LC4256C-75FT256AI Equivalent & Substitute Parts

Part Overview

The LC4256C-75FT256AI is a Complex Programmable Logic Device (CPLD) from Lattice Semiconductor's ispMACH® 4000C series, featuring 256 macrocells and 128 I/O pins in a 256-FTBGA package. This device is classified as obsolete, making identification of suitable substitute components essential for ongoing system support and new design implementations.

The ispMACH® 4000C series operates with internal voltage supply between 1.65V and 1.95V and delivers a maximum propagation delay of 7.5 nanoseconds. With 16 logic element blocks and in-system programmability, this CPLD serves embedded applications requiring moderate logic density and fast switching performance.

Substiute Parts

LC4256C-75FT256AI

Lattice Semiconductor CorporationIn Stock: 1492LC4256C-75FT256AI Datasheet

Current PartRFQ

LC4256V-75FTN256AC

Lattice SemiconductorIn Stock: 743LC4256V-75FTN256AC Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the LC4256C-75FT256AI is determined by strict alignment of the following critical parameters:

Mandatory Matching Parameters:

• Number of Macrocells: 256
• Number of I/O: 128
• Delay Time tpd(1) Max: 7.5 ns
• Package / Case: 256-LBGA
• Supplier Device Package: 256-FTBGA (17x17)
• Mounting Type: Surface Mount
• Number of Logic Elements/Blocks: 16
• Programmable Type: In System Programmable

Allowable Variation Parameters:

• Voltage Supply - Internal: May differ based on application requirements
• Operating Temperature Range: May differ based on application requirements
• Product Status: Active substitutes are preferred for obsolete devices
• RoHS Compliance: May improve in substitute parts

The LC4256V-75FTN256AC qualifies as a direct substitute based on matching all mandatory parameters while offering improved product status and compliance characteristics.

Parameter Comparison

Engineering Selection Recommendations

The LC4256V-75FTN256AC is the qualified substitute for the obsolete LC4256C-75FT256AI. Both devices share identical logic architecture, I/O count, and timing specifications, ensuring functional equivalence at the circuit level.

Key Considerations:

The primary difference lies in voltage supply requirements. The LC4256C operates at 1.65V–1.95V internal supply, while the LC4256V requires 3V–3.6V. System designs must accommodate this voltage differential through appropriate power supply configuration and interface circuitry.

The LC4256V operates across a narrower temperature range (0°C–90°C) compared to the LC4256C (-40°C–105°C). Applications requiring extended temperature operation below 0°C or above 90°C must evaluate thermal requirements against the substitute's specifications.

The LC4256V holds active product status with ROHS3 compliance, providing advantages for new designs and long-term supply chain stability. The LC4256C is obsolete and non-compliant with current RoHS standards.

Both devices maintain identical MSL ratings, REACH status, ECCN classification, and HTSUS codes, ensuring regulatory and logistics compatibility.

Frequently Asked Questions (FAQ)

Q: Can the LC4256V-75FTN256AC directly replace the LC4256C-75FT256AI in existing designs?

A: Functional replacement is possible due to matching macrocell count, I/O configuration, and timing specifications. However, the voltage supply difference (1.65V–1.95V versus 3V–3.6V) requires circuit redesign to accommodate the higher supply voltage of the LC4256V. Direct socket substitution without power supply modification is not feasible.

Q: What are the critical parameters that define substitution eligibility?

A: Substitution eligibility is determined by matching macrocell count (256), I/O pin count (128), maximum propagation delay (7.5 ns), package type (256-FTBGA 17x17), and programmable architecture (in-system programmable). These parameters ensure functional and physical compatibility.

Q: Are there temperature range limitations when using the LC4256V substitute?

A: Yes. The LC4256V operates from 0°C to 90°C, which is narrower than the LC4256C range of -40°C to 105°C. Applications requiring operation below 0°C or above 90°C must evaluate whether the substitute meets thermal specifications or if alternative solutions are necessary.

Q: Does the LC4256V meet current compliance standards?

A: The LC4256V is ROHS3 compliant and maintains REACH unaffected status, meeting current regulatory requirements. The obsolete LC4256C is RoHS non-compliant, making the LC4256V preferable for new designs and regulated applications.

Q: Are the package dimensions and pin configurations identical?

A: Yes. Both devices use the 256-FTBGA (17x17) package with identical physical dimensions and pin layout, ensuring mechanical compatibility on printed circuit boards.