Simplified sensing circuit and sample and hold circuit for improving uniformity in OLED driver

A sensing circuit for an organic light-emitting diode (OLED) driver, comprising:

• a sample and hold circuit, configured to sample a sensing signal received via an input terminal;
• and
• a gain amplifier, coupled to the sample and hold circuit, having a first input terminal, a second input terminal, a first output terminal and a second output terminal, the gain amplifier comprising:
• an eighth switch, coupled between the first input terminal and the first output terminal, wherein a first terminal of the eighth switch is coupled to the first input terminal, and a second terminal of the eighth switch is coupled to the first output terminal;
• and
• a ninth switch, coupled between the second input terminal and the second output terminal, wherein a first terminal of the ninth switch is coupled to the second input terminal, and a second terminal of the ninth switch is coupled to the second output terminal;
• wherein the sample and hold circuit comprises:
• a first capacitor, coupled between the input terminal and the gain amplifier,
• the first capacitor comprising:
• a first terminal, coupled to the input terminal, and
• a second terminal, coupled to the gain amplifier;
• a second capacitor, coupled between a reference terminal and the gain amplifier;
• a first switch, directly connected between the first terminal of the first capacitor and the input terminal;
• a second switch, directly connected between the second capacitor and the reference terminal;
• a third switch, connected between the second terminal of the first capacitor and the gain amplifier, wherein a first terminal of the third switch is directly connected to the first capacitor and a second terminal of the third switch is directly connected to the gain amplifier;
• and
• a fourth switch, connected between the second capacitor and the gain amplifier, wherein a first terminal of the fourth switch is directly connected to the second capacitor and a second terminal of the fourth switch is directly connected to the gain amplifier.