
ML610Q421/ML610Q422/ML610421 User’s Manual
Chapter 24 RC Oscillation Type A/D Converter
24 – 16
To convert from an RT0 value to a digital value, the ratio is used between a) the oscillation frequency by the thermistor
connected to the RT0 pin and the capacitor connected to the CS0 pin and b) the oscillation frequency by the reference
resistor (which ideally should have no temperature characteristics) connected to the RS0 pin and the capacitor
connected to the CS0 pin. This is for making the conditions other than resistance equal to eliminate the error factor in
oscillation characteristics.
As shown in Figures 24-9 and 24-11, the RT0 value depends on temperature T and the RS0 value is assumed to be
constant regardless of temperature T. It is ideal if the characteristics of the oscillation frequency fOSC to temperature
T using these resistances will be like the solid lines in Figures 24-12 and 24-13; however, in reality, it would appear that
they will be like the dotted lines due to error factors such as IC temperature characteristics.
Since the condition of f
RCCLK
(RT0) and that of f
RCCLK
(RS0) are the same except for the resistances, the error ratios are
almost the same; therefore, errors can almost be eliminated by using the ratio between f
RCCLK
(RT0) and f
RCCLK
(RS0).
The ratio between f
RCCLK
(RT0) and f
RCCLK
(RS0) is equivalent to the above-mentioned A/D conversion value nT0 that
should ideally depend only on RT0.
R
ef
er
e
nc
e r
es
is
tanc
e
RS
0
Temperature T
f
RCCLK
(RT0)
Temperature T
Ideal
Includes errors due to factors other
than RT0
f
RCLK
(RS0) =
k
RCCLK
·(CS0+CVR)·RT0
1
Figure 24-11 Temperature Characteristics of
Reference Resistor
Temperature T
Includes errors due to factors
other than RT0
f
RCCLK
(RS0) =
k
RCCLK
·(CS0+CVR)·RS0
1
Ideal
f
RCLK
(RS0)
Figure 24-13 Oscillation Characteristics of Reference Resistor
Figure 24-12 Oscillation Characteristics
of Thermistor
Содержание ML610421
Страница 1: ...ML610Q421 ML610Q422 ML610421 User s Manual Issue Date Feb 9 2015 FEUL610Q421 06...
Страница 15: ...Chapter 1 Overview...
Страница 44: ...Chapter 2 CPU and Memory Space...
Страница 49: ...Chapter 3 Reset Function...
Страница 53: ...Chapter 4 MCU Control Function...
Страница 69: ...Chapter 5 Interrupts INTs...
Страница 93: ...Chapter 6 Clock Generation Circuit...
Страница 110: ...Chapter 7 Time Base Counter...
Страница 121: ...Chapter 8 Capture...
Страница 129: ...Chapter 9 1 kHz Timer 1kHzTM...
Страница 135: ...Chapter 10 Timers...
Страница 160: ...Chapter 11 PWM...
Страница 172: ...Chapter 12 Watchdog Timer...
Страница 180: ...Chapter 13 Synchronous Serial Port...
Страница 195: ...Chapter 14 UART...
Страница 216: ...Chapter 15 I2 C Bus Interface...
Страница 231: ...Chapter 16 NMI Pin...
Страница 237: ...Chapter 17 Port 0...
Страница 246: ...Chapter 18 Port 1...
Страница 252: ...Chapter 19 Port 2...
Страница 259: ...Chapter 20 Port 3...
Страница 270: ...Chapter 21 Port 4...
Страница 282: ...Chapter 22 Port A...
Страница 290: ...Chapter 23 Melody Driver...
Страница 304: ...Chapter 24 RC Oscillation Type A D Converter...
Страница 327: ...Chapter 25 Successive Approximation Type A D Converter...
Страница 338: ...Chapter 26 LCD Drivers...
Страница 371: ...Chapter 27 Battery Level Detector...
Страница 378: ...Chapter 28 Power Supply Circuit...
Страница 381: ...Chapter 29 On Chip Debug Function...
Страница 384: ...Appendixes...
Страница 435: ...Revision History...