REV. A
Information furnished by Analog Devices is believed to be accurate and
reliable. However, no responsibility is assumed by Analog Devices for its
use, nor for any infringements of patents or other rights of third parties that
may result from its use. No license is granted by implication or otherwise
under any patent or patent rights of Analog Devices.
a
OP90
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781/329-4700
www.analog.com
Fax: 781/326-8703
Analog Devices, Inc., 2002
Precision Low-Voltage Micropower
Operational Amplifier
PIN CONNECTIONS
8-Lead Hermetic DIP
(Z-Suffix)
8-Lead Epoxy Mini-DIP
(P-Suffix)
8-Lead SO
(S-Suffix)
8
7
6
5
1
2
3
4
NC = NO CONNECT
V
OS
NULL
IN
+IN
NC
V+
OUT
V
OS
NULL
V
FEATURES
Single/Dual Supply Operation: 1.6 V to 36 V,
0.8 V to 18 V
True Single-Supply Operation; Input and Output
Voltage Ranges Include Ground
Low Supply Current: 20 A Max
High Output Drive: 5 mA Min
Low Input Offset Voltage: 150 V Max
High Open-Loop Gain: 700 V/mV Min
Outstanding PSRR: 5.6 V/V Max
Standard 741 Pinout with Nulling to V
GENERAL DESCRIPTION
The OP90 is a high performance, micropower op amp that
operates from a single supply of 1.6 V to 36 V or from dual
supplies of
0.8 V to 18 V. The input voltage range includes
the negative rail allowing the OP90 to accommodate input
signals down to ground in a single-supply operation. The OP90's
output swing also includes a ground when operating from a
single-supply, enabling "zero-in, zero-out" operation.
The OP90 draws less than 20
A of quiescent supply current,
while able to deliver over 5 mA of output current to a load. The
input offset voltage is below 150
V eliminating the need for
*ELECTRONICALLY ADJUSTED ON CHIP
FOR MINIMUM OFFSET VOLTAGE
NULL
NULL
IN
+IN
V+
OUTPUT
V
*
*
Figure 1. Simplied Schematic
external nulling. Gain exceeds 700,000 and common-mode
rejection is better than 100 dB. The power supply rejection
ratio of under 5.6
V/V minimizes offset voltage changes experi-
enced in battery-powered systems.
The low offset voltage and high gain offered by the OP90 bring
precision performance to micropower applications. The minimal
voltage and current requirements of the OP90 suit it for battery
and solar powered applications, such as portable instruments,
remote sensors, and satellites.
REV. A
2
OP90
(V
S
= 1.5 V to 15 V, T
A
= 25 C, unless otherwise noted.)
OP90A/E
OP90G
Parameter
Symbol
Conditions
Min
Typ
Max
Min
Typ
Max Unit
INPUT OFFSET VOLTAGE
V
OS
50
150
125
450
V
INPUT OFFSET CURRENT
I
OS
V
CM
= 0 V
0.4
3
0.4
5
nA
INPUT BIAS CURRENT
I
B
V
CM
= 0 V
4.0
15
4.0
25
nA
LARGE-SIGNAL
V
S
=
15 V, V
O
=
10 V
VOLTAGE GAIN
A
VO
R
L
= 100 k
700
1200
400
800
V/mV
A
VO
R
L
= 10 k
350
600
200
400
V/mV
A
VO
R
L
= 2 k
125
250
100
200
V/mV
V+ = 5 V, V = 0 V,
1 V < V
O
< 4 V
A
VO
R
L
= 100 k
200
400
100
250
V/mV
A
VO
R
L
= 10 k
100
180
70
140
V/mV
INPUT VOLTAGE RANGE
1
IVR
V+ = 5 V, V = 0 V
0/4
0/4
V
V
S
=
15 V
15/13.5
15/13.5
V
OUTPUT VOLTAGE SWING
V
O
V
S
=
15 V
R
L
= 10 k
14
14.2
14
14.2
V
R
L
= 2 k
11
12
11
12
V
V
OH
V+ = 5 V, V = 0 V
R
L
= 2 k
4.0
4.2
4.0
4.2
V
V
OL
V+ = 5 V, V = 0 V
R
L
= 10 k
100
500
100
500
V
COMMON-MODE
CMR
V+ = 5 V, V = 0 V,
REJECTION
0 V < V
CM
< 4 V
90
110
80
100
dB
CMR
V
S
=
15 V,
15 V < V
CM
< 13.5 V
100
130
90
120
dB
POWER SUPPLY
REJECTION RATIO
PSRR
1.0
5.6
3.2
10
V/V
SLEW RATE
SR
V
S
=
15 V
5
12
5
12
V/ms
SUPPLY CURRENT
I
SY
V
S
=
1.5 V
9
15
9
15
A
I
SY
V
S
=
15 V
14
20
14
20
A
CAPACITIVE LOAD
A
V
= 1
STABILITY
2
No Oscillations
250
650
250
650
pF
INPUT NOISE VOLTAGE
e
n p-p
f
O
= 0.1 Hz to 10 Hz
V
S
=
15 V
3
3
V p-p
INPUT RESISTANCE
DIFFERENTIAL MODE
R
IN
V
S
=
15 V
30
30
M
INPUT RESISTANCE
COMMON-MODE
R
INCM
V
S
=
15 V
20
20
G
NOTES
1
Guaranteed by CMR test.
2
Guaranteed but not 100% tested.
Specifications subject to change without notice.
ELECTRICAL CHARACTERISTICS
SPECIFICATIONS
REV. A
3
OP90
(V
S
= 1.5 V to 15 V, 55 C T
A
+125 C, unless otherwise noted.)
Parameter
Symbol
Conditions
Min
Typ
Max
Unit
INPUT OFFSET VOLTAGE
V
OS
80
400
V
AVERAGE INPUT OFFSET
VOLTAGE DRIFT
TCV
OS
0.3
2.5
V/C
INPUT OFFSET CURRENT
I
OS
V
CM
= 0 V
1.5
5
nA
INPUT BIAS CURRENT
I
B
V
CM
= 0 V
4.0
20
nA
LARGE-SIGNAL
VOLTAGE GAIN
A
VO
V
S
=
15 V, V
O
=
10 V
R
L
= 100 k
225
400
V/mV
R
L
= 10 k
125
240
V/mV
R
L
= 2 k
50
110
V/mV
A
VO
V+ = 5 V, V = 0 V,
1 V < V
O
< 4 V
R
L
= 100 k
100
200
V/mV
R
L
= 10 k
50
110
V/mV
INPUT VOLTAGE RANGE
*
IVR
V+ = 5 V, V = 0 V
0/3.5
V
V
S
=
15 V
15/13 5
V
OUTPUT VOLTAGE SWING
V
O
V
S
=
15 V
R
L
= 10 k
13.5
13.7
V
R
L
= 2 k
10.5
11.5
V
V
OH
V+ = 5 V, V = 0 V
R
L
= 2 k
3.9
4.1
V
V
OL
V+ = 5 V, V = 0 V
R
L
= 10 k
100
500
V
COMMON-MODE
REJECTION
CMR
V+ = 5 V, V = 0 V,
0 V < V
CM
< 3.5 V
85
105
dB
V
S
=
15 V,
15 V < V
CM
< 13.5 V
95
115
dB
POWER SUPPLY
REJECTION RATIO
PSRR
3.2
10
V/V
SUPPLY CURRENT
I
SY
V
S
=
1.5 V
15
25
A
V
S
=
15 V
19
30
A
NOTE
*Guaranteed by CMR test.
ELECTRICAL CHARACTERISTICS
REV. A
4
OP90
OP9OE
OP9OG
Parameter
Symbol
Conditions
Min
Typ
Max
Min
Typ
Max
Unit
INPUT OFFSET VOLTAGE
V
OS
70
270
180
675
V
AVERAGE INPUT OFFSET
VOLTAGE DRIFT
TCV
OS
0.3
2
1.2
5
V/C
INPUT OFFSET CURRENT
I
OS
VCM = 0 V
0.8
3
1.3
7
nA
INPUT BIAS CURRENT
I
B
VCM = 0 V
4.0
15
4.0
25
nA
LARGE-SIGNAL
A
VO
V
S
=
15 V, V
O
=
10 V
VOLTAGE GAIN
R
L
= 100 k
500
800
300
600
V/mV
R
L
= 10 k
250
400
150
250
V/mV
R
L
= 2 k
100
200
75
125
V/mV
A
VO
V+ = 5 V, V = 0 V,
1 V < V
O
< 4 V
R
L
= 100 k
150
280
80
160
V/mV
R
L
= 10 k
75
140
40
90
V/mV
INPUT VOLTAGE RANGE
*
IVR
V+ = 5 V, V = 0 V
0/3.5
0/3.5
V
V
S
=
15 V
15/13.5
15/13.5
V
OUTPUT VOLTAGE SWING
V
O
V
S
=
15 V
R
L
= 10 k
13.5
14
13.5
14
V
R
L
= 2 k
10.5
11.8
10.5
11.8
V
V
OH
V+ = 5 V, V = 0 V
R
L
= 2 k
3.9
4.1
3.9
4.1
V
V
OL
V+ = 5 V, V = 0 V
R
L
= 10 k
100
500
100
500
V
COMMON-MODE
CMR
V+ = 5 V, V = 0 V,
REJECTION
0 V < V
CM
< 3.5 V
80
100
80
100
dB
V
S
=
15 V,
15 V < V
CM
< 13.5 V
100
120
90
110
dB
POWER SUPPLY
REJECTION RATIO
PSRR
10
5.6
5.6
17.8
V/V
SUPPLY CURRENT
I
SY
V
S
=
1.5 V
13
25
12
25
A
V
S
=
15 V
17
30
16
30
A
NOTE
*Guaranteed by CMR test.
ELECTRICAL CHARACTERISTICS
(V
S
= 1.5 V to 15 V, 25 C T
A
+85 C for OP90E/F, 40 C
T
A
+85 C for
OP90G, unless otherwise noted.)
REV. A
OP90
5
ORDERING GUIDE
Package Options
T
A
= 25 C
Operating
V
OS
Max
CERDIP
Plastic
Temperature
(mV)
8-Lead
8-Lead
Range
150
OP90AZ/883
*
MIL
150
OP90EZ
*
IND
450
OP90GP
XIND
450
OP90GS
XIND
*Not for new design, obsolete April 2002.
ABSOLUTE MAXIMUM RATINGS
1
Supply Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
18 V
Differential Input Voltage . . . . [(V) 20 V] to [(V+) + 20 V]
Common-Mode Input Voltage . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . [(V) 20 V] to [(V+) + 20 V]
Output Short-Circuit Duration . . . . . . . . . . . . . . . . Indefinite
Storage Temperature Range
Z Package . . . . . . . . . . . . . . . . . . . . . . . . . 65
C to +150C
P Package . . . . . . . . . . . . . . . . . . . . . . . . . 65
C to +150C
Operating Temperature Range
OP90A . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
C to +125C
OP90E . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
C to +85C
OP90G . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
C to +85C
Junction Temperature (T
J
) . . . . . . . . . . . . . 65
C to +150C
Lead Temperature (Soldering 60 sec) . . . . . . . . . . . . . . 300
C
CAUTION
ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily
accumulate on the human body and test equipment and can discharge without detection. Although
the OP90 features proprietary ESD protection circuitry, permanent damage may occur on devices
subjected to high-energy electrostatic discharges. Therefore, proper ESD precautions are
recommended to avoid performance degradation or loss of functionality.
WARNING!
ESD SENSITIVE DEVICE
Package Type
JA
2
JC
Unit
8-Lead Hermetic DIP (Z)
148
16
C/W
8-Lead Plastic DIP (P)
103
43
C/W
8-Lead SO (S)
158
43
C/W
NOTES
1
Absolute Maximum Ratings apply to packaged parts, unless otherwise noted.
2
JA
is specified for worst-case mounting conditions; i.e.,
JA
is specified for
device in socket for CerDIP, and P-DIP;
JA
is specified for devices soldered to
printed circuit board for SO package.
REV. A
OP90
6
TEMPERATURE C
INPUT OFFSET
V
O
L
T
A
GE
V
100
80
0
75
50
125
0
25
100
40
60
20
75
50
25
V
S
= 15V
TPC 1. Input Offset Voltage
vs. Temperature
TEMPERATURE C
SUPPL
Y CURRENT
A
22
18
2
75
50
125
0
25
100
10
14
6
75
50
25
NO LOAD
V
S
= 1.5V
20
16
8
12
4
V
S
= 15V
TPC 4. Supply Current vs.
Temperature
FREQUENCY Hz
CLOSED-LOOP GAIN
dB
60
40
20
10
100k
1k
20
0
10k
100
V
S
= 15V
T
A
= 25 C
TPC 7. Closed-Loop Gain
vs. Frequency
Typical Performance Characteristics
TEMPERATURE C
INPUT OFFSET CURRENT
nA
1.6
0.2
75
50
125
0
25
100
0.8
1.0
0.4
75
50
25
1.4
1.2
0.6
V
S
= 15V
TPC 2. Input Offset Current
vs. Temperature
SINGLE-SUPPLY VOLTAGE V
OPEN-LOOP GAIN
V/mV
600
0
0
30
10
15
25
300
100
20
5
500
400
200
R
L
= 10k
T
A
= 25 C
T
A
= 85 C
T
A
= 125 C
TPC 5. Open-Loop Gain vs.
Single-Supply Voltage
LOAD RESISTANCE
OUTPUT V
O
L
T
A
GE
SWING
V
6
4
0
100
100k
1k
3
1
10k
V+ = 5V, V = 0V
T
A
= 25 C
5
2
TPC 8. Output Voltage Swing
vs. Load Resistance
TEMPERATURE C
INPUT BIAS CURRENT
nA
4.2
4.0
3.0
75
50
125
0
25
100
3.6
3.8
3.4
75
50
25
V
S
= 15V
3.2
TPC 3. Input Bias Current
vs. Temperature
FREQUENCY Hz
OPEN-LOOP GAIN
dB
140
120
0
0.1
1
100k
10
100
10k
80
100
60
1k
V
S
= 15V
T
A
= 25 C
R
L
= 100k
40
20
GAIN
45
0
90
135
180
PHASE SHIFT
DEG
TPC 6. Open-Loop Gain and
Phase Shift vs. Frequency
LOAD RESISTANCE
OUTPUT SWING
V
16
12
0
100
100k
1k
8
4
10k
T
A
= 25 C
V
S
= 15V
14
6
10
2
POSITIVE
NEGATIVE
TPC 9. Output Voltage Swing
vs. Load Resistance
REV. A
7
OP90
+18V
18V
2
3
4
6
7
OP90
Figure 2. Burn-In Circuit
APPLICATION INFORMATION
Battery-Powered Applications
The OP90 can be operated on a minimum supply voltage of 1.6 V,
or with dual supplies
0.8 V, and draws only 14 pA of supply
current. In many battery-powered circuits, the OP90 can be
continuously operated for thousands of hours before requiring
battery replacement, reducing equipment down time and
operating cost.
High-performance portable equipment and instruments frequently
use lithium cells because of their long shelf-life, light weight, and
high-energy density relative to older primary cells. Most lithium
cells have a nominal output voltage of 3 V and are noted for a
flat discharge characteristic. The low-supply voltage requirement
of the OP90, combined with the flat discharge characteristic of
the lithium cell, indicates that the OP90 can be operated over
the entire useful life of the cell. Figure 1 shows the typical dis-
charge characteristic of a 1Ah lithium cell powering an OP90
which, in turn, is driving full output swing into a 100 k
load.
FREQUENCY Hz
PO
WER SUPPL
Y REJECTION
dB
120
100
20
1
1k
10
100
T
A
= 25 C
60
80
40
POSITIVE SUPPLY
NEGATIVE SUPPLY
TPC 10. Power Supply Rejection
vs. Frequency
FREQUENCY Hz
CURRENT NOISE DENSITY
pA/
Hz
100
0.1
0.1
1k
1
10
10
1
V
S
= 15V
T
A
= 25 C
100
TPC 13. Current Noise Density
vs. Frequency
FREQUENCY Hz
COMMON-MODE REJECTION
dB
140
120
40
1
1k
10
100
V
S
= 15V
T
A
= 25 C
80
100
60
TPC 11. Common-Mode Rejection
vs. Frequency
T
A
= 25 C
V
S
= 15V
A
V
= +1
R
L
= 10k
C
L
= 500pF
TPC 14. Small-Signal Transient
Response
FREQUENCY Hz
NOISE V
O
L
T
A
GE
DENSITY
nV/
Hz
1000
1
0.1
1k
1
10
100
10
V
S
= 15V
T
A
= 25 C
100
TPC 12. Noise Voltage Density
vs. Frequency
T
A
= 25 C
V
S
= 15V
A
V
= +1
R
L
= 10k
C
L
= 500pF
TPC 15. Large-Signal Transient
Response
REV. A
OP90
8
Single-Supply Output Voltage Range
In single-supply operation, the OP90's input and output ranges
include ground. This allows true "zero-in, zero-out" operation.
The output stage provides an active pull-down to around 0.8 V
above ground. Below this level, a load resistance of up to 1 M
to ground is required to pull the output down to zero.
In the region from ground to 0.8 V, the OP90 has voltage gain
equal to the data sheet specification. Output current source
capatibility is maintained over the entire voltage range includ-
ing ground.
APPLICATIONS
Battery-Powered Voltage Reference
The circuit of Figure 6 is a battery-powered voltage reference
that draws only 17
A of supply current. At this level, two AA
cells can power this reference over 18 months. At an output voltage
of 1.23 V @ 25
C, drift of the reference is only at 5.5 V/C over
the industrial temperature range. Load regulation is 85
V/mA
with line regulation at 120
V/V.
Design of the reference is based on the bandgap technique.
Scaling of resistors R1 and R2 produces unequal currents in Q1
and Q2. The resulting V
BE
mismatch creates a temperature
proportional voltage across R3 which, in turn, produces a larger
temperature-proportional voltage across R4 and R5. This volt-
age appears at the output added to the V
BE
of Q1, which has an
opposite temperature coefficient. Adjusting the output to l.23 V
at 25
C produces minimum drift over temperature. Bandgap
references can have start-up problems. With no current in R1
and R2, the OP90 is beyond its positive input range limit and
has an undefined output state. Shorting Pin 5 (an offset adjust
pin) to ground, forces the output high under these conditions
and ensures reliable start-up without significantly degrading the
OP90's offset drift.
4
2
3
5
6
7
OP90
R1
240k
R2
1.5M
C1
1000pF
V+
(2.5V TO 36V)
V
OUT
(1.23V @ 25 C)
6
5
7
3
2
1
R3
68k
R4
130k
R5
20k
OUTPUT
ADJUST
MAT-01AH
Figure 6. Battery-Powered Voltage Reference
HOURS
LITHIUM SULPHUR DIO
XIDE
CELL V
O
L
T
A
GE
V
4
3
0
0
2000
7000
4000
2
1
1000
3000
6000
5000
Figure 3. Lithium Sulphur Dioxide Cell Discharge
Characteristic with OP90 and 100 k
Load
Input Voltage Protection
The OP90 uses a PNP input stage with protection resistors in
series with the inverting and noninverting inputs. The high
breakdown of the PNP transistors coupled with the protection
resistors provides a large amount of input protection, allowing
the inputs to be taken 20 V beyond either supply without dam-
aging the amplifier.
Offset Nulling
The offset null circuit of Figure 4 provides 6 mV of offset adjust-
ment range. A 100 k
resistor placed in a series with the wiper
of the offset null potentiometer, as shown in Figure 5, reduces
the offset adjustment range to 400
V and is recommended for
applications requiring high null resolution. Offset nulling does not
affect TCV
OS
performance.
TEST CIRCUITS
V+
1
2
3
5
6
7
OP90
4
100k
V
Figure 4. Offset Nulling Circuit
V+
1
2
3
5
6
7
OP90
4
100k
V
100k
Figure 5. High Resolution Offset Nulling Circuit
REV. A
OP90
9
Single Op Amp Full-Wave Rectifier
Figure 7 shows a full-wave rectifier circuit that provides the
absolute value of input signals up to
2.5 V even though operated
from a single 5 V supply. For negative inputs, the amplifier acts
as a unity-gain inverter. Positive signals force the op amp output
to ground. The 1N914 diode becomes reversed-biased and the
signal passes through R1 and R2 to the output. Since output
impedance is dependent on input polarity, load impedances
cause an asymmetric output. For constant load impedances, this
can be corrected by reducing R2. Varying or heavy loads can be
buffered by a second OP90. Figure 8 shows the output of the
full-wave rectifier with a 4 V
p-p
, 10 Hz input signal.
+5V
2
3
4
6
OP90FZ
7
R3
100k
HP5082-2800
V
IN
R1
10k
R2
10k
1N914
V
OUT
Figure 7. Single Op Amp Full-Wave Rectifier
Figure 8. Output of Full-Wave Rectifier with 4 V
p-p
,
10 Hz Input
2-WIRE 4 mA TO 20 mA CURRENT TRANSMITTER
The current transmitter of Figure 9 provides an output of 4 mA
to 20 mA that is linearly proportional to the input voltage.
Linearity of the transmitter exceeds 0.004% and line rejection is
0.0005%/volt.
Biasing for the current transmitter is provided by the REF-02EZ.
The OP90EZ regulates the output current to satisfy the current
summation at the noninverting node:
I
R
V
R
R
V R
R
OUT
IN
=
+
1
6
5
2
5
5
1
For the values shown in Figure 9,
I
V
mA
OUT
IN
=
+
16
100
4
giving a full-scale output of 20 mA with a 100 mV input.
Adjustment of R2 will provide an offset trim and adjustment of
R1 will provide a gain trim. These trims do not interact since
the noninverting input of the OP90 is at virtual ground. The
Schottky diode, D1, prevents input voltage spikes from pulling
the noninverting input more than 300 mV below the inverting
input. Without the diode, such spikes could cause phase reversal of
the OP90 and possible latch-up of the transmitter. Compliance of
this circuit is from 10 V to 40 V. The voltage reference output
can provide up to 2 mA for transducer excitation.
2
3
4
6
7
I
OUT
=
16V
IN
100
+ 4mA
V
IN
R2
5k
6
4
2
R6
100
R3
4.7k
R4
100k
R1
1M
D1
HP
5082-
2800
R5
80k
+5V
REFERENCE
2mA MAX
+
I
OUT
R
L
2N1711
V+
(10V TO 40V)
OP90EZ
REF-02EZ
Figure 9. 2-Wire 4 mA to 20mA Transmitter
REV. A
OP90
10
Micropower Voltage-Controlled Oscillator
Two OP90s in combination with an inexpensive quad CMOS
switch comprise the precision VCO of Figure 10. This circuit
provides triangle and square wave outputs and draws only 50
A
from a single 5 V supply. A1 acts as an integrator; S1 switches
the charging current symmetrically to yield positive and negative
ramps. The integrator is bounded by A2 which acts as a Schmitt
trigger with a precise hysteresis of 1.67 V, set by resistors R5,
R6, and R7, and associated CMOS switches. The resulting output
of A1 is a triangular wave with upper and lower levels of 3.33 V
and 1.67 V. The output of A2 is a square wave with almost
rail-to-rail swing. With the components shown, frequency of
operation is given by the equation:
f
V
V
Hz V
OUT
CONTROL
=
( )
10
/
but this is easily changed by varying C1. The circuit operates
well up to a few hundred hertz.
Micropower Single-Supply Instrumentation Amplifier
The simple instrumentation amplifier of Figure 11 provides over
110 dB of common-mode rejection and draws only 15
A of
supply current. Feedback is to the trim pins rather than to the
inverting input. This enables a single amplifier to provide differ-
ential to single-ended conversion with excellent common-mode
rejection. Distortion of the instrumentation amplifier is that of a
differential pair, so the circuit is restricted to high gain applica-
3
7
C1
75nF
6
4
2
R3
100k
R4
200k
R1
200k
R2
200k
V
CONTROL
+5V
TRIANGLE
OUT
R8
200k
+5V
R5
200k
3
7
6
4
2
SQUARE
OUT
R6
200k
R7
200k
IN/OUT
OUT/IN
IN/OUT
CONT
CONT
CONT
1
IN/OUT
IN/OUT
V
SS
+5V
CONT
2
3
4
5
6
7
14
13
12
11
10
9
8
CD4066
+5V
+5V
+5V
V
DD
OUT/IN
OUT/IN
OUT/IN
OP90EZ
A2
S1
S2
S3
S4
OP90EZ
A1
Figure 10. Micropower Voltage Controlled Oscillator
tions. Nonlinearity is less than 0.1% for gains of 500 to 1000
over a 2.5 V output range. Resistors R3 and R4 set the voltage
gain and, with the values shown, yield a gain of 1000. Gain
tempco of the instrumentation amplifier is only 50 ppm/
C.
Offset voltage is under 150
V with drift below 2 V/C. The
OP90's input and output voltage ranges include the negative
rail which allows the instrumentation amplifier to provide true
"zero-in, zero-out" operation.
R1
4.3M
R4
3.9M
R3
1M
R2
500k
GAIN
ADJUST
V
OUT
3
7
6
4
2
5
IN
1
+IN
0.1 F
+5V
OP90EZ
Figure 11. Micropower Single-Supply Instrumentation
Amplifier
REV. A
OP90
11
Single-Supply Current Monitor
Current monitoring essentially consists of amplifying the voltage
drop across a resistor placed in a series with the current to be
measured. The difficulty is that only small voltage drops can be
tolerated and with low precision op amps this greatly limits the
overall resolution. The single supply current monitor of Figure 12
has a resolution of 10
A and is capable of monitoring 30 mA of
current. This range can be adjusted by changing the current
sense resistor R1. When measuring total system current, it may
be necessary to include the supply current of the current moni-
tor, which bypasses the current sense resistor, in the final result.
This current can be measured and calibrated (together with the
residual offset) by adjustment of the offset trim potentiometer,
R2. This produces a deliberate offset that is temperature
dependent. However, the supply current of the OP90 is also
proportional to temperature and the two effects tend to track.
Current in R4 and R5, which also bypasses R1, can be accounted
for by a gain trim.
R1
1
R4
9.9k
R2
100k
R3
100k
3
7
6
4
2
5
1
V+
R5
100
I
TEST
V
OUT
= 100mV/mA (I
TEST
)
TO CIRCUIT
UNDER TEST
+
OP90EZ
Figure 12. Single-Supply Current Monitor
12
C0032101/02(A)
PRINTED IN U.S.A.
OUTLINE DIMENSIONS
Dimensions shown in inches and (mm).
Revision History
Location
Page
9/01--Data Sheet changed from REV. 0 to REV. A.
Edits to PIN CONNECTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Edits to ELECTRICAL CHARACTERISTICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2, 3, 4
Edits to ORDERING INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Edits to ABSOLUTE MAXIMUM RATINGS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Edits to PACKAGE TYPE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
DELETED OP90 DICE CHARACTERISTICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
DELETED WAFER TEST LIMITS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
8-Lead Soic Package
(R-8)
0.0098 (0.25)
0.0075 (0.19)
0.0500 (1.27)
0.0160 (0.41)
0.0196 (0.50)
0.0099 (0.25)
45
8
0
0.102 (2.59)
0.094 (2.39)
SEATING
PLANE
0.0098 (0.25)
0.0040 (0.10)
0.0192 (0.49)
0.0138 (0.35)
8
5
4
1
0.1968 (5.00)
0.1890 (4.80)
PIN 1
0.1574 (4.00)
0.1497 (3.80)
0.0500 (1.27)
BSC
0.2440 (6.20)
0.2284 (5.80)
8-Lead PDIP Package
(N-8)
SEATING
PLANE
0.060 (1.52)
0.015 (0.38)
0.210
(5.33)
MAX
0.022 (0.558)
0.014 (0.356)
0.160 (4.06)
0.115 (2.93)
0.070 (1.77)
0.045 (1.15)
0.130
(3.30)
MIN
8
1
4
5
PIN 1
0.280 (7.11)
0.240 (6.10)
0.100 (2.54)
BSC
0.430 (10.92)
0.348 (8.84)
0.195 (4.95)
0.115 (2.93)
0.015 (0.381)
0.008 (0.204)
0.325 (8.25)
0.300 (7.62)
8-Lead Hermetic Package
(Q-8)
1
4
8
5
0.310 (7.87)
0.220 (5.59)
PIN 1
0.005 (0.13)
MIN
0.055 (1.4)
MAX
0.100 (2.54) BSC
15
0
0.320 (8.13)
0.290 (7.37)
0.015 (0.38)
0.008 (0.20)
SEATING
PLANE
0.200 (5.08)
MAX
0.405 (10.29) MAX
0.150
(3.81)
MIN
0.200 (5.08)
0.125 (3.18)
0.023 (0.58)
0.014 (0.36)
0.070 (1.78)
0.030 (0.76)
0.060 (1.52)
0.015 (0.38)
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