WT41U-E-AI4C Equivalent & Substitute Parts

Part Overview

The WT41U-E-AI4C is a Bluetooth v2.1 +EDR Class 1 transceiver module manufactured by Silicon Labs, designed for RF transmission and reception applications requiring external antenna connectivity via U.FL connector. The module operates at 18dBm output power with -96.5dBm sensitivity and supports multiple serial interfaces including UART, SPI, GPIO, and USB. The product is classified as Obsolete, necessitating identification of functionally compatible alternatives for ongoing system design and production requirements.

Substiute Parts

WT41U-E-AI4C

Silicon LabsIn Stock: 1239WT41U-E-AI4C Datasheet

Current PartRFQ

BT122-A-V2

Silicon LabsIn Stock: 1065BT122-A-V2 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the WT41U-E-AI4C is determined by the following critical parameters:

RF Compatibility Parameters:

• Bluetooth protocol support (minimum v2.1 +EDR or higher version)
• RF Family/Standard classification (Bluetooth)
• Operating frequency band alignment (2.4GHz ISM band)
• Output power and sensitivity specifications suitable for Class 1 operation

Electrical Interface Parameters:

• Supply voltage range compatibility (3V ~ 3.6V nominal operation)
• Serial interface availability (UART, GPIO minimum requirement)
• Current consumption specifications for receiving and transmitting modes

Physical & Mechanical Parameters:

• Surface Mount packaging format
• Operating temperature range (-40°C ~ 85°C)
• Module form factor and connector type

Regulatory & Compliance Parameters:

• ECCN classification (5A992C)
• HTSUS code (8517.62.0090)

The BT122-A-V2 qualifies as a substitute based on shared RF family (Bluetooth), surface mount technology, compatible operating temperature range, overlapping supply voltage specifications, and identical regulatory classifications.

Parameter Comparison

Engineering Selection Recommendations

Product Status Consideration: The WT41U-E-AI4C is classified as Obsolete, indicating discontinued manufacturing and limited availability. The BT122-A-V2 maintains Active product status with current manufacturing support and documented inventory availability.

Regulatory Compliance: Both parts share identical ECCN (5A992C) and HTSUS (8517.62.0090) classifications, ensuring equivalent regulatory treatment for export and tariff purposes.

Compliance Certifications: The BT122-A-V2 provides documented RoHS3 compliance and REACH unaffected status, offering enhanced environmental and chemical compliance documentation compared to the obsolete WT41U-E-AI4C.

Protocol Advancement: The BT122-A-V2 implements Bluetooth v4.2 +EDR, representing a protocol generation advancement from the v2.1 +EDR specification of the WT41U-E-AI4C. This upgrade provides enhanced backward compatibility and extended feature support within the Bluetooth ecosystem.

Design Integration Factors: Selection between these parts requires evaluation of specific design requirements regarding antenna implementation (external U.FL versus integrated trace), serial interface requirements (USB/SPI availability on WT41U-E-AI4C versus I2C/ADC on BT122-A-V2), and output power specifications (18dBm versus 11dBm).

Frequently Asked Questions (FAQ)

Q: Can the BT122-A-V2 directly replace the WT41U-E-AI4C in existing designs?

A: Direct replacement requires design modification. The BT122-A-V2 uses an integrated trace antenna instead of the external U.FL connector found on the WT41U-E-AI4C. Additionally, the serial interface set differs: the BT122-A-V2 provides I2C and ADC but lacks USB and SPI interfaces present on the WT41U-E-AI4C. PCB layout and firmware interface code require adjustment.

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

A: The WT41U-E-AI4C operates at 18dBm output power with -96.5dBm sensitivity, while the BT122-A-V2 provides 11dBm output power with -95dBm sensitivity. The BT122-A-V2 supports a lower supply voltage floor (2.2V minimum versus 3V minimum), expanding operational flexibility in power-constrained applications. Current consumption specifications are not provided for the BT122-A-V2.

Q: Are these modules compatible with the same Bluetooth devices?

A: Both modules operate within the 2.4GHz ISM band and support Bluetooth protocols. The WT41U-E-AI4C implements Bluetooth v2.1 +EDR Class 1, while the BT122-A-V2 implements Bluetooth v4.2 +EDR. Bluetooth v4.2 maintains backward compatibility with earlier versions, enabling communication with legacy Bluetooth v2.1 devices.

Q: What packaging differences exist between these modules?

A: The WT41U-E-AI4C uses a 59-SMD Module package, while the BT122-A-V2 uses a 20-SMD Module package. The BT122-A-V2 represents a more compact form factor. Both employ surface mount technology suitable for automated assembly processes.

Q: How do the antenna specifications affect system design?

A: The WT41U-E-AI4C requires external antenna selection and integration via U.FL connector, providing design flexibility for antenna optimization. The BT122-A-V2 incorporates an integrated trace antenna, eliminating external antenna components but reducing antenna design customization options.

Q: What is the significance of the Obsolete product status?

A: Obsolete status indicates the WT41U-E-AI4C is no longer manufactured. Existing inventory may be available through component distributors, but long-term supply cannot be guaranteed. The BT122-A-V2 maintains Active status with ongoing manufacturing support and predictable availability.