DF2268FA13V Renesas Electronics America, DF2268FA13V Datasheet - Page 511

• Manufacturer Part Number: DF2268FA13V
• Description: IC H8S/2268 MCU FLASH 100QFP
• Manufacturer: Renesas Electronics America
• Series: H8® H8S/2200r

Specifications of DF2268FA13V

• Core Processor: H8S/2000
• Core Size: 16-Bit
• Speed: 13MHz
• Connectivity: I²C, SCI, SmartCard
• Peripherals: LCD, POR, PWM, WDT
• Number Of I /o: 67
• Program Memory Size: 256KB (256K x 8)
• Program Memory Type: FLASH
• Ram Size: 16K x 8
• Voltage - Supply (vcc/vdd): 3 V ~ 5.5 V
• Data Converters: A/D 10x10b, D/A 2x8b
• Oscillator Type: Internal
• Operating Temperature: -20°C ~ 75°C
• Package / Case: 100-QFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -

15.8
15.8.1
Operation of the A/D converter can be disabled or enabled using the module stop control register.
The initial setting is for operation of the A/D converter to be halted. Register access is enabled by
clearing module stop mode. For details, refer to section 22, Power-Down Modes.
15.8.2
This LSI's analog input is designed such that conversion accuracy is guaranteed for an input signal
for which the signal source impedance is 5 kΩ or less. This specification is provided to enable the
A/D converter's sample-and-hold circuit input capacitance to be charged within the sampling time;
if the sensor output impedance exceeds 5 kΩ, charging may be insufficient and it may not be
possible to guarantee A/D conversion accuracy. However, for A/D conversion in single mode with
a large capacitance provided externally, the input load will essentially comprise only the internal
input resistance of 10 kΩ, and the signal source impedance is ignored. However, as a low-pass
filter effect is obtained in this case, it may not be possible to follow an analog signal with a large
differential coefficient (e.g., 5 mV/μs or greater) (see figure 15.9). When converting a high-speed
analog signal, a low-impedance buffer should be inserted.
15.8.3
Adding capacitance results in coupling with GND, and therefore noise in GND may adversely
affect absolute accuracy. Be sure to make the connection to an electrically stable GND such as
AVss.
Care is also required to insure that filter circuits do not communicate with digital signals on the
mounting board (i.e., acting as antennas).
Usage Notes
Module Stop Mode Setting
Permissible Signal Source Impedance
Influences on Absolute Accuracy
Sensor input
Sensor output
impedance
to 5 k
Low-pass
filter
C to 0.1 mF
Figure 15.9 Example of Analog Input Circuit
Ω
This LSI
C
15 pF
in
=
Rev. 5.00 Sep. 01, 2009 Page 459 of 656
10 k
equivalent circuit
A/D converter
Ω
Section 15 A/D Converter
20 pF
REJ09B0071-0500