L6217, L6217A two-phase stepper motor micro-step driver circuit

In a pulse period, when the H-bridge is turned on, the motor winding current is determined by the time constant
//R and begins to rise. When it reaches the predetermined current value, the comparator flips,
triggers the monostable trigger, and starts the monostable delay. determined off time. During this time,
the upper-side switch of the H-bridge is turned off, while the lower-side switch is still on. The winding current freewheels through the detection resistor and
freewheeling diode, and the winding current decreases until the next PWM pulse arrives. Chopping control is used
to maintain the winding current at a predetermined value.
  The final H-bridge uses NPN Darlington transistors and freewheeling diodes. The drive
circuit design ensures that the upper and lower bridge arms will not be turned on at the same time during commutation. The total output saturation
voltage is 7V. The junction temperature detection circuit protects the chip and
automatically shuts down the output stage when the temperature exceeds the set value .
    2 Applications with greater output power The single-chip L6217A can be used to realize bipolar current chopper control of
26V0, 4A two- phase stepper motors
, including full-step, half-step and micro-step control. Its application wiring is shown in Figure 5-30. When it is necessary to drive a larger power stepper
motor, a high-power H-bridge circuit can be connected externally . For example, using L6202 can provide
1 SA current per phase, while using L6203, the current per phase can reach 3A. If using two pieces
of I. When the 6203 output is used in parallel, the power supply to each phase winding can reach 6A, and the power supply voltage
can reach 48V. If higher voltage and high current driving capabilities are required, external discrete
power devices can be used to achieve this.