NXP Semiconductors BF862,235

Overview

BF862,235 from NXP Semiconductors is a silicon N-channel symmetrical junction field-effect transistor (JFET) in SOT23 package, with drain-source voltage rating of 20 V, gate-source cut-off voltage of −0.3 to −1.2 V, drain-source current of 10–25 mA, transfer admittance of 35–45 mS, and transition frequency of 715 MHz - optimized for low-noise RF pre-amplification in AM car radio front-ends.

For engineers reviewing the BF862,235 datasheet, BF862,235 pinout, BF862,235 application, or BF862,235 equivalent, key selection criteria include its high f_T, ultra-low noise (0.8 nV/√Hz at 100 kHz), symmetrical source/drain interchangeability, SOT23 thermal resistance (200 K/W), and gate-forward voltage limit of 1 V - all critical for sensitive analog RF signal chain design.

Technical Context

The BF862,235 operates as a depletion-mode N-channel JFET with symmetrical source and drain terminals, enabling flexible layout in common-source or common-gate configurations. Its high y_fs and low C_iss (10 pF) support wideband amplification up to UHF frequencies.

Thermal management relies primarily on conduction through the gate lead (R_{th j–s} = 200 K/W), and maximum junction temperature is rated at 150 °C. Gate leakage is tightly controlled (I_GSS ≤ −1 nA at V_GS = −15 V), ensuring stable bias in high-impedance gain stages.

Key Specifications

Pinout & Package

Package: SOT23 (TO-236AB), plastic surface-mounted, 3-lead package with 1.9 mm × 1.3 mm footprint and 1.1 mm height. Main heat transfer occurs via the gate lead.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar low-noise JFET amplifier applications.

Compared with 2SK208-4-TB-E and J310, the BF862,235 delivers superior RF performance in AM front-ends due to its 715 MHz f_T, 0.8 nV/√Hz noise, and SOT23 thermal efficiency - making it the preferred choice where miniaturization, low-noise gain, and UHF stability are jointly required.

Availability

BF862,235 is available at Aetrix Electronics and suitable for AM radio front-end preamplifiers, low-noise IF amplifier stages, and high-impedance sensor interfaces requiring stable component supply, consistent parametric distribution, and long-term obsolescence mitigation.

Supply support for BF862,235 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 delivering high-performance mixed-signal and standard products, with leadership in RF, analog, power management, and interface technologies.

The BF862,235 belongs to NXP's discrete RF JFET product line, engineered specifically for low-noise, high-frequency amplification in consumer broadcast receivers - emphasizing noise performance, gain consistency, and SMT manufacturability.

FAQ

What is the maximum drain-source voltage rating for BF862,235?

The BF862,235 has a maximum drain-source voltage (V_DS) rating of 20 V, as specified in the Absolute Maximum Ratings table. This value defines the upper limit for DC or peak RF voltage applied between drain and source under any operating condition. Exceeding this rating risks permanent device failure. The BF862,235 is not rated for automotive or industrial high-voltage applications beyond this threshold.

Does BF862,235 support interchangeable source and drain connections?

Yes, the BF862,235 is a symmetrical N-channel junction FET, meaning its source and drain terminals are physically and electrically interchangeable. This feature is explicitly stated in the device description and allows flexible PCB layout in common-source, common-gate, or source-follower configurations without polarity constraints - a key advantage over asymmetrical MOSFETs or bipolar transistors.

What is the typical input noise voltage of BF862,235 and at what frequency is it measured?

The BF862,235 has a typical equivalent input noise voltage (e_n) of 0.8 nV/√Hz, measured at 100 kHz under standard conditions (T_j = 25 °C, V_GS = 0 V, V_DS = 8 V). This low noise performance is critical for AM radio front-end applications where preserving weak-signal integrity dominates system-level noise figure requirements.

What thermal resistance specification applies to BF862,235 and how is it defined?

The BF862,235 has a thermal resistance from junction to soldering point (R_{th j–s}) of 200 K/W, with heat transfer occurring primarily through the gate lead. This parameter is defined with the soldering point located at the gate terminal (note 1 in Thermal Characteristics), and it governs safe power dissipation - e.g., at 300 mW, junction temperature rise above solder point is 60 K.

Is BF862,235 qualified for automotive applications per AEC-Q101?

No, the BF862,235 is not automotive-qualified. Per NXP's disclaimers in the datasheet, unless explicitly stated, the device is not tested or warranted for automotive use. It lacks AEC-Q101 qualification, temperature cycling validation, and extended reliability testing required for under-hood deployment. For automotive AM radio modules, designers must perform independent qualification or select an AEC-Q101-compliant alternative.