BF1108R,235

Overview

The BF1108R,235 is a silicon RF switch combining a depletion-type FET and a band-switching diode in an SOT143R package. It provides low insertion loss of up to 2 dB and high off-state isolation of at least 30 dB up to 1 GHz. Key electrical parameters include a drain-source on-state resistance of 12 Ω typical, gate-source pinch-off voltage of -4 V typical, and input/output capacitance of 0.65 pF typical. The device features integrated protection diodes between gate-source and gate-drain terminals.

Feature Summary

• Combines a depletion-type FET with a band-switching diode for optimized RF switching performance
• Provides low signal loss and high isolation capabilities across the operational frequency range
• Includes integrated protection diodes between gate-source and gate-drain to prevent excessive voltage surges

Applications

• Passive loop through circuits for VCR tuners
• Transceiver switching applications

Procurement Notes

Verify the specific ordering suffix matches the required package variant. Confirm that the component status aligns with current production requirements. Ensure handling procedures account for ElectroStatic Discharge sensitivity during transport and assembly. Cross-reference the marking code NHp to validate the physical unit received against the ordered specification.

Selection Notes

Select this component when designing circuits requiring low-loss RF switching up to 1 GHz. The SOT143R package suits surface-mount layouts with reverse pinning configurations. Consider the integrated diode structure for simplified biasing networks. Evaluate the static and dynamic characteristics against system impedance requirements to ensure optimal signal integrity.

Part Context

This part belongs to NXP's silicon RF switch portfolio, designed for general-purpose radio frequency applications. It utilizes a combination of field-effect transistor technology and band-switching diodes to achieve efficient signal routing. The product line supports various consumer electronics and communication equipment designs requiring reliable RF path control.

Replacement Considerations

BF1108 serves as a direct functional equivalent utilizing the SOT143B package with standard pinning. Verify pin compatibility if substituting into existing PCB footprints designed for the reverse-pinning SOT143R variant.

FAQ

How does the integrated diode affect the MOSFET gate?

The integrated diode isolates the MOSFET gate from ground, which contributes to achieving lower signal losses during operation.

What protection mechanisms are included in the BF1108R?

Integrated diodes are placed between the gate-source and gate-drain terminals to protect the device against excessive input voltage surges.

Are the drain and source pins interchangeable?

Yes, the pinning information confirms that the drain and source connections are interchangeable for this device.