FSA644UCX Equivalent & Substitute Parts

Part Overview

The FSA644UCX is a specialized interface integrated circuit manufactured by onsemi, designed for cell phone applications. This component is packaged in a 36-WLCSP (2.43x2.43mm) ball grid array format and operates across a supply voltage range of 1.65V to 4.5V. The FSA644UCX is currently classified as obsolete, making identification of functionally equivalent alternatives essential for ongoing system support, legacy device maintenance, and design continuity in applications where this component was originally specified.

Substiute Parts

FSA644UCX

onsemiIn Stock: 29103FSA644UCX Datasheet

Current PartRFQ

AD8174ARZ-RL

Analog Devices Inc.In Stock: 966AD8174ARZ-RL Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the FSA644UCX is constrained by its specialized interface function and compact 36-WLCSP package format. The primary substitute identified is the AD8174ARZ-RL, manufactured by Analog Devices Inc. This substitution is based on functional category alignment (both classified as Interface components) and shared compliance certifications (ROHS3 Compliant, REACH Unaffected, EAR99 classification). However, critical differences exist in package format, voltage supply specifications, and product status that must be evaluated during component selection.

Key parameters determining substitution feasibility:

• Functional category: Interface
• RoHS and REACH compliance status
• Mounting type: Surface Mount
• Supply voltage compatibility requirements
• Package physical and electrical compatibility

Parameter Comparison

Engineering Selection Recommendations

The AD8174ARZ-RL presents a functionally equivalent alternative to the obsolete FSA644UCX within the Interface component category. Both components maintain identical RoHS3 compliance, REACH unaffected status, and EAR99 export classification, ensuring regulatory continuity in applications requiring these certifications.

The AD8174ARZ-RL maintains active product status with current manufacturing availability (896 pcs in stock), providing supply chain reliability compared to the FSA644UCX obsolete classification. Both components feature unlimited moisture sensitivity level (MSL 1), eliminating moisture-related handling constraints during assembly and storage.

Critical design considerations include voltage supply specification differences: the FSA644UCX operates at 1.65V to 4.5V, while the AD8174ARZ-RL requires ±4V to 6V supply rails. Package format differs significantly, with the FSA644UCX utilizing a compact 36-WLCSP (2.43x2.43mm) ball grid array versus the AD8174ARZ-RL 14-SOIC (0.154", 3.90mm width) dual inline package. Application scope also differs, with the FSA644UCX specified for cell phone interfaces and the AD8174ARZ-RL designed for multiplexer with amplifier functions.

Frequently Asked Questions (FAQ)

Q: Can the AD8174ARZ-RL directly replace the FSA644UCX in existing designs?

A: Direct replacement requires evaluation of three critical factors: voltage supply compatibility (FSA644UCX operates 1.65V–4.5V; AD8174ARZ-RL requires ±4V–6V), package footprint differences (36-WLCSP versus 14-SOIC), and functional application alignment. Physical board layout modifications are necessary due to package format differences.

Q: What compliance certifications are maintained across both components?

A: Both the FSA644UCX and AD8174ARZ-RL maintain ROHS3 compliance, REACH unaffected status, and EAR99 export classification. Moisture sensitivity level is identical (MSL 1, unlimited), eliminating differential handling requirements.

Q: Why is the FSA644UCX classified as obsolete?

A: The FSA644UCX is designated obsolete by onsemi, indicating discontinued manufacturing and end-of-life status. The AD8174ARZ-RL maintains active product status with current manufacturing support.

Q: Are there package compatibility considerations for PCB assembly?

A: Yes. The FSA644UCX uses a 36-WLCSP ball grid array package (2.43x2.43mm footprint), while the AD8174ARZ-RL uses a 14-SOIC dual inline package (0.154" width, 3.90mm). These formats require different PCB land patterns, assembly processes, and board layout designs. Substitution necessitates complete footprint redesign.

Q: What supply voltage range must be verified before substitution?

A: The FSA644UCX operates within 1.65V to 4.5V single supply range. The AD8174ARZ-RL requires ±4V to 6V dual supply configuration. System power architecture must support the substitute component's voltage requirements.