The integrated circuits are small, but all have markings that can be clearly seen with the help of a magnifying glass:
CY7C63743:
The CY7C63743 is a „enCoRe™ USB Combination Low-Speed USB and PS/2 Peripheral Controller“
The part is obsolete, but its datasheet can still be found on Digikey:
https://www.digikey.de/de/products/detail/infineon-technologies/CY7C63743-SXC/700489?srsltid=AfmBOor_j9Yhy9k8ZLSYBRZxxDzuzlYWbWMns4F9Gg-iDvqfuoNuzlsE
The part works directly from the VBUS USB voltage (~5 Volts).
24LC512:
The 24LC512 is a 512kBit I²C serial EEPROM.
Presumably it is used for storing the calibration data.
It works from 2.5V up to 5.5V.
ADR431:
The ADR431 is a 2.5 Volt voltage reference.
It works from 4.5 up to 18V, which becomes important later on.
C44:
This device is presumably an ADC. The case looks like MSOP-10.
Looking through the product selectors and the datasheets on www.analog.com, one can easily find out that it is a AD7791BRMZ Low Power, Buffered 24-Bit Sigma-Delta ADC.
The part works from 2.5V up to 5.25V.
CGA:
This device is presumably a temperature sensor. The case looks like SOT23-5.
Looking through the product selectors and the datasheets on ww.analog.com, one can easily find out that it is a AD7415ARTZ-0 ±0.5°C Accurate, 10-Bit Digital Temperature Sensor in SOT-23
to be continued…