Modern DRAM DDR3 LPDDR2 LPDDR3 DDR4 Pcb Printed Circuit Board 2.0mm

2.0mm HDI PCBs for LPDDR3 Socket Interposer stack up 4-2-4  immersion gold 

The demand for higher data rates and larger data densities lead to the evolution of SDR into the DDR concept. The demand for higher data rates and larger data densities lead to the evolution of SDR into the DDR. In the DDR SDRAM, the data is clocked at both edges – positive as well as negative edge – which results in doubling the data rate. In this way, DDR achieves greater bandwidth compared to SDR SDRAM; it doubles the transfer rate without increasing the frequency of the clock.

Over the last few decades, many memory improvements have occurred in DDR technology. The DDR has become extremely popular in the market and is used extensively in notebooks, laptops, servers, and embedded computing systems. The DDR offers many enhancements such as increased speed of operation, improved storage densities, reduced power consumption, and adds error detection functions such as CRC, reduced SSN noise by implementing the bit inversion concept. In the following section, we will discuss the evolution of DDR memories and their benefits.

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1 . Descriptions:

What is the PCB Layout Changes Needed for DDR4 Implementation?

DDR4 or Double Data Rate 4 comes in two distinct module types. So-DIMM or small outline dual in-line memory modules (260-pins) that are in use in portable computing devices like laptops. The other module type is DIMM or dual in-line memory modules (288-pins) that are in use in devices like desktops and servers.

So, the first change in architecture is, of course, due to the pin count. The previous iteration (DDR3) uses 240-pins for a DIMM and 204-pins for a So-DIMM. Whereas the previously mentioned, DDR4 uses 288-pins for its DIMM application. With the increase in pins or contacts, DDR4 offers higher DIMM capacities, enhanced data integrity, faster download speed, and an increase in power efficiency.

Accompanying this overall improvement in performance is also a curved design (bottom) that enables better, more secure attachment, and it improves stability and strength during installation. Also, there are bench tests that confirm that DDR4 offers a 50% increase in performance and can achieve up to 3,200 MTs (Mega Transfers per Second).

Furthermore, it achieves these increases in performance in spite of using less power; 1.2 volts (per DIMM) instead of the 1.5 to 1.35-volt requirement of its predecessor. All of these changes mean that the PCB designers must reassess their design approach for the implementation of DDR4.