HD64F2338VFC25 Renesas Electronics America, HD64F2338VFC25 Datasheet - Page 752

• Manufacturer Part Number: HD64F2338VFC25
• Description: MCU 3V 256K 144-QFP
• Manufacturer: Renesas Electronics America
• Series: H8® H8S/2300r

Specifications of HD64F2338VFC25

• Core Processor: H8S/2000
• Core Size: 16-Bit
• Speed: 25MHz
• Connectivity: SCI, SmartCard
• Peripherals: DMA, POR, PWM, WDT
• Number Of I /o: 106
• Program Memory Size: 256KB (256K x 8)
• Program Memory Type: FLASH
• Ram Size: 8K x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 3.6 V
• Data Converters: A/D 12x10b; D/A 4x8b
• Oscillator Type: Internal
• Operating Temperature: -20°C ~ 75°C
• Package / Case: 144-QFP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Eeprom Size: -

Permissible Signal Source Impedance: The chip’s analog input is designed so that conversion
precision 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 the A/D conversion
precision.
If a large capacitance is provided externally, the input load will essentially comprise only the
internal input resistance of 10 kΩ, and the signal source impedance is ignored. However, since 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).
When converting a high-speed analog signal, a low-impedance buffer should be inserted.
Influences on Absolute Precision: Adding capacitance results in coupling with GND, and
therefore noise in GND may adversely affect absolute precision. Be sure to make the connection to
an electrically stable GND such as AV
Care is also required to insure that filter circuits do not communicate with digital signals on the
mounting board, so acting as antennas.
Rev.4.00 Sep. 07, 2007 Page 720 of 1210
REJ09B0245-0400
Sensor input
Note: Values are reference values.
Sensor output
impedance
Max. 5 kΩ
Low-pass
filter C
to 0.1 µF
Figure 16.10 Example of Analog Input Circuit
SS
.
Chip
C
in
= 15 pF
A/D converter
equivalent circuit
10 kΩ
20 pF