STK672-120 Sanyo Semicon Device, STK672-120 Datasheet - Page 4

• Manufacturer Part Number: STK672-120
• Description: Two-Phase Stepping Motor Driver (Square Wave Drive) Output Current: 2.4 A
• Manufacturer: Sanyo Semicon Device

Sample Application Circuit
• To minimize noise in the 5-V system, locate the ground side of capacitor CO2 in the above circuit as close as possible
• Insert resistor RO3 (47 to 100 Ω) so that the discharge energy from capacitor CO4 is not directly applied to the CMOS IC
• Standard or HC type input levels are used for the pin 7, 8, and 9 inputs.
• If open-collector type circuits are used for the pin 7, 8, and 9 inputs, these circuit will be in the high-impedance state
• Taking the input bias current (I
• The following circuit (for a lowered current of over 0.2 A) is recommended if the application needs to temporarily
Input Pin Functions (CMOS input levels)
• A simple reset function is formed from D1, CO4, and RO3 in this application circuit. With the CLOCK input held low,
• See the timing chart for the specific details on circuit operation.
CLOCK
MODE
CWB
RESETB
to pin 1 of the IC.
in this hybrid device. If the diode D1 has Vf characteristics with Vf less than or equal to 0.6 V (when If = 0.1 A), this will
be smaller than the CMOS IC input pin diode Vf. If this is the case RO3 may be replaced with a short without problem.
for high level inputs. As a result, chopping circuit noise may cause the input circuits to operate incorrectly. To prevent
incorrect operation due to such noise, capacitors with values between 470 and 1000 pF must be connected between pins
7 and 11, 8 and 11, and 9 and 11. (A capacitor with a value between 470 and 1000 pF must be connected between pins
6 and 11 as well if an open-collector output IC is used for the RESETB pin (pin 6) input.)
lower the motor current. Here, a value of close to 100 kΩ must be used for resistor RO1 to make the transistor output
saturation voltage as low as possible.
when the 5-V supply voltage is brought up a reset is applied if the motor output phases A and BB are driven. If the 5-V
supply voltage rise time is slow (over 50 ms), the motor output phases A and BB may not be driven. Increase the value
of the capacitor CO4 and check circuit operation again.
Pin
Pin No.
9
8
7
6
Reference clock for motor phase current switching
Excitation mode selection
Motor direction switching
System reset and A, AB, B, and BB outputs cutoff.
Applications must apply a reset signal for at least 20 µs when power is first applied.
IB
) characteristics into account, the resistor RO1 must not exceed 100 kΩ.
Function
STK672-120
Two-phase stepping motor
Operates on the rising edge of the signal
Low: 2-phase excitation
High: 1-2 phase excitation
Low: CW (forward)
High: CCW (reverse)
A reset is applied by a low level
Input conditions when operating
At least 100 µF
No. 6042-4/9