HT46R64 Holtek Semiconductor Inc., HT46R64 Datasheet - Page 29

• Manufacturer Part Number: HT46R64
• Description: Ht46r64/ht46c64 -- A/d With Lcd Type 8-bit Mcu
• Manufacturer: Holtek Semiconductor Inc.

Application Circuits
The following table shows the C1, C2 and R1 values corresponding to the different crystal values. (For reference only)
Note:
Rev. 1.80
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
VMAX connect to VDD or VLCD or V1 refer to the table.
LCD bias type
VMAX
Crystal or Resonator
LCD Type
If V
else VMAX connect to V
1/2 bias
DD
>V
LCD
R Type
, then VMAX connect to V
1/3 bias
LCD
C1, C2
300pF
300pF
300pF
10pF
25pF
25pF
35pF
0pF
0pF
29
1/2 bias
DD
,
If V
else VMAX connect to V1
DD
> 3/2V
C Type
LCD
9.1k
, then VMAX connect to V
10k
12k
10k
10k
10k
27k
10k
10k
HT46R64/HT46C64
R1
1/3 bias
February 14, 2006
DD
,