4-20mA signal to MSP430 questions....

Howdy everybody!

School and work has had me snowed under, I am finally getting back to getting a bit further into the MSP's

For a 4-20mA signal input to a MSP430 2 wire signal

I know I need to setup the ADC to read the signal, I found some of the TI documentation on setting it up but I think I am more confused now than I was when I started. 

If I have the transmitter running at 3.3 volts I can go right to the MSP with it right?

If I need to run higher voltages I can use an OP amp to work around the higher voltage level, or measure the V difference across the transmitter?

Any ideas or direction to point me in?

Thanks guys! 

I plan on using the signal in to generate a PWM output signal