Part Number: LM5113
We are developing a product which will use the LM5113 to drive FET half bridge which will drive a heater. We will actually be using two of these configurations to create a full bridge. We used the EPC9049 development board to test the circuit and it works great. We are about to add it to the board layout but have a couple questions. In figure 18 of the LM5113 spec sheet there is a parallel diode / resistor on each of the LM5113’s inputs. This diode & resistor are also on the EPC development board. We tried removing the diode and resistor and it had no effect on the performance of the circuit. Can you tell me what the purpose is of the diode and resistor on the two input? The other question is related to shoot-through. The EPC9049 development board has two gates driving the HI and LI inputs, but it doesn’t appear they are doing anything to eliminate shoot-through. Does the LM5113 add any delays to the outputs to protect against shoot-through or is this something we should handle? We would like to eliminate the two gates and drive the two inputs from separate clocks, but if shoot-threw is a potential problem we will need to modify the two clocks which could be difficult to do. Our system is extremely sensitive to noise and shoot-through would be a source of noise.
Thanks,
Bob