Low-voltage-difference voltage-stablizer

A low-dropout linear, voltage-stabilizer technology, applied in instruments, control/regulating systems, regulating electrical variables, etc., can solve the problem that LDO circuits cannot simultaneously achieve high output voltage accuracy, high stability and high power supply voltage rejection ratio, etc. Achieve the effect of overcoming system stability reduction, low output noise, and ensuring stability

CN100495281CInactive Publication Date: 2009-06-03BEIJING MXTRONICS CORP +2
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
Publication Date
2009-06-03
Estimated Expiration
Not applicable · inactive patent

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Patent Text Reader

Abstract

A low voltage difference linear voltage regulator realizes the performance targets such as high output voltage precision, high stability and high supply-voltage rejection ratio by using variable slope gm / C filter circuit module at the output terminal of error amplifier. Variable slope mechanism of the filter circuit module reduces static power consumption of the voltage regulator when the regulator is ideal loaded or light loaded, and produces a parasitic pole whose frequency goes to high when the regulator load voltage increases, accordingly to develop unit gain band width of the voltage regulator and strengthen stability of the heavy loaded or full loaded voltage regulator. Moreover, variable current high-gain amplifier stage used in voltage circuit increases slew rate of voltage regulator internal node and improves interaction capability of the voltage regulator.
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Description

technical field

[0001] The invention relates to a low-dropout linear regulator, in particular to a variable transconductance gm / C filter circuit module and a variable current high-gain amplifier stage to achieve high stability, high precision, high power supply voltage rejection ratio, and fast response low dropout linear regulator. Background technique

[0002] The power management circuit is one of the important modules in portable electronic applications, and it usually includes a switching power supply circuit and a low-dropout voltage regulator (LDO, Low-Dropout Voltage Regulator) circuit. The conversion efficiency of the switching power supply circuit can usually reach more than 90%, but its chip area is large, the output voltage ripple is large, and it needs to use magnetic components; while the LDO circuit has the characteristics of small chip area and small output voltage ripple, so it is widely used For powering high-performance analog circuits.

[0003] High-per...

Examples

Embodiment Construction

[0044] Figure 5 A typical LDO principle block diagram of the present invention is given. The LDO is composed of a voltage reference circuit 101, an error amplifier 102, a variable transconductance filter circuit module 302, a variable current high-gain amplifier stage 103 (the current flowing through this stage increases with the increase of the LDO load current), a power tube 104 , a voltage dividing sampling network 105 , an output capacitor 106 and a load 107 . its with image 3 The difference of the shown circuit is that the fixed current high gain amplifier stage 109 is replaced by the variable current high gain amplifier stage 103, and a variable current high gain amplifier stage 109 is added between the output terminal of the error amplifier 102 and the input terminal of the variable current high gain amplifier stage 103. A filter circuit module 302 with variable transconductance.

[0045] The filter circuit module 302 of the variable transconductance is made up of ...