Renesas Electronics 508MLFT Clock Generator IC Equivalent & Substitute Parts

Part Overview

The Renesas Electronics 508MLFT is a Clock Generator IC operating at 250MHz maximum frequency, housed in an 8-SOIC (0.154", 3.90mm Width) surface mount package. This device features PECL input and CMOS output with a 1:1 input-to-output ratio and operates across a supply voltage range of 2.375V to 5.5V. The 508MLFT is classified as obsolete, making identification of functionally compatible substitute components essential for ongoing system support and new design implementations.

Substiute Parts

508MLFT

Renesas Electronics CorporationIn Stock: 1081508MLFT Datasheet

Current PartRFQ

8T73S1802NLGI8

Renesas Electronics CorporationIn Stock: 11068T73S1802NLGI8 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the 508MLFT requires evaluation based on the following critical parameters:

• Functional Type: Clock generation or clock distribution capability
• Frequency Range: Maximum operating frequency must meet or exceed 250MHz
• Input/Output Signal Compatibility: PECL input and CMOS output support
• Supply Voltage Range: Overlap with 2.375V ~ 5.5V operating window
• Package Compatibility: Surface mount form factor suitable for 8-SOIC footprint applications
• Product Status: Active or current production status preferred for long-term availability

The Renesas Electronics 8T73S1802NLGI8 is identified as a manufacturer-recommended substitute. While this device functions as a clock fanout buffer with distribution and divider capabilities rather than a pure clock generator, it provides compatible signal conditioning for PECL-based clock distribution networks. The 8T73S1802NLGI8 operates at frequencies up to 1GHz, exceeding the 250MHz requirement of the 508MLFT, and maintains PECL output compatibility.

Parameter Comparison

Engineering Selection Recommendations

The 508MLFT is classified as obsolete, necessitating substitution for new production and ongoing system support. The 8T73S1802NLGI8 is an active product from the same manufacturer, ensuring continued availability and supply chain stability.

Key considerations for substitution:

• Supply Voltage Constraint: The 8T73S1802NLGI8 operates within a narrower supply voltage range (2.375V ~ 3.465V) compared to the 508MLFT (2.375V ~ 5.5V). System designs operating above 3.465V require voltage regulation or alternative substitutes.
• Package Footprint Change: Substitution requires PCB layout modification, as the 8T73S1802NLGI8 uses a 16-VFQFN package versus the 8-SOIC package of the 508MLFT.
• Operating Temperature Range: The 8T73S1802NLGI8 extends the lower operating temperature to -40°C, providing broader environmental coverage than the 508MLFT.
• Compliance Status: Both devices maintain REACH Unaffected status and EAR99 ECCN classification, ensuring regulatory consistency.

Frequently Asked Questions (FAQ)

Q: Can the 8T73S1802NLGI8 directly replace the 508MLFT without circuit modifications?

A: Direct pin-for-pin replacement is not possible due to package differences (8-SOIC versus 16-VFQFN). PCB layout redesign is required. Additionally, the 8T73S1802NLGI8 functions as a fanout buffer with divider capability rather than a clock generator, requiring circuit topology evaluation.

Q: What is the maximum frequency capability of the 8T73S1802NLGI8 compared to the 508MLFT?

A: The 8T73S1802NLGI8 operates at frequencies up to 1GHz, significantly exceeding the 250MHz maximum of the 508MLFT. This provides frequency headroom for future design enhancements.

Q: Are there supply voltage compatibility issues when substituting?

A: Yes. The 8T73S1802NLGI8 maximum supply voltage is 3.465V, while the 508MLFT supports up to 5.5V. Systems designed for higher supply voltages require voltage regulation or alternative substitutes.

Q: What packaging considerations apply to this substitution?

A: The 8T73S1802NLGI8 uses a 16-pin VFQFN package with exposed pad, compared to the 8-pin SOIC package of the 508MLFT. This requires PCB redesign, including trace routing and thermal management evaluation for the exposed pad.

Q: Does the 8T73S1802NLGI8 support PECL input and CMOS output like the 508MLFT?

A: The 8T73S1802NLGI8 supports LVPECL input (compatible with PECL signaling) and offers both LVCMOS and LVPECL output options, providing signal compatibility with the 508MLFT architecture.

Q: What is the moisture sensitivity level difference between these devices?

A: The 508MLFT has MSL 1 (Unlimited), while the 8T73S1802NLGI8 has MSL 3 (168 Hours). The substitute requires more stringent moisture control during storage and handling.