Method and device of obtaining electrical data of pixel unit, and array substrate

A method of obtaining electrical data of a pixel unit through an external compensation circuit, the external compensation circuit comprising a multiplexer, an operational amplifier, an integrating capacitor, an integrating reset switch, a first switch, a first capacitor, a second switch, and a second switch, and a second capacitor, wherein a negative input end of the operational amplifier is connected to an output end of the multiplexer, a positive input end of the operational amplifier is connected to a reference voltage line, an output end of the operational amplifier is respectively connected to a first end of the first switch and a first end of the second switch, the integrating capacitor and the integrating reset switch are connected in parallel and connected between the negative input end of the operational amplifier and the output end of the operational amplifier, a first end of the first capacitor is connected to a second end of the first switch, a second end of the first capacitor is grounded, a first end of the second capacitor is connected to a second end of the second switch, and a second end of the second capacitor is grounded, the method comprises:

• acquiring first data in a first detection state, the first data comprising noise data caused by a level jump of the multiplexer of the external compensation circuit;
• acquiring second data in a second detection state, the second data comprising the noise data and the electrical data;
• and
• obtaining the electrical data according to the first data and the second data.