User Manual
95
Rev. 1.1
2019-03-18
TLE984xQX
Microcontroller with LIN and Power Switches for Automotive Applications
System Control Unit - Digital Modules (SCU-DM)
Note:
The not allowed settings are related to the fact that the maximum system frequency f
sys_max
is
exceeded. The whole range in between two f
VCO
columns in the above table is allowed if the
specification for the parameter f
REF
is maintained as f
DIV
is compared to f
REF
.
The N-divider output frequency
f
DIV
is then compared with
f
REF
in the phase detector logic, within the VCO logic.
The phase detector determines the difference between the two clock signals and accordingly controls the
output frequency of the VCO,
f
VCO
.
Note:
Due to this operation, the VCO clock of the PLL has a frequency which is a multiple of f
DIV
. The factor
for this is controlled through the value applied to the N-divider in the feedback path. For this reason
this factor is often called a multiplier, although it actually controls division.
The output frequency of the VCO,
f
VCO
, is divided by K2 to provide the final desired output frequency
f
PLL
.
shows the output frequency range depending on the K2 divisor and the VCO frequency range:
Notes
1. The whole range in between two f
vco
columns in the above table is only allowed if the maximum specified
system frequency f
sys
is not exceeded.
For the K1-divider the same table is valid as for the K2-divider. The only difference is that not
f
VCO
is used as
reference,
f
R
is used instead.
78
0.96
1.23
not allowed not allowed not allowed
80
0.94
1.2
not allowed not allowed not allowed
0.85
1.09
not allowed not allowed not allowed
90
0.83
1.07
1.24
not allowed not allowed
94
0.80
1.02
1.19
not allowed not allowed
100
not allowed 0.96
1.12
not allowed not allowed
160
not allowed not allowed not allowed 0.85
1.00
others not
accessible
Table 36 K2
Divisor
Table
K2
f
PLL
for
f
VCO
=
Typ. Duty Cycle
[%]
75
96
112
136
160
2
37.5
not
allowed
not
allowed
not
allowed
not
allowed
50
3
25.0
32.0
37.3
not
allowed
not
allowed
40
4
18.8
24.0
28.0
34.0
40.0
50
5
15.0
19.2
22.4
27.2
32.0
44
others
not accessible
Table 35 N Loop Division Rates
(cont’d)
N
f
DIV
for
f
VCO
=
75
96
112
136
160