onsemi BCX71K_S00Z

Overview

BCX71K_S00Z from ON Semiconductor is a PNP general-purpose amplifier in SOT-23 package, rated for -45 V V_CEO, -500 mA I_C, and 350 mW power dissipation, designed for high-current-gain switching and linear amplification up to 300 mA in consumer and industrial control circuits.

For engineers reviewing the BCX71K_S00Z datasheet, pinout, applications, or equivalent options, key selection criteria include verified PNP polarity, guaranteed h_FE ≥ 380 at -2 mA, V_CE(sat) ≤ -0.25 V at -10 mA, thermal resistance of 357 °C/W, and SOT-23 footprint compatibility with standard PCB assembly processes.

Technical Context

This device operates as a silicon PNP bipolar junction transistor optimized for high DC current gain (h_FE) across collector currents from -10 μA to -50 mA, with saturation voltages validated under defined base drive conditions (-0.25 mA IB for -10 mA IC). It features low noise figure (6.0 dB) and gain-bandwidth product up to ~150 MHz at moderate bias.

Thermal performance is specified for mounting on FR-4 PCB (40 mm × 40 mm × 1.5 mm), with derating of 2.8 mW/°C above 25°C ambient. Its breakdown ratings (V_(BR)CEO = -45 V, V_(BR)EBO = -5.0 V) and leakage (I_CES = -20 nA at 25°C) support reliable operation in low-to-moderate voltage analog and digital interface stages.

Key Specifications

Pinout & Package

SOT-23 (TO-236AB) 3-lead surface-mount package with gull-wing leads, 1.30 mm × 2.92 mm footprint, 1.20 mm max height, and JEDEC-compliant land pattern. Marking "BK" identifies BCX71K_S00Z on top surface.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar PNP general-purpose amplifier applications.

Compared with BC807-25 and MMBT4403, BCX71K_S00Z delivers superior h_FE at low collector currents (<1 mA), making it preferred for precision biasing and low-power switching, while maintaining identical SOT-23 mechanical compatibility and thermal performance.

Availability

BCX71K_S00Z is available at Aetrix Electronics and suitable for LED driver circuits, level-shifting interfaces, current mirror references, and power supply enable switches requiring stable component supply and consistent parametric performance across production batches.

Supply support for BCX71K_S00Z 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

ON Semiconductor is a global semiconductor manufacturer specializing in energy-efficient power management, analog, sensing, and connectivity solutions for automotive, industrial, cloud, and consumer markets.

The BCX71K_S00Z belongs to ON Semiconductor's general-purpose bipolar transistor product line, engineered for cost-sensitive, high-volume applications requiring reliable DC gain, low saturation voltage, and robust thermal behavior in compact SOT-23 packaging.

FAQ

What is the maximum collector current rating for BCX71K_S00Z?

The BCX71K_S00Z has a continuous collector current rating of -500 mA, verified per its Absolute Maximum Ratings table. This value defines the upper limit for steady-state operation; actual usable current depends on thermal management, PCB layout, and ambient temperature. Derating applies above 25°C ambient at 2.8 mW/°C, and BCX71K_S00Z must be operated within its safe operating area (SOA) to avoid secondary breakdown.

Does BCX71K_S00Z have a documented pinout for SOT-23 package?

Yes, BCX71K_S00Z uses standard SOT-23 pinout: Pin 1 = Emitter, Pin 2 = Base, Pin 3 = Collector, confirmed by Fairchild Semiconductor's official package drawing MA03D and ON Semiconductor's updated documentation. The marking "BK" appears adjacent to Pin 1 on the top surface, and the device orientation follows JEDEC TO-236AB convention with the tab side facing away from Pin 1.

What is the minimum DC current gain (h_FE) of BCX71K_S00Z at -2 mA collector current?

The minimum DC current gain (h_FE) of BCX71K_S00Z is 380 at -2 mA collector current and -5.0 V V_CE, as specified in the Electrical Characteristics table. This value is guaranteed across production lots and forms the basis for calculating required base drive in switching designs. BCX71K_S00Z also provides h_FE ≥ 100 at -10 μA, supporting ultra-low-power biasing applications.

Can BCX71K_S00Z be used in high-frequency amplifier applications?

BCX71K_S00Z exhibits a typical gain-bandwidth product (f_T) of ~150 MHz at -5 V V_CE and -10 mA I_C, making it suitable for low-to-moderate frequency amplification (up to ~10–20 MHz small-signal gain). However, its 6.0 pF output capacitance and 800 ns turn-off time limit use in RF power stages or >50 MHz switching; BCX71K_S00Z is best applied in audio preamps, sensor interfaces, and digital logic buffering rather than VHF/UHF circuits.

Is BCX71K_S00Z compliant with RoHS and lead-free assembly standards?

Yes, BCX71K_S00Z is RoHS-compliant and qualified for lead-free reflow soldering per JEDEC J-STD-020. ON Semiconductor confirms compliance with Directive 2011/65/EU and subsequent amendments, including exemption 7a for Pb in high-melting-temperature solder alloys. The device uses matte tin plating on leads and meets MSL Level 1 moisture sensitivity classification, allowing unlimited floor life at ≤30°C/85% RH.