Voltage buffer circuit for linear potentiostat

Abstract

The invention relates to a voltage buffer circuit used in a linear voltage regulator. The circuit consists of a basic voltage buffer circuit, an output current monitoring circuit and a current mirror circuit; wherein the input end of the basic voltage buffer circuit is connected with the output end of a voltage difference amplifier of the linear voltage regulator which is also the output of a dynamic bias power source buffer circuit; the output end of the output current monitoring circuit is connected with the input end of the current mirror circuit; the output end of the current mirror circuit is in parallel connection with a static bias current source. Under the condition that the static power loss of voltage regulator circuit is not increased, the impact of a pole of the output end of the voltage buffer circuit to system phase margin and stability is reduced; the invention doesn't need the traditional linear voltage regulator and utilizes an outer wave filtering capacitance equivalent series resistance to generate zero point, which lowers the system cost, reduces use difficulty and reduces the impact of the equivalent series resistance to the transient state response and noise restraint capacity of the voltage regulator circuit; a chip upper frequency compensation capacitance is not needed, which saves chip area.

Description

technical field [0001] The invention relates to a semiconductor integrated circuit, in particular to a voltage buffer circuit inside a linear voltage regulator. Background technique [0002] In recent years, monolithic integrated linear regulated power supplies are widely used in battery-powered electronic systems, such as mobile phones, Consumer electronics such as handheld computers, as well as medical equipment and test instruments. [0003] The basic composition of a monolithic integrated linear regulator is shown in Figure 1, including a dropout amplifier (1), a voltage buffer (2), a voltage adjustment transistor (3) (pass transistor), and a feedback network (4). The reference voltage Vref(7) is a stable voltage signal generated internally or from outside the chip that does not change with temperature, input voltage, etc., and the capacitor Cb and its equivalent series resistance (5) and resistor RL(6) are integrated linear regulators The off-chip filter capacitor and...

AI Technical Summary

Problems solved by technology

However, on-chip frequency compensation requires a large amount of on-chip capacitance (generally greater than 10pF), which occupies a large chip area

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