Overview

The STK673-010-E is a 3-phase stepping motor driver hybrid IC with built-in microstep controller having a bipolar constant current PWM system, in which a power MOSFET is employed at an output stage. It includes a 3-phase distributed controller for a 3-phase stepping motor to realize a simple configuration of the motor driver circuit.

The number of motor revolution can be controlled by the frequency of external clock input. 2, 2-3, W2-3 and 2W2-3-phase excitation modes are available. The basic step angle of the stepping motor can be separated as much as one-eighth 2-3-phase to 2W2-3-phase excitation mode control quasi-sine wave current, thereby realizing low vibration and low noise.

Features

• Number of motor revolution can be controlled by the frequency of external clock input.

• 4 types of modes, i.e., 2, 2-3, W2-3 and 2W2-3-phase excitations, are available which can be selected based on rising of clock signals, by switching Highs and Lows of Mode A and Mode B terminals.

• Setting a Mode C terminal Low allows an excitation mode that is based on rising and falling of a clock signal. By setting the Mode C terminal Low, phases that are set only by Mode A and Mode B can be changed to other phases as follows without changing the number of motor revolution: 2-phase may be switched to 2-3-phase; 2-3-phase may be switched to W2-3-phase; and W2-3-phase may be switched to 2W2-3-phase.

• Phase is maintained even when the excitation mode is changed.

• An MOI output terminal which outputs 1 pulse per 1 cycle of phase current.

• A CW/CCW terminal which switches the rotational direction.

• A Hold terminal which temporarily holds the motor in a state where the phase current is conducted.

• An Enable terminal which can forcibly turns OFF a MOSFET of a 6 output driving element in normal operation.

• Schmitt inputs with built-in pull-up resistor (20kΩ typ)

• Motor current can be set by changing the voltage of the Vref terminal (0.63V per 1A, dealing as much as 0 to 1/2VCC2 (4A)).

• The clock input for controlling the number of motor revolution lies in a range of 0 to 50kHz.

• Supply voltage: VCC1 = 16 to 30V, VCC2 = 5.0V ±5

• A built-in current detection resistor (0.227Ω)

• A motor current during revolution can deal with as high as 2.4A at Tc = 105°C and as high as 4A at Tc = 50°C or lower.

Applications

• As a 3-phase stepping motor driver for transmission and reception in a facsimile.

• As a 3-phase stepping motor driver for feeding paper feed or for an optical system in a copying machine.

• Industrial machines or products employing 3-phase stepping motor driving.