STMicroelectronics MLPF-WB55-02E3

Overview

MLPF-WB55-02E3 from STMicroelectronics is a 2.4 GHz bumpless CSP low-pass filter with integrated impedance matching network and harmonic rejection filter, optimized for the STM32WB55Vx Bluetooth 5/IEEE 802.15.4 system-on-chip. It delivers 1.2 dB typical insertion loss, 17 dB typical input return loss, 50 Ω antenna-side impedance, deep harmonic attenuation (≥43 dB at 2f₀), and operates across –40 °C to +105 °C.

For engineers reviewing the MLPF-WB55-02E3 datasheet, MLPF-WB55-02E3 pinout, MLPF-WB55-02E3 application, or MLPF-WB55-02E3 equivalent, this component enables RF front-end simplification in ultra-compact wireless modules requiring precise 56 Ω-to-50 Ω matching, ESD-hardened (2 kV HBM) operation, and ECOPACK2-compliant packaging under tight thickness constraints (≤450 µm).

Technical Context

This device implements a monolithic IPD (Integrated Passive Device) structure on non-conductive glass substrate, enabling high-Q passive filtering without discrete inductors/capacitors. Its 56 Ω input port matches the STM32WB55Vx RF output impedance, while the 50 Ω output port interfaces directly to standard 50 Ω antenna traces.

The filter provides band-selective suppression of 2nd–5th harmonics (4.8–12.5 GHz) with ≥43 dB attenuation, meeting regulatory spectral mask requirements for Bluetooth LE and Zigbee® transmitters. All five ground terminals (GND1–GND4) are electrically isolated but functionally common, supporting low-inductance RF grounding in dense PCB layouts.

Key Specifications

Pinout & Package

Bumpless CSP (Chip-Scale Package) with glass substrate, 5-pad layout, 1000 × 1600 µm die size, and 450 µm maximum overall thickness. Coated construction meets ECOPACK2 environmental compliance.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar RF front-end filter applications.

Compared with MLPF-WB55-02E3, the 01E3 variant misaligns impedance matching for WB55Vx use, while QPF4559 adds complexity and cost for applications where the SoC's integrated PA suffices - making MLPF-WB55-02E3 optimal for size-, cost-, and power-constrained BLE/Zigbee nodes.

Availability

MLPF-WB55-02E3 is available at Aetrix Electronics and suitable for Bluetooth 5 wireless sensor nodes, Zigbee® smart home hubs, and OpenThread border routers requiring stable component supply and guaranteed long-term lifecycle support.

Supply support for MLPF-WB55-02E3 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, designing and manufacturing microcontrollers, analog ICs, power management, and RF solutions for industrial, automotive, and consumer markets.

This part belongs to ST's RF IPD Filter product line, engineered specifically to simplify RF front-end design for STM32 Wireless MCUs by replacing discrete matching networks with monolithic, application-tuned passive filters.

FAQ

What is the recommended PCB stack-up for optimal RF performance?

ST specifies a 4-layer stack-up with 3.69 dielectric constant materials: Copper1 (62 µm)/Dielectric1 (82 µm)/Copper2 (41 µm)/Dielectric2 (1180 µm)/Copper3 (42 µm)/Dielectric3 (87 µm)/Copper4 (66 µm). Controlled-impedance traces - 56 Ω from SoC to IN and 50 Ω from OUT to antenna - must be maintained per layer-specific calculations.

Can MLPF-WB55-02E3 be used with other STM32WB series SoCs?

No - it is specifically tuned for the STM32WB55Vx family's 56 Ω RF output impedance and internal PA characteristics. Using it with WB55Rx (50 Ω output) or WB35xx (different biasing) results in ≥3 dB mismatch loss and degraded harmonic rejection.

Is reflow soldering compatible with the bumpless CSP package?

Yes - the device is qualified for standard lead-free reflow profiles (J-STD-20D, peak 260 °C). ST recommends 100 µm stencil thickness, halide-free ROL0 flux, and closed vias under pads to prevent solder voiding and tombstoning during reflow.

Does this filter require external DC blocking capacitors?

No - the IPD structure is inherently DC-coupled. Both IN and OUT ports pass DC bias required by the STM32WB55Vx PA; no series capacitors are needed, preserving signal integrity and saving board space.