Transient response enhancement circuit

Abstract

A transient response enhancement circuit comprises an operational amplifier unit, a first pull-irrigation unit and a second pull-irrigation unit, and is characterized in that the two sides of the first pull-irrigation unit and the second pull-irrigation unit are connected in parallel, one side is connected with the positive phase input end of the operational amplifier unit and reference voltage Vref, and the other side is connected with the negative phase input end and the negative phase output end of the operational amplifier unit; when the output end of the operational amplifier unit generates instantaneous pull current, the first pull-irrigation unit is conducted, the second pull-irrigation unit is cut off, and the first pull-irrigation unit generates irrigation current based on the instantaneous pull current of the output end so as to stabilize the voltage of the output end of the operational amplifier unit. The transient response enhancement circuit can solve the problem of overshoot or negative shoot of an LDO circuit and the problem of offset voltage of an operational amplifier circuit in the prior art, does not need to additionally consume circuit bandwidth, and has a better output effect.

Description

technical field [0001] The present invention relates to the field of integrated circuits, and more particularly, to a transient response enhancement circuit. Background technique [0002] At present, with the wide application of integrated circuits, LDO (Low Dropout Regulator, low dropout linear regulator) is widely used in various chips. However, the circuit characteristics of the LDO make it have the following problems: when the load of the LDO has a large current change, the output voltage of the LDO is prone to overshoot or undershoot. This will cause a large change in the input signal of the op amp circuit connected below the LDO. Due to the characteristics of the op amp circuit, its output cannot always follow the rapid changes of the input, so it will also cause the amplifier to generate an offset voltage V os . [0003] In the prior art, the bandwidth of the circuit can be increased by increasing the quiescent current of the circuit, thereby making the response fa...

AI Technical Summary

Problems solved by technology

However, the circuit characteristics of the LDO make it have the following problems: when the load of the LDO has a large current change, its output voltage is prone to overshoot or undershoot

However, the above two methods to adjust the overshoot and undershoot of the LDO output voltage, as well as the offset voltage of the operational amplifier circuit have great limitations.

First of all, the cost of wasting circuit bandwidth to obtain a fast response is high. Secondly, only when the circuit has overshoot, undershoot and offset voltage, the auxiliary circuit can work, so the overshoot and undershoot or VOS will be large.

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