2015. 5. 13

17/20

KIA7805AF/API~KIA7824AF/API

Revision No : 8

(4) Connect the input terminal and GND, and the output terminal and GND, by capacitor respectively.

The capacitances should be determined experimentally because they depend on printed patterns. In particular,

adequate investigation should be made so that there is no problem even at time of high or low temperature.

(5) Installation of IC for power supply

For obtaining high reliability on the heat sink design of the regulator IC, it is generally required to derate more than 20%

(a) Heat sink design

The thermal resistance of IC itself is required from the viewpoint of the design of elements, but the thermal resistance from the

IC package to the open air varies with the contact thermal resistance. Table 1 shows how much the value of the contact thermal

resistance (

θ

TABLE 1.

UNIT:

℃/W

The figures given in parentheses denote the values at time of no grease.

The package of regulator IC serves as GND, therefore, usually use the value at time of "no mica"

(b) Silicon grease

When a circuit not exceeding maximum rating is designed, it is to be desired that the grease should be used if possible.

If it is required that the contact thermal resistance is reduced from the view-point of the circuit design,

It is recommended that the following methods be adopted.

A: Use Thercon (Fuji High Polymer Kogyo K.K)

B: Use SC101 (Torei Silicon) or G-640 (GE), if grease is used.

(c) Torque

When installing IC on a heat sink or the like, tighten the IC with the torque of less than the rated value. If it is tightened with

the torque in excess of the rated value, sometimes the internal elements of the IC are adversely affected. Therefore, great care

should be given to the installing operation. Further, if polycarbonate screws are used, the torque causes a change with the passage

of time, which may lessen the effect of radiation.

PACKAGE

MODEL NO.

TORQUE

MICA

θ

S

TO-220IS

KIA78xxAPI

6kg

・cm

Not Provided

0.3

～0.5(1.5～2.0)

Provided

2.0

～2.5(4.0～6.0)