Characteristic

·        No PWM generator, need to connect external microcontroller or 3525 and other control circuits.

·        The built-in 12v300ma buck provides the voltage of the driving part and the control circuit.

·        The four logic control pins are led out and are all positive logic, supporting

3.3v / 5v level.

·        PWM is recommended not to exceed 90% and 200KHz.

·        Wide voltage input range 10-36V, built-in undervoltage protection,

the power input voltage can reach up to 50V when the drive part is independently powered (filter capacitor needs to be replaced).

·        The chip has a built-in dead time generator, Mos tube parallel Schottky diode freewheeling, effective protection of the H bridge when commutating with inductive loads frequently, to avoid through damage, software programming is simpler.

Welding and use instructions

·        H1L1H2LL2 four terminals are used to connect MCU, control the full bridge mos tube

·        The VCC terminal is the output of the onboard buck, and it can carry a 12v fan with a current not greater than 200ma

·        The Vin terminal is the input of the onboard buck. When disconnecting R12, you need to input 15-40v here.

·        Vpower is the main power input, the full bridge will modulate the voltage input here

·        R12 is the selection jumper for the input of the buck, short-circuit to take power from Vpower

·        Adjusting the ratio of R10 and R11 can adjust the output voltage of the buck, but it is not recommended to be lower than 10v and higher than 15v,

the default is 12v

Example of bipolar modulation

SPWM based on STM32F0: code see attachment spwm_test1.7z

·        Short circuit L1 and H2, and L2 and H1 on the hardware, because bipolar modulation only needs one complementary PWM,

and the diagonal tubes are driven by the same logic.

STM32 uses two timers, TIM1 uses CH3 complementary output 48K PWM,

as a carrier, TIM17 as an interrupt time base, interrupt frequency 12.8khz (fundamental wave 50Hz X modulation ratio 256). 

Use the equal area method to calculate the SPWM duty cycle sequence, rewrite the TIM17 interrupt callback function, update the value of TIM1-> CCR3 every interrupt, dynamically change the duty cycle,

the output is SPWM, and the sine wave after filtering.