Transimpedance operational amplifier for high-speed systems-on-a-chip

Abstract

The paper describes a transimpedance operational amplifier designed to be used as an IP block. The amplifier is developed in the standard process of 130 nm silicon-germanium (SiGe) BiCMOS and can be used in designing super high-speed devices of the system-on-a-chip type, and signal reception nodes of radar systems and MEMS of reference-frequency generators. The layout of the transimpedance amplifier has been developed, and the area of this amplifier does not exceed 0.005 mm2. Modeling of the schematic and the layout of the transimpedance operational amplifier is performed in Cadence software. As a result of modeling, it has been found that the amplifier ensures safe operation in the temperature range from −40 °C to + 85 °C with the supply voltage deviation up to 10%. Under the worst-case conditions of voltage slump and simultaneous thermal overload, the amplifier voltage gain does not go below 55.2 dB, the unity gain frequency is not less than 2.05 GHz, and the phase margin on the unity gain frequency is more than 60.2 °. High-speed performance of the circuit is achieved by using bipolar transistors as an input differential pair. These transistors have a significant advantage over the field transistors in terms of greater cutoff frequency of operation.