IC RF SWITCH SPDT 42551-52 Equivalent & Substitute Parts

Part Overview

The 42551-52 is a general-purpose RF switch IC with SPDT (Single Pole Double Throw) topology manufactured by pSemi. This component operates across a frequency range of 9 kHz to 6 GHz with 50 Ohm impedance and is housed in a 20-QFN (4x4) surface mount package. The part is currently classified as obsolete, making identification of functionally compatible alternatives essential for ongoing system support and new design implementations.

Substiute Parts

42551-52

pSemiIn Stock: 87842551-52 Datasheet

Current PartRFQ

PE42553B-Z

pSemiIn Stock: 26780PE42553B-Z Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the 42551-52 is determined by the following critical parameters:

• Circuit Topology: SPDT configuration is mandatory for functional equivalence
• Impedance: 50 Ohm characteristic impedance must be maintained
• Frequency Coverage: The substitute must support the required operating frequency range
• Supply Voltage Compatibility: The substitute voltage range must accommodate the system design
• Package Compatibility: Physical dimensions and pin configuration must be compatible with the PCB layout
• Operating Temperature Range: Must meet or exceed the specified temperature limits

The PE42553B-Z qualifies as a substitute based on matching SPDT topology, 50 Ohm impedance, overlapping frequency coverage, compatible temperature range, and surface mount configuration. The substitute extends frequency capability to 8 GHz and offers improved electrical performance in isolation and IIP3 specifications.

Parameter Comparison

Engineering Selection Recommendations

The PE42553B-Z is an active product with current manufacturing support and ROHS3 compliance, providing regulatory advantage over the obsolete 42551-52. The substitute demonstrates superior electrical performance with 45 dB isolation versus 21 dB, lower insertion loss at 0.85 dB, and higher IIP3 rating of 66 dBm. The expanded supply voltage range of 2.3 V to 5.5 V provides greater design flexibility compared to the 2.5 V to 3 V specification of the original part.

Package transition from 20-QFN (4x4) to 16-QFN (3x3) requires PCB layout modification. The smaller footprint of the substitute may reduce board space requirements. Both parts maintain identical operating temperature specifications and 50 Ohm impedance, supporting direct functional replacement in RF switching applications within the 6 GHz operating band.

Frequently Asked Questions (FAQ)

Q: Can the PE42553B-Z directly replace the 42551-52 without circuit modifications?

A: Functional replacement is possible due to matching SPDT topology, 50 Ohm impedance, and overlapping frequency range. However, the package change from 20-QFN (4x4) to 16-QFN (3x3) requires PCB layout redesign. Pin configuration differences must be evaluated against the specific application schematic.

Q: What are the key electrical differences between these parts?

A: The PE42553B-Z offers improved isolation (45 dB versus 21 dB), lower insertion loss (0.85 dB versus 0.9 dB), and higher IIP3 performance (66 dBm versus 50 dBm). Frequency coverage extends to 8 GHz compared to 6 GHz for the 42551-52. Supply voltage range is broader at 2.3 V to 5.5 V.

Q: Is the PE42553B-Z suitable for applications requiring 6 GHz operation?

A: Yes. The PE42553B-Z supports the full 9 kHz to 6 GHz frequency range of the original part and extends capability to 8 GHz. Both parts maintain 50 Ohm impedance and SPDT topology required for RF switching at 6 GHz.

Q: What compliance advantages does the PE42553B-Z offer?

A: The PE42553B-Z is ROHS3 compliant and REACH unaffected, providing regulatory compliance for current manufacturing standards. The 42551-52 has vendor-undefined compliance status due to obsolete product classification.

Q: Are there supply voltage compatibility concerns?

A: The 42551-52 requires 2.5 V to 3 V supply. The PE42553B-Z accepts 2.3 V to 5.5 V. Systems designed for the original 2.5 V to 3 V range operate within the substitute's specification. Systems requiring higher supply voltages benefit from the expanded range of the substitute.

Q: How does the package size reduction affect implementation?

A: The transition from 20-QFN (4x4) to 16-QFN (3x3) reduces board footprint. PCB layout must be redesigned to accommodate the smaller package and different pin arrangement. Thermal management characteristics may differ due to package geometry changes.