Patent ID: 7881457

Claim:
A single-in-line modem constructed on a printed circuit board having a portion for analog circuits and a portion for digital circuits, the single-in-line modem comprising: an analog circuit configured to bi-directionally communicate with an external data communication equipment over a phone line using an analog protocol; a digital circuit isolated from the analog circuit and configured to bi-directionally communicate with a host system over a digital interface; an isolation region with a predetermined separation distance between the analog circuit and the digital circuit on the printed circuit board to protect from over-voltage hazards; a set of isolation capacitors over the isolation region to connect the digital circuit and the analog circuit; at most one pin header coupled with the printed circuit board and disposed along an edge of the printed circuit board; at most one single-in-line interface having at most one single row of pins selectively coupled to the analog circuit and the digital circuit, the single row of pins protruding from the pin header in a direction parallel to or coplanar with the printed circuit board for enabling the printed circuit board to be vertically coupled with a second printed circuit board, the single row of pins including at least an isolation spacer, a ground pin, and a power pin, the ground pin being disposed between the isolation spacer and the power pin and wherein the isolation region includes at least a first section, a second section, and a third section, the first section being connected to the third section through the second section, the first section being perpendicular to the second section, the second section being perpendicular to the third section.