AS7C256A-12TIN Equivalent & Substitute Parts

Part Overview

The AS7C256A-12TIN is a 256Kbit asynchronous SRAM manufactured by Alliance Memory, Inc., configured as 32K x 8 with parallel interface and 12 ns access time. This component operates across the industrial temperature range of -40°C to 85°C and is housed in a 28-TSSOP package. The part maintains Active product status and holds ROHS3 compliance with REACH unaffected classification.

Substitute parts become necessary when the primary part experiences supply constraints, inventory depletion, or when design requirements permit operation at different access times within the same memory architecture. All substitute candidates maintain identical memory organization, package form factor, and voltage specifications.

Substiute Parts

AS7C256A-12TIN

Alliance Memory, Inc.In Stock: 995AS7C256A-12TIN Datasheet

Current PartRFQ

AS7C256A-10TIN

Alliance Memory, Inc.In Stock: 1314AS7C256A-10TIN Datasheet

MFR RecommendedRFQ

AS7C256A-15TIN

Alliance Memory, Inc.In Stock: 1753AS7C256A-15TIN Datasheet

MFR RecommendedRFQ

71V256SA15PZGI

Renesas Electronics CorporationIn Stock: 541471V256SA15PZGI Datasheet

MFR RecommendedRFQ

IS61C256AL-12TLI

ISSI, Integrated Silicon Solution IncIn Stock: 4529IS61C256AL-12TLI Datasheet

MFR RecommendedRFQ

IS62C256AL-45TLI

ISSI, Integrated Silicon Solution IncIn Stock: 16845IS62C256AL-45TLI Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the AS7C256A-12TIN is determined by the following criteria:

Primary Compatibility Requirements:

• Memory Size: 256Kbit (fixed)
• Memory Organization: 32K x 8 (fixed)
• Memory Interface: Parallel (fixed)
• Package / Case: 28-TSSOP (fixed)
• Voltage Supply Range: 4.5V ~ 5.5V (fixed)
• Operating Temperature: -40°C ~ 85°C (fixed)
• Mounting Type: Surface Mount (fixed)

Variable Parameter:

• Access Time: Parts with equal or faster access times (≤12 ns) are direct substitutes. Parts with slower access times (>12 ns) are functional substitutes where timing margins permit.

The substitute parts are grouped into two categories:

Category 1 - Faster or Equal Access Time (Direct Substitutes):

• AS7C256A-10TIN (10 ns) - Alliance Memory
• IS61C256AL-12TLI (12 ns) - ISSI

Category 2 - Slower Access Time (Functional Substitutes):

• AS7C256A-15TIN (15 ns) - Alliance Memory
• 71V256SA15PZGI (15 ns) - Renesas Electronics (Obsolete status)
• IS62C256AL-45TLI (45 ns) - ISSI

Parameter Comparison

Engineering Selection Recommendations

AS7C256A-10TIN - Recommended as primary substitute. Manufactured by Alliance Memory with Active product status. Faster 10 ns access time provides timing margin improvement over the original 12 ns specification. Maintains identical voltage supply range, temperature operating range, and package configuration. ROHS3 compliant with equivalent MSL rating.

IS61C256AL-12TLI - Recommended as secondary substitute. Manufactured by ISSI with Active product status. Matches the original 12 ns access time specification exactly. Maintains all electrical and mechanical compatibility parameters. ROHS3 compliant with equivalent MSL rating. Provides alternative sourcing from established memory manufacturer.

AS7C256A-15TIN - Acceptable substitute where timing analysis confirms system tolerance for 15 ns access time. Manufactured by Alliance Memory with Active product status. Slower access time requires verification that design margins accommodate the 3 ns increase. ROHS3 compliant with equivalent MSL rating.

IS62C256AL-45TLI - Acceptable substitute only where system design permits 45 ns access time operation. Manufactured by ISSI with Active product status. Significant access time increase requires comprehensive timing validation. ROHS3 compliant with equivalent MSL rating.

71V256SA15PZGI - Not recommended for new designs. Renesas Electronics part carries Obsolete product status. Voltage supply range differs (3V ~ 3.6V versus 4.5V ~ 5.5V), creating incompatibility with the original circuit design. Obsolete classification indicates discontinued manufacturing and limited future availability.

Frequently Asked Questions (FAQ)

Q: Can AS7C256A-10TIN replace AS7C256A-12TIN directly without circuit modification?

A: Yes. The AS7C256A-10TIN provides faster access time (10 ns versus 12 ns) while maintaining identical voltage supply range (4.5V ~ 5.5V), temperature operating range (-40°C ~ 85°C), memory organization (32K x 8), and 28-TSSOP package configuration. Faster access time improves timing margins without requiring design changes.

Q: What is the impact of using IS62C256AL-45TLI with its 45 ns access time?

A: The 45 ns access time represents a 33 ns increase from the original 12 ns specification. This substitution requires comprehensive timing analysis of the system design to confirm that all memory access cycles, bus timing, and dependent logic operations remain within acceptable margins. Circuit-level validation is mandatory before implementation.

Q: Why is 71V256SA15PZGI listed as incompatible?

A: The 71V256SA15PZGI operates at 3V ~ 3.6V supply voltage, while the AS7C256A-12TIN requires 4.5V ~ 5.5V. This voltage incompatibility prevents direct substitution without additional power supply circuitry. Additionally, Renesas has classified this part as Obsolete, indicating discontinued production and unavailable future supply.

Q: Are all substitute parts available in the same 28-TSSOP package?

A: Yes. All listed substitute parts use the 28-TSSOP (0.465", 11.80mm Width) package configuration, ensuring identical PCB footprint and mounting compatibility. No layout modifications are required for package-compatible substitutes.

Q: Which substitute offers the best long-term availability?

A: AS7C256A-10TIN and IS61C256AL-12TLI both carry Active product status from established manufacturers (Alliance Memory and ISSI respectively), indicating ongoing production and supply continuity. Both parts are preferred for designs requiring long-term component availability.

Q: Do all substitutes maintain ROHS3 compliance?

A: Yes. All substitute parts listed carry ROHS3 Compliant status with Moisture Sensitivity Level 3 (168 Hours), matching the original AS7C256A-12TIN compliance profile. REACH status remains unaffected across all candidates.