LC4256B-5FTN256AI Equivalent & Substitute Parts

Part Overview

The LC4256B-5FTN256AI is a Complex Programmable Logic Device (CPLD) from Lattice Semiconductor Corporation's ispMACH® 4000B series. This embedded integrated circuit features 256 macrocells, 128 I/O pins, and a maximum propagation delay of 5 nanoseconds in a 256-pin fine-pitch ball grid array package. The device is classified as obsolete, making identification of compatible substitute parts essential for ongoing system support and component procurement.

Substiute Parts

LC4256B-5FTN256AI

Lattice Semiconductor CorporationIn Stock: 965LC4256B-5FTN256AI Datasheet

Current PartRFQ

LC4256V-5FTN256AC

Lattice Semiconductor CorporationIn Stock: 1482LC4256V-5FTN256AC Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the LC4256B-5FTN256AI is determined by the following critical parameters that must remain consistent:

• Macrocell Count: 256 macrocells (functional logic capacity)
• I/O Pin Count: 128 I/O pins (interface capability)
• Propagation Delay: 5 ns maximum (timing performance)
• Package Type: 256-LBGA (17x17) (physical and electrical compatibility)
• Programmable Architecture: In System Programmable (programming methodology)

The LC4256V-5FTN256AC from the ispMACH® 4000V series meets these core functional and physical requirements. Differences in voltage supply ranges and operating temperature specifications do not affect the fundamental substitution relationship when the application environment is compatible with the substitute part's ratings.

Parameter Comparison

Engineering Selection Recommendations

The LC4256V-5FTN256AC is the primary substitute for the obsolete LC4256B-5FTN256AI. Selection of this substitute is supported by:

• Active Product Status: The LC4256V-5FTN256AC maintains active production status, ensuring long-term availability and supply chain continuity.
• Regulatory Compliance: The substitute part carries ROHS3 compliance certification, meeting current environmental and material restriction requirements.
• Functional Equivalence: Both devices maintain identical macrocell count (256), I/O pin count (128), and maximum propagation delay (5 ns), ensuring logic capacity and timing performance parity.
• Package Compatibility: Both parts use the 256-FTBGA (17x17) package, maintaining physical and electrical interface compatibility.

Design integration requires verification that the substitute part's voltage supply range (3V ~ 3.6V) and operating temperature range (0°C ~ 90°C) align with the target application's power delivery and thermal environment specifications.

Frequently Asked Questions (FAQ)

Q: Can the LC4256V-5FTN256AC directly replace the LC4256B-5FTN256AI in existing designs?

A: Direct replacement is possible when the application's power supply voltage and operating temperature environment are compatible with the LC4256V-5FTN256AC specifications. The substitute operates at 3V ~ 3.6V internal supply voltage and 0°C ~ 90°C operating temperature, compared to the original part's 2.3V ~ 2.7V and -40°C ~ 105°C range. Verify these parameters against your system design requirements.

Q: Are the package dimensions identical between these two parts?

A: Yes. Both the LC4256B-5FTN256AI and LC4256V-5FTN256AC use the 256-FTBGA (17x17) package format, ensuring identical physical footprint and pin layout compatibility on printed circuit boards.

Q: What is the significance of the different series designations (4000B vs. 4000V)?

A: The series designation indicates the voltage class of the device. The 4000B series operates at lower voltage (2.3V ~ 2.7V), while the 4000V series operates at standard voltage (3V ~ 3.6V). Both series maintain the same logic architecture, macrocell count, and I/O configuration, making them functionally equivalent within their respective voltage domains.

Q: Why is the LC4256B-5FTN256AI classified as obsolete?

A: Obsolete status indicates that the manufacturer has discontinued production and support for this part. The LC4256V-5FTN256AC represents the active production equivalent, ensuring continued availability and manufacturer support for new designs and system maintenance.

Q: Does the substitute part support in-system programming like the original?

A: Yes. The LC4256V-5FTN256AC maintains in-system programmable functionality, identical to the LC4256B-5FTN256AI. Programming methodology and toolchain compatibility remain consistent across both devices.

Q: What is the moisture sensitivity level, and does it differ between parts?

A: Both parts carry MSL 3 (168 Hours) rating, indicating identical moisture sensitivity classification. Storage and handling requirements are equivalent for both devices.