STK672-080 Sanyo Semicon Device, STK672-080 Datasheet - Page 7

• Manufacturer Part Number: STK672-080
• Description: Stepping Motor Driver (Sine Wave Drive) Output Current : 2.8 A (No Heat Sink)
• Manufacturer: Sanyo Semicon Device

Functional Description
External Excitation Chopper Drive Block Description
Since this hybrid IC adopts an external excitation method, no external oscillator circuit is required.
When a high level is input to øA in the basic driver block circuit shown in the figure and the MOSFET is turned on, the
comparator + input will go low and the comparator output will go low. Since a set signal with the PWM period will be
input, the Q output will go high, and the MOSFET will be turned on as its initial value.
The current I
potential and the Vref potential become the same, the comparator output will invert, and the reset signal Q output will
invert to the low level. Then, the MOSFET will be turned off and the energy stored in L1 will be induced in L2 and the
current I
latch circuit set pin occurs.
In this manner, the Q output is turned off and on repeatedly by the reset and set signals, thus implementing constant
current control. The resistor and capacitor on the comparator input are spike removal circuit elements and synchronize
with the PWM frequency. Since this hybrid IC uses a fixed frequency due to the external excitation method and at the
same time also adopts a synchronized PWM technique, it can suppress the noise associated with holding a position when
the motor is locked.
Input Pin Functions
Pin No.
8, 9, 12
11
10
15
13
7
D1
L2
OFF
I OFF
M1, M2, M3
ENABLE
Symbol
RESET
CWB
ON
CLK
Vref
will be regenerated to the power supply. This state will be maintained until the time when an input to the
Rs
flowing in the MOSFET passes through L1 and generates a potential difference in Rs. Then, when the Rs
V CC 1
Phase switching clock
Rotation direction setting (CW/CCW)
Output cutoff
Excitation mode setting
System reset
Current setting
I ON
MOSFET
L1
Function
Enable
AND
Driver Block Basic Circuit Structure
ØA (control signal)
Q
Built-in pull-up resistor CMOS Schmitt trigger input
Built-in pull-up resistor CMOS Schmitt trigger input
Built-in pull-up resistor CMOS Schmitt trigger input
Built-in pull-up resistor CMOS Schmitt trigger input
Built-in pull-up resistor CMOS Schmitt trigger input
Input impedance 6 kΩ (typ.) ±30%
45kHz
STK672-080
Latch circuit
Divider
S
Pin circuit type
R
oscillator
Noise
filter
CR
800kHz
Current
divider
–
+
A=1
Vref
A13263
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