Test Procedure for the LV8711TGEVB Evaluation Board For Stepper Motor Control Figure 1: Setup for Stepper Motor Control 1/8/2014 1 www.onsemi.com Table1: Required Equipment Equipment Power supply1 Power supply2 Function generator Multimeter Oscilloscope Current probe1 Current probe2 LV8711T Evaluation Board Stepper Motor Efficiency 5V-0.5A 18V-1.5A 1kHz 4 channel 18V-1A Allowable Operating Ratings • • • Motor supply voltage (VM): 4 to 16V Logic supply voltage (VCC): 2.7 to 5.5V Reference voltage for constant current (VREF): 0 to VCC-1.8V Each constant setting method for the above circuit diagram example is as follows: • Current LIMIT (100%) set VREF=1V (when internal regulator REG1 output is connected) (I)limit = VREF/5/RNF = 1V/5/0.47Ω = 425mA • Chopping frequency setting Fchop = (I)chop/(Cchop×Vt×2) = 10uA/(180pF×0.5V×2) = 55.5kHz Test Procedure: 1. Connect the test setup as shown Figure 1. 2. Apply input voltage to the terminal VREF.（The terminal REG1 short circuit is assumed.） 3. Turn the switch of “PS” on.（Knock it down for above in Figure 1.） 4. Check VREG5 and frequency of the triangle waveform on the terminal CHOP. 5. Keep other switches in middle position. Input drive signals to IN1A, IN1B, IN2A and IN2B from DSP. Refer to the following timing charts. 6. Check the drive signals and output current waveforms at scope whether they are similar to the charts. And check the waveform of PWM constant current control. 1/8/2014 2 www.onsemi.com Timing chart of Full-step Timing chart of Half-step Table2: Desired Results INPUT OUTPUT VCC=3.3V (Power Supply 1) VREG5=4.5V to 5.5V VM=8.5V (Power Supply 2) VREG1= VREF=REG1(=1V) 0.95V to PS=High 1.05V ATT1=ATT2=Low When it controls in Full-Step IN1A/IN1B/IN2A/IN2B=10Hz(Duty50%) When it controls in Half-Step IN1A/IN1B/IN2A/IN2B=10Hz(Duty40%) 1ch: IN1A 5V/DIV 2ch: IN2A 5V/DIV 3ch: IOUT1 500mA/ DIV Waveforms when it controls in Full-Step 1/8/2014 4ch: IOUT2 500mA/ DIV 3 Waveforms when it controls in Half-Step www.onsemi.com For smaller DC motor(s) control (When a motor is connected between OUT1A and OUT1B.) Figure 2. Setup for smaller DC motor(s) control 1/8/2014 4 www.onsemi.com Table3: Required Equipment Equipment Efficiency Power supply1 5V-0.5A Power supply2 18V-1.5A Function generator 200kHz Multimeter Oscilloscope 4 channel Current probe1 Current probe2 LV8711T Evaluation Board DC Motor 18V-1A 1/8/2014 5 www.onsemi.com Test Procedure ・ Connect DC motor(s) between OUT1A and OUT1B, OUT2A and OUT2B. ・ Connect the motor power supply with the terminal VM, the control power supply with the terminal VCC. Connect the GND line with the terminal GND. ・ Input the reference voltage to the terminal VREF. （The terminal REG1 short circuit is assumed.） ・ Turn the switch of “PS” on.（Knock it down for above in follow image.） ・ Turn the swith of IN1A, IN1B, IN2A and IN2B ON or OFF. When DSP is connected to previous Input pins, keep their switches middle position. Refer to the following timing chart. Timing chart of DC motor Table4: Desired Results INPUT OUTPUT VCC=3.3V (Power Supply 1) VREG5=4.5V to VM=8.5V (Power Supply 2) 5.5V VREF=REG1(=1V) VREG1= PS=High 0.95V to ATT1=ATT2=Low 1.05V When it controls in Direct-PWM (CW/Brak e) IN1A/IN2A=High IN1B/IN2B=20kHz(Duty20%) 1ch: IN1B (5V/DIV) 2ch: VOUT1A (5V/DIV) 3ch: VOUT1B (5V/DIV) 4ch: IOUT1 (200mA/DIV) 1/8/2014 6 Waveforms when it controls DC motor by Direct-PWM (CW/Brake) www.onsemi.com For a larger DC motor control Figure 3. Setup for a larger DC motor control 1/8/2014 7 www.onsemi.com Table5: Required Equipment Equipment Efficiency Power supply1 5V-0.5A Power supply2 18V-2.5A Function generator 200kHz Multimeter Oscilloscope 4 channel Current probe1 Current probe2 LV8711T Evaluation Board With RNF resistors 0Ω DC Motor 18V-2A 1/8/2014 8 www.onsemi.com Test Procedure ・ Change each RNF resistors to 0Ω. ・ Connect Output pin OUT1A with OUT2A, OUT1B with OUT2B each other directly. ・ Connect Input pin IN1A with IN2A, IN1B with IN2B each other directly. ・ Connect DC motor between OUT1A/2A and OUT1B/2B. ・ Connect the motor power supply with the terminal VM, the control power supply with the terminal VCC. Connect the GND line with the terminal GND. ・ Connect REG1 to VREF directly. ・ Turn the switch of “PS” on.（Knock it down for above in previous image.） ・ Turn the swith of IN1A/2A and IN1B/2B ON or OFF. When DSP is connected to previous Input pins, keep their switches middle position. Refer to the timing chart on P.5. Table6: Desired Results INPUT OUTPUT VCC=3.3V (Power Supply 1) VREG5=4.5V to VM=12V (Power Supply 2) 5.5V VREF=REG1(=1V) VREG1= PS=High 0.95V to ATT1=ATT2=Low 1.05V When it controls in Direct-PWM (CW/Brak e) IN1A/IN2A=High IN1B/IN2B=100kHz(Duty50%) In this case, waveforms are similar to them on P.5. 1/8/2014 9 www.onsemi.com