QADC64E Legacy Mode Operation
MPC561/MPC563 Reference Manual, Rev. 1.2
13-68
Freescale Semiconductor
Figure 13-49. Equivalent Analog Input Circuitry
Since the sample amplifier is powered by V
DDA
and V
SSA
, it can accurately transfer input signal levels up
to but not exceeding V
DDA
and down to but not below V
SSA.
If the input signal is outside of this range, the
output from the sample amplifier is clipped.
In addition, V
RH
and V
RL
must be within the range defined by V
DDA
and V
SSA
. As long as V
RH
is less than
or equal to V
DDA
and V
RL
is greater than or equal to V
SSA
and the sample amplifier has accurately
transferred the input signal, resolution is ratiometric within the limits defined by V
RL
and V
RH
. If V
RH
is
greater than V
DDA
, the sample amplifier can never transfer a full-scale value. If V
RL
is less than V
SSA
, the
sample amplifier can never transfer a zero value.
shows the results of reference voltages outside the range defined by V
DDA
and V
SSA
. At the
top of the input signal range, V
DDA
is 10 mV lower than V
RH
. This results in a maximum obtainable 10-bit
conversion value of 0x3FE. At the bottom of the signal range, V
SSA
is 15 mV higher than V
RL
, resulting in
a minimum obtainable 10-bit conversion value of three.
Sample
AMP
16 Channels
VSSA
VRL
VDDA
QADC64E 16CH SAMPLE AMP
VRH
S/H
RC DAC
Comparator
CP
Summary of Contents for MPC561
Page 84: ...MPC561 MPC563 Reference Manual Rev 1 2 lxxxiv Freescale Semiconductor...
Page 144: ...Signal Descriptions MPC561 MPC563 Reference Manual Rev 1 2 2 46 Freescale Semiconductor...
Page 206: ...Central Processing Unit MPC561 MPC563 Reference Manual Rev 1 2 3 62 Freescale Semiconductor...
Page 302: ...Reset MPC561 MPC563 Reference Manual Rev 1 2 7 14 Freescale Semiconductor...
Page 854: ...Time Processor Unit 3 MPC561 MPC563 Reference Manual Rev 1 2 19 24 Freescale Semiconductor...
Page 968: ...Development Support MPC561 MPC563 Reference Manual Rev 1 2 23 54 Freescale Semiconductor...
Page 1144: ...Internal Memory Map MPC561 MPC563 Reference Manual Rev 1 2 B 34 Freescale Semiconductor...
Page 1212: ...TPU3 ROM Functions MPC561 MPC563 Reference Manual Rev 1 2 D 60 Freescale Semiconductor...
Page 1216: ...Memory Access Timing MPC561 MPC563 Reference Manual Rev 1 2 E 4 Freescale Semiconductor...