AD8566ARM 데이터 시트보기 (PDF) - Analog Devices

부품명

상세내역

제조사

AD8566ARM

16 V Rail-to-Rail Operational Amplifiers

Analog Devices 

AD8565/AD8566/AD8567

Output Phase Reversal

The AD856x family is immune to phase reversal. Although

the device’s output will not change phase, large currents due

to input overvoltage could damage the device. In applications

where the possibility of an input voltage exceeding the supply

voltage exists, overvoltage protection should be used as described

in the previous section.

Power Dissipation

The maximum allowable internal junction temperature of 150°C

limits the AD856x family Maximum Power Dissipation. As the

ambient temperature increases, the maximum power dissipated

by the AD856x family must decrease linearly to maintain the

maximum junction temperature. If this maximum junction

temperature is exceeded momentarily, the part will still operate

properly once the junction temperature is reduced below 150°C.

If the maximum junction temperature is exceeded for an extended

period of time, overheating could lead to permanent damage of

the device.

The maximum safe junction temperature, TJMAX, is 150°C. Using

the following formula, we can obtain the maximum power that

the AD856x family can safely dissipate as a function of temperature.

PDISS = TJMAX – TA/θJA

where:

PDISS = AD856x power dissipation

TJMAX = AD856x maximum allowable junction temp (150°C)

TA = Ambient Temperature of the circuit

θJA = AD856x package thermal resistance, junction-to-ambient

The power dissipated by the device can be calculated as;

PDISS = (VS – VOUT) ϫ ILOAD

where:

VS = supply voltage

VOUT = output voltage

ILOAD = output load current

Figure 3 shows the maximum power dissipation versus temperature.

To achieve proper operation, use the previous equation to calculate

PDISS for a specific package at any given temperature, or use the

chart below.

1.25

14-LEAD SOIC

1.00

0.75

14-LEAD TSSOP

8-LEAD MSOP

0.50

5-LEAD SOT-23

THD + N

The AD856x family features low total harmonic distortion. Figure

4 shows a graph of THD + N versus frequency. The Total Harmonic

Distortion plus Noise for the AD856x over the entire supply range

is below 0.008%. When the device is powered from a 16 V supply,

the THD + N stays below 0.003%. Figure 4 shows the AD8566

in a unity noninverting configuration.

10

1

0.1

VS = ؎2.5V

VS = ؎8V

0.01

20

100

1k

FREQUENCY – Hz

10k 30k

Figure 4. THD + N vs. Frequency Graph

Short Circuit Output Conditions

The AD856x family does not have internal short circuit protection

circuitry. As a precautionary measure, it is recommended not to

short the output directly to the positive power supply or to ground.

It is not recommended to operate the AD856x with more than

35 mA of continuous output current. The output current can be

limited by placing a series resistor at the output of the amplifier

whose value can be derive using the following equation:

RX

≥

VS

35 mA

For a 5 V single supply operation, RX should have a minimum

value of 143 Ω.

LCD Panel Applications

The AD856x amplifier is designed for LCD panel applications

or applications where large capacitive load drive is required. It

can instantaneously source/sink greater than 250 mA of current.

At unity gain, it can drive 1 µF without compensation. This

makes the AD856x ideal for LCD VCOM driver applications.

To evaluate the performance of the AD856x family, a test circuit

was developed to simulate the VCOM Driver application for an

LCD panel.

0.25

0

–35

–15

5

25

45

65

85

AMBIENT TEMPERATURE – ؇C

Figure 3. Maximum Power Dissipation vs. Temperature

for 5-, 8-, and 14-Lead Packages

REV. A

–9–

Share Link: