TPS1120, TPS1120Y

DUAL P-CHANNEL ENHANCEMENT-MODE MOSFETS

SLVS080A – MARCH 1994 – REVISED AUGUST 1995

10

POST OFFICE BOX 655303

THERMAL INFORMATION

The profile of the heat sinks used for thermal measurements is shown in Figure 14. Board type is FR4 with 1-oz copper

and 1-oz tin/lead (63/37) plate. Use of vias or through-holes to enhance thermal conduction was avoided.

flow. Power remained fixed at 0.25 W per device or 0.50 W per package. This testing was done at 25

°C.

As Figure 14 illustrates, there are two separated heat sinks for each package. Each heat sink is coupled to the lead

that is internally tied to a single MOSFET source and is half the total area, as shown in Figure 15. For example, if the

1DRAIN

2DRAIN

1SOURCE

1GATE

2GATE

The Combined Area

of These Two Heat

Sinks Is 4 cm2

TPS1120D IC

HS: 4 cm2

8P SOIC Thermal Analysis

≅ 2 cm

2SOURCE

Figure 14. Profile of Heat Sinks

70

60

50

0

50

100

150

80

90

THERMAL RESISTANCE, JUNCTION-TO-AMBIENT

vs

AIRFLOW, 25

°C

100

200

250

300

Airflow, 25

°C – ft/min

110

120

130

140

150

TJ = 25°C

P = 0.5 W

Heat Sink Areas

as Shown

0.5 cm2

1 cm2

2 cm2

4 cm2

0 cm2

8 cm2

Figure 15