Nexperia USA Inc. BF820,235

Overview

BF820 from Nexperia is an NPN high-voltage transistor in SOT23 package, rated for 300 V collector-base and collector-emitter voltage, 50 mA DC collector current, and 60 MHz transition frequency. It serves as a high-voltage switching or amplification device in telephony line interface circuits where compact size and voltage robustness are critical.

For engineers reviewing the BF820 datasheet, BF820 pinout, BF820 application, or BF820 equivalent, key selection criteria include its 300 V breakdown rating, SOT23 footprint compatibility, low leakage (≤10 nA ICBO at 200 V), hFE ≥50 at 25 mA, and thermal resistance of 500 K/W on FR4.

Technical Context

The BF820 operates as a discrete NPN bipolar junction transistor optimized for high-voltage, low-current switching and linear amplification. Its design targets stable gain (hFE ≥50) under 20 V VCE and 25 mA IC, with minimal feedback capacitance (Cre ≤1.6 pF) to support RF-adjacent signal integrity.

It features absolute maximum ratings including 300 V VCBO/VCEO, 5 V VEBO, 100 mA peak collector current, and 250 mW total power dissipation at Tamb ≤25 °C on FR4 PCB. Junction temperature is rated to 150 °C, with storage and ambient ranges from –65 °C to +150 °C.

Key Specifications

Pinout & Package

SOT23 plastic surface-mount package: 3-terminal, 1.9 mm pitch, 2.9 × 1.3 × 1.0 mm body, FR4-compatible footprint per Fig. 2 and Fig. 3.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BF820, BF821 offers matched high-voltage PNP functionality but requires schematic inversion, while ZTX653 trades 100 V voltage headroom for higher gain and greater leakage-making it viable only in sub-200 V applications where amplification fidelity dominates.

Availability

BF820 is available at Aetrix Electronics and suitable for telephone line interface, DSL line driver, and industrial sensor signal conditioning applications requiring stable component supply, long-term manufacturability, and RoHS-compliant SMT discretes.

Supply support for BF820 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

Nexperia is a global semiconductor expert focused on high-volume, high-reliability essential semiconductors, serving automotive, industrial, mobile, and computing markets with discrete, logic, and MOSFET solutions.

The BF820 belongs to Nexperia's high-voltage bipolar transistor product line, engineered specifically for telephony, line interface, and industrial signal conditioning where voltage endurance, low leakage, and SMT scalability are primary design drivers.

FAQ

Is BF820 automotive qualified?

No. The BF820 is explicitly designated as non-automotive qualified per Nexperia's 2023 revision history. It is not tested to AEC-Q101 or automotive reliability standards, and its use in safety-critical or vehicle systems is unsupported and not warranted by Nexperia.

What is the maximum allowable base current for BF820?

The absolute maximum peak base current is 50 mA for single pulses ≤1 ms, as specified in Table 5 (Limiting values). Continuous base current must be limited to ensure IC ≤50 mA and Ptot ≤250 mW, typically requiring IB <10 mA in steady-state switching applications.

Can BF820 replace BC817 in high-voltage applications?

No. BC817 has VCEO = 45 V and VCBO = 50 V-far below BF820's 300 V rating. Substituting BC817 in a 300 V circuit will cause immediate breakdown. BF820 is not a drop-in replacement; it serves a distinct high-voltage niche where BC817 cannot operate.

Does BF820 require heatsinking in typical operation?

Not under standard conditions. With Rth(j-a) = 500 K/W and Ptot = 250 mW, junction-to-ambient rise is ~125 °C at full power-exceeding Tj(max) = 150 °C. Heatsinking is unnecessary below ~100 mW dissipation; above that, thermal relief via copper pour or reduced duty cycle is recommended.