Specifications for I2C Display:
Model: PCF8574
Supply voltage: 2,5 V - 6 V
Power consumption: 100 µA during data transfer, 10 µA in stand-by
Logic level: depends on supply voltage 3,3 V or 5 V
Interface: I2C (TWI), addresses from 0x38 to 0x3F
Current output in LOW state: 25 mA
Current output in HIGH state: 300 µA