73M1822/73M1922 Schematic and Layout Guidelines


This application note describes the schematics and provides layout guidelines for designing with the 73M1822/73M1922 data access arrangement (DAA) devices for fax, modem, and voice applications. Circuit performance can be optimized with careful consideration of analog signal routing and components layout. Topics to optimize device performance include: power dissipation within the line-side circuits; power-supply; connections to tip and ring (PSTN) and to the ring detect and caller ID path; pulse transformer; power dissipation and other considerations for the line-side circuits; special layout considerations for the 73M1822; exposed bottom pad on the QFN packages; high-voltage layout, with particular references to creepage and clearances; EMI, EMC, and high-frequency signals. Reference schematics and designs to reduce cost are shown. Read full article.