Part Number: PGA305EVM-034
Dear, support team.
I have questions in circuitry around OWI in EVM.
No.1
This is OWI Block Diagram in datasheet (PGA305 EVM).
What are the functions of Offset Voltage and Current Compensating Voltage.
Is the circuit required for OWI communication?
Or is there any inconvenience without it?
No.2
(PGA305 EVM datasheet P21 Figure19. OWI Power Amplifier Schematic)
The PGA305 device communicates with the master by modulating the current on the PWR pin.
How much current does it change?
The current consumption when not communicating is about 3mA, and the datasheet says that it increases by an additional 6mA in programing process.
The shunt resistor is 30Ω and the gain of the Current-Shunt Monitor IC (INA271) is 20x,
so if current is 9mA, the output of the IC will exceed the supply voltage of 3.3V.
However, the actual measurement showed that the output of the IC change from 2.0V to 3.0V.
Does the current consumption actually increases that much?
Or am I misunderstanding something?
Best Regards,
Masahiro Morita
