4

MC68L300EC16/D

Table 3 MC68L332 Typical Ratings

Num

Rating

Symbol

Value

Unit

1

Supply Voltage

VDD

3.3

V

2

Operating Temperature

TA

25

°C

3

VDD Supply Current

RUN

LPSTOP, External clock, max fsys

IDD

45

1.0

mA

mA

4

Clock Synthesizer Operating Voltage

V

DDSYN

3.3

V

5

VDDSYN Supply Current

External Clock, maximum fsys

I

DDSYN

2.0

mA

6

RAM Standby Current

Normal RAM operation

Standby operation

ISB

3.0

10

µA

µA

7

Power Dissipation

PD

148.0

mW

Table 4 Thermal Characteristics

Num

Rating

Symbol

Value

Unit

1

Thermal Resistance

Plastic 132-Pin Surface Mount

Plastic 144-Pin Surface Mount

Θ

JA

38

49

°C/W

The average chip-junction temperature (TJ) in C can be obtained from:

(1)

where:

TA = Ambient Temperature, °C

Θ

JA= Package Thermal Resistance, Junction-to-Ambient, °C/W

PD = PINT + PI/O

PINT= IDD × VDD, Watts — Chip Internal Power

PI/O= Power Dissipation on Input and Output Pins — User Determined

For most applications PI/O < PINT and can be neglected. An approximate relationship between PD and TJ (if PI/O is

neglected) is:

(2)

Solving equations 1 and 2 for K gives:

(3)

where K is a constant pertaining to the particular part. K can be determined from equation (3) by measuring PD (at

equilibrium) for a known TA. Using this value of K, the values of PD and TJ can be obtained by solving equations (1)

and (2) iteratively for any value of TA.

T

J

T

A

P

D

Θ

JA

×

()

+

=

P

D

KT

J

273

°C

+

()

÷

=

KP

D

T

A

273

°C

+

() Θ

JA

P

D

2

×

++

=

Freescale Semiconductor, Inc.

For More Information On This Product,

Go to: www.freescale.com