MC908KX2MDWE Datasheet, PDF (189/210 Pages) Freescale Semiconductor, Inc – High-performance M68HC08 architecture, Fully upward-compatible object code with M6805, M146805, and M68HC05 Families

Trimmed Accuracy of the Internal Clock Generator
Figure 17-1 through Figure 17-4 illustrate typical performance. The formula for this variation of frequency
is (measured-nominal)/nominal. Figure 17-1 shows the variation in ICG frequency for a part trimmed at
nominal voltage and temperature across V_DD and temperature for a 3-V application with multiply register
(N) set to 1. Figure 17-2 shows 5 V.
6.00%
4.00%
2.00%
2.7
3
0.00%
3.3
-2.00%
-4.00%
-6.00%
-40
25
85
125
2.7 0.00862069 -0.004310345 -0.021551724 -0.036637931
3 0.012931034
0
-0.023706897 -0.034482759
3.3 0.00862069
0
-0.019396552 -0.034482759
Figure 17-1. Example of Frequency Variation Across Temperature,
Trimmed at Nominal 3 Volts, 25°C, and N = 1
6.00%
4.00%
2.00%
2.7
3
0.00%
3.3
-2.00%
-4.00%
-6.00%
-40
25
85
125
2.7 0.021688017
3 0.027728231
3.3 0.033525215
-0.004114642
0
0.006019945
-0.035937247 -0.054665964
-0.033768445 -0.055436193
-0.032552294 -0.055456462
Figure 17-2. Example of Frequency Variation Across Temperature,
Trimmed at Nominal 3 Volts, 25°C, and N = 104
MC68HC908KX8 • MC68HC908KX2 • MC68HC08KX8 Data Sheet, Rev. 2.1
Freescale Semiconductor
189