OP495GBC [ADI]
DUAL/QUAD RAIL-TO-RAIL OPERATIONAL AMPLIFIERS; 双/四路轨到轨运算放大器
| 型号： | OP495GBC |
| 厂家： | 
ADI |
| 描述： | DUAL/QUAD RAIL-TO-RAIL OPERATIONAL AMPLIFIERS |
| 文件： | 总12页 (文件大小：330K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
Dual/Quad Rail-to-Rail
Operational Amplifiers
a
OP295/OP495
P IN CO NNECTIO NS
FEATURES
Rail-to-Rail Output Sw ing
8-Lead Narrow-Body SO
8-Lead Epoxy D IP
(P Suffix)
Single-Supply Operation: +3 V to +36 V
Low Offset Voltage: 300 V
Gain Bandw idth Product: 75 kHz
High Open-Loop Gain: 1000 V/ m V
Unity-Gain Stable
(S Suffix)
8
7
OUT A
1
2
3
4
V+
OUT A
–IN A
+IN A
V–
1
8
7
6
5
V+
OUT B
–IN B
–IN A
+IN A
V–
2
3
4
OUT B
OP295
6
Low Supply Current/ Per Am plifier: 150 A m ax
–IN B
+IN B
5
+IN B
APPLICATIONS
Battery Operated Instrum entation
Servo Am plifiers
Actuator Drives
Sensor Conditioners
Pow er Supply Control
OP295
14-Lead Epoxy D IP
(P Suffix)
16-Lead SO (300 Mil)
(S Suffix)
16 OUT D
15 –IN D
OUT A
1
2
3
4
5
6
7
8
OUT A
1
2
14 OUT D
–IN D
–IN A
+IN A
V+
–IN A
+IN A
13
12 +IN D
14
+IN D
3
4
5
13 V–
OP495
V+
11
10
V–
OP495
12
+IN B
+IN C
+IN B
+IN C
11
10
9
–IN C
OUT C
NC
–IN B
OUT B
NC
6
7
9
8
–IN B
–IN C
GENERAL D ESCRIP TIO N
OUT B
OUT C
Rail-to-rail output swing combined with dc accuracy are the key
features of the OP495 quad and OP295 dual CBCMOS opera-
tional amplifiers. By using a bipolar front end, lower noise and
higher accuracy than that of CMOS designs has been achieved.
Both input and output ranges include the negative supply, pro-
viding the user “zero-in/zero-out” capability. For users of 3.3
volt systems such as lithium batteries, the OP295/OP495 is
specified for three volt operation.
NC = NO CONNECT
that require driving inductive loads, such as transformers, in-
creases in efficiency are also possible. Stability while driving
capacitive loads is another benefit of this design over CMOS
rail-to-rail amplifiers. T his is useful for driving coax cable or
large FET transistors. T he OP295/OP495 is stable with loads in
excess of 300 pF.
Maximum offset voltage is specified at 300 µV for +5 volt opera-
tion, and the open-loop gain is a minimum of 1000 V/mV. T his
yields performance that can be used to implement high accuracy
systems, even in single supply designs.
T he OP295 and OP495 are specified over the extended indus-
trial (–40°C to +125°C) temperature range. OP295s are avail-
able in 8-pin plastic and ceramic DIP plus SO-8 surface mount
packages. OP495s are available in 14-pin plastic and SO-16
surface mount packages. Contact your local sales office for
MIL-ST D-883 data sheet.
T he ability to swing rail-to-rail and supply +15 mA to the load
makes the OP295/OP495 an ideal driver for power transistors
and “H” bridges. T his allows designs to achieve higher efficien-
cies and to transfer more power to the load than previously pos-
sible without the use of discrete components. For applications
REV. B
Inform ation furnished by Analog Devices is believed to be accurate and
reliable. However, no responsibility is assum ed by Analog Devices for its
use, nor for any infringem ents of patents or other rights of third parties
which m ay result from its use. No license is granted by im plication or
otherwise under any patent or patent rights of Analog Devices.
© Analog Devices, Inc., 1995
One Technology Way, P.O. Box 9106, Norw ood. MA 02062-9106, U.S.A.
Tel: 617/ 329-4700
Fax: 617/ 326-8703
OP295/OP495–SPECIFICATIONS
(@ V = +5.0 V, V = +2.5 V, T = +25؇C unless otherwise noted)
S
CM
A
ELECTRICAL CHARACTERISTICS
P aram eter
Sym bol
Conditions
Min
Typ
Max
Units
INPUT CHARACT ERIST ICS
Offset Voltage
VOS
IB
30
8
300
800
20
30
±3
µV
µV
nA
nA
nA
nA
–40°C ≤ T A ≤ +125°C
–40°C ≤ T A ≤ +125°C
–40°C ≤ T A ≤ +125°C
Input Bias Current
Input Offset Current
IOS
±1
±5
Input Voltage Range
VCM
0
+4.0
V
Common-Mode Rejection Ratio
Large Signal Voltage Gain
CMRR
AVO
0 V ≤ VCM ≤ 4.0 V, –40°C ≤ T A ≤ +125°C
RL = 10 kΩ, 0.005 ≤ VOUT ≤ 4.0 V
RL = 10 kΩ, –40°C ≤ TA ≤ +125°C
90
1000
500
110
10,000
dB
V/mV
V/mV
µV/°C
Offset Voltage Drift
∆VOS/∆T
1
5
OUT PUT CHARACT ERIST ICS
Output Voltage Swing High
VOH
RL = 100 kΩ to GND
RL = 10 kΩ to GND
IOUT = 1 mA, –40°C ≤ T A ≤ +125°C
RL = 100 kΩ to GND
RL = 10 kΩ to GND
4.98
4.90
5.0
4.94
4.7
0.7
0.7
90
V
V
V
mV
mV
mV
mA
Output Voltage Swing Low
Output Current
VOL
2
2
IOUT = 1 mA, –40°C ≤ T A ≤ +125°C
IOUT
±11
±18
POWER SUPPLY
Power Supply Rejection Ratio
PSRR
±1.5 V ≤ VS ≤ ±15 V
±1.5 V ≤ VS ≤ ±15 V,
–40°C ≤ T A ≤ +125°C
90
85
110
dB
dB
Supply Current Per Amplifier
ISY
VOUT = 2.5 V, RL = ∞, –40°C ≤ TA ≤ +125°C
150
µA
DYNAMIC PERFORMANCE
Skew Rate
Gain Bandwidth Product
Phase Margin
SR
GBP
θO
RL = 10 kΩ
0.03
75
86
V/µs
kHz
Degrees
NOISE PERFORMANCE
Voltage Noise
Voltage Noise Density
Current Noise Density
en
en
in
0.1 Hz to 10 Hz
f = 1 kHz
f = 1 kHz
1.5
51
<0.1
µV p-p
nV/√Hz
pA/√Hz
p-p
Specifications subject to change without notice.
ELECTRICAL CHARACTERISTICS (@ V = +3.0 V, V = +1.5 V, T = +25؇C unless otherwise noted)
S
CM
A
P aram eter
Sym bol
Conditions
Min
Typ
Max
Units
INPUT CHARACT ERIST ICS
Offset Voltage
Input Bias Current
VOS
IB
30
8
500
20
µV
nA
Input Offset Current
Input Voltage Range
Common-Mode Rejection Ratio
Large Voltage Gain
IOS
VCM
CMRR
AVO
∆VOS/∆T
±1
±3
+2.0
nA
V
dB
V/mV
µV/°C
0
90
0 V ≤ VCM ≤ 2.0 V, –40°C ≤ T A ≤ +125°C
RL = 10 kΩ
110
750
1
Offset Voltage Drift
OUT PUT CHARACT ERIST ICS
Output Voltage Swing High
Output Voltage Swing Low
VOH
VOL
RL = 10 kΩ to GND
RL = 10 kΩ to GND
2.9
V
mV
0.7
2
POWER SUPPLY
Power Supply Rejection Ratio
PSRR
ISY
±1.5 V ≤ VS ≤ ±15 V
±1.5 V ≤ VS ≤ ±15 V,
–40°C ≤ T A ≤ +125°C
VOUT = 1.5 V, RL = ∞, –40°C ≤ TA ≤ +125°C
90
85
110
dB
dB
µA
Supply Current Per Amplifier
150
DYNAMIC PERFORMANCE
Slew Rate
Gain Bandwidth Product
Phase Margin
SR
GBP
θO
RL = 10 kΩ
0.03
75
85
V/µs
kHz
Degrees
NOISE PERFORMANCE
Voltage Noise
Voltage Noise Density
Current Noise Density
en
en
in
0.1 Hz to 10 Hz
f = 1 kHz
f = 1 kHz
1.6
53
<0.1
µV p-p
nV/√Hz
pA/√Hz
p-p
Specifications subject to change without notice.
–2–
REV. B
OP295/OP495
(@ V = ±15.0 V, T = +25؇C unless otherwise noted)
S
A
ELECTRICAL CHARACTERISTICS
P aram eter
Sym bol
Conditions
Min
Typ
Max
Units
INPUT CHARACT ERIST ICS
Offset Voltage
VOS
IB
30
7
300
800
20
30
±3
µV
µV
nA
nA
–40°C ≤ T A ≤ +125°C
VCM = 0 V
VCM = 0 V, –40°C ≤ T A ≤ +125°C
VCM = 0 V
Input Bias Current
Input Offset Current
IOS
±1
nA
VCM = 0 V, –40°C ≤ T A ≤ +125°C
±5
nA
Input Voltage Range
VCM
CMRR
AVO
–15
90
1000
+13.5
V
dB
V/mV
µV/°C
Common-Mode Rejection Ratio
Large Signal Voltage Gain
Offset Voltage Drift
–15.0 V ≤ VCM ≤ +13.5 V, –40°C ≤ TA ≤ +125°C
RL = 10 kΩ
110
4000
1
∆VOS/∆T
OUT PUT CHARACT ERIST ICS
Output Voltage Swing High
VOH
VOL
IOUT
RL = 100 kΩ to GND
RL = 10 kΩ to GND
RL = 100 kΩ to GND
RL = 10 kΩ to GND
14.95
14.80
V
V
V
V
Output Voltage Swing Low
Output Current
–14.95
–14.85
±15
±25
mA
POWER SUPPLY
Power Supply Rejection Ratio
PSRR
ISY
VS = ±1.5 V to ±15 V
90
85
110
dB
dB
VS = ±1.5 V to ±15 V, –40°C ≤ TA ≤ +125°C
VO = 0 V, RL = ∞, VS = ±18 V,
–40°C ≤ T A ≤ +125°C
Supply Current
175
µA
Supply Voltage Range
VS
+3 (±1.5)
+36 (±18)
V
DYNAMIC PERFORMANCE
Slew Rate
Gain Bandwidth Product
Phase Margin
SR
GBP
θO
RL = 10 kΩ
0.03
85
83
V/µs
kHz
Degrees
NOISE PERFORMANCE
Voltage Noise
Voltage Noise Density
en p-p
en
0.1 Hz to 10 Hz
f =1 kHz
1.25
45
µV p-p
nV/√Hz
Current Noise Density
in
f = 1 kHz
<0.1
pA/√Hz
Specifications subject to change without notice.
(@ V = +5.0 V, V = 2.5 V, T = +25؇C unless otherwise noted)
WAFER TEST LIMITS
P aram eter
S
CM
A
Sym bol
Conditions
Lim it
Units
Offset Voltage
Input Bias Current
Vos
IB
IOS
VCM
CMRR
PSRR
AVO
VOH
ISY
300
20
±2
0 to +4
90
90
1000
4.9
150
µV max
nA max
nA max
V min
dB min
µV/V
V/mV min
V min
µA max
Input Offset Current
Input Voltage Range1
Common-Mode Rejection Ratio
Power Supply Rejection Ratio
Large Signal Voltage Gain
Output Voltage Swing High
Supply Current Per Amplifier
0 V ≤ VCM ≤ 4 V
±1.5 V ≤ VS ≤ ±15 V
RL = 10 kΩ
RL = 10 kΩ
VOUT = 2.5 V, RL = ∞
NOT ES
Electrical tests and wafer probe to the limits shown. Due to variations in assembly methods and normal yield loss, yield after packaging is not guaranteed for standard
product dice. Consult factory to negotiate specifications based on dice lot qualifications through sample lot assembly and testing.
1Guaranteed by CMRR test.
O RD ERING GUID E
Tem perature
Range
P ackage
D escription
P ackage
O ption
Tem perature
Range
P ackage
D escription
P ackage
O ption
Model
Model
OP295GP
OP295GS
OP295GBC +25°C
–40°C to +125°C 8-Pin Plastic DIP N-8
–40°C to +125°C 8-Pin SOIC SO-8
OP495GP
OP495GS
OP495GBC +25°C
–40°C to +125°C 14-Pin Plastic DIP N-14
–40°C to +125°C 16-Pin SOL R-16
DICE
DICE
REV. B
–3–
OP295/OP495
ABSO LUTE MAXIMUM RATINGS1
D ICE CH ARACTERISTICS
Supply Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .±18 V
Input Voltage2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .±18 V
Differential Input Voltage2. . . . . . . . . . . . . . . . . . . . . . . +36 V
Output Short-Circuit Duration . . . . . . . . . . . . . . . . . Indefinite
Storage T emperature Range
P, S Package . . . . . . . . . . . . . . . . . . . . . . . . –65°C to +150°C
Operating T emperature Range
OP295G, OP495G . . . . . . . . . . . . . . . . . . . –40°C to +125°C
Junction T emperature Range
P, S Package . . . . . . . . . . . . . . . . . . . . . . . . –65°C to +150°C
Lead T emperature Range (Soldering, 60 Sec) . . . . . . . +300°C
3
P ackage Type
JC
Unit
JA
8-Pin Plastic DIP (P)
8-Pin SOIC (S)
14-Pin Plastic DIP (P)
16-Pin SO (S)
103
158
83
43
43
39
30
°C/W
°C/W
°C/W
°C/W
98
OP295 Die Size 0.066 × 0.080 inch, 5,280 sq. m ils.
Substrate (Die Backside) Is Connected to V+.
Transistor Count, 74.
NOT ES
1Absolute maximum ratings apply to both DICE and packaged parts, unless
otherwise noted.
2For supply voltages less than ±18 V, the absolute maximum input voltage is equal
to the supply voltage.
3θJA is specified for the worst case conditions, i.e., θJA is specified for device in socket
for cerdip, P-DIP, and LCC packages; θJA is specified for device soldered in circuit
board for SOIC package.
OP495 Die Size 0.113 × 0.083 inch, 9,380 sq. m ils.
Substrate (Die Backside) Is Connected to V+.
Transistor Count, 196.
Typical Characteristics
140
15.2
VS = ±15V
RL = 100k
15.0
120
14.8
14.6
14.4
14.2
RL = 10k
RL = 2k
100
80
VS = +36V
VS = +5V
VS = +3V
–14.4
–14.6
–14.8
–15.0
–15.2
60
RL = 2k
RL = 10k
RL = 100k
40
20
–50
–25
0
25
50
75
100
–50
–25
0
25
50
75
100
TEMPERATURE – °C
TEMPERATURE – °C
Supply Current Per Am plifier vs. Tem perature
Output Voltage Swing vs. Tem perature
–4–
REV. B
Typical Characteristics–OP295/OP495
5.10
3.10
V
= +5V
V
= +3V
S
S
5.00
4.90
4.80
4.70
4.60
4.50
3.00
2.90
2.80
2.70
2.60
2.50
R
= 100k
= 10k
L
R
R
= 100k
= 10k
L
R
L
L
R
= 2k
L
R
= 2k
L
–50
–25
0
25
50
75
100
–50
–25
0
25
50
75
100
TEMPERATURE – °C
TEMPERATURE – °C
Output Voltage Swing vs. Tem perature
Output Voltage Swing vs. Tem perature
200
175
150
125
100
75
500
450
400
350
300
250
200
150
100
50
BASED ON 1200 OP AMPS
BASED ON 600 OP AMPS
VS = +5V
V
T
= +5V
S
A
= +25°C
TA = +25°C
50
25
0
–100
0
–50
0
50
100
150
200
250
300
–250 –200 –150 –100 –50
0
50
100 150 200 250
INPUT OFFSET VOLTAGE – µV
INPUT OFFSET VOLTAGE – µV
OP295 Input Offset (VOS) Distribution
OP495 Input Offset (VOS) Distribution
250
225
200
175
150
125
100
75
500
450
400
350
300
250
200
150
100
50
BASED ON 1200 OP AMPS
BASED ON 600 OP AMPS
VS = +5V
V
= +5V
S
–40° ≤ T ≤ +85°C
A
–40° ≤ TA ≤ +85°C
50
25
0
0
0
0.4
0.8
1.2
1.6
2.0
2.4
2.8
3.2
0
0.4
0.8
1.2
T
1.6 2.0
– µV/°C
OS
2.4
2.8
3.2
– V
TC – VOS – µV/°C
C
OP295 TC–VOS Distribution
OP495 TC–VOS Distribution
REV. B
–5–
OP295/OP495–Typical Characteristics
100
20
V
V
= ±15V
= ±10V
S
V
= +5V
S
O
16
12
8
R
= 100k
L
10
R
= 10k
L
4
R
= 2k
L
1
–50
0
–50
0
75
100
25
50
–25
–25
0
25
50
75
100
TEMPERATURE – °C
TEMPERATURE – °C
Open-Loop Gain vs. Tem perature
Input Bias Current vs. Tem perature
12
40
35
30
25
20
15
10
5
V
S
= +5V
= +4V
SOURCE
V
O
10
8
V
= ±15V
SINK
S
SOURCE
R
= 100k
= 10k
L
6
R
L
SINK
4
V
= +5V
S
R
= 2k
L
2
0
–50
0
–50
–25
0
25
50
75
100
–25
0
25
50
75
100
TEMPERATURE – °C
TEMPERATURE – °C
Output Current vs. Tem perature
Open-Loop Gain vs. Tem perature
1V
100mV
10mV
1mV
SOURCE
V
= +5V
S
T
= +25°C
A
SINK
100µV
1µA
10µA
100µA
1mA
10mA
LOAD CURRENT
Output Voltage to Supply Rail vs. Load Current
–6–
REV. B
OP295/OP495
0.1µF
AP P LICATIO NS
Rail-to-Rail Applications Infor m ation
LED
T he OP295/OP495 has a wide common-mode input range ex-
tending from ground to within about 800 mV of the positive
supply. T here is a tendency to use the OP295/OP495 in buffer
applications where the input voltage could exceed the common-
mode input range. T his may initially appear to work because of
the high input range and rail-to-rail output range. But above the
common-mode input range the amplifier is, of course, highly
nonlinear. For this reason it is always required that there be
some minimal amount of gain when rail-to-rail output swing is
desired. Based on the input common-mode range this gain
should be at least 1.2.
R1
10µF
Q2
2N3906
3
5
R6
VIN
10Ω
2
6
MAT- 03
Q1
1
Q2
R5
10kΩ
C2
10µF
7
2
3
8
VOUT
R7
OP295/
OP495
1
510Ω
4
C1
1500pF
R2
27kΩ
R3
R4
Low D r op-O ut Refer ence
R8
100Ω
T he OP295/OP495 can be used to gain up a 2.5 V or other low
voltage reference to 4.5 volts for use with high resolution A/D
converters that operate from +5 volt only supplies. T he circuit
in Figure 1 will supply up to 10 mA. Its no-load drop-out volt-
age is only 20 mV. T his circuit will supply over 3.5 mA with a
+5 volt supply.
Figure 2. Low Noise Single Supply Pream plifier
T he input noise is controlled by the MAT 03 transistor pair and
the collector current level. Increasing the collector current re-
duces the voltage noise. T his particular circuit was tested with
1.85 mA and 0.5 mA of current. Under these two cases, the in-
put voltage noise was 3.1 nV/√Hz and 10 nV/√Hz, respectively.
T he high collector currents do lead to a tradeoff in supply cur-
rent, bias current, and current noise. All of these parameters will
increase with increasing collector current. For example, typically
the MAT 03 has an hFE = 165. T his leads to bias currents of
11 µA and 3 µA, respectively. Based on the high bias currents,
this circuit is best suited for applications with low source imped-
ance such as magnetic pickups or low impedance strain gages.
Furthermore, a high source impedance will degrade the noise
performance. For example, a 1 kΩ resistor generates 4 nV/√Hz
of broadband noise, which is already greater than the noise of
the preamp.
16k
+5V
0.001µF
+5V
20k
10Ω
VOUT = 4.5V
2
REF43
4
6
1/2
OP295/
OP495
1 TO 10µF
Figure 1. 4.5 Volt, Low Drop-Out Reference
Low Noise, Single Supply P r eam plifier
Most single supply op amps are designed to draw low supply
current, at the expense of having higher voltage noise. T his
tradeoff may be necessary because the system must be powered
by a battery. However, this condition is worsened because all
circuit resistances tend to be higher; as a result, in addition to
the op amp’s voltage noise, Johnson noise (resistor thermal
noise) is also a significant contributor to the total noise of the
system.
T he collector current is set by R1 in combination with the LED
and Q2. T he LED is a 1.6 V “Zener” that has a temperature co-
efficient close to that of Q2’s base-emitter junction, which pro-
vides a constant 1.0 V drop across R1. With R1 equal to 270 Ω,
the tail current is 3.7 mA and the collector current is half that,
or 1.85 mA. T he value of R1 can be altered to adjust the collec-
tor current. Whenever R1 is changed, R3 and R4 should also be
adjusted. T o maintain a common-mode input range that in-
cludes ground, the collectors of the Q1 and Q2 should not go
above 0.5 V—otherwise they could saturate. T hus, R3 and R4
have to be small enough to prevent this condition. T heir values
and the overall performance for two different values of R1 are
summarized in T able I. Lastly, the potentiometer, R8, is needed
to adjust the offset voltage to null it to zero. Similar perfor-
mance can be obtained using an OP90 as the output amplifier
with a savings of about 185 µA of supply current. However, the
output swing will not include the positive rail, and the band-
width will reduce to approximately 250 Hz.
T he choice of monolithic op amps that combine the characteris-
tics of low noise and single supply operation is rather limited.
Most single supply op amps have noise on the order of 30 nV/√Hz
to 60 nV/√Hz and single supply amplifiers with noise below
5 nV/√Hz do not exist.
In order to achieve both low noise and low supply voltage opera-
tion, discrete designs may provide the best solution. T he circuit
on Figure 2 uses the OP295/OP495 rail-to-rail amplifier and a
matched PNP transistor pair—the MAT 03—to achieve zero-in/
zero-out single supply operation with an input voltage noise of
3.1 nV/√Hz at 100 Hz. R5 and R6 set the gain of 1000, making
this circuit ideal for maximizing dynamic range when amplifying
low level signals in single supply applications. The OP295/OP495
provides rail-to-rail output swings, allowing this circuit to oper-
ate with 0 to 5 volt outputs. Only half of the OP295/OP495 is
used, leaving the other uncommitted op amp for use elsewhere.
REV. B
–7–
OP295/OP495
Table I. Single Supply Low Noise P ream p P erform ance
unless this was a low distortion application such as audio. If this
is used to drive inductive loads, be sure to add diode clamps to
protect the bridge from inductive kickback.
IC = 1.85 m A
IC = 0.5 m A
R1
270 Ω
1.0 kΩ
D ir ect Access Ar r angem ent
R3, R4
200 Ω
910 Ω
OP295/OP495 can be used in a single supply Direct Access Ar-
rangement (DAA) as is shown an in Figure 4. T his figure shows
a portion of a typical DM capable of operating from a single
+5 volt supply and it may also work on +3 volt supplies with
minor modifications. Amplifiers A2 and A3 are configured so
that the transmit signal T XA is inverted by A2 and is not in-
verted by A3. T his arrangement drives the transformer differen-
tially so that the drive to the transformer is effectively doubled
over a single amplifier arrangement. T his application takes ad-
vantage of the OP295/OP495’s ability to drive capacitive loads,
and to save power in single supply applications.
en @ 100 Hz
en @ 10 Hz
ISY
3.15 nV/√Hz
4.2 nV/√Hz
4.0 mA
11 µA
1 kHz
1000
8.6 nV/√Hz
10.2 nV/√Hz
1.3 mA
3 µA
1 kHz
1000
IB
Bandwidth
Closed-Loop Gain
D r iving H eavy Loads
T he OP295/OP495 is well suited to drive loads by using a
power transistor, Darlington or FET to increase the current to
the load. T he ability to swing to either rail can assure that the
device is turned on hard. T his results in more power to the load
and an increase in efficiency over using standard op amps with
their limited output swing. Driving power FET s is also possible
with the OP295/OP495 because of its ability to drive capacitive
loads of several hundred picofarads without oscillating.
390pF
37.4kΩ
20kΩ
0.1µF
OP295/
OP495
A1
RXA
0.0047µF
Without the addition of external transistors the OP295/OP495
can drive loads in excess of ±15 mA with ±15 or +30 volt
supplies. T his drive capability is somewhat decreased at lower
supply voltages. At ±5 volt supplies the drive current is ±11 mA.
3.3kΩ
20kΩ
475Ω
OP295/
OP495
A2
22.1kΩ
Driving motors or actuators in two directions in a single supply
application is often accomplished using an “H” bridge. T he
principle is demonstrated in Figure 3a. From a single +5 volt
supply this driver is capable of driving loads from 0.8 V to 4.2 V
in both directions. Figure 3b shows the voltages at the inverting
and noninverting outputs of the driver. There is a small crossover
glitch that is frequency dependent and would not cause problems
0.1µF
20kΩ
750pF
TXA
1:1
0.033µF
20kΩ
20kΩ
OP295/
OP495
A3
2.5V REF
+5V
Figure 4. Direct Access Arrangem ent
2N2222
10k
2N2222
A Single Supply Instr um entation Am plifier
T he OP295/OP495 can be configured as a single supply instru-
OUTPUTS
0 ≤ V ≤ 2.5V
5k
IN
mentation amplifier as in Figure 5. For our example, VREF is set
V+
1.67V
10k
equal to
and VO is measured with respect to VREF. T he in-
2N2907
2
2N2907
10k
put common-mode voltage range includes ground and the out-
put swings to both rails.
V+
1/2
OP295/
5
6
8
4
OP495
1/2
VIN
7
Figure 3a. “H” Bridge
VO
OP295/
OP495
3
2
1
100
90
R1
R2
R4
100k
R3
20k
20k
100k
VREF
RG
200k
RG
V
IN + VREF
VO
= 5 +
(
)
10
0%
Figure 5. Single Supply Instrum entation Am plifier
2V
2V
1ms
Resistor RG sets the gain of the instrumentation amplifier. Mini-
mum gain is 6 (with no RG). All resistors should be matched in
absolute value as well as temperature coefficient to maximize
Figure 3b. “H” Bridge Outputs
–8–
REV. B
OP295/OP495
common-mode rejection performance and minimize drift. T his
instrumentation amplifier can operate from a supply voltage as
low as 3 volts.
T o calibrate, immerse the thermocouple measuring junction in a
0°C ice bath, adjust the 500 Ω Zero Adjust pot to zero volts out.
T hen immerse the thermocouple in a 250°C temperature bath
or oven and adjust the Scale Adjust pot for an output voltage of
2.50 V, which is equivalent to 250°C. Within this temperature
range, the K-type thermocouple is quite accurate and produces
a fairly linear transfer characteristic. Accuracy of ±3°C is achiev-
able without linearization.
A Single Supply RTD Ther m om eter Am plifier
T his RT D amplifier takes advantage of the rail-to-rail swing of
the OP295/OP495 to achieve a high bridge voltage in spite of a
low 5 V supply. T he OP295/OP495 amplifier servos a constant
200 µA current to the bridge. T he return current drops across
the parallel resistors 6.19 kΩ and the 2.55 MΩ, developing a
voltage that is servoed to 1.235 V, which is established by the
AD589 bandgap reference. T he 3-wire RT D provides an equal
line resistance drop in both 100 Ω legs of the bridge, thus im-
proving the accuracy.
Even if the battery voltage is allowed to decay to as low as 7 volts,
the rail-to-rail swing allows temperature measurements to
700°C. However, linearization may be necessary for tempera-
tures above 250°C where the thermocouple becomes rather
nonlinear. T he circuit draws just under 500 µA supply current
from a 9 V battery.
T he AMP04 amplifies the differential bridge signal and converts
it to a single-ended output. T he gain is set by the series resis-
tance of the 332 Ω resistor plus the 50 Ω potentiometer. T he
gain scales the output to produce a 4.5 V full scale. T he
0.22 µF capacitor to the output provides a 7 Hz low-pass filter
to keep noise at a minimum.
A 5 V O nly, 12-Bit D AC That Swings 0 V to 4.095 V
Figure 8 shows a complete voltage output DAC with wide out-
put voltage swing operating off a single +5 V supply. T he serial
input 12-bit D/A converter is configured as a voltage output
device with the 1.235 V reference feeding the current output pin
(IOUT ) of the DAC. T he VREF which is normally the input now
becomes the output.
ZERO ADJ
200Ω
50Ω
10-TURNS
+5V
7
T he output voltage from the DAC is the binary weighted volt-
age of the reference, which is gained up by the output amplifier
such that the DAC has a 1 mV per bit transfer function.
332Ω
26.7k
0.5%
26.7k
0.5%
1
3
2
0.22µF
8
VO
AMP04
6
+5V
+5V
4.5V = 450°C
0V = 0°C
5
100Ω
RTD
1
1/2
4
100Ω
0.5%
8
OP295/
OP495
+5V
8
R1
2
1
V
17.8kΩ
DD
R
FB
2
3
D
4096
1.235
37.4k
3
I
3
2
V
=
(4.096V)
V
+5V
O
REF
+1.23V
DAC8043
OUT
6.19k
1%
OP295/
OP495
1
2.55M
1%
AD589
GND CLK SRI LD
4
AD589
4
6
5
7
R4
100kΩ
Figure 6. Low Power RTD Am plifier
R2
41.2k
DIGITAL
A Cold Junction Com pensated, Batter y P ower ed
Ther m ocouple Am plifier
CONTROL
R3
5kΩ
TOTAL POWER DISSIPATION = 1.6mW
T he OP295/OP495’s 150 µA quiescent current per amplifier
consumption makes it useful for battery powered temperature
measuring instruments. T he K-type thermocouple terminates
into an isothermal block where the terminated junctions’ ambi-
ent temperatures can be continuously monitored and corrected
by summing an equal but opposite thermal EMF to the ampli-
fier, thereby canceling the error introduced by the cold junctions.
Figure 8. A 5 Volt 12-Bit DAC with 0 V to +4.095 Output
Swing
4–20 m A Cur r ent Loop Tr ansm itter
Figure 9 shows a self powered 4–20 mA current loop transmit-
ter. T he entire circuit floats up from the single supply (12 V to
36 V) return. T he supply current carries the signal within the 4
to 20 mA range. T hus the 4 mA establishes the baseline
24.9k
1.235V
AD589
ISOTHERMAL
9V
SCALE
BLOCK
NULL ADJ
6
2
24.3k
1%
REF02
GND
4
7.15k
ADJUST
1%
1N914
20k
1.33MΩ
100kΩ
10-TURN
SPAN ADJ
4.99k
1%
1.5M
1%
24.9k
1%
5V
ALUMEL
10kΩ
10-TURN
182k 1.21M
100Ω
8
2
3
1%
1%
+12V
TO
8
4
AL
COLD
JUNCTIONS
OP295/
OP495
4
VIN
0 + 3V
3
2
500Ω
10-TURN
V
1
220Ω
O
+36V
1
0V = 0°C
5V = 500°C
ZERO
ADJUST
CR
1/2
OP295/
OP495
2N1711
CHROMEL
K-TYPE
475Ω
1%
2.1k
1%
4–20mA
RL
100Ω
THERMOCOUPLE
40.7µV/°C
220pF
100k
1%
100Ω
1%
HP
5082-2800
Figure 7. Battery Powered, Cold-J unction Com pensated
Therm ocouple Am plifier
Figure 9. 4–20 m A Current Loop Transm itter
REV. B
–9–
OP295/OP495
current budget with which the circuit must operate. T his circuit
consumes only 1.4 mA maximum quiescent current, making 2.6
mA of current available to power additional signal conditioning
circuitry or to power a bridge circuit.
current limit loop. At this point A2’s lower output resistance
dominates the drive to the power MOSFET transistor, thereby
effectively removing the A1 voltage regulation loop from the
circuit.
A 3 Volt Low-D r opout Linear Voltage Regulator
If the output current greater than 1 amp persists, the current
limit loop forces a reduction of current to the load, which causes
a corresponding drop in output voltage. As the output voltage
drops, the current limit threshold also drops fractionally, result-
ing in a decreasing output current as the output voltage de-
creases, to the limit of less than 0.2 A at 1 V output. T his
“fold-back” effect reduces the power dissipation considerably
during a short circuit condition, thus making the power supply
far more forgiving in terms of the thermal design requirements.
Small heat sinking on the power MOSFET can be tolerated.
Figure 10 shows a simple 3 V voltage regulator design. T he
regulator can deliver 50 mA load current while allowing a 0.2 V
dropout voltage. T he OP295/OP495’s rail-to-rail output swing
handily drives the MJE350 pass transistor without requiring spe-
cial drive circuitry. At no load, its output can swing less than the
pass transistor’s base-emitter voltage, turning the device nearly
off. At full load, and at low emitter-collector voltages, the tran-
sistor beta tends to decrease. T he additional base current is eas-
ily handled by the OP295/OP495 output.
T he amplifier servos the output to a constant voltage, which
feeds a portion of the signal to the error amplifier.
T he OP295’s rail-to-rail swing exacts higher gate drive to
the power MOSFET , providing a fuller enhancement to the
transistor. T he regulator exhibits 0.2 V dropout at 500 mA of
load current. At 1 amp output, the dropout voltage is typically
5.6 volts.
Higher output current, to 100 mA, is achievable at a higher
dropout voltage of 3.8 V.
IL < 50mA
MJE 350
RSENSE
0.1Ω
1/4W
IO (NORM) = 0.5A
IO (MAX) = 1A
VO
100µF
IRF9531
44.2k
S
D
VIN
5V TO 3.2V
+5V VO
1%
8
3
2
G
210k
1%
205k
1%
6V
1/2
OP295/
OP495
1
30.9k
1%
8
5
6
4
A2
7
1N4148
1000pF
1/2
OP295/
OP495
45.3k
1%
45.3k
1%
1.235V
AD589
100k
5%
0.01µF
43k
3
2
124k
1%
A1
124k
1
1%
1/2
OP295/
OP495
4
Figure 10. 3 V Low Dropout Voltage Regulator
Figure 11 shows the regulator’s recovery characteristic when its
output underwent a 20 mA to 50 mA step current change.
2.500V
REF43
2
6
4
2V
100
Figure 12. Low Dropout, 500 m A Voltage Regulator with
Fold-Back Current Lim iting
50mA
90
STEP
CURRENT
CONTROL
Squar e Wave O scillator
WAVEFORM
20mA
T he circuit in Figure 13 is a square wave oscillator (note the
positive feedback). T he rail-to-rail swing of the OP295/OP495
helps maintain a constant oscillation frequency even if the sup-
ply voltage varies considerably. Consider a battery powered sys-
tem where the voltages are not regulated and drop over time.
T he rail-to-rail swing ensures that the noninverting input sees
the full V+/2, rather than only a fraction of it.
OUTPUT
10
0%
20mV
1ms
Figure 11. Output Step Load Current Recovery
T he constant frequency comes from the fact that the 58.7 kΩ
feedback sets up Schmitt T rigger threshold levels that are di-
rectly proportional to the supply voltage, as are the RC charge
voltage levels. As a result, the RC charge time, and therefore the
frequency, remains constant independent of supply voltage. T he
slew rate of the amplifier limits the oscillation frequency to a
maximum of about 800 Hz at a +5 V supply.
Low-D r opout, 500 m A Voltage Regulator with Fold-Back
Cur r ent Lim iting
Adding a second amplifier in the regulation loop as shown in
Figure 12 provides an output current monitor as well as fold-
back current limiting protection.
Amplifier A1 provides error amplification for the normal voltage
regulation loop. As long as the output current is less than 1 am-
pere, amplifier A2’s output swings to ground, reverse biasing the
diode and effectively taking itself out of the circuit. However, as
the output current exceeds 1 amp, the voltage that develops
across the 0.1 Ω sense resistor forces the amplifier A2’s output
to go high, forward-biasing the diode, which in turn closes the
Single Supply D iffer ential Speaker D r iver
Connected as a differential speaker driver, the OP295/OP495
can deliver a minimum of 10 mA to the load. With a 600 Ω
load, the OP295/OP495 can swing close to 5 volts peak-to-peak
across the load.
–10–
REV. B
OP295/OP495
V+
R2
2
1
1
5
6
7
8
9
8
9
5
2
2
3
3
6
5E3
CIN
IOS
D1
D2
EOS
Q1
Q2
R3
2E-12
0.5E-9
DZ
100k
58.7k
DZ
POLY (1) (31,39) 30E-6 0.024
4
4
8
4
3
2
5
7
QP
QP
1/2
1
FREQ OUT
1
OP295/
OP495
50 25.8E3
50 25.8E3
fOSC
=
< 350Hz @ V+ = +5V
RC
100k
R4
*
* GAIN ST AGE
*
R
C
R7
G1
EREF 98
R5
R6
*
10 98 270E6
98 10 POLY (1) (9,8) –4.26712E-9 27.8E-6
(39, 0) 1
99 39 100E3
39 50 100E3
Figure 13. Square Wave Oscillator Has Stable Frequency
Regardless of Supply Changes
0
90.9k
* COMMON MODE ST AGE
*
10k
V+
ECM 30 98 POLY(2) (1,39) (2,39) 0 0.5 0.5
2.2µF
R12
R13
*
30 31 1E6
31 98 100
1/4
V
IN
OP295/
OP495
10k
100k
SPEAKER
* OUT PUT ST AGE
*
I2
V2
18 50 1.59E-6
99 12 DC 2.2763
10 14 50 QNA 1.0
14 50 33
15 10 13 13 MN L=9E-6 W=102E-6 AD=15E-10 AD=15E-10
13 10 50 50 MN L=9E-6 W=50E-6 AD=75E-11 AS=75E-11
10 22 DX
1/4
1/4
OP295/
OP495
OP295/
OP495
Q4
R11
M3
M4
D8
V3
M2
Q5
Q6
R8
20k
20k
V+
22 50 DC
6
Figure 14. Single Supply Differential Speaker Driver
20 10 14 14 MN L=9E-6 W=2000E-6 AD=30E-9 AS=30E-9
17 17 99 QPA 1.0
18 17 99 QPA 4.0
18 99 2.2E6
18 19 99 QPA 1.0
H igh Accur acy, Single-Supply, Low P ower Com par ator
T he OP295/OP495 makes an accurate open-loop comparator.
With a single +5 V supply, the offset error is less than 300 µV. Fig-
ure 15 shows the OP295/OP495’s response time when operating
open-loop with 4 mV overdrive. It exhibits a 4 ms response time at
the rising edge and a 1.5 ms response time at the falling edge.
Q7
R9
99 19
8
C2
M6
M1
D4
V4
18 99 20E-12
15 12 17 99 MP L=9E-6 W=27E-6 AD=405E-12 AS=405E-12
20 18 19 99 MP L=9E-6 W=2000E-6 AD=30E-9 AS=30E-9
21 18 DX
99 21 DC
10 11 6E3
6
1V
R10
C3
100
90
11 20 50E-12
INPUT
.MODEL QNA NPN (IS=1.19E-16 BF=253 NF=0.99 VAF=193 IKF=2.76E-3
+ ISE=2.57E-13 NE=5 BR=0.4 NR=0.988 VAR=15 IKR=1.465E-4
+ ISC=6.9E-16 NC=0.99 RB=2.0E3 IRB=7.73E-6 RBM=132.8 RE=4
RC=209
(5mV OVERDRIVE
@ OP295 INPUT)
+ CJE=2.1E-13 VJE=0.573 MJE=0.364 FC=0.5 CJC=1.64E-13 VJC=0.534
MJC=0.5
OUTPUT
+ CJS=1.37E-12 VJS=0.59 MJS=0.5 T F=0.43E-9 PT F=30)
.MODEL QPA PNP (IS=5.21E-17 BF=131 NF=0.99 VAF=62 IKF=8.35E-4
+ ISE=1.09E-14 NE=2.61 BR=0.5 NR=0.984 VAR=15 IKR=3.96E-5
+ ISC=7.58E-16 NC=0.985 RB=1.52E3 IRB=1.67E-5 RBM=368.5 RE=6.31
RC=354.4
10
0%
2V
5ms
+ CJE=1.1E-13 VJE=0.745 MJE=0.33 FC=0.5 CJC=2.37E-13 VJC=0.762
MJC=0.4
Figure 15. Open-Loop Com parator Response Tim e with
5 m V Overdrive
+ CJS =7.11E-13 VJS=0.45 MJS=0.412 T F=1.0E-9 PT F=30)
.MODEL MN NMOS (LEVEL=3 VT O=1.3 RS=0.3 RD=0.3
+ TOX=8.5E-8 LD=1.48E-6 NSUB=1.53E16 UO=650 DELTA=10 VMAX=2E5
+ XJ=1.75E-6 KAPPA=0.8 ET A=0.066 T HET A=0.01 T PG=1 CJ=2.9E-4
PB=0.837
O P 295/O P 495 SP ICE MO D EL Macr o-Model
* Node Assignments
*
*
Noninverting Input
Inverting Input
+ MJ=0.407 CJSW=0.5E-9 MJSW=0.33)
*
*
Positive Supply
Negative Supply
.MODEL MP PMOS (LEVEL=3 VT O=–1.1 RS=0.7 RD=0.7
+ T OX=9.5E-8 LD=1.4E-6 NSUB=2.4E15 UO=650 DELT A=5.6 VMAX=1E5
+ XJ=1.75E-6 KAPPA=1.7 ET A=0.71 T HET A=5.9E-3 T PG=–1 CJ=1.55E-4
PB=0.56
+ MJ=0.442 CJSW=0.4E-9 MJSW=0.33)
.MODEL DX D(IS=1E-15)
*
Output
*
*
.SUBCKT OP295
1
2
99
50
20
*
.MODEL DZ D (IS=1E-15, BV=7)
.MODEL QP PNP (BF=125)
* INPUT ST AGE
*
.ENDS
I1
R1
99
1
4
6
2E-6
5E3
REV. B
–11–
OP295/OP495
O UTLINE D IMENSIO NS
D imensions shown in inches and (mm)
8-Lead Narrow-Body SO (S Suffix)
8 Lead P lastic D IP (P Suffix)
8
1
5
4
0.280 (7.11)
0.240 (6.10)
8
1
5
4
0.1574 (4.00)
0.1497 (3.80)
PIN 1
0.070 (1.77)
0.045 (1.15)
0.2440 (6.20)
0.2284 (5.80)
0.325 (8.25)
0.300 (7.62)
0.430 (10.92)
0.348 (8.84)
0.015
0.1968 (5.00)
0.1890 (4.80)
0.210
(5.33)
MAX
0.0196 (0.50)
0.0099 (0.25)
0.195 (4.95)
0.115 (2.93)
(0.381) TYP
x 45
°
0.0688 (1.75)
0.0532 (1.35)
0.0098 (0.25)
0.0040 (0.10)
0.130
(3.30)
MIN
0.015 (0.381)
0.008 (0.204)
0.160 (4.06)
0.115 (2.93)
8
0
°
°
0.0500 (1.27)
0.0160 (0.41)
0.0500
(1.27)
BSC
0.0192 (0.49)
0.0138 (0.35)
0.0098 (0.25)
0.0075 (0.19)
SEATING
0°- 15°
0.022 (0.558)
0.014 (0.356)
0.100
(2.54)
BSC
PLANE
16-Lead Wide-Body SO (S Suffix)
14-Lead P lastic D IP (P Suffix)
14
1
8
0.280 (7.11)
0.240 (6.10)
9
16
PIN 1
0.2992 (7.60)
0.2914 (7.40)
7
0.325 (8.25)
0.300 (7.62)
0.795 (20.19)
0.725 (18.42)
0.4193 (10.65)
PIN 1
0.3937 (10.00)
8
0.015
(0.381)
MIN
1
0.210
(5.33)
MAX
0.130
(3.30)
MIN
0.015 (0.38)
0.008 (0.20)
0.160 (4.06)
0.115 (2.92)
0.1043 (2.65)
0.4133 (10.50)
0.0926 (2.35)
0.3977 (10.10)
0.0291 (0.74)
0.0098 (0.25)
15°
0°
x 45
°
SEATING
PLANE
0.022 (0.558)
0.014 (0.36)
0.070 (1.77)
0.045 (1.15)
0.100
(2.54)
BSC
0.0500 (1.27)
0.0157 (0.40)
8
0
°
°
0.0118 (0.30)
0.0040 (0.10)
0.0500 (1.27)
BSC
0.0192 (0.49)
0.0138 (0.35)
0.0125 (0.32)
0.0091 (0.23)
–12–
REV. B
相关型号：
OP495GS-REEL7
IC QUAD OP-AMP, 800 uV OFFSET-MAX, 0.085 MHz BAND WIDTH, PDSO16, MS-013AA, SOIC-16, Operational Amplifier
ADI
OP496GBC
IC QUAD OP-AMP, 300 uV OFFSET-MAX, 0.35 MHz BAND WIDTH, UUC14, 0.062 X 0.092 INCH, DIE-14, Operational Amplifier
ADI
©2020 ICPDF网 联系我们和版权申明