Negative Charge Pump Feedback Circuit

Abstract

The invention discloses a feedback circuit of a negative voltage charge pump. The circuit comprises a bleeder circuit which is formed by connecting a plurality of MOS transistors in series, the drain electrodes and the grid electrodes of the MOS transistors being in short circuit. The bleeder circuit is connected between the negative voltage output by the charge pump and first reference voltage, and outputs branch voltage as feedback voltage. The feedback voltage is connected with a first input end of a first operational amplifier. The second input end of the first operational amplifier is connected with ground. An amplification signal output by the first operational amplifier is used as a clock control signal. The clock signal inputs to the input end of the charge pump through a clock control circuit. The clock control signal inputs to the clock control circuit to adjust amplitude of the clock signal input to the charge pump, and values of the negative voltage are controlled through adjusting the amplitude of the clock signal. The circuit area is reduced.

Description

technical field [0001] The invention relates to a semiconductor integrated circuit, in particular to a negative pressure charge pump feedback circuit. Background technique [0002] Such as figure 1 As shown, it is a schematic diagram of an existing negative pressure charge pump feedback circuit; the clock signal Clock is connected to an input end of the AND gate 102, and the output end of the AND gate 102 is connected to the input end of the negative pressure charge pump 101, and the negative pressure charge pump 101 The output terminal of the negative voltage Vneg is output, and the feedback circuit is connected between the output terminal of the negative pressure charge pump 101 and the other input terminal of the AND gate 102. The feedback circuit includes a comparator 103, a resistor divider circuit 104 and a positive and negative voltage conversion circuit 105. figure 1 The resistor voltage divider circuit 104 is composed of a plurality of resistors in series, and the...

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Problems solved by technology

[0003] Depend on figure 1 It can be seen that the resistor divider circuit 104 in the existing feedback circuit is composed of multiple resistors connected in series, which will occupy a larger area

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