
0
DNP
0
OPEN
R26
R23
C8
TO IN+
OPEN
R22
C9
+
4.7µF
TO OUT
TO IN-
C10
DNP
DNP
RINA2+
100M
R13
0
6
DNP
DNP
R3
RINA+
R11
10M
OPEN R
IN2+ J8
RREFA+
R14
R9
C7
RREF
OPEN
RINA1+
R7
IN1+ J7
0
DNP
10k
C5
OPEN
DNP
RREFAR15
R12
DNP
DNP
R2
1M
RINA2-
R8
R5
IN- J6
0
C6
R17
RINAR10
R18
REF1
RGA+
FIGURE 4. OUTPUT STAGE
FIGURE 3. INPUT STAGE
ISL28194EVAL1Z, ISL28195EVAL1Z Components Parts List
DEVICE NUMBER
C1, C2, C5
C3, C4
C6 to C10
D1, D2
DESCRIPTION
CAP-TANTALUM, SMD, D, 4.7µF, 50V, 10%, LOW ESR, ROHS
Power supply decoupling
CAP, SMD, 0603, 0.1µF, 25V, 10%, X7R, ROHS
Power supply decoupling
CAP, SMD, 0603, DNP-PLACE HOLDER, ROHS
User-selectable capacitors - not
populated
DIODE-RECTIFIER, SMD, SOD-123, 2P, 40V, 0.5A, ROHS
Reverse power protection
U1 (ISL28194EVAL1Z)
ISL28194FHZ-T7, IC-RAIL-TO-RAIL OP AMP, SOT-23, ROHS
U1 (ISL28195EVAL1Z)
ISL28195FHZ-T7, IC-RAIL-TO-RAIL OP AMP, SOT-23, ROHS
R2, R3, R6, R8, R9, R12, RESISTOR, SMD, 0603, 0.1%, MF, DNP-PLACE HOLDER
R13, R15, R23, R25, R27
R1, R5, R11, R17, R20,
R21, R22, R24, R26
R4, R18
R16
R7, R10
R14, R19
COMMENTS
User-selectable resistors - not
populated
RES, SMD, 0603, 0Ω, 1/10W, TF, ROHS
0Ω user-selectable resistors
RES, SMD, 0603, 10k, 1/10W, 1%, TF, ROHS
Gain and other user-selectable
resistors
RES, SMD, 0603, 100k, 1/10W, 1%, TF, ROHS
Gain resistors
RES, SMD, 0603, 1M, 1/10W, 1%, TF, ROHS
Gain and other user-selectable
resistors
RES, SMD, 0603, 10M, 1/10W, 1%, TF, ROHS
Gain resistors
2
AN1352.1
May 26, 2010
Application Note 1352
ISL28194EVAL1Z, ISL28195EVAL1Z Top View
Intersil Corporation reserves the right to make changes in circuit design, software and/or specifications at any time without notice. Accordingly, the
reader is cautioned to verify that the Application Note or Technical Brief is current before proceeding.
For information regarding Intersil Corporation and its products, see www.intersil.com
3
AN1352.1
May 26, 2010
C2
R1
0
0
C1
+
D1 4.7µF
RREFA+
R14
EN
DNP
100k
J9
R4
10k
2
S1
3ENABLE
1
DISABLE
VP
R16
VM
2
3
3
4
SOT23_6
VP
5
4
DNP
6
0
J5
R27
1
6
GENERIC
2 PACK 5
0
DNP
1
R26
R25
U1
R22
DNP
R13
RGA+
OPEN
10M
R23
OPEN
C9
R19
DNP
R9
R3
DNP
RINA2+
C10
OPEN
0
R6
DNP
IN2+
C8
OPEN
J8
10M
RINA+
R11
DNP
1M
C7
0
R24
R20
0
VP
OUT
Application Note 1352
RINA1+
R7
J7
CLOSE TO PART
0.1µF
VM
IN1+
C3
0.1µF
+
4.7µF
R12
CLOSE TO PART
10k
C5
DNP
0
R17
OPEN
V+
RREF
C4
R18
RREFAR15
DNP
R8
R2
DNP
0
RINA2-
1M
C6
DNP
4
IN-
R5
J6
R21
+
4.7µF D2
RINAR10
J1
J2
V-
REF1
J3
J4
ISL28194EVAL1Z, ISL28195EVAL1Z Schematic Diagram
AN1352.1
May 26, 2010
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