RN42HCI-I/RM Equivalent & Substitute Parts

Part Overview

The RN42HCI-I/RM is a Bluetooth v2.1 +EDR Class 2 transceiver module manufactured by Microchip Technology, designed for 2.4GHz wireless communication applications. This module features an integrated trace antenna and operates across a supply voltage range of 3V to 3.6V with a maximum transmit current of 30mA. The product is classified as obsolete, necessitating identification of active alternative components for new designs and ongoing production requirements.

Substiute Parts

RN42HCI-I/RM

Microchip TechnologyIn Stock: 1476RN42HCI-I/RM Datasheet

Current PartRFQ

RN4678-V/RM122

Microchip TechnologyIn Stock: 1149RN4678-V/RM122 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the RN42HCI-I/RM is determined by the following critical parameters:

RF Compatibility: Both the main part and substitute must operate in the 2.4GHz Bluetooth frequency band with UART serial interface support.

Voltage Supply Range: The substitute must accommodate the system voltage requirements. The RN42HCI-I/RM operates at 3V to 3.6V; substitutes with overlapping or compatible supply ranges are acceptable.

Mounting and Package: Both components utilize surface mount technology with integrated antenna solutions, ensuring mechanical and electrical compatibility in existing PCB layouts.

Protocol Compatibility: While the RN42HCI-I/RM implements Bluetooth v2.1 +EDR, substitutes with newer Bluetooth protocols (v5.0) maintain backward compatibility and offer enhanced performance characteristics.

Environmental and Compliance Requirements: Both components must meet ROHS3 compliance and operate within acceptable temperature ranges for the target application.

The RN4678-V/RM122 qualifies as a direct substitute based on these parameters, offering improved performance metrics while maintaining functional compatibility.

Parameter Comparison

Engineering Selection Recommendations

The RN4678-V/RM122 is the manufacturer-recommended substitute for the obsolete RN42HCI-I/RM. Both components are ROHS3 compliant and manufactured by Microchip Technology, ensuring regulatory alignment and supply chain continuity.

The RN4678-V/RM122 maintains UART serial interface compatibility and operates within the 2.4GHz Bluetooth frequency band. The substitute offers improved receiver sensitivity (-92dBm versus -80dBm) and higher data rate capability (1Mbps versus 300kbps), supporting modern Bluetooth v5.0 protocol implementation.

Design considerations include voltage supply range adjustment from 3V–3.6V to 3.3V–4.2V and operating temperature range modification from -40°C–85°C to -20°C–70°C. The substitute exhibits higher transmit current (43mA versus 30mA) and features an integrated chip antenna rather than trace antenna, requiring PCB layout evaluation for antenna performance validation.

The RN4678-V/RM122 demonstrates superior moisture sensitivity characteristics (MSL 1 versus MSL 3), reducing handling and storage constraints during manufacturing and logistics operations.

Frequently Asked Questions (FAQ)

Q: Can the RN4678-V/RM122 directly replace the RN42HCI-I/RM in existing designs?

A: The RN4678-V/RM122 provides functional substitution with UART interface compatibility and 2.4GHz Bluetooth operation. Design modifications are required to accommodate the expanded voltage supply range (3.3V–4.2V), modified operating temperature range (-20°C–70°C), and increased transmit current (43mA). PCB layout adjustment may be necessary due to antenna type differences (chip versus trace).

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

A: The RN4678-V/RM122 operates at higher data rates (1Mbps versus 300kbps), provides improved receiver sensitivity (-92dBm versus -80dBm), and implements Bluetooth v5.0 protocol versus v2.1 +EDR. Transmit current increases from 30mA to 43mA. Supply voltage range expands from 3V–3.6V to 3.3V–4.2V.

Q: Are there packaging or mounting differences?

A: Both components utilize surface mount technology. The RN42HCI-I/RM employs a module package with integrated trace antenna, while the RN4678-V/RM122 uses a 33-SMD module package with integrated chip antenna. PCB footprint and antenna placement require verification during design transition.

Q: What compliance certifications apply to both components?

A: Both the RN42HCI-I/RM and RN4678-V/RM122 are ROHS3 compliant and REACH unaffected. Both carry ECCN classification 5A992C. The RN4678-V/RM122 demonstrates improved moisture sensitivity handling with MSL 1 rating versus MSL 3 for the original component.

Q: What is the impact of the operating temperature range difference?

A: The RN42HCI-I/RM operates from -40°C to 85°C, while the RN4678-V/RM122 operates from -20°C to 70°C. Applications requiring operation below -20°C or above 70°C must evaluate alternative solutions or implement thermal management strategies to maintain the substitute within specified operating limits.