Driving circuit with high speed and large output swing

Abstract

The invention discloses a driving circuit with high speed and large output swing. The driving circuit comprises a first-stage emitter follower circuit used for level displacement and impedance matching, and a second-stage differential structure grounded emitter amplifier circuit used for amplifying an input signal and providing a sufficient bandwidth, wherein the first-stage emitter follower circuit comprises an emitter follower formed by Q1 and Q2, a bias current source, an impedance matching resistor R1 and an impedance matching resistor R2; the bias current source is of a parallel structureof M1 and M4 which adopt a diode connection mode and M2 and M3 which are crossly coupled; the second-stage differential structure grounded emitter amplifier circuit comprises a main amplifier tube Q3and a main amplifier tube Q4 of a grounded emitter amplifier of the differential structure, and a large-resistance driving source electrode follower which is formed by R3/M5 and R4/M6 and has an inductance characteristic. The MOS tubes adopting the diode connection mode and the MOS tubes which are crossly coupled are connected in parallel, and an MOS device whose grid electrode has large resistance forms an active inductor, the formed driving circuit has the advantages of high speed and large output swing, the gain is improved, the linearity is improved, the circuit bandwidth is expanded, thechip area is saved, and the cost is reduced.

Description

technical field [0001] The invention relates to a high-speed large output swing driving circuit, specifically a driving circuit with high working speed and large driving capability, and belongs to the technical field of ultra-high-speed optical communication sending end driver circuits and power amplifier circuits in radio frequency communication systems. Background technique [0002] With the explosive growth of information capacity, the requirements for circuit bandwidth are getting higher and higher, and at the same time, large output signal swing is required, that is to say, the driver or power amplifier in the circuit should have high operating speed and large driving capability. Therefore, the design goal of the driving circuit is to obtain high bandwidth and large output modulation swing performance. Although the bandwidth can be improved by adopting advanced CMOS technology, the power supply voltage is also gradually reduced, which reduces the swing of the output sig...

AI Technical Summary

Problems solved by technology

[0017] The circuits disclosed in Chinese invention patents "Low Power Consumption Bandwidth Multiplication Operational Amplifier Realized by MOS Devices" (201110061084.6) and "A Gain-Boosted Operational Transconductance Amplifier" (201510631301.9) are both gain-boosting circuits composed of operational amplifiers , its shortcomings are: the bandwidth is not high, and the comprehensive performance of the circuit cannot meet the technical requirements of the amplifier required by modern optical fiber communication.

[0018] To sum up, in the existing driver integrated circuits, passive inductors occupy a large area, which greatly increases the cost of chip manufacturing; on the other hand, for high-gain multi-stage amplifier circuits or multi-channel parallel optical transceiver circuits, due to Due to the chip area, the number of passive inductors cannot be increased without limit

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