Using Break Functionality as interrupt in stm32f4

[Jeflet]

For PWM channels to be disabled during a trip instant we use the break input circuit and the function worked well in the Nucleo board. But while using the same in the real circuit having half-bridge, cross conduction occurs every time the break input gets active.

we observed that the complementary waveform degrades to zero instead of immediately being pulled down to zero

1. Is there any option to use the break as an interrupt?
2. Is there any other option to force the output and its complementary channel to zero while using the break functionality?

[Jack Peacock_2]

How did you configure the gate inputs on the bridge? If the STM32 PWM outputs go to tri-state (analog) mode do you have a pull-down to shut off the high side and a pull-up to short the motor windings to ground side? If you see shoot-through, how is that both high sides are enabled since only one should be active when the shutdown occurs?

Jack Peacock

[waclawek.jan · Accepted solution]

1. Yes, see TIMx_DIER.BIE, and the related interrupts (TIM1_BRK_TIM9, TIM8_BRK_TIM12 in case of STM32F4xx covered by RM0090).
2. Yes, that's the purpose of TIMx_BDTR.OSSI bit (and related bits like TIMx_CR2.OISx/OISxN bits), see Output control bits for complementary OCx and OCxN channels with break feature table.

Read the Advanced Timers chapter in RM.

JW

[Amel NASRI]

Hi @Jeflet​ ,

Besides to the reference manual already mentioned by @Community member​ , look to the application note AN4277: Using STM32 device PWM shut-down features for motor control and digital power conversion.

-Amel