UPD78F0034BGC-8BS-A Renesas Electronics America, UPD78F0034BGC-8BS-A Datasheet - Page 278

• Manufacturer Part Number: UPD78F0034BGC-8BS-A
• Description: MCU 8-Bit 78K0 CISC 32KB Flash 2.5V/3.3V/5V 64-Pin LQFP
• Manufacturer: Renesas Electronics America

Specifications of UPD78F0034BGC-8BS-A

• Package: 64LQFP
• Family Name: 78K0
• Maximum Speed: 12 MHz
• Ram Size: 1 KB
• Program Memory Size: 32 KB
• Operating Supply Voltage: 2.5|3.3|5 V
• Data Bus Width: 8 Bit
• Program Memory Type: Flash
• Number Of Programmable I/os: 51
• Interface Type: 3-Wire/UART
• On-chip Adc: 8-chx10-bit
• Operating Temperature: -40 to 85 °C
• Number Of Timers: 3

(14) Input impedance of ANI0 to ANI7 pins
276
Output impedance
of sensor
Remark n = 0 to 7
This A/D converter executes sampling by charging the internal sampling capacitor for approximately 1/10 of the
conversion time.
Therefore, only the leakage current flows during other than sampling, and the current for charging the capacitor
flows during sampling. The input impedance therefore varies and has no meaning.
To achieve sufficient sampling, it is recommended that the output impedance of the analog input source be 10
k
<Sensor internal circuit>
or less, or attach a capacitor of around 100 pF to the ANI0 to ANI7 pins (see Figure 13-20).
Table 13-3. Resistances and Capacitances of Equivalent Circuit (Reference Values)
Figure 13-20. Example of Connection If Signal Source Impedance Is High
Caution
CHAPTER 13 8-BIT A/D CONVERTER ( PD780024A, 780024AY SUBSERIES)
Lowpass filter
is created.
AV
2.7 V
4.5 V
R0
REF
C0
The resistances and capacitances in Table 13-3 are not guaranteed values.
0.1 F
Reference
voltage input
12 k
4 k
R1
C0
User’s Manual U14046EJ5V0UD
8.0 k
2.7 k
R2
AV
ANIn
REF
<Microcontroller internal circuit>
If a noise of AV
may be generated, clamp using a diode with
a low V
8.0 pF
8.0 pF
C1
C1
F
(0.3 V or lower).
R1
REF
3.0 pF
1.4 pF
or higher or AV
C2
C2
2.0 pF
2.0 pF
SS
C3
(TYP.)
or lower
R2
C3