5

Application Information

The Intersil HA-2842 is a state of the art monolithic device

which also approaches the “ALL-IN-ONE” amplifier concept.

This device features an outstanding set of AC parameters

augmented by excellent output drive capability providing for

suitable application in both high speed and high output drive

circuits.

Primarily intended to be used in balanced 50

Ω and 75Ω

coaxial cable systems as a driver, the HA-2842 could also be

used as a power booster in audio systems as well as a

power amp in power supply circuits. This device would also

be suitable as a small DC motor driver.

Prototyping Guidelines

For best overall performance in any application, it is

recommended that high frequency layout techniques be

used. This should include:

1. Mounting the device through a ground plane.

2. Connecting unused pins (NC) to the ground plane.

3. Mounting feedback components on Teflon standoffs

and/or locating these components as close to the device

as possible.

4. Placing power supply decoupling capacitors from device

supply pins to ground.

Power Dissipation Considerations

At high output currents, especially with the 8 lead SOIC

package, care must be taken to ensure that the Maximum

table) isn’t exceeded. As an example consider the HA-2842 in

the SOIC package, with a required output current of 50mA at

quiescent power (450mW = 30V x 15mA) plus the power

dissipated in the output stage

The thermal resistance (

would be required for operation at ambient temperatures

Allowable output power can be increased by decreasing the

quiescent dissipation via lower supply voltages.

For more information please refer to Application Note AN556,

Thermal Safe Operating Areas for High Current Op Amps.

8 LEAD SOIC

(

Heatsink Required

60mW

350mW

FIGURE 1. FREQUENCY RESPONSE FOR VARIOUS GAINS

FIGURE 2. GAIN BANDWIDTH PRODUCT vs SUPPLY VOLTAGE

10

100

1K

10K

100K

1M

10M

100M

FREQUENCY (Hz)

120

100

80

60

40

20

0

0

90

180

OPEN LOOP

OPEN LOOP

= 1000

= 100

= 10

= 2

56

78

9

10

11

12

13

14

15

SUPPLY VOLTAGE (

±V)

90

80

70

60

50

40

30

100

HA-2842