TPS70445, TPS70448, TPS70451, TPS70458, TPS70402

DUAL-OUTPUT LOW-DROPOUT VOLTAGE REGULATORS

WITH INTEGRATED SVS FOR SPLIT VOLTAGE SYSTEMS

SLVS307B – SEPTEMBER 2000 – REVISED APRIL 2003

21

POST OFFICE BOX 655303

THERMAL INFORMATION

thermally enhanced TSSOP-24 (PWP – PowerPad

) (continued)

The thermal pad is directly connected to the substrate of the IC, which for the TPS704xx series is a secondary

electrical connection to device ground. The heat-sink surface that is added to the PWP can be a ground plane

or left electrically isolated. In TO220-type surface-mount packages, the thermal connection is also the primary

electrical connection for a given terminal which is not always ground. The PWP package provides up to 24

independent leads that can be used as inputs and outputs (Note: leads 1, 12, 13, and 24 are internally connected

to the thermal pad and the IC substrate).

100

75

50

25

02

3

5

125

THERMAL RESISTANCE

vs

COPPER HEAT-SINK AREA

150

78

14

6

0.3

Natural Convection

50 ft/min

250 ft/min

300 ft/min

Copper Heat-Sink Area – cm2

100 ft/min

150 ft/min

200 ft/min

Figure 34