SBOSA33A September 2021 – December 2021 LMH5485-SP
ADVANCE INFORMATION
Refer to the PDF data sheet for device specific package drawings
One of the most useful features supported by the FDA device is an easy conversion from a single-ended input to a differential output centered on a user-controlled, common-mode level. While the output side is relatively straightforward, the device input pins move in a common-mode sense with the input signal. This common-mode voltage at the input pins moving with the input signal acts to increase the apparent input impedance to be greater than the Rg value. This input active impedance issue applies to both AC- and DC-coupled designs, and requires somewhat more complex solutions for the resistors to account for this active impedance, as shown in the following subsections.