Automotive-Range Characterization of a 11 Gb/s Transceiver for Automotive Microcontroller Applications with 8-Tap FFE, 1-Tap Unrolled/3-Tap DFE and Offset-Compensated Samplers

This paper presents the experimental characterization of a High-Speed Serial Interface (HSSI) for automotive microcontroller applications designed in 28 nm planar CMOS technology, verified over automotive corners and operating up to 11 Gb/s. The impedance of the full-rate voltage-mode transmitter can be tuned by activating several driver replicas. It also features an 8-tap Feed-Forward Equalizer (FFE) with taps programmable in steps of 1/16. The analog front-end of the receiver cascades a Variable-Gain Amplifier (VGA) and a Continuous-Time Linear Equalizer (CTLE), which can be individually tuned. The receiver is based on a half-rate architecture and features a 3-tap Decision-Feedback Equalizer (DFE), one tap being speculative to relax timing constraints; another VGA is embedded in the DFE summing node. The subsequent data and edge samplers are offset-compensated. The circuit is experimentally characterized over automotive corners at 6.25 Gb/s and 11 Gb/s on highly-reflecting PCB channels with up to 14.5 dB loss, demonstrating operations at bit-error ratio (BER) below 10 −12 up to 11 Gb/s. The HSSI occupies an area of 0.08 mm 2 and consumes 8.4 mW/Gb/s at 11 Gb/s and 6.2mW/Gb/s at 6.25 Gb/s.