Equivalent & Substitute Parts for 7164S85DB

Part Overview

The 7164S85DB is a 64Kbit asynchronous SRAM memory IC manufactured by Renesas Electronics Corporation, packaged in a 28-CDIP configuration. This device operates as a volatile parallel memory with an 8K x 8 organization and 85 ns access time. The part is classified as obsolete, making identification of compatible substitute components essential for system maintenance, repair, and legacy equipment support. Substitute parts must maintain electrical and mechanical compatibility while meeting the same functional requirements.

Substiute Parts

7164S85DB

Renesas Electronics CorporationIn Stock: 10697164S85DB Datasheet

Current PartRFQ

7164L45DB

Renesas Electronics CorporationIn Stock: 8857164L45DB Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the 7164S85DB is determined by the following critical parameters:

• Memory Capacity & Organization: Substitute parts must provide 64Kbit capacity with 8K x 8 organization to ensure pin-compatible operation and identical address/data bus requirements.
• Package & Pinout: The 28-CDIP package is mandatory for through-hole mounting compatibility. Pin assignments must be identical.
• Electrical Specifications: Supply voltage range (4.5V ~ 5.5V) and operating temperature range (-55°C ~ 125°C) must be met or exceeded.
• Access Time: Substitute parts may have equal or faster access times. Faster access times (lower ns values) are acceptable as they maintain backward compatibility.
• Memory Interface: Parallel interface configuration must be preserved.

The 7164L45DB qualifies as a direct substitute based on these criteria. It maintains identical memory capacity, organization, package configuration, voltage specifications, and temperature range. The 45 ns access time is faster than the original 85 ns specification, ensuring compatible operation in all applications designed for the 7164S85DB.

Parameter Comparison

Engineering Selection Recommendations

The 7164L45DB is the qualified substitute for the 7164S85DB based on the following engineering criteria:

• Functional Equivalence: Both devices are 64Kbit asynchronous SRAM ICs with identical memory organization, capacity, and parallel interface configuration.
• Pin Compatibility: Both parts use the 28-CDIP package with identical pinout, enabling direct socket replacement without circuit board modifications.
• Electrical Compatibility: Both devices operate within the same supply voltage range (4.5V ~ 5.5V) and temperature range (-55°C ~ 125°C), ensuring compatibility with existing power distribution and thermal management systems.
• Performance Enhancement: The 7164L45DB provides faster access and write cycle times (45 ns versus 85 ns), which improves system performance without introducing compatibility issues.
• Product Status: The 7164L45DB is classified as Active, ensuring continued availability and supply chain support compared to the obsolete 7164S85DB.
• Compliance: Both devices share identical RoHS status, REACH status, ECCN, and HTSUS classifications, maintaining regulatory compliance in replacement scenarios.

Frequently Asked Questions (FAQ)

Q: Can the 7164L45DB be used as a direct replacement for the 7164S85DB?

A: Yes. The 7164L45DB is a direct pin-compatible substitute. Both devices share identical memory capacity (64Kbit), organization (8K x 8), package type (28-CDIP), supply voltage range (4.5V ~ 5.5V), and operating temperature range (-55°C ~ 125°C). No circuit modifications are required.

Q: What is the difference between the 7164S85DB and 7164L45DB?

A: The primary difference is access time and write cycle time. The 7164S85DB has 85 ns timing, while the 7164L45DB has 45 ns timing. The faster timing of the 7164L45DB makes it suitable for all applications designed for the 7164S85DB. The 7164L45DB is also currently in active production, whereas the 7164S85DB is obsolete.

Q: Are there any package or pinout differences between these parts?

A: No. Both devices use the 28-CDIP package with identical pinout and through-hole mounting configuration. Direct socket replacement is possible without any board-level modifications.

Q: Will the faster access time of the 7164L45DB cause compatibility issues?

A: No. Faster access times are backward compatible. Systems designed for 85 ns operation will function correctly with 45 ns memory, as the memory responds more quickly than the circuit expects.

Q: What are the voltage and temperature specifications for both parts?

A: Both the 7164S85DB and 7164L45DB operate at 4.5V to 5.5V supply voltage and support an operating temperature range of -55°C to 125°C. These specifications are identical.

Q: Is the 7164L45DB available in the same packaging as the 7164S85DB?

A: Yes. The 7164L45DB is supplied in a 28-CDIP package identical to the 7164S85DB, with the same 0.600" (15.24mm) body width for through-hole PCB mounting.