NXP Semiconductors BF420,116

Overview

BF420,116 from NXP Semiconductors is an NPN high-voltage transistor in a TO-92 (SC-43A/SOT54) plastic through-hole package, rated for 300 V collector-base and collector-emitter voltage, 830 mW power dissipation at 25 °C ambient, and 1.6 pF feedback capacitance - used in class-B video output stages of colour television and professional monitor equipment.

For engineers reviewing the BF420,116 datasheet, BF420,116 pinout, BF420,116 application, or BF420,116 equivalent, this discrete NPN transistor supports high-voltage switching with low capacitive coupling, stable DC gain (h_FE ≥ 50 at 25 mA), and thermal resistance of 150 K/W - critical for video amplifier stability and EMI-sensitive analog signal paths.

Technical Context

The BF420,116 operates as a high-voltage NPN switching and amplification device with fixed three-terminal topology (base-collector-emitter), optimized for linear video output stages where low feedback capacitance (≤1.6 pF) minimizes signal distortion and oscillation risk at RF frequencies up to 60 MHz transition frequency (f_T).

Its absolute maximum ratings include 300 V V_CBO/V_CEO, 100 mA peak collector current, and 150 °C junction temperature, with thermal performance defined for PCB-mounted operation (R_th(j-a) = 150 K/W), and DC gain specified at V_CE = 20 V and I_C = 25 mA.

Key Specifications

Pinout & Package

BF420,116 is housed in a plastic single-ended leaded (through-hole) TO-92 package, designated SC-43A and SOT54, with 3 leads and standardized mechanical dimensions per IEC/JEDEC outlines.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar NPN high-voltage transistor applications.

Compared with BF422,116 and BC639,116, the BF420,116 uniquely delivers 300 V capability in a legacy-compatible TO-92 footprint - essential for maintaining reliability in high-slew-rate CRT deflection while avoiding redesign of PCB layout or thermal management.

Availability

BF420,116 is available at Aetrix Electronics and suitable for colour television repair, professional monitor refurbishment, and legacy analog video system maintenance requiring stable component supply and long-term obsolescence mitigation.

Supply support for BF420,116 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 high-reliability analog, RF, and mixed-signal components for industrial, automotive, and consumer electronics.

The BF420,116 belongs to NXP's legacy discrete transistor product line, engineered specifically for high-voltage analog video applications including CRT-based television and monitor deflection circuitry.

FAQ

What is the maximum collector-emitter voltage rating for BF420,116?

The BF420,116 has a maximum collector-emitter voltage (V_CEO) rating of 300 V under open-base conditions. This rating is validated per IEC 60134 limiting values and applies to continuous DC or peak repetitive operation in class-B video output stages. Exceeding this voltage risks irreversible junction breakdown. The BF420,116 must not be substituted with lower-rated alternatives like BF422,116 (250 V) in circuits where flyback transients approach 300 V.

Is BF420,116 compatible with TO-92 socket footprints?

Yes, BF420,116 uses the standard TO-92 outline (SC-43A / SOT54) with 2.54 mm lead pitch and defined mechanical dimensions per IEC/JEDEC. Its pin 1–2–3 assignment (base–collector–emitter) matches conventional TO-92 orientation, enabling direct insertion into legacy sockets designed for devices such as BC547 or 2N3904 - provided voltage and power ratings are verified for the target application.

What is the typical transition frequency (f_T) of BF420,116 and how does it affect video performance?

The BF420,116 has a minimum transition frequency (f_T) of 60 MHz at V_CE = 10 V and I_C = 10 mA. This provides substantial bandwidth margin over standard analog video bandwidths (e.g., 4.2–5.5 MHz for PAL/NTSC), ensuring minimal phase shift and amplitude roll-off in baseband video amplification - critical for preserving edge sharpness and chroma delay matching in CRT display systems using the BF420,116.

Does BF420,116 have a PNP complement, and if so, what is it?

Yes, the PNP complement to BF420,116 is BF421,116. Both share identical voltage ratings (300 V V_CBO/V_CEO), package (TO-92), and thermal characteristics. BF421,116 is explicitly listed in the same NXP datasheet as the complementary device, enabling push-pull or differential video output configurations where matched high-voltage gain and capacitance are required alongside the BF420,116.

How is thermal performance specified for BF420,116 in real-world PCB mounting?

BF420,116 specifies a junction-to-ambient thermal resistance (R_th(j-a)) of 150 K/W when mounted on a standard printed-circuit board, per note 1 in the NXP datasheet. This value assumes no added heatsinking and reflects conduction through leads and convection from the plastic body. At 830 mW total dissipation, this yields a theoretical 124.5 K rise above ambient - confirming the need for conservative derating above 25 °C ambient, especially in enclosed CRT chassis where airflow is restricted.