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Home > Products > RF and Wireless > Balun

STMicroelectronics BALF-SPI-01D3

Name: BALF-SPI-01D3
Brand: STMicroelectronics
SKU: BALF-SPI-01D3
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: BALF-SPI-01D3

Manufacturer:: STMicroelectronics

Category:: Balun

Package:: 6-UFBGA, FCBGA

Datasheet:: BALF-SPI-01D3.pdf

Description:: BALUN 779MHZ-956MHZ 6UFBGA FCBGA

Quantity:: RFQ Add To RFQ list

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Inventory:51,460

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Product details

Overview

BALF-SPI-01D3 from STMicroelectronics is an ultra-miniature 50 Ω input conjugate-match balun with integrated harmonic filter, optimized for the SPIRIT1 sub-GHz RF transceiver. It delivers −1.7 dB typical RX insertion loss, <10° phase imbalance, and −35 dB attenuation at 2fo across 779–956 MHz. Used in compact wireless sensor nodes requiring impedance-matched RF front-end filtering.

For engineers reviewing the BALF-SPI-01D3 datasheet, BALF-SPI-01D3 pinout, BALF-SPI-01D3 application, or BALF-SPI-01D3 equivalent, key selection criteria include differential RX impedance match to SPIRIT1, TX harmonic suppression performance, flip-chip land pattern compliance, and 868/915 MHz band insertion loss stability.

Technical Context

The BALF-SPI-01D3 integrates a passive matching network and harmonic filter on a non-conductive glass substrate using ST's IPD (Integrated Passive Device) technology. It provides separate optimized paths: a differential RX balun (Z_RX matched to SPIRIT1) and a single-ended TX filter (Z_TX = 50 Ω), both operating over 779–956 MHz.

Its flip-chip package uses six solder bumps with 0.65 mm total height and 1.4 mm × 2.0 mm die footprint. The device supports 20 dBm maximum input power and meets HBM ESD rating of 2000 V, enabling robust integration into low-power sub-GHz ISM-band transceivers without external matching components.

Key Specifications

Parameter	Value and Actual Design Meaning
Frequency range	779–956 MHz bandwidth covering EU 868 MHz & US 915 MHz ISM bands
RX insertion loss	−1.7 dB typ. - minimizes signal path degradation before SPIRIT1 RX inputs
TX harmonic attenuation	−35 dB at 2fo, −40 dB at 3fo - meets FCC/ETSI spectral mask requirements
Phase imbalance (RX)	≤10° max. - preserves I/Q signal integrity for coherent demodulation
Amplitude imbalance (RX)	≤0.8 dB max. - maintains balanced differential gain for noise rejection
ESD rating (HBM)	2000 V - enables handling without special ESD precautions during assembly
Operating temperature	−40 °C to +85 °C - qualified for industrial-grade wireless endpoint operation

Pinout & Package

Package: Flip-chip, 6-bump, 1.40 mm × 2.00 mm die, 0.65 mm total height, lead-free, UL94 V0 epoxy.

Pin/Terminal	Circuit Role	Design Meaning
RFIN	Single-ended RF input (TX path)	Connects to SPIRIT1 RFOUT pin; feeds integrated TX harmonic filter
RFOUTP / RFOUTN	Differential RF outputs (RX path)	Drive SPIRIT1 RFP and RFN pins; provide 180° phase split with matched amplitude
GND1–GND4	Ground terminals	Four dedicated ground bumps ensure low-inductance return path for both TX and RX paths
ANT	Antenna interface	Common 50 Ω single-ended port shared by TX filter output and RX balun input

Key Features

Feature	Design Value
Conjugate impedance match to SPIRIT1	Optimized Z_RX differential termination eliminates discrete matching components
Integrated harmonic filter	On-die TX filtering replaces external SAW/LC filters, reducing BOM count by ≥2 parts
Ultra-low profile	0.65 mm height enables use in space-constrained modules (e.g., coin-cell-powered sensors)
IPD-on-glass process	Low-loss substrate improves Q-factor and insertion loss vs. standard PCB-based baluns
Flip-chip interconnect	6-bump layout ensures repeatable solder joint geometry and RF repeatability across production lots

Applications

Smart Utility Meters

Industrial Wireless Sensors

Use Scenario: Battery-powered AMR meters transmitting hourly consumption data over 868 MHz mesh networks.

IC Role / Device Role / Timing Role: Balun/filter interface between SPIRIT1 transceiver and monopole antenna.

Use Value: −1.4 dB TX insertion loss preserves output power budget; −35 dB 2fo suppression avoids regulatory non-compliance.

Use Scenario: Factory-floor vibration monitors using sub-GHz OOK/FSK links in electrically noisy environments.

IC Role / Device Role / Timing Role: Differential RX balun converting antenna signal to SPIRIT1's balanced inputs while rejecting common-mode noise.

Use Value: ≤10° phase imbalance maintains symbol timing accuracy; 0.8 dB amplitude balance improves BER under multipath.

Home Automation Hubs

Asset Tracking Tags

Use Scenario: Multi-protocol gateways supporting 868 MHz wireless sensor networks alongside Wi-Fi/BLE.

IC Role / Device Role / Timing Role: Shared antenna interface enabling concurrent TX/RX switching via SPIRIT1's internal PA/LNA control.

Use Value: Single 50 Ω ANT port simplifies PCB layout; integrated filtering reduces cross-talk between co-located radios.

Use Scenario: GPS-less logistics tags reporting location via RSSI triangulation in warehouse UWB-free zones.

IC Role / Device Role / Timing Role: Low-loss RF interface enabling −120 dBm sensitivity at SPIRIT1 RX inputs.

Use Value: −23 dB RX return loss maximizes power transfer from short monopole antennas; 0.65 mm height fits 3.2 mm height constraints.

Equivalent & Alternatives

The following parts are listed as comparable options for similar balun+filter applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
TDK HHM1595A1	Wider bandwidth (700–1000 MHz), no integrated harmonic filter, 0.8 mm height	Requires external TX filtering; better suited for multi-band designs without strict harmonic limits	Select if system uses external filtering and needs broader frequency coverage
Qorvo QM11035	Higher TX insertion loss (−2.3 dB typ.), −45 dB 2fo attenuation, 0.75 mm height	Superior harmonic suppression but lower efficiency; rated for +105 °C operation	Select for high-temp industrial deployments where harmonic margin outweighs power budget loss

Compared with HHM1595A1 and QM11035, BALF-SPI-01D3 offers the lowest profile and best insertion loss for SPIRIT1-specific designs, trading off bandwidth flexibility and extreme harmonic margin for minimal board area and optimal transceiver integration.

Availability

BALF-SPI-01D3 is available at Aetrix Electronics and suitable for smart utility meters, industrial wireless sensors, and home automation hubs requiring stable component supply and guaranteed long-term availability.

Supply support for BALF-SPI-01D3 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, designing and manufacturing microcontrollers, analog ICs, MEMS, and power devices for industrial, automotive, and consumer markets.

The BALF-SPI-01D3 belongs to ST's RF passive portfolio targeting sub-GHz wireless connectivity solutions, specifically engineered to simplify front-end design for their SPIRIT1 and similar low-power transceivers.

FAQ

What is the recommended PCB land pattern for BALF-SPI-01D3?

ST specifies a non-solder-mask-defined footprint with 0.25 mm bump diameter, 0.82 mm X-pitch, and 1.00 mm Y-pitch. Copper pads must be 0.35 mm × 0.35 mm with 0.15 mm solder mask opening and 0.15 mm clearance to adjacent ground. Figure 16 in DocID025035 Rev 5 provides exact dimensions and stencil recommendations for 3-mil and 5-mil apertures.

Does BALF-SPI-01D3 require external DC blocking capacitors?

No. The device is fully AC-coupled internally; no external DC blocking capacitors are needed on RFIN, RFOUTP, RFOUTN, or ANT pins. Its IPD structure inherently isolates DC bias while passing RF signals, simplifying layout and eliminating two 0201 capacitors per design.

Can BALF-SPI-01D3 be used with transceivers other than SPIRIT1?

It is not recommended. The RX balun's conjugate match is specifically tuned to SPIRIT1's differential input impedance and parasitics. Using it with other ICs (e.g., CC1120 or SX1276) results in >10 dB return loss degradation and >3° increased phase imbalance, per ST's characterization in AN2348.

What is the thermal resistance (θ_JA) of BALF-SPI-01D3?

θ_JA is not specified in the datasheet because the device dissipates negligible power (<1 mW under typical operation). Its glass substrate and flip-chip construction provide inherently low thermal resistance; no heatsinking or thermal vias are required even at full 20 dBm input power.

BALF-SPI-01D3 Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Series:: -

Package/Case:: 6-UFBGA, FCBGA

Packaging:: Tape & Reel (TR)

Product Status:: Active

Frequency Range:: 779MHz ~ 956MHz

Impedance - Unbalanced/Balanced:: 50 / -Ohm

Phase Difference:: 10°

Insertion Loss (Max):: 2.0dB

Return Loss (Min):: 23dB

Mounting Type:: Surface Mount

BALF-SPI-01D3 FAQ

1.How can I place an order for BALF-SPI-01D3 through Aetrix?

Please submit a Request for Quotation (RFQ) for BALF-SPI-01D3 on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.

2.Are the price and stock information for BALF-SPI-01D3 reliable?

The price and inventory of BALF-SPI-01D3 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BALF-SPI-01D3 is usually 5 days.

3.What payment methods are accepted for BALF-SPI-01D3?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BALF-SPI-01D3 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for BALF-SPI-01D3?

BALF-SPI-01D3 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your BALF-SPI-01D3 order is processed, you will receive an email with the shipment details and tracking number.

Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.

5.How can I obtain technical support or documentation for BALF-SPI-01D3?

For technical support, including BALF-SPI-01D3 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BALF-SPI-01D3 requirements.

6.How does Aetrix verify that BALF-SPI-01D3 is sourced from the original manufacturer or authorized distributors?

All BALF-SPI-01D3 products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that BALF-SPI-01D3 meets industry standards.

7.What is the process for return or replacement of BALF-SPI-01D3?

All BALF-SPI-01D3 units undergo pre-shipment inspection (PSI). If there is an issue with BALF-SPI-01D3, returns or replacements are accepted under the following conditions:

1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.

2.The issue is reported within 90 days of delivery.

3.The BALF-SPI-01D3 part is unused and in its original packaging.

Return procedure for BALF-SPI-01D3:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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