27-70
MCF5282 User’s Manual
MOTOROLA
Signal Connection Considerations
Figure 27-51. Input Signal Subjected to Positive Stress
The current into the signal (I
INJN
or I
INJP
) under negative or positive stress is determined by
these equations:
Where:
V
Stress
= Adjustable voltage source
V
EB
= Parasitic PNP emitter/base voltage
V
BE
= Parasitic NPN base/emitter voltage
R
Stress
= Source impedance (10 k
Ω
resistor in Figure 27-50 and Figure 27-51 on stressed
channel)
R
Selected
= Source impedance on channel selected for conversion
The current into (I
In
) the neighboring pin is determined by the K
N
(current coupling ratio)
of the parasitic bipolar transistor (K
N
‹‹ 1). The I
In
can be expressed by this equation:
I
In
= – K
N
* I
INJ
Where:
I
INJ
is either I
INJN
or I
INJP
.
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.
R
STRESS
R
SELECTED
Adjacent
10 k
Ω
Signal Under
Parasitic
I
injP
I
IN
+
Stress
V
STRESS
Device
Signal
V
IN
V
DDA
AN
n
AN
n+1
IINJN
VStress VBE
–
(
)
–
RStress
---------------------------------------------
=
IINJP
VStress VEB
–
VDDA
–
RStress
-------------------------------------------------------------
=
Summary of Contents for ColdFire MCF5281
Page 124: ...3 20 MCF5282 User s Manual MOTOROLA EMAC Instruction Set Summary ...
Page 141: ...MOTOROLA Chapter 5 Static RAM SRAM 5 5 SRAM Programming Model ...
Page 142: ...5 6 MCF5282 User s Manual MOTOROLA SRAM Programming Model ...
Page 168: ...6 26 MCF5282 User s Manual MOTOROLA Interrupts ...
Page 186: ...7 18 MCF5282 User s Manual MOTOROLA Functional Description ...
Page 228: ...9 22 MCF5282 User s Manual MOTOROLA Functional Description ...
Page 246: ...10 18 MCF5282 User s Manual MOTOROLA Low Power Wakeup Operation ...
Page 254: ...11 8 MCF5282 User s Manual MOTOROLA Memory Map and Registers ...
Page 264: ...12 10 MCF5282 User s Manual MOTOROLA Chip Select Registers ...
Page 280: ...13 16 MCF5282 User s Manual MOTOROLA Misaligned Operands ...
Page 314: ...14 34 MCF5282 User s Manual MOTOROLA MCF5282 External Signals ...
Page 339: ...MOTOROLA Chapter 15 Synchronous DRAM Controller Module 15 25 SDRAM Example ...
Page 340: ...15 26 MCF5282 User s Manual MOTOROLA SDRAM Example ...
Page 356: ...16 16 MCF5282 User s Manual MOTOROLA DMA Controller Module Functional Description ...
Page 408: ...17 52 MCF5282 User s Manual MOTOROLA Buffer Descriptors ...
Page 446: ...20 24 MCF5282 User s Manual MOTOROLA Interrupts ...
Page 474: ...22 18 MCF5282 User s Manual MOTOROLA Programming Model ...
Page 510: ...23 36 MCF5282 User s Manual MOTOROLA Operation ...
Page 526: ...24 16 MCF5282 User s Manual MOTOROLA I2C Programming Examples ...
Page 672: ...28 12 MCF5282 User s Manual MOTOROLA Functional Description ...
Page 718: ...29 46 MCF5282 User s Manual MOTOROLA Motorola Recommended BDM Pinout ...
Page 750: ...32 8 MCF5282 User s Manual MOTOROLA Ordering Information ...