DF2345TE20 Renesas Electronics America, DF2345TE20 Datasheet - Page 553

• Manufacturer Part Number: DF2345TE20
• Description: MCU 5V 128K 100-TQFP
• Manufacturer: Renesas Electronics America
• Series: H8® H8S/2300r

Specifications of DF2345TE20

• Core Processor: H8S/2000
• Core Size: 16-Bit
• Speed: 20MHz
• Connectivity: SCI, SmartCard
• Peripherals: POR, PWM, WDT
• Number Of I /o: 71
• Program Memory Size: 128KB (128K x 8)
• Program Memory Type: FLASH
• Ram Size: 4K x 8
• Voltage - Supply (vcc/vdd): 4.5 V ~ 5.5 V
• Data Converters: A/D 8x10b; D/A 2x8b
• Oscillator Type: Internal
• Operating Temperature: -20°C ~ 75°C
• Package / Case: 100-TQFP, 100-VQFP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Eeprom Size: -
• Other names: HD64F2345TE20; HD64F2345TE20

Permissible Signal Source Impedance: H8S/2345 Group analog input is designed so that
conversion precision is guaranteed for an input signal for which the signal source impedance is 10
k 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
10 k , charging may be insufficient and it may not be possible to guarantee the A/D conversion
precision.
However, if a large capacitance is provided externally, the input load will essentially comprise
only the internal input resistance of 10 k , 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.
Sensor input
Note: Values are reference values.
Sensor output
impedance
to 10 k
Low-pass
filter
C to 0.1 µF
Figure 14.11 Example of Analog Input Circuit
SS
.
H8/2345 Group
C
15 pF
in
=
Rev. 4.00 Feb 15, 2006 page 527 of 900
A/D converter
equivalent circuit
10 k
Section 14 A/D Converter
REJ09B0291-0400
20 pF