HT45RM03 Datasheet, PDF (33/54 Pages) Holtek Semiconductor Inc – Brushless DC Motor Type 8-Bit OTP MCU

HT45RM03
Application Circuits
Application Circuits 1
V DD
0 .0 1 m F *
VDD
100kW
0 .1 m F
RES
10kW
P C 0~P C 5
M O SFET
&
D r iv e r
0 .1 m F *
B LD C
VSS
O SC
C ir c u it
S e e R ig h t S id e
O SC1
O SC2
P A 4 /IN T 0 A
P A 5 /IN T 0 B
P A 6 /IN T 0 C
P A 7 /IN T 1
P A 2 /C V IN N
P A 1 /C V IN P
P A 3 /C O U T
P B 7 /A N 7 /T M R 0 /T M R 1
P B 0 /A N 0 ~ P B 1 /A N 1
P B 4 /A N 4 ~ P B 6 /A N 6
P B 2 /A N 2 /O P O U T
P B 3 /A N 3 /O P IN N
P A 0 /O P IN P
P D 0 /P F D
H T45R M 03
H A L L S e n s o r In p u t
V DD
470pF
R O SC
fS Y S /4
O SC1
O SC2
C1
O SC1
C2
R1
O SC2
R C S y s te m O s c illa to r
24kW < R OSC< 1M W
C r y s ta l S y s te m O s c illa to r
F o r th e v a lu e s ,
s e e ta b le b e lo w
O S C C ir c u it
The following table shows the C1, C2 and R1 values corresponding to the different crystal values. (For reference only)
Crystal or Resonator
C1, C2
R1
8MHz Crystal
0pF
5.3kW
8MHz Resonator
10pF
6.3kW
4MHz Crystal
0pF
13kW
4MHz Resonator
10pF
12kW
3.58MHz Crystal
0pF
15kW
3.58MHz Resonator
25pF
10kW
2MHz Crystal
25pF
10kW
2MHz Resonator
25pF
12kW
1MHz Crystal
35pF
15kW
480kHz Resonator
300pF, 100pF
9.1kW
455kHz Resonator
300pF
10kW
429kHz Resonator
300pF
10kW
400kHz Resonator
300pF
10kW
The function of the resistor R1 is to ensure that the oscillator will switch off should low voltage conditions occur.
Such a low voltage, as mentioned here, is one which is less than the lowest value of the MCU operating volt-
age. Note however that if the LVR is enabled then R1 can be removed.
Note:
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 high.
²*² Make the length of the wiring, which is connected to the RES pin as short as possible, to avoid noise
interference.
Rev. 1.10
33
February 16, 2007