We´d like to use LM5045 as a class-D amplifier to drive a full-bridge load as part of a transmitter for a sonar system devised for small boats. In our design, a 200Khz-sinusoidal signal is directly input to pin COMP to be PWM modulated, with the bit stream driving the H-bridge, whose load is the primary of a step-up transformer.
The example on LM5045 application note is oriented for DC/DC converters, with a control signal fed back to COMP pin, which is not our case. No external feedback control is employed in the LM5045 in our approach.
ISSUE:
It seems that the ramp generation is heavily affected when pin SLOPE feeds back into pin RAMP. We´ve checked datasheet instructions carefully, but still have no hint on how to cope with this problem. This issue can be observed either from simulation using LM5045 behavioral model or from experimental results with samples.
We´d appreciate receiving a promptly analysis of this question as our schedule is now quite aggressive, and we can´t miss the market opportunity.
Looking forward for a soon contact,
Best Regards.
Jader A. De Lima
