Adaptive line loss compensation circuit for DC-DC (direct current) converter

Abstract

The invention discloses an adaptive line loss compensation circuit for a DC-DC (direct current) converter. The adaptive line loss compensation circuit comprises an operational amplifier, an NMOS (N-channel metal oxide semiconductor) tube, a low-side current sampling resistor and a compensation resistor, one end of the low-side current sampling resistor and one end of the compensation resistor are jointly grounded, the other end of the low-side current sampling resistor is connected with a CS end, the other end of the compensation resistor is connected with a Vcom end, an in-phase input end of the operational amplifier is connected with the CS end, an inverted input end of the operational amplifier is connected with the Vcom end, an output end of the operational amplifier is connected with a grid electrode of the NMOS tube, a source electrode of the NMOS tube is connected with the Vcom end, and a drain electrode of the NMOS tube is connected with an FB end of the DC-DC converter. The adaptive line loss compensation circuit has the advantages that the conversion efficiency of the DC-DC converter cannot be affected, the adaptive line loss compensation circuit is high in precision and easy to implement, and a full CMOS (complementary metal oxide semiconductor) process can be adopted. The adaptive line loss compensation circuit can be widely applied to the field of integrated circuits.

Description

technical field [0001] The invention relates to the technical field of integrated circuits, in particular to an adaptive line loss compensation circuit of a DC-DC converter. Background technique [0002] The DC-DC converter is a power supply that uses modern power electronics technology to maintain a stable output voltage by controlling the time ratio of the switching device on and off. With the development and application of large-scale and ultra-large-scale integrated circuits, the operating current range of DC-DC converters is increasing. When powering remote loads, DC-DC converters require very long power lines to connect. In the past, it was generally believed that the resistance of the power line was very small, so the influence of the resistance of the power line was directly ignored when considering the output voltage of the converter. However, as the supply current increases, the voltage loss on the power line can no longer be ignored. Such as figure 1 As shown,...

AI Technical Summary

Problems solved by technology

Therefore, for a DC-DC converter that already contains an external current limiting resistor, adding a high-side current sense resistor will significantly reduce its conversion efficiency

[0007] Second, the chip uses a transistor current mirror, and with the deviation of the process, there will be a certain error when the current mirror mirrors the current

[0008] Third, the chip needs to use a high-precision and small offset (offset) op amp, which requires high performance and is difficult to achieve.

[0009] Fourth, the chip needs to use BJT transistors, which limits the technology used, and cannot use the full CMOS process, which increases the process cost of the chip

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