OP467ARCSLASH883C datasheet(14/20 Pages) AD

14 / 20 page

OP467

Rev. F | Page 14 of 20

amplifier. Stray capacitance on the PCB can be reduced by making

the traces narrow and as short as possible. Further reduction

can be realized by choosing a smaller pad size, increasing the

spacing between the traces, and using PCB material with a low

dielectric constant insulator (dielectric constant of some common

insulators: air = 1, Teflon® = 2.2, and FR4 = 4.7, with air being

an ideal insulator).

Removing segments of the ground plane directly under the

input and output pads is recommended.

Outputs of high speed amplifiers are very sensitive to capacitive

loads. A capacitive load introduces a pair of pole and zero to the

frequency response of the circuit, reducing the phase margin,

leading to unstable operation or oscillation.

Generally, it is good design practice to isolate the output of the

amplifier from any capacitive load by placing a resistor between

the output of the amplifier and the rest of the circuits. A series

resistor of 10 Ω to 100 Ω is normally sufficient to isolate the

output from a capacitive load.

The OP467 is internally compensated to provide stable

operation and is capable of driving large capacitive loads

without oscillation.

Sockets are not recommended because they increase the lead

inductance/capacitance and reduce the power dissipation of the

package by increasing the thermal resistance of the leads. If

sockets must be used, use Teflon or pin sockets with the shortest

possible leads.

PHASE REVERSAL

The OP467 is immune to phase reversal; its inputs can exceed

the supply rails by a diode drop without any phase reversal.

OUTPUT

INTPUT

15.8V

ΔV1

200µs

10V

100

Figure 41. No Phase Reversal (AV = +1)

SATURATION RECOVERY TIME

The OP467 has a fast and symmetrical recovery time from

either rail. This feature is very useful in applications such as

high speed instrumentation and measurement circuits, where

the amplifier is frequently exposed to large signals that overload

the amplifier.

DLY 9.824µs

20ns

100

Figure 42. Saturation Recovery Time, Positive Rail

DLY 4.806µs

20ns

100

Figure 43. Saturation Recovery Time, Negative Rail

HIGH SPEED INSTRUMENTATION AMPLIFIER

The OP467 performance lends itself to a variety of high speed

applications, including high speed precision instrumentation

amplifiers. Figure 44 represents a circuit commonly used for

data acquisition, CCD imaging, and other high speed

applications.

The circuit gain is set by RG. A 2 kΩ resistor sets the circuit gain

to 2; for unity gain, remove RG. For any other gain settings, use

the following formula

G = 2/RG (Resistor Value is in kΩ)

RC is used for adjusting the dc common-mode rejection, and CC

is used for ac common-mode rejection adjustments.

+VIN

–VIN

1kΩ

2kΩ

OUTPUT

1kΩ

10kΩ

1.9kΩ

200Ω

10T

5pF

10kΩ

Figure 44. A High Speed Instrumentation Amplifier

OP467ARC/883C Datasheet(PDF) 14 Page - Analog Devices

OP467ARC/883C Datasheet(HTML) 14 Page - Analog Devices

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

Datasheet Descarga

Enlace URL