Please select the most similar patent number from A, B, C and D. Which number is?
The present application provides a power supply circuit, a chip, and a display screen. The circuit comprises: a reference circuit configured to generate a first-stage mirror current; a first current mirror group connected to the reference circuit; a first switch connected to the first current mirror group and configured to control turning-on or turning-off of the first current mirror group; a second current mirror group connected to the first current mirror group; a second switch connected to the second current mirror group and configured to control turning-on or turning-off of the second current mirror group, when the first switch and the second switch are turned on, the first current mirror group and the second current mirror group cooperating to form a current mirror, which is configured to perform mirror processing on the first-level mirror current, so as to obtain an output current; and an output stage connected to the second current mirror group and configured to output the output current. According to the present application, the current precision in the whole current range of an output constant-current source is effectively improved.
A: The present invention provides an alternating-current test circuit, comprising: a live wire input end and a null wire input end; a first diode and a second diode formed by Zener diodes of which the anodes are connected to each other; a first resistor and a second resistor; a rectification module connecting the live wire input end and the null wire input end; a power supply for supplying power; a current mirror module, the current values of a first output end and a second output end thereof having a fixed ratio; a unidirectional conduction module, used for enabling the current mirror module to conduct the first diode unidirectionally; and a current comparison module, comprising an oscillator, a timer, a current comparator, and a reference current source, and being used for comparing the current value of the second output end of the current mirror module with a reference current value. In the present invention, a power supply state of an alternating-current power supply is determined by measuring a resistance value between a null wire and a live wire of the alternating-current power supply, and a high level is outputted when there is no alternating-current voltage between the null wire and the live wire and the resistance value between the null wire and the live wire is less than a set value; and a test threshold for determining a power supply state is not affected by fluctuation of a power supply, providing high reliability, and the circuit structure is simple, and the design and debugging are convenient.
B: A memory data reading circuit and a memory, which relate to the technical field of integrated circuits, and can solve the problem of data read by a memory data reading circuit being inaccurate. The memory data reading circuit (01) comprises a first current mirror (301), a first resistor (303) and a voltage amplifier (40), wherein an input end (a) of the first current mirror (301) is connected to a first data reading end (p) of a memory cell, and an output end (b) of the first current mirror (301) is connected to a grounding end by means of the first resistor (303); the first current mirror (301) is used for amplifying a current mirror image, which is output by the first data reading end (p) of the memory cell, to a first mirror current (IRO), and outputting the first mirror current (IRO) to the output end (b) of the first current mirror (301); a first input end (c) of the voltage amplifier (40) is connected to the output end (b) of the first current mirror (301), and a second input end (d) of the voltage amplifier (40) is used for receiving a reference voltage (Iref); and an output end (e) of the voltage amplifier (40) is connected to an output end of the memory data reading circuit (01).
C: Disclosed in the present invention are a drive circuit and a display device. The drive circuit comprises a substrate circuit and at least one additional circuit, wherein the at least one additional circuit is connected to the substrate circuit. The substrate circuit comprises a first light emitting device, a first drive unit and a first capacitor unit. The first drive unit is respectively connected to the first light emitting device and the first capacitor unit; and the first capacitor unit is charged by means of the first drive unit until the compensation voltage value of the first drive unit is met. After the charging of the first capacitor unit is completed, the first capacitor unit is coupled with a first reference potential so that the first drive unit obtains an adjustable cross voltage, and the first drive unit outputs a stable current according to the adjustable cross voltage to drive the first light emitting device to operate. The present invention improves the problem of brightness uniformity caused by voltage drop, thereby improving the image quality of a display.
D: The present invention provides a reading circuit for reading the resistance state of a storage unit, comprising: a power-on unit, a current mirror unit, and an output unit, wherein the first end of the power-on unit is connected to a read voltage signal, the second end of the power-on unit is connected to the bit line of a storage unit to be read, and the power-on unit provides said storage unit with a read voltage required for a read operation to generate a read current, the read current being output by the third end of the power-on unit; the input end of the current mirror unit is connected to the third end of the power-on unit to receive the read current, and the output end of the current mirror unit outputs a mirror current, and the mirror current is proportional to the read current; and the output unit is configured to output the reading result according to the mirror current. The reading circuit of the present invention has a simple structure and is easy to implement.
Answer: C