UPD78F0034BGC-8BS-A Renesas Electronics America, UPD78F0034BGC-8BS-A Datasheet - Page 299

• 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
Output impedance
of sensor
<Sensor internal circuit>
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
or less, or attach a capacitor of around 100 pF to the ANI0 to ANI7 pins (see Figure 14-21).
Table 14-3. Resistances and Capacitances of Equivalent Circuit (Reference Values)
Figure 14-21. Example of Connection If Signal Source Impedance Is High
Lowpass filter
is created.
Caution
CHAPTER 14 10-BIT A/D CONVERTER ( PD780034A, 780034AY SUBSERIES)
R0
AV
2.7 V
4.5 V
C0
REF
0.1 F
The resistances and capacitances in Table 14-3 are not guaranteed values.
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
or higher or AV
3.0 pF
1.4 pF
C2
C2
SS
2.0 pF
2.0 pF
or lower
C3
R2
(TYP.)
C3
297