Original Part
Alternative Part
SDRAM - DDR Memory IC 128Mbit Parallel 200 MHz 700 ps 66-TSOP II
SDRAM - DDR Memory IC 128Mbit Parallel 166 MHz 700 ps 66-TSOP II
1. IS43R16800E-5TL-TR Substitution Conclusion
From a review of the core specifications, the IS43R16800E-5TL-TR is identical to the original part, W9412G6KH-5I, in terms of memory density (128Mbit), organization (8Mx16), operating voltage (2.3V-2.7V), package (66-TSSOP), and critical timing (200MHz clock, 15ns write cycle time). This establishes the physical and fundamental electrical basis for a direct substitution.
Noted discrepancies are the "Memory Interface" listed as "Parallel" instead of "SSTL_2," and the "Access Time" listed as "700 ps" instead of "50 ns." For first-generation DDR SDRAM, SSTL_2 (Stub Series Terminated Logic for 2.5V) is the standard parallel interface electrical standard. The difference in description here is typically a matter of manufacturer terminology and emphasis, with no practical difference in substance. The significant variance in the Access Time value (700ps vs. 50ns) is highly likely due to differing data sheet conventions or definitions. For instance, a parameter like tAC (clock to output time) is on the nanosecond scale, making 700ps more plausible, while 50ns may refer to a pre-DDR era parameter or be a misprint. Verification against the detailed timing parameter tables is advised. However, given the identical clock frequency and key timing parameters, the actual operational performance should be compatible.
Therefore, this part can be considered a direct functional and performance replacement for the Original Part. Substitution is highly feasible, provided the PCB layout meets signal integrity requirements for the target application.
2. IS43R16800E-6TL Substitution Conclusion
The IS43R16800E-6TL matches the original part in memory density, organization, operating voltage, and package. However, its core performance specifications are downgraded: the clock frequency is 166MHz (corresponding to a 6ns clock period) versus the original part's 200MHz (5ns), and its write cycle time is specified as 12ns. This results in an approximate 17% reduction in peak data transfer bandwidth. Furthermore, its internal timing parameters (such as CL, tRCD, tRP) are optimized for the 166MHz operating frequency.
Although its access time is also listed as 700ps, the lower clock frequency directly prevents it from operating reliably in a system designed with 200MHz timing requirements. Forced substitution would likely cause timing violations, leading to read/write errors or failure to initialize.
Consequently, due to its lower core clock frequency, this part is a performance-downgraded version. It cannot meet the original design's requirements for memory bandwidth and timing, and therefore is not a suitable direct replacement.
Analysis ID: CB56-0616000
Based on part parameters and for reference only. Not to be used for procurement or production.
SkyChip © 2026, Email: sales@skychip.com