THS3111CD datasheet(23/37 Pages) TI

23 / 37 page

T =125 C

Free-AirTemperature

A -

- °

DMax

Max

THS3110

THS3111

www.ti.com........................................................................................................................................ SLOS422E – SEPTEMBER 2003 – REVISED OCTOBER 2009

entire circumference of the plated-through hole.

Maximum power dissipation levels are depicted in

Figure 65 for the available packages. The data for the

6. The top-side solder mask should leave the

PowerPAD packages assume a board layout that

terminals of the package and the thermal pad

follows the PowerPAD layout guidelines referenced

area with its five holes exposed. The bottom-side

above and detailed in the PowerPAD application note

solder mask should cover the five holes of the

(literature

number

SLMA002).

Figure

also

thermal pad area. This prevents solder from

illustrates the effect of not soldering the PowerPAD to

being pulled away from the thermal pad area

PCB.

The

thermal

impedance

increases

during the reflow process.

substantially which may cause serious heat and

7. Apply solder paste to the exposed thermal pad

performance issues. Be sure to always solder the

area and all of the IC terminals.

PowerPAD to the PCB for optimum performance.

8. With these preparatory steps in place, the IC is

simply placed in position and run through the

solder

reflow

operation

any

standard

surface-mount component. This results in a part

that is properly installed.

POWER DISSIPATION AND THERMAL

CONSIDERATIONS

The THS3110 and THS3111 incorporate automatic

thermal shutoff protection. This protection circuitry

shuts down the amplifier if the junction temperature

exceeds approximately +160°C. When the junction

temperature reduces to approximately +140°C, the

amplifier

turns

again.

But,

for

maximum

performance and reliability, the designer must take

care to ensure that the design does not exceed a

junction temperature of +125°C. Between +125°C

Results are with no airflow and PCB size = 3 in × 3 in (7,62 mm ×

7,62 mm);

θJA = 58.4°C/W for MSOP-8 with PowerPAD (DGN); θJA

and +150°C, damage does not occur, but the

= 95°C/W for SOIC-8 High-K Test PCB (D);

θJA = 158°C/W for

performance of the amplifier begins to degrade and

MSOP-8 with PowerPAD, without solder.

long

term

reliability

suffers.

The

thermal

characteristics of the device are dictated by the

Figure 65. Maximum Power Distribution

package

and

the

board.

Maximum

power

vs Ambient Temperature

dissipation for a given package can be calculated

using the following formula.

When determining whether or not the device satisfies

the maximum power dissipation requirement, it is

important to not only consider quiescent power

(1)

dissipation, but also dynamic power dissipation. Often

Where:

times, this is difficult to quantify because the signal

•

PDMax is the maximum power dissipation in the

pattern is inconsistent, but an estimate of the RMS

amplifier (W)

power dissipation can provide visibility into a possible

•

TMax is the absolute maximum junction

problem.

temperature (°C)

•

TA is the ambient temperature (°C)

DESIGN TOOLS

•

θJA = θJC + θCA

Evaluation Fixtures, Spice Models, and

•

θJC is the thermal coefficient from the silicon

Application Support

junctions to the case (°C/W)

•

θCA is the thermal coefficient from the case to

Texas Instruments is committed to providing its

ambient air (°C/W)

customers with the highest quality of applications

support. To support this goal an evaluation board has

For systems where heat dissipation is more critical,

been developed for the THS3110 and THS3111

the THS3110 and THS3111 are offered in an

operational amplifiers. The board is easy to use,

MSOP-8 with PowerPAD package offering even

allowing for straightforward evaluation of the device.

better thermal performance. The thermal coefficient

The evaluation board can be ordered through the

for

the

PowerPAD

packages

are

substantially

Texas Instruments web site, www.ti.com, or through

improved over the traditional SOIC.

your local Texas Instruments sales representative.

Submit Documentation Feedback

Product Folder Link(s): THS3110 THS3111

THS3111CD Datasheet(PDF) 23 Page - Texas Instruments

THS3111CD Datasheet(HTML) 23 Page - Texas Instruments

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37

Datasheet Download

Link URL