JEDEC Updates Standards for LPDDR3 And LPDDR4
JEDEC Solid State Technology Association has updated the standards for LPDDR3 And LPDDR4 mobile memory, offering enhanced performance capabilities for mobile computing devices such as smartphones, tablets, and ultra-thin notebooks. JEDEC released the JESD209-4A, Low Power Double Data Rate 4 (LPDDR4) and JESD209-3C Low Power Double Data Rate 3 SDRAM (LPDDR3).
The latest revision adds skew definitions between dies on the channel (rank to rank parameters such as tDQS2DQ_rank2rank and tDQSCK_rank2rank). These definitions address DRAM process variation and allow the SoC to better manage DRAM timing with less complexity. JESD209-4A also adds new eMCP (embedded multi-chip packages) and provides key errata missing from the original standard.
Still widely used in array of mobile products, this latest update to LPDDR3 offers new package configurations:
- 136-ball PoP (eMMC + LPDDR3)
- 272-ball dual-Channel POP
- 221-ball single channel MCP
In addition, lower DRAM densities addressing has been added and a "refresh multiplier" parameter (tREFIM = RM x tREFI) was also introduced.