MC7900

10

MOTOROLA ANALOG IC DEVICE DATA

Figure 10. D2PAK Thermal Resistance and Maximum

Power Dissipation versus P.C.B. Copper Length

PD(max) for TA = +50°C

30

40

50

60

70

80

010

20

30

25

15

5.0

L, LENGTH OF COPPER (mm)

Minimum

Size Pad

2.0 oz. Copper

L

L

Free Air

Mounted

Vertically

R

θJA

1.0

1.5

2.0

2.5

3.0

3.5

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.