MMCCMB2107 Freescale, MMCCMB2107 Datasheet - Page 495

• Manufacturer Part Number: MMCCMB2107
• Manufacturer: Freescale

Specifications of MMCCMB2107

• Lead Free Status / RoHS Status: Not Compliant

18.11.6 Analog Input Considerations
MMC2107 – Rev. 2.0
MOTOROLA
The current into the pin (I
determined by these equations:
where:
The current into (I
coupling ratio) of the parasitic bipolar transistor (K
expressed by this equation:
where:
A method for minimizing the impact of stress conditions on the QADC is
to strategically allocate QADC inputs so that the lower accuracy inputs
are adjacent to the inputs most likely to see stress conditions.
Also, suitable source impedances should be selected to meet design
goals and minimize the effect of stress conditions.
The source impedance of the analog signal to be measured and any
intermediate filtering should be considered whether external
multiplexing is used or not.
typical analog signal sources to one QADC analog input pin through a
separate multiplexer chip. Also, an example of an analog signal source
connected directly to a QADC analog input channel is displayed.
V
V
V
R
R
I
I
Freescale Semiconductor, Inc.
In
INJ
Stress
EB
BE
Stress
Selected
For More Information On This Product,
Queued Analog-to-Digital Converter (QADC)
= – K
is either I
N
= Adjustable voltage source
= Parasitic PNP emitter/base voltage
= Parasitic NPN base/emitter voltage
= Source impedance (10 K resistor in
= Source impedance on channel selected for conversion
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* I
INJ
INJN
Figure 18-52
In
) the neighboring pin is determined by the K
or I
I INJP
INJP
I INJN
INJN
Figure 18-53
.
or I
=
=
on stressed channel)
V
-------------------------------------------------------------- -
–
---------------------------------------------- -
INJP
Stress
V
Queued Analog-to-Digital Converter (QADC)
Stress
) under negative or positive stress is
R Stress
R Stress
–
V
–
EB
shows the connection of eight
V
BE
–
Pin Connection Considerations
V
DDA
N
Figure 18-51
‹‹ 1). The I
Technical Data
N
In
(current
can be
and
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