S9S08SG8E2VTG Freescale Semiconductor, S9S08SG8E2VTG Datasheet - Page 124

• Manufacturer Part Number: S9S08SG8E2VTG
• Description: 8-bit Microcontrollers - MCU 9S08 UC W/ 8K 0.25UM SGF
• Manufacturer: Freescale Semiconductor

Specifications of S9S08SG8E2VTG

• Rohs: yes
• Core: S08
• Processor Series: MC9S08SG8
• Data Bus Width: 8 bit
• Maximum Clock Frequency: 40 MHz
• Program Memory Size: 8 KB
• Data Ram Size: 8 KB
• On-chip Adc: Yes
• Operating Supply Voltage: 2.7 V to 5.5 V
• Operating Temperature Range: - 40 C to + 105 C
• Package / Case: TSSOP-16
• Mounting Style: SMD/SMT
• A/d Bit Size: 10 bit
• A/d Channels Available: 12
• Interface Type: SCI, SPI
• Maximum Operating Temperature: + 105 C
• Minimum Operating Temperature: - 40 C
• Number Of Programmable I/os: 16
• Number Of Timers: 2
• Program Memory Type: Flash
• Supply Voltage - Max: 5.5 V
• Supply Voltage - Min: 2.7 V

Chapter 9 Analog-to-Digital Converter (S08ADCV1)
9.1.2
The ADC module is capable of performing conversions using the MCU bus clock, the bus clock divided
by two, the local asynchronous clock (ADACK) within the module, or the alternate clock, ALTCLK. The
alternate clock for the MC9S08SG8 MCU devices is the external reference clock (ICSERCLK).
The selected clock source must run at a frequency such that the ADC conversion clock (ADCK) runs at a
frequency within its specified range (f
determined by the ADIV bits.
ALTCLK is active while the MCU is in wait mode provided the conditions described above are met. This
allows ALTCLK to be used as the conversion clock source for the ADC while the MCU is in wait mode.
ALTCLK cannot be used as the ADC conversion clock source while the MCU is in either stop2 or stop3.
9.1.3
The ADC hardware trigger, ADHWT, is the output from the real time counter (RTC). The RTC counter
can be clocked by either ICSERCLK, ICSIRCLK or a nominal 1 kHz clock source.
The period of the RTC is determined by the input clock frequency, the RTCPS bits, and the RTCMOD
register. When the ADC hardware trigger is enabled, a conversion is initiated upon an RTC counter
overflow. The RTIE does not have to be set for RTC to cause a hardware trigger.
The RTC can be configured to cause a hardware trigger in MCU run, wait, and stop3.
9.1.4
To use the on-chip temperature sensor, the user must perform the following:
Equation 9-1
where:
120
•
•
•
•
•
•
Configure ADC for long sample with a maximum of 1 MHz clock
Convert the bandgap voltage reference channel (AD27)
— By converting the digital value of the bandgap voltage reference channel using the value of
Convert the temperature sensor channel (AD26)
— By using the calculated value of V
V
V
m is the hot or cold voltage versus temperature slope in V/C.
TEMP
TEMP25
V
Characteristics”.
Alternate Clock
Hardware Trigger
Temperature Sensor
BG
provides an approximate transfer function of the on-chip temperature sensor.
is the voltage of the temperature sensor channel at the ambient temperature.
the user can determine V
is the voltage of the temperature sensor channel at 25C.
Temp
MC9S08SG8 MCU Series Data Sheet, Rev. 7
C
= 25 - ((V
ADCK
DD
) after being divided down from the ALTCLK input as
. For value of bandgap voltage, see
DD
TEMP
, convert the digital value of AD26 into a voltage,
- V
TEMP25
)  m
Section A.6, “DC
Freescale Semiconductor
Eqn. 9-1
V
TEMP