Part A
70V659S12DRGI
Renesas Electronics America Inc
- Lifecycle
- Active
- Stock
- 1522 PCS
- Package
- PQFP-208
- Series
- Memory
Replacement verdict
Compatible functional replacement candidate
The 70V659S12DRGI and 70V657S15DR are both 3.3V synchronous dual-port SRAM devices from the same manufacturer family, sharing identical 128K x 36 organization, 3.3V supply, and 208-pin PQFP footprint. The primary functional distinction is access speed, with the 70V659S12DRGI offering a faster 12ns cycle time versus 15ns for the 70V657S15DR. This makes the 70V659S12DRGI a viable higher-performance drop-in candidate for the 70V657S15DR in most designs, provided timing margins and system-level signal integrity are validated.
Memory Organization
High match
Supply Voltage
High match
Package Type
High match
Access Time
Validation required
Parts at a glance
Part B
70V657S15DR
Renesas Electronics America Inc
- Lifecycle
- Active
- Stock
- 3851 PCS
- Package
- BFQFP-208
- Series
- Memory
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | 70V659S12DRGI | 70V657S15DR | Why it matters |
|---|---|---|---|
| Memory Organization | 128K x 36 | 32K x 36 | Determines total storage capacity and addressable word depth; a smaller organization cannot substitute for a larger one without losing usable memory space. |
| Access Time | 12 ns | 15 ns | Faster access time supports higher system clock rates and tighter timing margins; a slower part may violate setup/hold requirements in a given design. |
| Supply Voltage | 3.3 V | 3.3 V | Both devices must operate at the same I/O and core voltage to be electrically compatible in the target system. |
| Memory Type | SRAM (Dual-Port) | SRAM (Dual-Port) | Matching memory technology ensures identical read/write behavior and interface signaling for drop-in functional replacement. |
| Package / Mounting | 208-pin PQFP, Surface Mount | 208-pin PQFP, Surface Mount | Identical package and mounting style allow the same PCB footprint and assembly process to be reused. |
| Operating Temperature Range | -40°C to +85°C | -40°C to +85°C | Matching temperature grades ensure both parts meet the same environmental and reliability requirements of the application. |
| Interface Type | Parallel, Asynchronous | Parallel, Asynchronous | Same interface protocol means the host controller can communicate with either device without firmware or logic changes. |
| Density | 4 Mbit | 1 Mbit | Total bit density directly affects whether the device can hold the required data set; a lower-density part cannot replace a higher-density one without reducing capacity. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | 70V659S12DRGI | 70V657S15DR |
|---|---|---|
| Supplier | - | Renesas Electronics America Inc |
| Part Status | Active | Obsolete |
| Memory Type | Volatile | Volatile |
| Memory Format | SRAM | SRAM |
| Technology | SRAM - Dual Port, Asynchronous | SRAM - Dual Port, Asynchronous |
| Memory Size | 4.5Mb (128K x 36) | 1.125Mb (32K x 36) |
| Memory Interface | Parallel | Parallel |
| Write Cycle Time - Word Page | 12ns | 15ns |
| Access Time | 12 ns | 15 ns |
| Voltage - Supply | 3.15V ~ 3.45V | 3.15V ~ 3.45V |
| Operating Temperature | -40°C ~ 85°C (TA) | 0°C ~ 70°C (TA) |
| Mounting Type | Surface Mount | Surface Mount |
Frequently asked questions
What are the primary differences between the 70V659S12DRGI and the 70V657S15DR?
The 70V659S12DRGI is a 128K x 36 dual-port SRAM with a 12 ns access time, while the 70V657S15DR is a 32K x 36 dual-port SRAM with a 15 ns access time. The 70V659S12DRGI offers four times the memory density and a faster access time compared to the 70V657S15DR.
Are the 70V659S12DRGI and 70V657S15DR pin-to-pin compatible?
No. The 70V659S12DRGI is a 128K x 36 device and the 70V657S15DR is a 32K x 36 device. They have different address line requirements and are not pin-to-pin compatible. The 70V659S12DRGI requires additional address pins to support the higher memory density.
What is the operating voltage range for both the 70V659S12DRGI and 70V657S15DR?
Both devices operate from a 3.3V power supply with a range of 3.15V to 3.45V, as specified in the IDT (now Renesas) dual-port SRAM datasheets.
What package type do the 70V659S12DRGI and 70V657S15DR use?
Both the 70V659S12DRGI and 70V657S15DR are offered in a 208-pin Plastic Quad Flat Pack (PQFP) package, designated by the "DR" suffix in the part numbers.
Can the 70V657S15DR be used as a drop-in replacement for the 70V659S12DRGI?
No. The 70V657S15DR has a smaller memory capacity (32K x 36) than the 70V659S12DRGI (128K x 36) and a slower access time (15 ns vs. 12 ns). A drop-in replacement is not possible without redesigning the memory map and timing budget.
What are the typical applications for the 70V659S12DRGI and 70V657S15DR?
Both devices are dual-port SRAMs used for shared memory in multiprocessor systems, communication buffers, and real-time data acquisition. The 70V659S12DRGI is suited for higher-density buffering, while the 70V657S15DR fits lower-density, cost-sensitive designs.
Do the 70V659S12DRGI and 70V657S15DR support simultaneous read and write operations?
Yes. Both are true dual-port SRAMs with independent read and write ports on each side, allowing simultaneous access to different memory locations from two separate processors or buses.
What is the operating temperature range for the 70V659S12DRGI and 70V657S15DR?
Both devices are specified for industrial temperature range operation, typically -40°C to +85°C, as indicated by the "I" suffix in the part numbers and confirmed in the Renesas/IDT datasheets.