7

EL2210C/11C, EL2310C/11C, EL2410C/11C

Low Cost, Dual, Triple and Quad Video Op Amps

Application Information

Product Description

The EL2210C, EL2310C, and EL2410C are dual, triple,

and quad operational amplifiers stable at a gain of 1. The

EL2211C, EL2311C, and EL2411C are dual, triple, and

quad operational amplifiers stable at a gain of 2. All six

are built on Elantec's proprietary complimentary process

and share the same voltage mode feedback topology.

This topology allows them to be used in a variety of

applications where current mode feedback amplifiers are

not appropriate because of restrictions placed on the

feedback elements. These products are especially

designed for applications where high bandwidth and

good video performance characteristics are desired but

the higher cost of more flexible and sophisticated prod-

ucts are prohibitive.

Power Supplies

These amplifiers are designed to work at a supply volt-

age difference of 10V to 12V. These amplifiers will

work on any combination of ± supplies. All electrical

characteristics are measured with ±5V supplies. Below

9V total supply voltage the amplifiers’ performance will

degrade dramatically. The quiescent current is a direct

function of total supply voltage. With a total supply volt-

age of 12V the quiescent supply current will increase

from a typical 6.8mA per amplifier to 10mA per

amplifier.

Output Swing vs Load

Please refer to the simplified block diagram. These

amplifiers provide an NPN pull-up transistor output and

a passive 1250

Ω pull-down resistor to the most negative

supply. In an application where the load is connected to

connected to ground the negative swing is limited by the

voltage divider formed by the load, the internal 1250

Ω

150

Ω then it and the 1250Ω internal resistor limit the

maximum negative swing to

The negative swing can be increased by adding an exter-

nal resistor of appropriate value from the output to the

negative supply. The simplified block diagram shows an

820

Ω external pull-down resistor. This resistor is in par-

allel with the internal 1250

Ω resistor. This will increase

the negative swing to

Or -1.16V

Power Dissipation and Loading

Without any load and a 10V supply difference the power

dissipation is 70mW per amplifier. At 12V supply dif-

ference this increases to 105mW per amplifier. At 12V

this translates to a junction temperature rise above ambi-

ent of 33°C for the dual and 40°C for the quad amplifier.

When the amplifiers provide load current the power dis-

sipation can rapidly rise.

In ±5V operation each output can drive a grounded

150

Ω load to more than 2V. This operating condition

will not exceed the maximum junction temperature limit

as long as the ambient temperature is below 85°C, the

device is soldered in place, and the extra pull-down

resistor is 820

Ω or more.

If the load is connected to the most negative voltage

(ground in single supply operation) you can easily

exceed the absolute maximum die temperature. For

example the maximum die temperature should be

150°C. At a maximum expected ambient temperature of

85°C, the total allowable power dissipation for the SO8

package would be:

At 12V total supply voltage each amplifier draws a max-

imum of 10mA and dissipates 12V * 10mA = 120mW or

240mW for the dual amplifier. Which leaves 121mW of

increased power due to the load. If the load were 150

Ω

connected to the most negative voltage and the maxi-

be 6.67mA. Then an extra 146mW ((12V - 1V) *

6.67mA * 2) would be dissipated in the EL2210C or

VEE

150

1250 150

+

---------------------------

=

VEE

150 1250 820

×

1250 820

+

---------------------------

÷

150

+

=

PD

150 85

–

160

°C/W

------------------------

361mW

=

=