Power-supply conversion circuit, power-supply conversion method and manufacturing method of integrated circuit

Abstract

Disclosed are a power-supply conversion circuit, a power-supply conversion method and a manufacturing method of an integrated circuit. A sampling / holding circuit is used so as to sample current-sensing voltage signals corresponding to current, which passes through a high-level transistor switch, during a sampling time which is roughly synchronous with a switch-on time of the high-level transistor switch in a current output path and hold the sampled signals at a high potential at the remaining time. A current error amplifier outputs current error signals according to output of the sampling / holding circuit and a current reference voltage signal. When constant current is output, a comparator outputs pulse width modulation signals according to tooth-wave signals and the current error signals so as to control the work period of the switch-on time of the high-level transistor switch and a low-level transistor switch so that the output current is adjusted to a preset value.

Description

technical field [0001] The present invention relates to a switching power converter, in particular to a pulse width modulation mode, with an output current monitoring circuit, capable of adjusting the output pulse width according to the monitored output current to achieve a stable output preset power supply. A switching power conversion circuit with constant current output of flow rate, its power conversion method, and a manufacturing method of an integrated circuit with the circuit. Background technique [0002] figure 1 It is a circuit schematic diagram of a step-down constant current output switching power converter. [0003] refer to figure 1 , the switching power converter 10 includes a high transistor switch MH, a low transistor switch M L , a controller 12 , an inductor 14 , a capacitor 16 , and a current sensing resistor 18 . [0004] The controller 903 is connected to the high transistor switch M H The gate of the low-side transistor switches M L gate, and con...

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Problems solved by technology

[0011] However, on the switching mode power converter 10', the practical inductor 14 has a relatively low DC resistance value, and the difference in DC resistance value between inductors of the same size is often higher than 20 percent, resulting in practical installations that are identical. The finished product of each switching power converter with the inductor of the specified specification has a large error between the theoretical output current sensed and the actual output current.

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