TSI721 datasheet(39/67 Pages) RENESAS

39 / 67 page

Tsi721 Datasheet

April 4, 2016

Integrated Device Technology

The Level I long run defines a transmitter and receiver that use larger voltage swings and channel equalization that allows a

user to drive signals across two connectors and backplanes.

The two transmitter specifications allows for a medium run specification that also uses larger voltage swings that can drive

signals across a backplane but simplifies the receiver requirements to minimize power and complexity. This option has been

included to allow the system integrator to deploy links that take advantage of either channel materials and/or construction

techniques that reduce channel loss to achieve lower power systems.

All unit intervals are specified with a tolerance of ±100 ppm. The worst case frequency difference between any transmit and

receive clock is 200 ppm.

The electrical specifications are based on loss, jitter, and channel cross-talk budgets and defines the characteristics required to

communicate between a transmitter and a receiver using nominally 100 Ohm differential copper signal traces on a printed

circuit board. Rather than specifying materials, channel components, or configurations, this specification focuses on effective

channel characteristics. Therefore, a short length of poorer material should be equivalent to a longer length of premium

material. A 'length' is effectively defined in terms of its attenuation rather than physical distance.

3.7.3.2

Definition of Amplitude and Swing

LP-Serial links use differential signaling. This section defines the terms used in the description and specification of these

differential signals. Figure 6 shows how these signals are defined and sets out the relationship between absolute and

differential voltage amplitude. The figure shows waveforms for either the transmitter output (TD and TD_N) or a receiver input

(RD and RD_N).

Figure 6: S-RIO Definition of Transmitter Amplitude and Swing

TSI721 Datasheet(PDF) 39 Page - Renesas Technology Corp