ginngi engineering

Today's high speed digital products use frequencies that demand careful attention to design to ensure that not only do they work in the prototype phase, but that they will also work reliably in high volume and under adverse conditions. A typical design may have USB 2.0 running at 480Mhz, or a 10GHZ Ethernet connection. It is not uncommon for DDR memories to run well above 600 Mhz. DSPs are today running at over 1Ghz and FPGAs are able to handle well above 10Ghz.

Eliminate Design Risks

Choosing the right components isn't enough to ensure a working, reliable design. Many design risks exist when using high frequencies. FPGAs may not function because their switching capacity has been reached. Clocks may not work because they no longer look like clocks, DDRs may not work because their nets have not been laid out correctly, or an entire board may fail because the decoupling techniques used are not adequate.

Extensive Technology Specific Experience

Ginngi employs state-of-the-art design techniques to ensure that your product is designed correctly at the specified frequencies. In addition to the general design guidelines that we employ, we also have extensive experience with specific technologies such as FPGAs, DSPs, DDR memories, and high-speed interfaces such as USB 2.0 and Ethernet.

PCB Stackup

A proper PCB stackup is essential to ensure a working design at minimal manufacturing cost. Correct positioning of power and ground planes reduces signal cross-talk, and EMC emissions while also providing noise decoupling, and impedance matching. Correct positioning of signal layers ensures efficient routing of nets, cross-talk reduction, and minimization of buried and blind vias.

Analog and Digital Separation

In combined analog/digital designs an incorrect layout design can spell disaster for sensitive small-signals in the analog circuitry. Ginngi will carefully analyze the design and separate the analog and digital sections to ensure that digital noise never enters the analog regions.

Decoupling Strategies

All digital design require capacitive decoupling to ensure reliable operation by providing current during the switching of signals. Ginngi incorporate numerous techniques to ensure an optimal decoupling strategy that includes capacitor selection, capacitor distribution and the use of tightly coupled power/ground planes. Manufacturing recommendations are always strictly adhered to.

Critical Net Specification

While all nets in a high-speed design are important there are specific classes of nets that need special attention. Ginngi will carefully identify these critical nets and provide detailed layout instructions for them. Typical critical nets include: clocks, pseudo-clocks (DDR DS signal), balanced-pairs, equal length groups (DDR data), and digital traces that approach analog, such as 10GHZ Ethernet nets.

Signal Integrity Analysis

Some designs can be laid out using only the manufacturers recommendations. However, more complex and general designs demand that the signal traces on the PCB be analyzed in a simulation environment both before and after PCB layout. Ginngi uses the HyperLynx suite of tools to eliminate signal integrity, crosstalk, and EMC problems early in the design cycle, enabling us to verify your layout before manufacturing.

Layout Constraints

All nets in a design are defined in separate groups which are then assigned specific layout constraint instructions. These instructions may be used either manually by the PCB designer or they may be autorouter instructions.

Cross Talk Analysis

Excessive cross-talk can wreak havoc in a high-speed design. Ginngi analyzes the routing of all nets and provides effective isolation of signals to ensure that cross-talk is properly dealt with.