Design Of The CMOS Transimpedance Preamplifier Of1.25Gbps Optical Receiver

The rapid development of digital communication systems with fiber optics forultra-high-speed trunk network of social information processes and people’s pursuitof access to information to promote the information industry, the increasing amountof information exchange. In recent years, the sudden emergence of optical fibercommunications, the carrier of light waves, the spread of coal for the fiber, theyhave the main body of the optical fiber communication. In a few of the features inthe optical fiber transmission system, the preamplifier is a very critical circuit. Thepreamplifier has three types of low impedance, high impedance and transimpedancepreamplifier. This paper introduces the core of the optical system optical receiverpreamplifier circuit design.This design uses a single analog signal amplifier, that is, between the two endsof the CMOS inverter with a feedback resistor Rf structure. Such an invertingamplifier gain is high, its output can be provided directly to a DC level as the inputbias point to the circuit operating point within the desired range. With this amplifieralso eliminates the separate input plus the bias resistor trouble.This paper to adopt Chrt0.18μm CMOS process design to achieve a high gain,low noise and low-power transimpedance amplifier (Trans-Impedance Amplifier,the TIA). Transimpedance amplifier designed for the AGC input to a feedbackresistor of the circuit structure, the conclusion can be reasonably achieve varioustrade-offs among the performance indicators, including temperature, gain,bandwidth, noise, dynamic range and low supply voltage, etc.This thesis is designedtransimpedance amplifier operating voltage of3.3V, the module DC-DC module,transimpedance amplifier, AGC, the output circuit. In order to meet the rangerequirements of the optical fiber transmission signals, the AGC circuit to control thefeedback resistor of the transimpedance amplifier; the form of adjustable gaineffective control of the output signal range.Circuit design, and before and after thesimulation and verification.Circuit design and simulation were performed under Cadence.Spectre.