STK672-210 Sanyo Semicon Device, STK672-210 Datasheet - Page 5

• Manufacturer Part Number: STK672-210
• Description: Two-Phase Stepping Motor Driver Output Current: 1.4 A
• Manufacturer: Sanyo Semicon Device

Setting the Motor Current Peak Value (I
Current Switching Techniques
Due to the input bias current (I
The figures below present sample circuits that temporarily switch the motor current when, for example a held motor
stops.
We recommend using the circuit structure in the figure at the left to minimize as much as possible the effects of the
saturation voltage of the reference voltage switching transistor.
Input Pin Circuits
I
Vref: STK672-210 pin 12 input voltage
Rs: STK672-210 internal current detection resistor (0.195 Ω ±2%)
Vref = (Ro2 ÷ (Ro1 + Ro2)) V
V
Pin 6, 7, 8, and 9
OH
CC
Input pin
≈ Vref ÷ Rs
2 = 5 V
Pin 12
I
OH
Model of the Motor Phase Current Flowing into the Driver IC (pins 2, 3, 4, and 5)
0
Ro3
Switching Circuit 1
(XB phase)
X phase
Ro1
Ro2
5 V
IB
) specifications, Ro1 must be under 100 kΩ.
To one of the comparator
Vref
CC
10 k
2
10 k
CR input
Vref
OH
)
5 V
STK672-210
Circuit type
MOSFET gate signal
XB phase PWM signal
To XB phase
5 V
When switch 1 is in the ground
position, the input resistor will be
a 20 k pull-down resistor.
V CC 2
GND
Switching Circuit 2
Ro3
Ro2
Ro1
5 V
Vref
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