OP495GPZ Analog Devices Inc, OP495GPZ Datasheet - Page 10

• Manufacturer Part Number: OP495GPZ
• Description: IC OPAMP GP R-R 85KHZ QUAD 14DIP
• Manufacturer: Analog Devices Inc

Specifications of OP495GPZ

• Slew Rate: 0.03 V/µs
• Amplifier Type: General Purpose
• Number Of Circuits: 4
• Output Type: Rail-to-Rail
• Gain Bandwidth Product: 85kHz
• Current - Input Bias: 7nA
• Voltage - Input Offset: 300µV
• Current - Supply: 175µA
• Current - Output / Channel: 25mA
• Voltage - Supply, Single/dual (±): 3 V ~ 36 V, ±1.5 V ~ 18 V
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Through Hole
• Package / Case: 14-DIP (0.300", 7.62mm)
• Op Amp Type: Low Offset Voltage
• No. Of Amplifiers: 1
• Bandwidth: 85kHz
• Supply Voltage Range: ± 1.5V To ± 15V
• Amplifier Case Style: DIP
• No. Of Pins: 14
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• -3db Bandwidth: -
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant

OP295/OP495
Finally, the potentiometer, R8, is needed to adjust the offset
voltage to null it to zero. Similar performance can be obtained
using an OP90 as the output amplifier with a savings of about
185 μA of supply current. However, the output swing does not
include the positive rail, and the bandwidth reduces to approxi-
mately 250 Hz.
Table 6. Single-Supply Low Noise Preamp Performance
R1
R3, R4
e
e
I
I
Bandwidth
Closed-Loop Gain
DRIVING HEAVY LOADS
The OP295/OP495 are well suited to drive loads by using a
power transistor, Darlington, or FET to increase the current to
the load. The ability to swing to either rail can assure that the
device is turned on hard. This results in more power to the load
and an increase in efficiency over using standard op amps with
their limited output swing. Driving power FETs is also possible
with the OP295/OP495 because of their ability to drive capaci-
tive loads of several hundred picofarads without oscillating.
Without the addition of external transistors, the OP295/OP495
can drive loads in excess of ±15 mA with ±15 V or +30 V
supplies. This drive capability is somewhat decreased at lower
supply voltages. At ±5 V supplies, the drive current is ±11 mA.
Driving motors or actuators in two directions in a single-supply
application is often accomplished using an H bridge. The
principle is demonstrated in Figure 21. From a single 5 V
supply, this driver is capable of driving loads from 0.8 V to
4.2 V in both directions. Figure 22 shows the voltages at the
inverting and noninverting outputs of the driver. There is a
small crossover glitch that is frequency-dependent; it does not
cause problems unless used in low distortion applications, such
as audio. If this is used to drive inductive loads, diode clamps
should be added to protect the bridge from inductive kickback.
SY
B
n
n
@ 100 Hz
@ 10 Hz
0 ≤ V
IN
≤ 2.5V 5kΩ
10kΩ
1.67V
Figure 21. H Bridge
10kΩ
3.15 nV/√Hz
1 kHz
–
+
–
+
I
270 Ω
200 Ω
4.2 nV/√Hz
4.0 mA
11 μA
1000
10kΩ
C
= 1.85 mA
2N2222
2N2907
OUTPUTS
2N2907
5V
I
1.0 kΩ
910 Ω
8.6 nV/√Hz
10.2 nV/√Hz
1.3 mA
3 μA
1 kHz
1000
C
2N2222
= 0.5 mA
Rev. G | Page 10 of 16
DIRECT ACCESS ARRANGEMENT
The OP295/OP495 can be used in a single-supply direct access
arrangement (DAA), as shown in Figure 23. This figure shows
a portion of a typical DM capable of operating from a single 5 V
supply, and it may also work on 3 V supplies with minor modi-
fications. Amplifier A2 and Amplifier A3 are configured so that
the transmit signal, TxA, is inverted by A2 and is not inverted
by A3. This arrangement drives the transformer differentially so
the drive to the transformer is effectively doubled over a single
amplifier arrangement. This application takes advantage of the
ability of the OP295/OP495 to drive capacitive loads and to save
power in single-supply applications.
SINGLE-SUPPLY INSTRUMENTATION AMPLIFIER
The OP295/OP495 can be configured as a single-supply
instrumentation amplifier, as shown in Figure 24. For this
example, V
respect to V
includes ground, and the output swings to both rails.
2.5V REF
RxA
TxA
100
90
10
0%
REF
0.1µF
0.1µF
REF
is set equal to V+/2, and V
. The input common-mode voltage range
Figure 23. Direct Access Arrangement
2V
OP295/
OP495
OP295/
OP495
20kΩ
Figure 22. H Bridge Outputs
0.0047µF
2V
750pF
37.4kΩ
+
–
22.1kΩ
–
+
390pF
A2
20kΩ
20kΩ
A3
3.3kΩ
A1
–
+
OP295/
OP495
O
20kΩ
1ms
is measured with
0.033µF
20kΩ
475Ω
1:1