US 11,835,977 B2
Constant voltage circuit for improvement of load transient response with stable operation in high frequency, and electronic device therewith
Kenji Mii, Ibaraki (JP)
Assigned to Nisshinbo Micro Devices Inc., Tokyo (JP)
Appl. No. 17/602,053
Filed by Nisshinbo Micro Devices Inc., Tokyo (JP)
PCT Filed Jun. 12, 2019, PCT No. PCT/JP2019/023337
§ 371(c)(1), (2) Date Oct. 7, 2021,
PCT Pub. No. WO2020/250349, PCT Pub. Date Dec. 17, 2020.
Prior Publication US 2022/0197320 A1, Jun. 23, 2022
Int. Cl. G05F 1/40 (2006.01); G05F 1/46 (2006.01); G05F 3/04 (2006.01); G05F 3/26 (2006.01)
CPC G05F 1/40 (2013.01) [G05F 1/461 (2013.01); G05F 3/04 (2013.01); G05F 3/262 (2013.01)] 4 Claims
OG exemplary drawing
 
1. A constant voltage circuit comprising an operational amplifier including a constant current source, the operational amplifier amplifying an error between a predetermined reference voltage and an output voltage, the constant voltage circuit controlling a load current based on an amplified voltage so that the output voltage is controlled to be a predetermined constant voltage, the constant voltage circuit comprising:
a voltage detector that detects only high frequency of an AC components of the output voltage limited to a predetermined band, and outputs a detected voltage;
a voltage amplifier that amplifies AC components of the detected voltage and outputs the amplified voltage;
a judgment circuit that outputs a judgment signal indicating whether or not the amplified voltage is equal to or larger than a predetermined threshold, based on the amplified voltage; and
a controller configured to increase a current value of the constant current source of the operational amplifier based on the judgment signal, thereby temporarily increasing a current consumption of the operational amplifier.