RN42APL-I/RM545 Equivalent & Substitute Parts

Part Overview

The RN42APL-I/RM545 is a Bluetooth v2.1 + EDR Class 2 transceiver module manufactured by Microchip Technology, designed for 2.4GHz RF applications with PCB trace antenna integration. This surface mount module operates across a supply voltage range of 3V to 3.6V and delivers 3Mbps data rate with 4dBm output power and -86dBm sensitivity.

The RN42APL-I/RM545 carries an Obsolete product status. Locating equivalent or substitute components is necessary to support ongoing system maintenance, design updates, or production continuity when original inventory becomes unavailable.

Substiute Parts

RN42APL-I/RM545

Microchip TechnologyIn Stock: 1115RN42APL-I/RM545 Datasheet

Current PartRFQ

RN4678APL-V/RM122

Microchip TechnologyIn Stock: 2087RN4678APL-V/RM122 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the RN42APL-I/RM545 is evaluated based on the following critical parameters:

RF Compatibility: Both the main part and substitute operate within the 2.4GHz Bluetooth frequency band, ensuring RF compatibility within the same application domain.

Mounting Technology: Both components utilize surface mount technology, maintaining compatibility with existing PCB assembly processes.

Serial Interface Capability: The substitute part supports UART, which is present in the main part's interface set, enabling communication protocol compatibility.

Supply Voltage Overlap: The substitute operates at 3.3V to 4.2V, which encompasses the main part's 3V to 3.6V range, allowing operation within compatible power supply specifications.

Bluetooth Protocol Evolution: The substitute implements Bluetooth v5.0, a forward-compatible evolution of the main part's Bluetooth v2.1 + EDR specification, supporting legacy device communication while enabling enhanced features.

The RN4678APL-V/RM122 qualifies as a substitute based on these shared functional and physical parameters.

Parameter Comparison

Engineering Selection Recommendations

Product Status Consideration: The RN42APL-I/RM545 is classified as Obsolete, making the RN4678APL-V/RM122 the appropriate selection for new designs or production continuity. The substitute carries Active product status with manufacturer support and availability.

Compliance and Certification: The RN4678APL-V/RM122 is RoHS3 Compliant and carries REACH Unaffected status, meeting current regulatory requirements for electronic components in regulated markets. The main part's ECCN classification as Obsolete reflects its discontinued status.

Supply Chain Availability: Current inventory of the RN4678APL-V/RM122 is documented at 2002 pieces, ensuring component availability for production and maintenance applications.

Functional Capability: The substitute provides enhanced sensitivity (-92dBm versus -86dBm) and supports Bluetooth v5.0 protocol, offering improved performance characteristics while maintaining backward compatibility with Bluetooth v2.1 + EDR devices.

Frequently Asked Questions (FAQ)

Q: Can the RN4678APL-V/RM122 directly replace the RN42APL-I/RM545 in existing designs?

A: Direct replacement requires evaluation of three factors: (1) Serial interface requirements—the substitute supports UART only, whereas the main part supports both SPI and UART; (2) Antenna integration—the substitute uses an integrated chip antenna instead of PCB trace, requiring PCB layout modifications; (3) Operating temperature range—the substitute operates to 70°C maximum versus 85°C for the main part, which may affect applications in high-temperature environments.

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

A: The RN4678APL-V/RM122 operates at 3.3V to 4.2V supply voltage compared to the main part's 3V to 3.6V range. Output power is reduced from 4dBm to 1.5dBm, and data rate decreases from 3Mbps to 1Mbps. Sensitivity improves to -92dBm from -86dBm. Current consumption is specified for the substitute (37mA receiving, 43mA transmitting) but not provided for the main part.

Q: How do the package differences affect PCB integration?

A: The main part uses a 35-SMD Module package, while the substitute uses a 33-SMD Module package. These are distinct physical packages requiring different PCB footprints and assembly considerations. PCB layout redesign is necessary for substitution.

Q: Is the Bluetooth protocol difference significant for compatibility?

A: The RN4678APL-V/RM122 implements Bluetooth v5.0, which maintains backward compatibility with Bluetooth v2.1 + EDR devices. Legacy devices will communicate with the v5.0 module using the older protocol version. New designs can leverage v5.0 features for enhanced range and data throughput.

Q: What is the impact of antenna type change?

A: The main part uses an external PCB trace antenna requiring specific PCB layout design. The substitute integrates the antenna on the chip, eliminating external antenna design requirements but potentially affecting RF performance characteristics and PCB space allocation.