onsemi BC516_D74Z

Overview

BC516_D74Z 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 −30 V V_CEO, −1 A continuous collector current, and TO-92-3 package. It serves as a high-gain interface switch in relay drivers and power supply enable circuits.

For engineers reviewing the BC516_D74Z datasheet, pinout, applications, or equivalent options, key selection criteria include guaranteed h_FE >30k 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 compliance per J-STD-020.

Technical Context

This device implements a monolithic Darlington pair structure with integrated emitter-base resistor to stabilize bias and improve turn-off speed. Its PNP polarity enables high-side switching in grounded-load configurations, and its f_T = 200 MHz supports moderate-frequency switching up to ~100 kHz without significant gain roll-off.

The BC516_D74Z operates within a junction temperature range of −55 °C to +150 °C and delivers 625 mW total dissipation at T_A = 25 °C. Its −40 V V_CBO and −10 V V_EBO ratings support robust reverse-bias margin in inductive load snubbing and flyback protection.

Key Specifications

Pinout & Package

BC516_D74Z is housed in a Pb-free TO-92-3 plastic package (Case 135AR), with 4.83 mm × 4.76 mm footprint and lead-formed terminals. Standard orientation places lead 1 (Collector) leftmost when flat side faces viewer and leads point downward.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BC516_D74Z, BC517-D27Z offers higher minimum gain with identical form factor and electrical envelope, while MPSA92 trades gain and saturation performance for extreme voltage ruggedness-making it unsuitable as a direct replacement unless V_CEO >100 V is critical and base drive can be increased tenfold.

Availability

BC516_D74Z is available at Aetrix Electronics and suitable for relay driver circuits, linear regulator pass stages, power supply enable switches, and DC motor direction control requiring stable component supply across industrial automation, test equipment, and embedded power management designs.

Supply support for BC516_D74Z 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 focused on energy-efficient electronics, delivering silicon solutions for automotive, industrial, cloud, and IoT applications.

The BC516_D74Z belongs to onsemi's general-purpose bipolar transistor family designed specifically for high-gain, medium-power discrete switching and amplification in cost-sensitive, space-constrained applications.

FAQ

What is the maximum continuous collector current rating for BC516_D74Z?

The BC516_D74Z has a maximum continuous collector current (I_C) rating of −1 A at T_A = 25 °C. This rating assumes adequate PCB thermal relief and derates linearly above 25 °C ambient per the R_θJA = 200 °C/W specification. At 70 °C ambient, the practical I_C limit drops to approximately −0.7 A to maintain T_J ≤ 150 °C. The BC516_D74Z must not exceed this limit in sustained operation.

Does BC516_D74Z have an integrated base resistor?

Yes, the BC516_D74Z incorporates an internal base-emitter resistor network to improve turn-off speed and reduce external component count. This resistor stabilizes bias under varying temperature conditions and prevents latch-up in Darlington configurations. Unlike basic PNP transistors, the BC516_D74Z does not require an external base resistor for basic switching, though current-limiting remains necessary at the base input. This feature is documented in onsemi's BC516/D datasheet Rev. 4.

Is BC516_D74Z pin-compatible with BC517_D74Z?

Yes, BC516_D74Z and BC517_D74Z share identical TO-92-3 package dimensions, pin assignment (Collector-Base-Emitter), and mechanical outline (Case 135AR). Both devices use the same leadform and marking orientation. However, BC517_D74Z specifies a higher minimum h_FE (40,000 vs. 30,000) and slightly tighter V_CE(sat) limits. The BC516_D74Z may be substituted into BC517_D74Z designs only if gain margin is acceptable.

What is the junction-to-ambient thermal resistance of BC516_D74Z?

The BC516_D74Z has a specified R_θJA of 200 °C/W under standard JEDEC test conditions (FR-4 board, 76 mm × 114 mm, minimum land pattern). This value assumes no added copper pour or heatsinking. In real-world layouts with 1 cm² of 2-oz copper connected to the emitter pad, R_θJA typically improves to ~120 °C/W. Thermal design must ensure T_J stays below 150 °C under worst-case I_C and ambient conditions.

Can BC516_D74Z be used in linear amplifier applications?

The BC516_D74Z supports linear operation with verified f_T = 200 MHz and h_FE stability across I_C = −1 mA to −100 mA, making it suitable for low-frequency audio preamplifiers and sensor signal conditioning where high gain and low noise are prioritized over bandwidth. However, its V_CE(sat) and thermal limitations restrict use to Class-A stages with I_C ≤ 50 mA. For high-fidelity audio, dedicated low-noise transistors are preferred-but the BC516_D74Z remains viable in cost-sensitive linear gain blocks.