USB50805C-A/TR7 Equivalent & Substitute Parts

Part Overview

The USB50805C-A/TR7 is a bidirectional transient voltage suppressor (TVS) diode manufactured by Microchip Technology, designed for protection in Ethernet applications. This surface-mount component operates with a 5V reverse standoff voltage and provides 13V clamping at peak pulse current. The device is classified as Active product status and is RoHS non-compliant.

Substitute parts are identified when equivalent electrical performance can be achieved within the specified parameter tolerances for the application, maintaining compatibility with the 8-SOIC package footprint and surface-mount assembly requirements.

Substiute Parts

USB50805C-A/TR7

Microchip TechnologyIn Stock: 981USB50805C-A/TR7 Datasheet

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SMDA05C.TBT

Semtech CorporationIn Stock: 8161SMDA05C.TBT Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the USB50805C-A/TR7 is determined by the following critical parameters:

Voltage Compatibility: The reverse standoff voltage (5V typical) and breakdown voltage minimum (6V) establish the primary protection threshold. Substitute parts must maintain these voltage specifications to ensure proper circuit protection without nuisance triggering.

Clamping Voltage: The maximum clamping voltage of 13V at peak pulse current defines the upper voltage limit during transient suppression. Substitute parts with lower clamping voltages provide enhanced protection; higher clamping voltages remain acceptable if within application tolerance.

Peak Pulse Current: The 5A peak pulse current (8/20µs) specification indicates the transient energy handling capability. Substitute parts with equal or higher current ratings maintain or exceed protection performance.

Package Footprint: The 8-SOIC package with 0.154" width (3.90mm) is mandatory for PCB assembly compatibility. All substitute parts must use identical package geometry.

Bidirectional Channels: The 2-channel configuration provides dual-line protection. Substitute parts with 2 or more channels are acceptable.

Operating Temperature: The -55°C to 150°C range defines thermal operating limits. Substitute parts must support this range or a subset that includes the application's operating environment.

Parameter Comparison

Engineering Selection Recommendations

SMDA05C.TBT (Semtech Corporation) qualifies as a functional substitute for the USB50805C-A/TR7 based on the following engineering criteria:

Voltage Parameters: Both devices maintain identical reverse standoff (5V) and breakdown (6V) specifications. The SMDA05C.TBT provides superior clamping performance at 11V compared to the 13V maximum of the USB50805C-A/TR7, resulting in lower transient voltage stress on protected circuitry.

Current Handling: The SMDA05C.TBT peak pulse current rating of 17A exceeds the USB50805C-A/TR7 specification of 5A, providing enhanced transient energy absorption capability.

Package Compatibility: Both devices use identical 8-SOIC packaging (0.154", 3.90mm width), ensuring direct PCB footprint compatibility without layout modifications.

Compliance Status: The SMDA05C.TBT is ROHS3 compliant, whereas the USB50805C-A/TR7 is RoHS non-compliant. This represents an improvement in environmental and regulatory compliance for new designs.

Temperature Derating: The SMDA05C.TBT maximum operating temperature of 125°C is 25°C lower than the USB50805C-A/TR7 specification of 150°C. Applications requiring operation above 125°C require the original part.

Capacitance Consideration: The SMDA05C.TBT exhibits significantly higher capacitance (350pF @ 1MHz) compared to the USB50805C-A/TR7 (3pF @ 1MHz). High-frequency applications sensitive to capacitive loading require evaluation of this parameter.

Frequently Asked Questions (FAQ)

Q: Can the SMDA05C.TBT directly replace the USB50805C-A/TR7 in existing designs?

A: Direct PCB footprint replacement is possible due to identical 8-SOIC packaging. However, the higher capacitance of the SMDA05C.TBT (350pF vs. 3pF) may affect high-frequency circuit performance. The lower maximum operating temperature (125°C vs. 150°C) requires verification against application thermal requirements. Functional testing is necessary to confirm performance in the specific circuit context.

Q: What are the key differences in transient protection performance?

A: The SMDA05C.TBT provides lower clamping voltage (11V vs. 13V), resulting in superior transient suppression. The higher peak pulse current rating (17A vs. 5A) indicates greater energy dissipation capability. The lower peak pulse power rating (300W vs. 500W) represents a reduced margin for sustained transient events.

Q: Are there compliance implications for substitution?

A: The SMDA05C.TBT is ROHS3 compliant, whereas the USB50805C-A/TR7 is RoHS non-compliant. New designs or products subject to RoHS regulations should prioritize the SMDA05C.TBT. Existing designs using the USB50805C-A/TR7 may continue operation without regulatory impact unless product refresh or regional market requirements mandate compliance updates.

Q: How does the capacitance difference affect circuit design?

A: The SMDA05C.TBT capacitance of 350pF is substantially higher than the USB50805C-A/TR7 at 3pF. In high-frequency applications (above 100MHz), this capacitive loading may introduce signal attenuation or impedance mismatches. Low-frequency or DC-biased protection circuits are unaffected by this parameter difference.

Q: What is the impact of the 25°C temperature rating reduction?

A: The SMDA05C.TBT maximum junction temperature of 125°C is 25°C lower than the USB50805C-A/TR7 at 150°C. Applications with ambient temperatures exceeding 100°C or sustained high-power transient events requiring operation near maximum ratings should retain the original USB50805C-A/TR7 specification.

Q: Are the 2-channel and 4-channel configurations interchangeable?

A: Both devices provide bidirectional protection on separate channels. The SMDA05C.TBT with 4 channels offers additional protection lines compared to the 2-channel USB50805C-A/TR7. In applications using only 2 protection lines, the extra channels remain unused but do not degrade performance. Multi-line protection applications benefit from the additional channels.