A 12-Gb/s -16.8-dBm OMA Sensitivity 23-mW Optical Receiver in 65-nm CMOS

A 32 Gb/s PAM-4 Optical Transceiver With Active Back Termination in 40 nm CMOS Technology

“…Since the ISI can be eliminated by incorporating an equalizer, the SNR can be further improved by exploring the design space in the narrow band region. Narrow band TIAs with equalizers, such as decision feedback equalizer (DFE) [1]- [4] or continuous time linear equalizer (CTLE) [13], have been proposed to demonstrate improved receiver sensitivity. As the CTLE restores the TIA bandwidth by providing high frequency gain peaking, it also boosts the high frequency noise at the same time.…”

“…The feedback signals are connected to the summer through a Gilbert-cell multiplier (M 3∼6 ), whose gain coefficient is controlled by W 1 . Compared to the prior art in [4], [14], it maintains a constant output common mode voltage level of the summer irrespective of its weighting coefficients, which is crucial to the proper operation of the succeeding data slicer. The data slicer for the PAM-4 demodulator is based on a StrongArm latch, as is shown in Fig.…”

“…A high gain and relatively low bandwidth TIA (∼ 0.3× baud rate) is adopted as the input stage. The residual ISI due to the insufficient front-end bandwidth is further compensated by DFE [1]- [4]. Given the nonlinearities of the E/O, O/E conversions and the receiver front-end, the threshold voltages of the PAM-4 slicer is critical to the overall bit error rate performance.…”

3 GHz, 1 mW inverter‐based TIA with capacitive feedback for enhanced gain and sensitivity in VLC applications

“…The TIA BW can be restored to 3 GHz by tuning R FA within ±20% (for the cases in both Tables 2 and 3), and R FC within ±50% (for the cases in Table 3 only). Therefore, it is important to make the TIA feedback resistance programmable to maintain its BW and stability under various process-voltage-temperature (PVT) conditions [5,8]. he eye diagrams of the reference TIA and the proposed TIA based on a 2 15 −1 pseudorandom binary sequence (PRBS-15) and on-off keying modulation are presented in Fig.…”

“…The TIA BW can be restored to 3 GHz by tuning R FA within ±20% (for the cases in both Tables 2 and 3), and R FC within ±50% (for the cases in Table 3 only). Therefore, it is important to make the TIA feedback resistance programmable to maintain its BW and stability under various process‐voltage‐temperature (PVT) conditions [5, 8].…”