STK672-400 Datasheet, PDF (5/19 Pages) Sanyo Semicon Device – Thick-Film Hybrid IC 2-phase Stepping Motor Driver

Precautions
STK672-400
[Internal MOSFET Destruction]
• The internal MOSFFET gate voltage is supplied from the 5V power supply. If the 5V power supply voltage is below
its allowable operating voltage range, the resultant insufficient gate drive state may destroy the MOSFET.
[GND wiring]
• To reduce noise in the 24V system, locate the ground side of CO1 in the circuit above as close as possible to pins 2
and 6 on the hybrid IC. Also, to assure that the current is set accurately, the Vref ground side must be connected to a
ground point that is a shared connection between the ground pin (pin 18, S.G) used for the current setting and P.G1
and P.G2.
• If the VSS pin (pin 16) near the driver, the S.G pin (pin 18), the P.G1 pin (pin 2), and the P.G2 pin (pin 6) cannot be
connected to a single-point ground, connect the VSS pin to the control system S.GND, and the S.G pin to the P.G1 pin
and the P.G2 pin.
[Input pins]
• The voltage range for the input pins is -0.3 to +5.8V. Design applications so that voltages lower than -0.3V and higher
than 5.8V are never applied to the input pin.
• Do not connect any of the NC pins (pins 7, and 8) shown in the internal equivalent circuit block diagram to the circuit
pattern on the printed circuit board.
• Connect a resistor (1kΩ) so that discharge energy of capacitor CO2 does not enter the hybrid IC.
• Inputs to pins 10, 11, 12, 13, 14, 15, and 17 are signal whose high level is 2.5V. Both TTL and CMOS inputs are
supported.
• Internal pull-up resistors are not provided for the input pins. If this hybrid IC's inputs are controlled by open-collector
type circuits, external pull-up resistors must be provided.
• If resistors are connected in series with the inputs, insert capacitors between the inputs and ground to prevent
malfunctions due to the hybrid IC's switching noise.
• In the application circuit example, a simple reset circuit is formed by D1, RO3, CO2, and a 1kΩ resistor. This circuit
will not create a reset signal if the 5V supply voltage drops briefly. This circuit structure requires the 5V supply
voltage to fall below 0.6V to operate.
Connect the hybrid IC directly to VDD to use the hybrid IC's power on reset function.
• A power on reset operation must be applied when the 5V power supply level is first applied.
[Vref Current Setting]
• To reduce the influence of input impedance 200kΩ input current of the terminal Vref, RO1 recommends about 1kΩ.
• We recommend using the following circuit to temporarily reduce the motor current.
• Although the driver provides a constant current control function, it does not have an overcurrent protection function to
assure that the maximum output current, IOH max, is not exceeded. If Vref is set by mistake to a voltage that such
that IOH max is exceeded, the driver will draw excessive current and the device will be destroyed.
• If the Vref pin (pin 19) is left open, the Vref voltage will be set to about 2.5V. With the STK672-400, the motor
current will then be about 1.8A. With the STK672-410, the motor current will be about 3.2A. These current settings
are close to IOH max.
5V
5V
RO1
Vref
R3
RO2
RO1
R3
Vref
RO2
No.A0751-5/19