DF71251AD50FPV Renesas Electronics America, DF71251AD50FPV Datasheet - Page 523

• Manufacturer Part Number: DF71251AD50FPV
• Description: MCU RISC FLASH 32K 8K 64LQFP
• Manufacturer: Renesas Electronics America
• Series: SuperH® SH Tinyr

Specifications of DF71251AD50FPV

• Core Processor: SH-2
• Core Size: 32-Bit
• Speed: 50MHz
• Connectivity: SCI
• Peripherals: POR, PWM, WDT
• Number Of I /o: 37
• Program Memory Size: 32KB (32K x 8)
• Program Memory Type: FLASH
• Ram Size: 8K x 8
• Voltage - Supply (vcc/vdd): 4 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: External
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 64-LQFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -

13.7.6
A protection circuit should be connected in order to prevent damage due to abnormal voltage, such
as an excessive surge at the analog input pins (AN0 to AN7), between AVcc and AVss, as shown
in figure 13.8. Also, the bypass capacitors connected to AVcc and the filter capacitor connected to
AN0 to AN7 must be connected to AVss.
If a filter capacitor is connected, the input currents at the analog input pins (AN0 to AN7) are
averaged, and so an error may arise. Also, when A/D conversion is performed frequently, as in
scan mode, if the current charged and discharged by the capacitance of the sample-and-hold circuit
in the A/D converter exceeds the current input via the input impedance (R
the analog input pin voltage. Careful consideration is therefore required when deciding circuit
constants.
Table 13.7 Analog Pin Specifications
Item
Analog input capacitance
Permissible signal source impedance
Notes on Noise Countermeasures
Notes:
* 1
Figure 13.8 Example of Analog Input Protection Circuit
Values are reference values.
1.
2. R in : Input impedance
10 µF
R
in
* 2
0.01 µF
100 Ω
0.1 µF
Min.
⎯
⎯
⎯
Max.
20
3
1
AV
AN0 to AN7
AV
cc
ss
Rev. 5.00 Mar. 06, 2009 Page 503 of 770
Unit
pF
kΩ
kΩ
Condition
⎯
Conversion time ≥ 4.0 μs
Conversion time < 4.0 μs
in
), an error will arise in
REJ09B0243-0500