49FCT805ASOG Equivalent & Substitute Parts

Part Overview

The 49FCT805ASOG is a Clock Fanout Buffer (Distribution) IC manufactured by Renesas Electronics Corporation, configured as a 1:5 clock distribution device in a 20-SOIC package. This component is classified as obsolete, making identification of suitable substitute parts essential for ongoing system support and new design implementations. The 49FCT805ASOG provides CMOS and LVTTL input/output compatibility with a 4.75V to 5.25V supply voltage range, designed for applications requiring single-input to multiple-output clock distribution in legacy systems.

Substiute Parts

49FCT805ASOG

Renesas Electronics CorporationIn Stock: 290649FCT805ASOG Datasheet

Current PartRFQ

8L30210NLGI

Renesas Electronics CorporationIn Stock: 9638L30210NLGI Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the 49FCT805ASOG requires evaluation of the following critical parameters that define functional equivalence:

Input/Output Configuration: The main part operates as a 1:5 fanout buffer with 2 circuits. Substitute parts must provide equivalent or greater distribution capability (input:output ratio) to maintain clock distribution functionality.

Logic Level Compatibility: The 49FCT805ASOG accepts CMOS and LVTTL inputs and produces CMOS and LVTTL outputs. Substitute parts must support at minimum LVTTL input and output to ensure signal compatibility with existing system interfaces.

Supply Voltage Range: Operating at 4.75V to 5.25V (5V nominal), the main part requires substitutes capable of functioning within this voltage specification or a compatible overlapping range.

Package and Mounting: Surface mount 20-SOIC packaging is the physical constraint. Substitutes may use alternative surface mount packages if board layout permits, but must maintain compatible pin counts and signal routing.

Temperature Range: Operating from 0°C to 70°C, substitutes must support this industrial temperature range or an extended range that encompasses it.

Product Status and Compliance: As an obsolete part, substitutes should preferably be active products with current manufacturing support. RoHS3 compliance and REACH unaffected status are required for regulatory alignment.

Parameter Comparison

Engineering Selection Recommendations

The 8L30210NLGI is identified as a manufacturer-recommended substitute for the 49FCT805ASOG. This substitution is based on functional clock distribution capability and regulatory compliance alignment.

Product Status Advantage: The 8L30210NLGI holds active product status with current manufacturing support from Renesas Electronics Corporation, providing long-term availability and supply chain stability compared to the obsolete 49FCT805ASOG.

Compliance Alignment: Both parts maintain ROHS3 compliance and REACH unaffected status, ensuring regulatory requirements are met in the substitution.

Functional Considerations: The 8L30210NLGI provides a 3:10 input:output ratio compared to the 1:5 ratio of the main part, offering greater distribution capability. The substitute supports LVTTL input and output, maintaining compatibility with the main part's logic levels. The substitute operates across a 1.4V to 3.465V supply range, which does not overlap with the 49FCT805ASOG's 4.75V to 5.25V specification. This voltage incompatibility requires circuit redesign or alternative power supply architecture.

Package Transition: The shift from 20-SOIC to 32-VFQFN (5x5) represents a package change requiring PCB layout modification. The increased pin count and different footprint necessitate board redesign.

Temperature Range: The 8L30210NLGI supports -40°C to 85°C operation, exceeding the 0°C to 70°C range of the main part and providing extended environmental capability.

Frequently Asked Questions (FAQ)

Q: Can the 8L30210NLGI directly replace the 49FCT805ASOG without circuit modification?

A: Direct pin-for-pin replacement is not possible. The 8L30210NLGI uses a 32-VFQFN package versus the 20-SOIC package of the 49FCT805ASOG, requiring PCB layout redesign. Additionally, the supply voltage range differs significantly (1.4V–3.465V versus 4.75V–5.25V), necessitating power supply circuit changes.

Q: What are the key differences in clock distribution capability?

A: The 49FCT805ASOG provides a 1:5 fanout ratio with 2 circuits, while the 8L30210NLGI offers a 3:10 fanout ratio with 1 circuit. The substitute provides greater total output distribution (10 outputs versus 5 outputs) but consolidates this into a single circuit rather than two independent circuits.

Q: Are the logic levels compatible between these parts?

A: Both parts support LVTTL input and output, ensuring logic level compatibility. The 8L30210NLGI additionally supports HCSL, LVCMOS, LVDS, LVPECL, and Crystal inputs, providing greater input flexibility than the main part.

Q: What is the impact of the different package types?

A: The 20-SOIC package is a dual-in-line surface mount format, while the 32-VFQFN is a fine-pitch quad flat no-lead package. The VFQFN package is smaller and denser but requires more precise PCB layout and assembly processes. Existing board designs cannot accommodate this package change without redesign.

Q: Does the 8L30210NLGI support the same operating temperature range?

A: No. The 8L30210NLGI operates from -40°C to 85°C, which exceeds the 0°C to 70°C range of the 49FCT805ASOG. For applications requiring only 0°C to 70°C operation, the substitute provides additional temperature margin.

Q: What is the moisture sensitivity difference between these parts?

A: The 49FCT805ASOG has MSL 1 (unlimited moisture exposure tolerance), while the 8L30210NLGI has MSL 3 (168-hour moisture exposure limit). The substitute requires more stringent moisture control during storage and handling.

Q: Is the 8L30210NLGI the only available substitute?

A: Based on the provided manufacturer recommendation, the 8L30210NLGI is the identified substitute. Alternative clock buffer or fanout buffer devices from other manufacturers may exist but are not included in this reference.