HD64F3048BF25 Renesas Electronics America, HD64F3048BF25 Datasheet - Page 588

• Manufacturer Part Number: HD64F3048BF25
• Description: IC H8 MCU FLASH 128K 100QFP
• Manufacturer: Renesas Electronics America
• Series: H8® H8/300Hr

Specifications of HD64F3048BF25

• Core Processor: H8/300H
• Core Size: 16-Bit
• Speed: 8MHz
• Connectivity: SCI, SmartCard
• Peripherals: DMA, PWM, WDT
• Number Of I /o: 70
• 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-QFP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Eeprom Size: -

Section 15 A/D Converter
7. Allowable Signal-Source Impedance: The analog inputs of the H8/3048B Group are designed
8. Effect on Absolute Accuracy: Attaching an external capacitor creates a coupling with ground,
Rev. 3.00 Sep 27, 2006 page 560 of 872
REJ09B0325-0300
Sensor
input
to assure accurate conversion of input signals with a signal-source impedance not exceeding
10 k (
rating is that it enables the input capacitor in the sample-and-hold circuit in the A/D converter
to charge within the sampling time. If the sensor output impedance exceeds 10 k , charging
may be inadequate and the accuracy of A/D conversion cannot be guaranteed.
If a large external capacitor is provided in scan mode, then the internal 10-k input resistance
becomes the only significant load on the input. In this case the impedance of the signal source
is not a problem.
A large external capacitor, however, acts as a low-pass filter. This may make it impossible to
track analog signals with high dv/dt (e.g. a variation of 5 mV/µs) (figure 15.11). To convert
high-speed analog signals or to use scan mode, insert a low-impedance buffer.
so if there is noise on the ground line, it may degrade absolute accuracy. The capacitor must be
connected to an electrically stable ground, such as AV
If a filter circuit is used, be careful of interference with digital signals on the same board, and
make sure the circuit does not act as an antenna.
Sensor output impedance
Up to 10 k
Up to 5 k
Low-pass
filter
Up to 0.1 F
13 MHz) or not exceeding 5 k ( > 13 MHz) (table 15.5). The reason for this
Figure 15.11 Analog Input Circuit (Example)
13 MHz)
13 MHz)
H8/3048B Group
Cin =
15 pF
SS
.
10 k
Equivalent circuit of
A/D converter
20 pF