Need help to generate 4 spwm signals out of MSP430g2553!!

[Tahsinhossain]

Hi All,

I have a modulating sine wave signal of 50Hz and triangular wave carrier signal of 2.5kHz, now I want to generate four spwm gating signals for four IGBTs of the H bridge inverter from my MSP430g2553. I could generate two signals using two Timers of A (A0 and A1) but I am being unable to program my msp to generate four signals (picture given below). Can you please suggest me any logic to generate my four gating signals from a single MSP? Please Help!

 

[red_alert]

You actually have one single sine modulated PWM signal (for the left low-side driver, let's say). For the left high side driver you just need a complementary one (including dead times though).

The right leg of the bridge only have steady signals (ON for the low side driver and OFF for the high side one).

After every half of the wave form, the signals are interchanged (left/right legs).

Are you generating those signals using a sine lookup table function or are you using analog comparators (do you already have the 2.5kHz sawtooth and 50Hz reference sinewave available)?