
ON Semiconductor
Overview
The STK672-040-E is a stepping motor driver hybrid IC that uses power MOSFETs in the output stage. It includes a built-in microstepping controller and is based on a unipolar constant-current PWM system. The STK672-040-E supports application simplification and standardization by providing a built-in 4 phase distribution stepping motor controller. It supports five excitation methods: 2 phase, 1-2 phase, W1-2 phase, 2W1-2 phase, and 4W1-2 phase excitations, and can provide control of the basic stepping angle of the stepping motor divided into 1/16 step units. It also allows the motor speed to be controlled with only a clock signal.
The use of this hybrid IC allows designers to implement systems that provide high motor torques, low vibration levels, low noise, fast response, and high-efficiency drive.
FEATUREs
• Can implement stepping motor drive systems simply by providing a DC power supply and a clock pulse generator.
<Control Block Features>
• One of five drive types can be selected with the drive mode settings (M1, M2, and M3)
1) 2 phase excitation drive
2) 1-2 phase excitation drive
3) W1-2 phase excitation drive
4) 2W1-2 phase excitation drive
5) 4W1-2 phase excitation drive
• Provides four freely selectable modes for the vector locus during microstepping drive: circular mode, one inside mode, and two outside modes.
• Phase retention even if excitation is switched.
• The excitation phase state can be verified in real time using the MO1, MO2, and MOI signal output pins.
• The CLK input counter block can be selected to be one of the following by the high/low setting of the M3 input pin.
1) Rising edge only
2) Both rising and falling edges
• The CLK and RETURN input pins include built-in malfunction prevention circuits for external pulse noise.
• ENABLE and RESET pins provided. These are Schmitt trigger inputs with built-in 20kΩ (typical) pull-up resistors.
• No noise generation due to the difference between the A and B phase time constants during motor hold since external excitation is used.
• Microstepping operation supported even for small motor currents, since the reference voltage Vref can be set to any value between 0V and 1/2VCC2.
<Driver Block>
• External excitation PWM drive allows a wide operating supply voltage range (VCC1 = 10 to 45V) to be used.
• Current detection resistor (0.33Ω) built-in the hybrid IC itself.
• Power MOSFETs adopted for low drive loss.
• Provides a motor output drive current of IOH = 1.5A.
APPLICATIONs
• Facsimile stepping motor drive (send and receive)
• Paper feed and optical system stepping motor drive in copiers
• Laser printer drum drive
• Printer carriage stepping motor drive
• X-Y plotter pen drive
• Other stepping motor applications