Complementary output PWM signals is the basis of motor control, by setting the corresponding register can be output with the complementary PWM signal of dead area, to control the MOS switch of two bridge legs,
Above as a basic principle of data for a microcontroller PWM signal, PHx as basic PWM signal, DTPHx and DTPHx_ as dead area complementary signals, can be seen in DTPHx signal, apparent insert two dead zone time,
Below we through OSC482L to check this with the complementary PWM output signal of dead area,
1, cycle and duty cycle test output
Through single chip microcomputer produced a 16 KHZ signal, duty ratio is 70%, as shown in the figure below, the actual measured signal information is:
High level pulse width 49.167 us, low level pulse width 13.333 us, frequency of 16.000 KHz, 78.667% duty cycle:
2, the duty ratio adjustment and dead zone time measuring
Will signal frequency remains the same, duty ratio adjustment was 50%, the dead zone of 2.778 us, as shown in the figure below, the actual measurement to the dead zone of 2.50 us
3, adjust the dead band time measuring
Adjust the dead band time of 5.556 us, as shown in the figure below, the actual measurement of dead zone of 5.42 us
Summary, due to the sampling rate is 2.4 MHz OSC482L oscilloscope, a resolution of 0.42 us, therefore, the measured signal within the scope of the actual measurement precision of the oscilloscope,