Low power linear repeater extends reach and robustness of high-speed serial links

The DS280BR820, from Texas Instruments, is an extremely low-power, high-performance eight-channel linear equaliser supporting multi-rate, multi-protocol interfaces up to 28Gbps. It is used to extend the reach and improve the robustness of high-speed serial links for backplane, front-port, and chip-to-chip applications. The linear nature of the device’s equalisation preserves the transmit signal characteristics, thereby allowing the host and link partner ASICs to freely negotiate transmit equaliser coefficients (100G-CR4/KR4). This transparency to the link training protocol facilitates system-level interoperability with minimal effect on the latency. Each channel operates independently, which allows it to support individual lane FEC pass-through. The device’s small package dimensions, optimised high-speed signal escape, and the pin-compatible Retimer portfolio make it ideal for high-density backplane applications. Simplified equalisation control, low power consumption, and ultra-low additive jitter make it suitable for front-port interfaces such as 100G-SR4/LR4/CR4. The small 8mm × 13mm footprint easily fits behind numerous standard front-port connectors like QSFP, SFP, CFP2/CFP4, and CDFP without the need for a heat sink. Integrated AC coupling capacitors (RX side) eliminate the need for external capacitors on the PCB. The device has a single power supply and minimal need for external components. These features reduce PCB routing complexity and bill of materials (BOM) cost. A pin-compatible Retimer device is available for longer reach applications. The device can be configured either via the SMBus or through an external EEPROM. Up to 16 devices can share a single EEPROM.