HT46C47 Holtek Semiconductor, HT46C47 Datasheet - Page 22

• Manufacturer Part Number: HT46C47
• Description: (HT46C46 / HT46C47) Cost-Effective A/D Type 8-Bit MCU
• Manufacturer: Holtek Semiconductor

Application Circuits
The following table shows the C1, C2 and R1 values corresponding to the different crystal values. (For reference only)
Note:
Rev. 1.00
4MHz Crystal
4MHz Resonator
3.58MHz Crystal
3.58MHz Resonator
2MHz Crystal & Resonator
1MHz Crystal
480kHz Resonator
455kHz Resonator
429kHz Resonator
The function of the resistor R1 is to ensure that the oscillator will switch off should low voltage condi-
tions occur. Such a low voltage, as mentioned here, is one which is less than the lowest value of the
MCU operating voltage. Note however that if the LVR is enabled then R1 can be removed.
The resistance and capacitance for reset circuit should be designed in such a way as to ensure that the VDD is
stable and remains within a valid operating voltage range before bringing RES to high.
interference.
* Make the length of the wiring, which is connected to the RES pin as short as possible, to avoid noise
Crystal or Resonator
C1, C2
300pF
300pF
300pF
10pF
25pF
25pF
35pF
0pF
0pF
HT46R46/HT46C46/HT46R47/HT46C47
22
9.1k
10k
12k
10k
10k
10k
27k
10k
10k
R1
December 28, 2004