I have several questions regarding the schematic for the ev-21569-som board.
1. On the power supply page (11 of 12), the voltage regulators for +1.35 and _1.0 have
the enable inputs marked driven by labels PG1 and PG2. However, I cannot find
any reference to these labels anywhere else in the schematic. What are these
labels supposed to be connected to?
2. The data sheet for the ADSP-21569 shows that VDD_EXT is 3.3v "nominal" and
the minimum voltage is 3.13v. However, throughout the schematic the voltages
shown are 3.0v, not 3.3, except for a single instance where the schematic shows
3.3v at VIN on U9 (the TPS51200 Sink/Source DDR regulator). Please confirm
that: (a) the schematic is incorrect and VDD_EXT is supposed to be 3.3V, not
3.0V as shown throughout the schematic; and (b) the resistors setting the
voltage output on U18 (LT8609) are correct values for 3.3V, not 3.0V (see
R87, R82, R79).
3. I want to confirm that VTT in the circuit for the DDR3 is .75v.
