NXP Semiconductors BF1108R,215

Overview

BF1108R,215 from NXP Semiconductors is a silicon RF switch combining a depletion-mode MOSFET and integrated band-switching diode in an SOT143R package. It delivers ≤2 dB on-state insertion loss and ≥30 dB off-state isolation up to 1 GHz, with 12 Ω typical R_DS(on), −3 V gate-source pinch-off voltage, and ESD-sensitive handling. It enables low-loss signal routing in VCR tuner loop-through and transceiver switching paths.

For engineers reviewing the BF1108R,215 datasheet, BF1108R,215 pinout, BF1108R,215 application, or BF1108R,215 equivalent, this page provides verified RF switching parameters, SOT143R terminal mapping, real-world use cases in analog RF front-ends, and validated alternative parts for design continuity and sourcing flexibility.

Technical Context

The BF1108R,215 integrates a depletion-type FET with a series-connected switching diode-cathode tied to the FET gate-to isolate the gate from ground during operation, minimizing parasitic capacitance and insertion loss. Its dual-device architecture enables fast, low-loss RF path control without external bias networks.

Static characteristics include −3 V to −4 V V_GS(p), 12–20 Ω R_DS(on), and 7 V V_(BR)GSS; dynamic performance is specified at 50 Ω system impedance with V_SK/V_DK = 0 V (on) or 5 V (off), supporting reliable RF switching up to 1 GHz under standard test conditions.

Key Specifications

Pinout & Package

SOT143R plastic surface-mounted package (4 leads, reverse pinning); dimensions: 3.0 × 1.4 × 1.1 mm (L × W × H), thermal resistance R_th(j-sp) = 250 K/W.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar RF switching applications.

Compared with BF1108,215 and PE42510-Z, the BF1108R,215 offers identical RF performance in a reverse-pin SOT143R package-enabling layout reuse in space-constrained tuner modules-while avoiding the bias complexity and cost premium of GaAs alternatives.

Availability

BF1108R,215 is available at Aetrix Electronics and suitable for VCR tuner loop-through, transceiver antenna switching, and FM radio front-end applications requiring stable component supply, consistent RF performance, and long-term obsolescence management.

Supply support for BF1108R,215 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

NXP Semiconductors is a global semiconductor company headquartered in Eindhoven, Netherlands, specializing in secure connectivity solutions for automotive, industrial, and consumer electronics.

The BF1108R,215 belongs to NXP's legacy silicon RF switch product line, designed specifically for cost-sensitive, analog-dominant RF signal routing in consumer video and communication equipment operating below 1 GHz.

FAQ

What is the maximum operating frequency of the BF1108R,215?

The BF1108R,215 is characterized for RF switching up to 1 GHz, with guaranteed on-state insertion loss ≤2 dB and off-state isolation ≥30 dB at frequencies ≤1 GHz under 50 Ω test conditions. Performance degrades above 1 GHz due to parasitic capacitance and package limitations, so it is not recommended for use beyond its specified frequency range.

How does the BF1108R,215 differ from the BF1108,215?

The BF1108R,215 and BF1108,215 share identical electrical specifications, thermal characteristics, and RF performance. Their sole difference is mechanical: BF1108R,215 uses SOT143R (reverse pinning), while BF1108,215 uses SOT143B (standard pinning). Pin 1–4 assignments are mirrored, requiring separate PCB footprints despite functional equivalence.

What bias voltage is required to turn off the BF1108R,215?

To turn off the BF1108R,215, apply +5 V to both V_SK and V_DK (Pins 2 and 2, respectively - shared cathode connection), forward-biasing the integrated diode and pulling the gate to ~+4.3 V relative to source/drain. This drives the depletion FET into cutoff, achieving ≥30 dB isolation. No negative bias is needed.

Is the BF1108R,215 suitable for bidirectional RF signal routing?

Yes-the BF1108R,215 supports bidirectional RF conduction because its drain and source terminals are interchangeable per datasheet specification. This allows flexible placement in RF paths where signal direction may vary, such as in transceiver T/R switching or loop-through configurations without polarity constraints.

Does the BF1108R,215 require external ESD protection?

No-external ESD protection is not required. The BF1108R,215 integrates internal gate-source and gate-drain diodes that clamp transient voltages, and it is rated for Class 1B ESD sensitivity (per JEDEC JS-001). However, proper handling procedures-including grounded workstations and ionized air-must still be followed during assembly to prevent damage.