ML63611 User’s Manual
Chapter 16 A/D Converter (ADC)
16 – 11
OPTION B (D): 1.5 V (3.0 V), With regulator
circuit for LCD bias
OPTION A (C): 1.5 V (3.0 V), Without regulator
circuit for LCD bias
16.3.3 Example of Usage of A/D Converter
The method to perform A/D conversion of sensor values by using Counter A reference mode and Counter B
reference mode is explained by taking temperature measurement with a thermistor as an example.
Figure 16-8 shows the layout of RC oscillation circuit.
ML63611 series
RS0
RT0
CS0
IN0
RS0
Thermistor
RT0
CS0
RI0
Reference
resistance
Figure 16-8 Layout of RC Oscillation Circuit of a Thermistor Using CROSC0
Figure 16-9 shows the temperature characteristics of the resistance value, RT0, of the thermistor.
T
hermist
or re
sis
tan
ce R
T
0
RT0 = f(T)
Temperature T
D
igita
l v
a
lu
e nT
0
nT0 = K • RT0
= K • f(T)
RT0
Figure 16-9
Temperature Characteristics
Figure 16-10 A/D Conversion
of Thermistor
Characteristics
(Ideal characteristics when nT0 is
proportional to RT0)
RT0 is expressed as a function of temperature T as
RT0 = f (T)
Figure 16-10 shows the ideal characteristics of A/D conversion taking RT0 as an analog quantity and it is ideal
that the A/D conversion value nT0 depends solely on RT0. Assuming that nT0 is proportional to RT0, the value
of nT0 is expressed by temperature T and the proportionality constant K as
nT0 = K • RT0 = K • f (T)
- - - - - equation (a)
Summary of Contents for ML63611
Page 9: ...Chapter 1 Overview...
Page 33: ...Chapter 2 CPU and Memory Spaces...
Page 42: ...Chapter 3 CPU Control Functions...
Page 49: ...Chapter 4 Interrupt INT...
Page 62: ...Chapter 5 Clock Generator Circuit OSC...
Page 71: ...Chapter 6 Time Base Counter TBC...
Page 75: ...Chapter 7 Timers TIMER...
Page 99: ...Chapter 8 100 Hz Timer Counter 100HzTC...
Page 103: ...Chapter 9 Watchdog Timer WDT...
Page 108: ...Chapter 10 Ports INPUT I O PORT...
Page 140: ...Chapter 11 Melody Driver MELODY...
Page 152: ...Chapter 12 Serial Port SIO...
Page 179: ...Chapter 13 LCD Driver LCD...
Page 200: ...Chapter 14 Battery Low Detect Circuit BLD...
Page 204: ...Chapter 15 Power Supply Circuit POWER...
Page 215: ...Chapter 16 A D Converter ADC...
Page 238: ...Appendixes...