Possible error in RDR-189 Schematic
Posted by: jerryc4174
on
Figure 3 of RDR-189 shows that the Controller GND signal is tied to the B- signal. Figure 4 shows that the Controller GND signal is separated from the B- signal by R55 and L7. I believe that this is a conflict. Can you please tell me what are the actual connections?
Comments
So, the Controller Ground and power ground are in fact the same signal but only connected at one place to prevent any common mode impedance coupling?
The way I look at it, is L7 provides impedance to filter the high current return path from U6 ground. The inductance is large enough to allow the control circuity to operate properly but low enough to provide a signal return for the gate drive.
Z. Cochrane
R55 and L7 seperate the high current paths from the signal ground. The grounding technique is explained in the device's application note and data sheet.
Z. Cochrane