TLC5916-Q1: I2C to 20kHz PWM Signal Generator

Due to the Chinese New Year, our Expert will reply you on 2.5

Hi Labib,

Thanks for your waiting!

I want to confirm the switching frequency, is the "20KHz" necessary? Can it be higher or lower than this value?

BR, Jared

We need 20kHz. Otherwise, we hear audible noise while driving solenoid with PWM.

Hi Labib,

Based on my experience, the audible noise is caused by a lower frequency PWM. So can I understand that it will be fine once the PWM frequency is higher than 20KHz?

BR, Jared

20KHz or higher should be okay. Can TLC5916-Q1 IC generate 20kHz or higher PWM frequency (30% t0 100% duty cycle) to drive low side MOSFET?

Hi Labib,

Out expert is currently out of office. He will reply to you later when back to office. Thanks for your understanding.

Best Regards,

Steven

Hi Labib,

Yes, I think TLC5916-Q1 can generate 20KHz or higher PWM frequency.

BR, Jared

Hello Jared, Just to be confirmed, we would like to generate PWM signal like below. Can we generator 20kHz PWM signal on all 8-channels? 

Hi Labib,

Since the interface of TLC5916-Q1 can up to 30MHz and internal is only a 8-bit shift register to control the output on/off. So, I think TLC5916-Q1 can generate 20KHz PWM signal on all 8-channel.

But please note that the output is a constant current driver. I think it can't connect the output directly to the Gate of N-MOS since the MOSFET is a voltage drive component.

BR, Jared

Is there any IC that can drive low side MOSFET with 20kHz PWM.

Thank you. It seems your later drawing works for us. I assume these output can handle up to 20V. What is the usual value of the pull-up resistor. Our typical voltage is around 9V to 16V. Is there any restriction on MOSFET (I mean gate charge of the MOSFET)?

Also, is there 16bit version that can do same as well?