10

will limit the short circuit current to ±200mA if the outputs are

directly shorted to the positive or the negative supply. If the

output is shorted indefinitely, the power dissipation could

easily increase such that the part will be destroyed.

Maximum reliability is maintained if the output continuous

current never exceeds ±30mA for the buffers and ±60mA for

internal metal interconnections.

The Unused Buffers

It is recommended that any unused buffers should have their

inputs tied to ground plane.

Power Dissipation

With the high-output drive capability of the EL5524, EL5624,

EL5724, and EL5824, it is possible to exceed the 125°C

“absolute-maximum junction temperature” under certain load

current conditions. Therefore, it is important to calculate the

maximum junction temperature for the application to

determine if load conditions need to be modified for the

buffer to remain in the safe operating area.

The maximum power dissipation allowed in a package is

determined according to:

where:

•

The maximum power dissipation actually produced by an IC

is the total quiescent supply current times the total power

supply voltage, plus the power in the IC due to the loads, or:

when sourcing, and:

when sinking.

where:

• i = 1 to total number of buffers

package power dissipation curves provide a convenient way

to see if the device will overheat. The maximum safe power

dissipation can be found graphically, based on the package

type and the ambient temperature. By using the previous

device's power derating curves.

Power Supply Bypassing and Printed Circuit

Board Layout

As with any high frequency device, good printed circuit

board layout is necessary for optimum performance. Ground

plane construction is highly recommended, lead lengths

should be as short as possible, and the power supply pins

must be well bypassed to reduce the risk of oscillation. For

connected to ground, one 0.1µF ceramic capacitor should be

ground. One 4.7µF capacitor may be used for multiple

devices. This same capacitor combination should be placed

at each supply pin to ground if split supplies are to be used.

Important Note: The metal plane used for heat sinking of

the device is electrically connected to the negative

thermal pad can be connected to ground. Otherwise, the

thermal pad must be isolated from any other power

planes.

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EL5524, EL5624, EL5724, EL5824