REV. B

AD8381

–4–

ABSOLUTE MAXIMUM RATINGS

1

Supply Voltages

AVCCx – AGND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 V

DVCC – DGND . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.5 V

Input Voltages

Maximum Digital Input Voltages . . . . . . . . DVCC + 0.5 V

Minimum Digital Input Voltages . . . . . . . . DGND – 0.5 V

Maximum Analog Input Voltages . . . . . . . . . AVCC + 0.5 V

Minimum Analog Input Voltages . . . . . . . . AGND – 0.5 V

Internal Power Dissipation

2

LQFP Package @ 25

∞C Ambient . . . . . . . . . . . . . . . . 2.7 W

Output Short Circuit Duration . . . . . . . . . . . . . . . . . . Infinite

Operating Temperature Range . . . . . . . . . . . . . . 0

∞C to 85∞C

Storage Temperature Range . . . . . . . . . . . . –65

∞C to +125∞C

Lead Temperature Range (Soldering 10 sec) . . . . . . . . 300

∞C

NOTES

permanent damage to the device. This is a stress rating only; functional operation

of the device at these or any other conditions above those indicated in the

operational section of this specification is not implied. Exposure to the absolute

maximum ratings for extended periods may reduce device reliability.

Overload Protection

The AD8381 employs a two-stage overload protection circuit

that consists of an output current limiter and a thermal shutdown.

The maximum current at any one output of the AD8381 is

internally limited to 100 mA average. In the event of a momen-

tary short circuit between a video output and a power supply rail

(VCC or AGND), the output current limit is sufficiently low to

provide temporary protection.

The thermal shutdown debiases the output amplifier when the

junction temperature reaches the internally set trip point. In the

event of an extended short circuit between a video output and a

power supply rail, the output amplifier current continues to

switch between 0 mA and 100 mA typ with a period determined by

the thermal time constant and the hysteresis of the thermal trip

point. The thermal shutdown provides long term protection by

limiting the average junction temperature to a safe level.

Recovery from a momentary short circuit is fast, approximately

100 ns. Recovery from a thermal shutdown is slow and is

dependent on the ambient temperature.

MAXIMUM POWER DISSIPATION

The maximum power that can be safely dissipated by the AD8381

is limited by its junction temperature. The maximum safe junc-

tion temperature for plastic encapsulated devices is determined

by the glass transition temperature of the plastic, approximately

150

∞C. Exceeding this limit temporarily may cause a shift in the

parametric performance due to a change in the stresses exerted

on the die by the package. Exceeding a junction temperature of

175

∞C for an extended period can result in device failure.

To ensure proper operation within the specified operating tem-

perature range, it is necessary to limit the maximum power

dissipation as follows:

where:

∞C.

AMBIENT TEMPERATURE – C

3.5

0

3.0

2.5

2.0

1.5

1.0

0.5

10

20

30

40

50

60

70

80

90

Figure 4. Maximum Power Dissipation vs. Temperature

ORDERING GUIDE

Temperature

Package

Package

Model

Range

Description

Option

AD8381JST

0

∞C to 85∞C

48-Lead LQFP

ST-48

AD8381-EB

Evaluation Board

CAUTION

ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily

accumulate on the human body and test equipment and can discharge without detection. Although

the AD8381 features proprietary ESD protection circuitry, permanent damage may occur on

devices subjected to high-energy electrostatic discharges. Therefore, proper ESD precautions are

recommended to avoid performance degradation or loss of functionality.