ZHCSKG2B September 2016 – October 2019 DS280BR820
PRODUCTION DATA.
The continuous-time linear equalizer (CTLE) in the DS280BR820 consists of two stages which are configurable via the SMBus channel registers. This CTLE is designed to be highly linear to allow the DS280BR820 to preserve the transmitter's pre-cursor and post cursor signal characteristics. This highly linear behavior enables the DS280BR820 to be used in applications that use protocols such as link training, where it is important to recover and pass through incremental changes in transmit equalization.
Each stage in the CTLE has 3-bit boost control. The first CTLE stage provides a coarse adjustment of the total boost. Larger settings correspond to higher total boost. The first stage can be bypassed entirely to achieve the lowest possible total boost. The second CTLE stage acts as a fine adjustment on the total boost and impacts the shape of the boost curve accordingly. Larger settings correspond to higher total boost. The bandwidth of the CTLE can be adjusted using a 2-bit bandwidth control. Larger settings correspond to higher total bandwidth. For information on how to program the CTLE refer to the DS280BR820 Programming Guide.
In addition to high-frequency boost, the CTLE can apply wide-band amplitude gain. There are two settings (high-gain and low-gain) which work together with the driver DC gain control to affect the total input-to-output wide-band amplitude gain.