OP492GSZ datasheet(13/20 Pages) AD

13 / 20 page

OP292/OP492

Rev. C | Page 13 of 20

APPLICATIONS INFORMATION

PHASE REVERSAL

The OP492 has built-in protection against phase reversal when

the input voltage goes to either supply rail. In fact, it is safe for

the input to exceed either supply rail by up to 0.6 V with no risk

of phase reversal. However, the input should not go beyond the

positive supply rail by more than 0.9 V; otherwise, the output

will reverse phase. If this condition occurs, the problem can be

fixed by adding a 5 kΩ current limiting resistor in series with

the input pin. With this addition, the input can go to more than

5 V beyond the positive rail without phase reversal.

An input voltage that is as much as 5 V below the negative rail

will not result in phase reversal.

OP492

2kΩ

11.8V p-p

100

5µs

Figure 34. Output Phase Reverse If Input Exceeds

the Positive Supply (V+) by More Than 0.9 V

2kΩ

10V p-p

1V/DIV

OP492

4ms/DIV

Figure 35. No Negative Rail Phase Reversal, Even with Input Signal

at 5 V Below Ground

POWER SUPPLY CONSIDERATIONS

The OP292/OP492 are designed to operate equally well at single

+5 V or ±15 V supplies. The lowest supply voltage recommended

is 4.5 V.

It is a good design practice to bypass the supply pins with a

0.1 μF ceramic capacitor. It helps improve filtering of high

frequency noise.

For dual-supply operation, the negative supply (V−) must be

applied at the same time, or before V+. If V+ is applied before V−,

or in the case of a loss of the V− supply, while either input is

connected to ground or another low impedance source, excessive

input current may result. Potentially damaging levels of input

current can destroy the amplifier. If this condition can exist,

simply add a l kΩ or larger resistor in series with the input to

eliminate the problem.

OP492GSZ Datasheet(PDF) 13 Page - Analog Devices

OP492GSZ Datasheet(HTML) 13 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