SPRS975H August 2016 – February 2020 DRA780 , DRA781 , DRA782 , DRA783 , DRA785 , DRA786 , DRA787 , DRA788
PRODUCTION DATA.
Refer to the PDF data sheet for device specific package drawings
High speed (HS) bypass capacitors are critcal for proper DDR3 interface operation. It is particularly important to minimize the parasitic series inductance of the HS bypass capacitors, processor/DDR power, and processor/DDR ground connections. Table 7-29 contains the specification for the HS bypass capacitors as well as for the power connections on the PCB. Generally speaking, it is good to:
NO. | PARAMETER | MIN | TYP | MAX | UNIT |
---|---|---|---|---|---|
1 | HS bypass capacitor package size(1) | 0201 | 0402 | 10 Mils | |
2 | Distance, HS bypass capacitor to processor being bypassed(2)(3)(4) | 400 | Mils | ||
3 | Processor HS bypass capacitor count per vdds_ddrx rail(12) | See Table 7-3 and (11) | Devices | ||
4 | Processor HS bypass capacitor total capacitance per vdds_ddrx rail(12) | See Table 7-3 and (11) | μF | ||
5 | Number of connection vias for each device power/ground ball(5) | Vias | |||
6 | Trace length from device power/ground ball to connection via(2) | 35 | 70 | Mils | |
7 | Distance, HS bypass capacitor to DDR device being bypassed(6) | 150 | Mils | ||
8 | DDR3 device HS bypass capacitor count(7) | 12 | Devices | ||
9 | DDR3 device HS bypass capacitor total capacitance(7) | 0.85 | μF | ||
10 | Number of connection vias for each HS capacitor(8)(9) | 2 | Vias | ||
11 | Trace length from bypass capacitor connect to connection via(2)(9) | 35 | 100 | Mils | |
12 | Number of connection vias for each DDR3 device power/ground ball(10) | 1 | Vias | ||
13 | Trace length from DDR3 device power/ground ball to connection via(2)(8) | 35 | 60 | Mils |