TPD6S300A: questions related with Rpd

Hi Team, 

several questions on TPD6S300A. 

1. what's the difference between TPD6S300 and TPD6S300A? Is there comparison table on it? 

2. In Dead battery mode, as red circle in below block diagram, if external C- CC is not connected to C-RPD,  how can we get the Rd? measuring  resistance between C-CCx-GND or measuring RPD-Gx-GND ? 

3. In datasheet, there is Rd ( effective resistance of Rd and FET in series) and also there is Vth_DB tested at Icc=80uA, but seems 0.9V/80uA is not 5.1kohm.  Please kindly help explain the relationship with these two parameters. 

And when test the Rd, is it tested on RPD-Gx-GND or need to connect C-CCx to RPD-G, then test on C-CCx pin? 

Thanks. 

BRs

Given