TLV4110, TLV4111, TLV4112, TLV4113

FAMILY OF HIGH OUTPUT DRIVE OPERATIONAL

AMPLIFIERS WITH SHUTDOWN

SLOS289A – DECEMBER 1999 – REVISED APRIL 2000

15

POST OFFICE BOX 655303

APPLICATION INFORMATION

general PowerPAD design considerations (continued)

TJ = 150°C

4

3

2

0

–55 –40

–10

20 35

MAXIMUM POWER DISSIPATION

vs

FREE-AIR TEMPERATURE

65

95

125

1

TA – Free-Air Temperature – °C

–25

5

50

80

110

3.5

2.5

1.0

0.5

DGN Package

Low-K Test PCB

θJA = 52.7°C/W

PDIP Package

Low-K Test PCB

θJA = 104°C/W

SOIC Package

Low-K Test PCB

θJA = 176°C/W

NOTE A: Results are with no air flow and using JEDEC Standard Low-K test PCB.

Figure 29. Maximum Power Dissipation vs Free-Air Temperature

The next consideration is the package constraints. The two sources of heat within an amplifier are quiescent

power and output power. The designer should never forget about the quiescent heat generated within the

device, especially muti-amplifier devices. Because these devices have linear output stages (Class A-B), most

of the heat dissipation is at low output voltages with high output currents.

The other key factor when dealing with power dissipation is how the devices are mounted on the PCB. The

PowerPAD devices are extremely useful for heat dissipation. But, the device should always be soldered to a

copper plane to fully use the heat dissipation properties of the PowerPAD. The SOIC package, on the other

hand, is highly dependent on how it is mounted on the PCB. As more trace and copper area is placed around

the device,

these graphs are for the total package. For the dual or quad amplifier packages, the sum of the RMS output

currents and voltages should be used to choose the proper package.