ZHCS488K October 2011 – December 2018 AM3351 , AM3352 , AM3354 , AM3356 , AM3357 , AM3358 , AM3359
PRODUCTION DATA.
The minimum stackup required for routing the AM335x device is a 4-layer stackup as shown in Table 7-47. Additional layers may be added to the PCB stackup to accommodate other circuitry, enhance signal integrity and electromagnetic interference performance, or to reduce the size of the PCB footprint.
LAYER | TYPE | DESCRIPTION |
---|---|---|
1 | Signal | Top signal routing |
2 | Plane | Ground |
3 | Plane | Split power plane |
4 | Signal | Bottom signal routing |
Complete stackup specifications are provided in Table 7-48.
NO. | PARAMETER | MIN | TYP | MAX | UNIT | |
---|---|---|---|---|---|---|
1 | PCB routing and plane layers | 4 | ||||
2 | Signal routing layers | 2 | ||||
3 | Full ground layers under DDR2 routing region | 1 | ||||
4 | Number of ground plane cuts allowed within DDR2 routing region | 0 | ||||
5 | Full VDDS_DDR power reference layers under DDR2 routing region | 1 | ||||
6 | Number of layers between DDR2 routing layer and reference ground plane | 0 | ||||
7 | PCB routing feature size | 4 | mils | |||
8 | PCB trace width, w | 4 | mils | |||
9 | PCB BGA escape via pad size(2) | 18 | 20 | mils | ||
10 | PCB BGA escape via hole size(2) | 10 | mils | |||
11 | Single-ended impedance, Zo(3) | 50 | 75 | Ω | ||
12 | Impedance control(4)(5) | Zo-5 | Zo | Zo+5 | Ω |