AN2433 Freescale Semiconductor / Motorola, AN2433 Datasheet - Page 11

• Manufacturer Part Number: AN2433
• Description: 5V to 3V Design Considerations
• Manufacturer: Freescale Semiconductor / Motorola

MOTOROLA
I n t e r n a l
I n t e r n a l
O u t p u t
O u t p u t
B u f f e r
B u f f e r
A characterization analysis was performed using five units of QFP
MC68HC908GP32 (0.5 micron microcontroller with 32Kbytes Embedded
Flash) in three different temperatures –40
chosen as a reference example because it is a general purpose microcontroller
and it works both at 5V and 3V. The results found can be extrapolated for other
5V and 3V microcontrollers.
V
source currents (I
high-side driver (V
Generally, the sinking capability is higher than the sourcing one due to the
higher mobility of n-channel devices over p-channel ones. This consideration
explains the bigger current values, when the port is outputting a logic ‘0’, which
will be highlighted in the data below.
Typically, for the normal current I/O Ports, the current sink and source
specifications are as follows:
@ V
@ V
P
P
N
N
V
V
OH
V
V
Freescale Semiconductor, Inc.
D D
D D
/I
S S
S S
DD
DD
For More Information On This Product,
OH
= 5.5V,
= 2.7V,
and V
5V to 3V Design Considerations
Figure 8. Output-Only Pin
Go to: www.freescale.com
OL
/I
LOAD
N
N
OH
OL
V
V
V
V
OH
OL
OH
OL
) at 2.7V and 5.5V.
measurements with varied loading in terms of sink and
) were carried out to characterize low-side (V
< 1.5V at sink current of 10mA
> (V
> (V
< 1.0V at sink current of 6mA
V
V
DD
DD
S S
S S
– 1.5V) at source current of 10mA
– 1.0V) at source current of 4mA
P r o t e c t i o n
P r o t e c t i o n
T h i c k
T h i c k
F i e l d
F i e l d
o
C, 25
o
C and 85
o
C. This device was
E x t e r n a l
E x t e r n a l
Microcontroller Outputs
P i n
P i n
OL
) and
AN2433/D
11