NXP Semiconductors BC517,112

Overview

BC517,112 from Nexperia (formerly Philips Semiconductors) is an NPN Darlington transistor in TO-92 (SOT54) package, rated for 30 V V_CE, 500 mA I_C, and minimum DC current gain of 30,000 at 20 mA collector current. It serves as a high-gain switching or amplification device in low-frequency sensor interface and relay driver circuits.

For engineers reviewing the BC517,112 datasheet, BC517,112 pinout, BC517,112 application, or BC517,112 equivalent, key selection criteria include its Darlington architecture enabling single-stage high-current drive, saturation voltage under 1 V at 100 mA, and thermal resistance of 200 K/W on FR4 PCB - critical for thermally constrained discrete logic-level interfacing.

Technical Context

The BC517,112 integrates two cascaded NPN transistors in a monolithic Darlington configuration, delivering ultra-high h_FE without external bias network complexity. Its base-emitter on-state voltage is 1.4 V at 10 mA, and it achieves 1 V V_CE(sat) with only 0.1 mA base drive at 100 mA collector load.

Designed for DC and low-frequency (<220 MHz f_T) operation, it operates within −65 °C to +150 °C ambient range and requires no heatsink below 312 mW dissipation (50% of 625 mW P_tot). The TO-92 mechanical outline complies with IEC 60134 limiting values and JEDEC TO-92 standards.

Key Specifications

Pinout & Package

BC517,112 uses a plastic through-hole TO-92 (SOT54/SC-43A) package with 3 leads. Lead spacing is 2.54 mm (e), body length 14.5 mm (L), and lead diameter 0.4–0.48 mm (b).

Key Features

Applications

Equivalent & Alternatives

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

Compared with BC517,112, BC516,112 provides matched performance in PNP configuration for complementary designs, while MPSA13,112 offers lower-cost alternative with 67% lower minimum h_FE and higher V_CE(sat), requiring re-evaluation of base drive and thermal design.

Availability

BC517,112 is available at Aetrix Electronics and suitable for relay drivers, microcontroller interface circuits, and thermal sensor amplifiers requiring stable component supply across industrial automation, building controls, and embedded instrumentation programs.

Supply support for BC517,112 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 - formerly Philips Semiconductors - is a global leader in high-volume, high-reliability discrete and logic semiconductors, headquartered in Nijmegen, Netherlands.

The BC517,112 belongs to Nexperia's general-purpose bipolar transistor portfolio, engineered for cost-sensitive, high-yield applications in industrial control, appliance, and automotive subsystems where robustness and parametric consistency are essential.

FAQ

What is the maximum continuous collector current for BC517,112?

The BC517,112 has a maximum DC collector current rating of 500 mA per its Absolute Maximum Ratings table. This value assumes operation at ambient temperatures ≤25 °C with proper PCB thermal relief; derating is required above 25 °C ambient, following the 200 K/W thermal resistance specification. Exceeding 500 mA risks permanent damage due to junction overheating.

Does BC517,112 have a documented PNP complement?

Yes, the BC516,112 is the officially documented PNP complement to BC517,112, sharing identical TO-92 (SOT54) packaging, voltage ratings (V_CEO = 30 V), current capability (500 mA), and minimum h_FE (30,000). Both devices are specified in the same Philips/Nexperia datasheet and intended for complementary circuit topologies such as push-pull drivers.

What is the typical base-emitter saturation voltage of BC517,112?

The BC517,112 exhibits a typical V_BE(sat) of 1.5 V under test conditions of I_C = 100 mA and I_B = 0.1 mA. This value reflects the combined forward voltage drop across both emitter-base junctions in the Darlington pair and must be accounted for when designing base drive circuitry to ensure sufficient forward bias.

Can BC517,112 be used in linear amplification applications?

While BC517,112 is characterized for switching use, its high h_FE and specified V_BE(on) of 1.4 V at I_C = 10 mA support DC-coupled linear amplification in low-frequency (<10 kHz) signal conditioning stages. However, its f_T of 220 MHz does not indicate optimized high-fidelity linearity; distortion and thermal drift should be verified per application.

Is BC517,112 RoHS compliant and halogen-free?

Yes, BC517,112 is RoHS compliant and halogen-free per Nexperia's product compliance documentation. The device meets EU Directive 2011/65/EU and IEC 61249-2-21:2013 standards, with all homogeneous materials verified to contain ≤1000 ppm bromine and chlorine and ≤900 ppm each of lead, mercury, cadmium, hexavalent chromium, and PBB/PBDE.