onsemi BC516_L34Z

Overview

BC516_L34Z from onsemi is a PNP Darlington transistor optimized for high-current-switching applications requiring DC current gain (h_FE) ≥ 30,000 at I_C = −20 mA, V_CE = −2 V, with V_CEO = −30 V, I_C = −1 A continuous, and TO-92-3 package. It serves as a high-gain interface switch in relay drivers, lamp controls, and low-frequency power amplifiers.

For engineers reviewing the BC516_L34Z datasheet, pinout, applications, or equivalent options, key selection criteria include guaranteed h_FE > 30,000 at low base drive, V_CE(sat) ≤ −1 V at I_C = −100 mA/I_B = −0.1 mA, thermal resistance R_θJA = 200 °C/W, and Pb-free TO-92-3 packaging compliance.

Technical Context

The BC516_L34Z integrates two cascaded PNP transistors in a monolithic Darlington configuration to achieve ultra-high current gain while maintaining single-package simplicity. Its design targets low-base-drive switching where I_B as low as −0.1 mA enables full saturation at I_C = −100 mA.

It operates within a junction temperature range of −55 °C to +150 °C and exhibits f_T = 200 MHz under specified conditions (I_C = −10 mA, V_CE = −5 V), confirming usable bandwidth beyond typical switching frequencies but not intended for RF amplification.

Key Specifications

Pinout & Package

BC516_L34Z is housed in a Pb-free TO-92-3 plastic package (Case 135AR), lead-formed, with standard 4.83 mm × 4.76 mm footprint and through-hole mounting compatibility.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar PNP Darlington transistor applications.

Compared with MPSA14 and BC639, BC516_L34Z delivers uniquely high h_FE ≥ 30,000 and low V_CE(sat), making it optimal for ultra-low-base-drive, high-current switching where thermal and layout constraints prohibit additional driver stages.

Availability

BC516_L34Z is available at Aetrix Electronics and suitable for relay driver circuits, lamp/LED load switching, DC motor control (low-speed), and linear power amplifier stages requiring stable component supply, long-term manufacturability, and RoHS-compliant discrete transistors.

Supply support for BC516_L34Z 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

onsemi (formerly ON Semiconductor) is a global semiconductor supplier specializing in energy-efficient power management, analog, sensors, and connectivity solutions for automotive, industrial, cloud, and consumer markets.

The BC516_L34Z belongs to onsemi's general-purpose bipolar transistor family, designed specifically for high-gain, medium-power switching applications where simplified drive requirements and thermal robustness are critical.

FAQ

What is the maximum continuous collector current rating for BC516_L34Z?

The BC516_L34Z has a maximum continuous collector current (I_C) rating of −1 A at T_A = 25 °C. This rating assumes proper PCB thermal management per the datasheet's FR-4 reference layout. Derating is required above 25 °C ambient, following the R_θJA = 200 °C/W thermal resistance curve. The BC516_L34Z must not exceed this limit in sustained operation to avoid junction overheating or parametric shift.

Is BC516_L34Z pin-compatible with BC517 or BC516 variants?

Yes, BC516_L34Z shares identical TO-92-3 pinout (Collector-Base-Emitter, Pin 1–2–3) and electrical specifications with BC516 and BC517, both of which are PNP Darlington transistors in the same onsemi family. However, BC517 specifies h_FE ≥ 20,000 (vs. ≥30,000 for BC516_L34Z), so BC516_L34Z offers higher guaranteed gain. No PCB changes are needed when substituting within this family.

What is the typical V_BE(on) for BC516_L34Z under normal operating conditions?

The BC516_L34Z exhibits a typical base-emitter on voltage (V_BE(on)) of −1.4 V when I_C = −10 mA and V_CE = −5 V. This reflects the stacked V_BE drop across two PNP junctions in the Darlington configuration. Designers must ensure sufficient base drive voltage headroom-typically ≥2.0 V-to guarantee full saturation, especially at elevated temperatures where V_BE decreases slightly.

Does BC516_L34Z support surface-mount assembly?

No, BC516_L34Z is packaged exclusively in the through-hole TO-92-3 (Case 135AR) format and is not offered in SMT variants such as SOT-23 or SC-70. Its lead-formed 4.83 mm × 4.76 mm outline requires wave soldering or hand soldering into plated-through holes. For surface-mount equivalents, consider onsemi's NSS12201MR6T1G (SOT-23) - though it is a standard PNP, not Darlington, and lacks comparable h_FE.

What is the junction-to-case thermal resistance (R_θJC) of BC516_L34Z?

The BC516_L34Z has a junction-to-case thermal resistance (R_θJC) of 83.3 °C/W, measured under standardized test conditions. This parameter is relevant when using an external heatsink attached to the transistor case; however, the TO-92-3 package does not feature a metal tab for heatsink attachment. Therefore, R_θJC is primarily useful for thermal modeling accuracy, while practical thermal design relies on R_θJA = 200 °C/W for PCB-based conduction.