AT27BV256-15JC Equivalent & Substitute Parts

Part Overview

The AT27BV256-15JC is a 256Kbit EPROM (Erasable Programmable Read-Only Memory) manufactured by Microchip Technology in a 32-PLCC package. This part operates with a 150 ns access time and supports dual voltage supplies (2.7V–3.6V and 4.5V–5.5V). The device is classified as obsolete, which necessitates identification of functionally equivalent alternatives for ongoing system support and new designs requiring this memory architecture.

Substiute Parts

AT27BV256-15JC

Microchip TechnologyIn Stock: 767AT27BV256-15JC Datasheet

Current PartRFQ

AT27BV256-70JU

Microchip TechnologyIn Stock: 1277AT27BV256-70JU Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the AT27BV256-15JC is determined by strict equivalence in the following parameters:

• Memory capacity (256Kbit) and organization (32K x 8)
• Memory interface type (Parallel)
• Package form factor (32-PLCC with identical physical dimensions)
• Voltage supply compatibility (2.7V–3.6V and 4.5V–5.5V ranges)
• Base product number (AT27BV256)

The AT27BV256-70JU qualifies as a direct substitute because it maintains identical memory specifications, package geometry, and voltage requirements. Differences in access time (70 ns versus 150 ns) and operating temperature range represent performance enhancements rather than incompatibilities. The substitute part operates faster and across a wider temperature range, making it suitable for applications originally designed for the AT27BV256-15JC.

Parameter Comparison

Engineering Selection Recommendations

The AT27BV256-70JU is the appropriate substitute for the AT27BV256-15JC based on the following factors:

The substitute part maintains active product status with Microchip Technology, ensuring continued availability and manufacturing support. The AT27BV256-70JU achieves ROHS3 compliance, whereas the original part does not, making the substitute suitable for applications subject to environmental regulations. The faster access time (70 ns) and extended operating temperature range (−40°C to 85°C) provide performance margins beyond the original specification without introducing incompatibility. Both parts share identical memory capacity, organization, interface architecture, voltage requirements, and physical package dimensions, enabling direct socket replacement in existing designs.

Frequently Asked Questions (FAQ)

Q: Can the AT27BV256-70JU replace the AT27BV256-15JC in existing circuit designs?

A: Yes. Both parts are functionally equivalent in memory capacity (256Kbit), organization (32K x 8), parallel interface, voltage supply ranges (2.7V–3.6V and 4.5V–5.5V), and 32-PLCC package geometry. The substitute operates at faster speed (70 ns access time) and across a wider temperature range, making it compatible with all applications designed for the original part.

Q: What is the significance of the access time difference between these parts?

A: The AT27BV256-15JC specifies 150 ns access time, while the AT27BV256-70JU specifies 70 ns. Faster access time in the substitute part represents improved performance. Systems designed for 150 ns operation will function correctly with the 70 ns part, as the substitute meets or exceeds all timing requirements of the original specification.

Q: Are there packaging differences between these parts?

A: No. Both parts use the 32-PLCC (J-Lead) package with identical physical dimensions (13.97 × 11.43 mm). The AT27BV256-15JC is supplied in standard packaging, while the AT27BV256-70JU is supplied in tube packaging. Both are surface-mount devices suitable for the same PCB assembly processes.

Q: What is the impact of RoHS compliance differences?

A: The AT27BV256-15JC is RoHS non-compliant, while the AT27BV256-70JU is ROHS3 compliant. For applications subject to environmental regulations or customer requirements mandating RoHS compliance, the substitute part satisfies these requirements. For legacy systems without such constraints, both parts are functionally interchangeable.

Q: Why is the original part listed as obsolete?

A: The AT27BV256-15JC is classified as obsolete by Microchip Technology. The AT27BV256-70JU remains in active production, ensuring long-term availability for new designs and system maintenance. Substitution to the active part provides supply chain continuity and access to current manufacturing support.