AT28BV256-20PI Equivalent & Substitute Parts

Part Overview

The AT28BV256-20PI is a 256Kbit parallel EEPROM memory IC manufactured by Microchip Technology, housed in a 28-DIP package with 200 ns access time. This component is classified as obsolete, which necessitates identification of functionally equivalent alternatives for ongoing system support and new designs. The part operates across a supply voltage range of 2.7V to 3.6V and supports operating temperatures from -40°C to 85°C.

Substiute Parts

AT28BV256-20PI

Microchip TechnologyIn Stock: 1292AT28BV256-20PI Datasheet

Current PartRFQ

AT28BV256-20SU

Microchip TechnologyIn Stock: 1000302AT28BV256-20SU Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the AT28BV256-20PI is determined by electrical and functional equivalence across the following critical parameters:

• Memory capacity (256Kbit) and organization (32K x 8)
• Parallel interface architecture
• Access time specification (200 ns)
• Write cycle time (10 ms)
• Supply voltage range (2.7V ~ 3.6V)
• Operating temperature range (-40°C ~ 85°C)
• Base product number (AT28BV256)

The AT28BV256-20SU maintains identical electrical specifications and functional performance. The primary difference is packaging: the substitute uses 28-SOIC surface-mount technology instead of 28-DIP through-hole mounting. This substitution is valid for applications where surface-mount assembly is compatible with the target system design.

Parameter Comparison

Engineering Selection Recommendations

The AT28BV256-20SU is the direct functional equivalent for the obsolete AT28BV256-20PI. Selection between these parts depends on system-level design constraints:

For through-hole PCB designs requiring DIP packaging, the AT28BV256-20PI remains available in inventory (1210 units) despite obsolete status. However, this part does not meet ROHS3 compliance requirements.

For new designs or systems undergoing modernization, the AT28BV256-20SU is the preferred selection. This part is in active production status with substantial inventory availability (1,000,199 units), meets ROHS3 compliance standards, and maintains identical electrical performance and memory specifications. The surface-mount 28-SOIC package requires compatible PCB layout and assembly processes.

Both parts share identical memory capacity, interface architecture, timing specifications, and voltage/temperature operating ranges, ensuring functional interchangeability at the component level when packaging constraints are satisfied.

Frequently Asked Questions (FAQ)

Q: Can AT28BV256-20SU replace AT28BV256-20PI in existing designs?

A: Electrical and functional replacement is direct. Physical replacement requires PCB redesign to accommodate the 28-SOIC surface-mount package instead of 28-DIP through-hole mounting. Pin-to-pin functionality is identical.

Q: What is the primary difference between these parts?

A: The parts are electrically identical. The AT28BV256-20PI uses through-hole DIP packaging; the AT28BV256-20SU uses surface-mount SOIC packaging. Both provide 256Kbit parallel EEPROM with 200 ns access time.

Q: Does the substitute part meet RoHS compliance?

A: Yes. The AT28BV256-20SU is ROHS3 compliant. The original AT28BV256-20PI is RoHS non-compliant. This is a significant advantage for new designs subject to RoHS requirements.

Q: Are there any timing or performance differences?

A: No. Both parts specify identical access time (200 ns), write cycle time (10 ms), supply voltage range (2.7V ~ 3.6V), and operating temperature range (-40°C ~ 85°C).

Q: What is the MSL difference, and does it matter?

A: The AT28BV256-20PI has MSL 1 (unlimited shelf life); the AT28BV256-20SU has MSL 3 (168-hour limit after moisture exposure). For surface-mount components, MSL 3 is standard and does not present practical constraints when proper storage and handling procedures are followed.

Q: Why is the original part listed as obsolete?

A: The AT28BV256-20PI is obsolete due to market transition toward surface-mount technology and RoHS-compliant components. The AT28BV256-20SU represents the current production equivalent.