how to make the PWM pulse by using clock generator?

Saemyi Jeon

Other Parts Discussed in Thread: LM5113, LMK04906

Hi all,

Samsung try to make the PWM pulse by using clock generator that received the signal from oscillator.

PWN pulse put into high side and low side of gate driver (LM5113) in Tx of wireless charging pad.

Since high side FET and low side FET shoudn't turn on at the same time, each pulse is need to have dead time.

What the frequency of pulse they want is 6.78MHz and duty cycle should be 50:50.

To prevent both pulses from operating simultaneously, the dead time will be needed between both pulses.

Could you suggest any idea?

Thank you.

Best regards,

Sammy Jeon.

0 Arvind Sridhar over 11 years ago

Hi Sammy Jeon,

You can achieve this using Digital Delay on LMK04906: http://www.ti.com/lit/ds/symlink/lmk04906.pdf

Operate the device in Single PLL mode (Page 4). Use a 19.44 MHz Crystal reference on OSCin.

Use Clock Design Tool for your frequency planning: http://www.ti.com/tool/clockdesigntool

OSCin=19.44 MHz: VCO=2562.84 MHz, Output Divider=378

The outputs can be configured as LVCMOS or Differential.

Digital Delay (Page 33) can be used to adjust the phase offset between the clocks precisely.

Regards

Arvind Sridhar

Clock & timing forum