MC78M00 MC78M00A Series

7

MOTOROLA ANALOG IC DEVICE DATA

DEFINITIONS

Line Regulation – The change in output voltage for a

change in the input voltage. The measurement is made under

conditions of low dissipation or by using pulse techniques

such that the average chip temperature is not significantly

affected.

Load Regulation – The change in output voltage for a

change in load current at constant chip temperature.

Maximum Power Dissipation – The maximum total

device dissipation for which the regulator will operate within

specifications.

Input Bias Current – That part of the input current that is

not delivered to the load.

Output Noise Voltage – The rms AC voltage at the

output, with constant load and no input ripple, measured over

a specified frequency range.

Long Term Stability – Output voltage stability under

accelerated life test conditions with the maximum rated

voltage listed in the devices’ electrical characteristics and

maximum power dissipation.

Figure 1. DPAK Thermal Resistance and Maximum

Power Dissipation versus P.C.B. Copper Length

Figure 2. Worst Case Power Dissipation

versus Ambient Temperature (TO–220)

θJC = 5°C/W

PD(max) = 7.52 W

No Heat Sink

θHS = 20°C/W

θHS = 10°C/W

Infinite Heat

Sink

L, LENGTH OF COPPER (mm)

R

θJA

10

5.0

3.0

2.0

1.0

0.5

0.3

0.2

0.1

40

50

60

70

80

90

100

TA, AMBIENT TEMPERATURE (°C)

25

50

75

100

125

150

0

102030

25

15

5.0

L

L

Free Air

Mounted

Vertically

2.0 oz. Copper

PD(max) for TA = 50°C

0

0.4

0.8

1.2

1.6

2.0

2.4

Minimum

Size Pad