onsemi BD682T

Overview

BD682T from onsemi is a plastic medium-power silicon PNP Darlington transistor rated for 100 V_CEO, 4.0 A collector current, and 40 W total device dissipation at T_C = 25 °C. It features high DC current gain (h_FE ≥ 750 at I_C = 1.5 A), V_CE(sat) ≤ 2.5 V, and operates across −55 to +150 °C junction temperature range - used as output stage devices in complementary audio power amplifiers and motor control circuits.

For engineers reviewing the BD682T datasheet, pinout, applications, or equivalent options, key selection considerations include its 100 V breakdown rating, TO-225 package thermal resistance (R_θJC = 3.13 °C/W), Darlington configuration enabling high current drive with low base drive, and RoHS-compliant Pb-free construction.

Technical Context

The BD682T implements a monolithic PNP Darlington pair with integrated base-emitter resistor network absent - requiring external base current limiting. Its safe operating area (SOA) is defined by thermal limits at low V_CE and secondary breakdown constraints at higher V_CE, with derating to zero power at T_C = 150 °C.

It is electrically complementary to NPN counterparts BD681 and BD681G, and shares identical TO-225 mechanical outline (Case 77−09, Style 1) with pin 1 = emitter, pins 2 & 4 = collector, pin 3 = base. Electrical characteristics are specified at T_C = 25 °C with pulse testing (≤300 µs, ≤2% duty cycle).

Key Specifications

Pinout & Package

BD682T uses the TO-225 package (Case 77−09, Style 1), a 3-lead plastic power package with collector leads on pins 2 and 4 (internally tied), emitter on pin 1, and base on pin 3. The metal tab is electrically connected to the collector.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BD682G and MJE703, the BD682T offers identical performance to BD682G with updated packaging logistics, and improves on MJE703's V_CE(sat) by 0.5 V - directly reducing power loss and thermal stress in continuous conduction mode.

Availability

BD682T is available at Aetrix Electronics and suitable for audio amplifier output stages, DC motor driver circuits, and linear regulator pass elements requiring stable component supply and long-term industrial availability.

Supply support for BD682T 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 manufacturer specializing in energy-efficient power, analog, sensing, and connectivity solutions for automotive, industrial, and cloud power applications.

The BD682T belongs to onsemi's plastic medium-power PNP Darlington transistor family, designed specifically for complementary output stages in general-purpose amplifiers and robust switching interfaces in industrial control systems.

FAQ

What is the maximum collector-emitter voltage rating for BD682T?

The BD682T has a maximum collector-emitter voltage (V_CEO) rating of 100 Vdc, verified per onsemi's BD676/D datasheet Rev. 15. This rating applies under specified test conditions (I_C = 50 mA, I_B = 0) and defines the upper limit for safe DC blocking capability. Exceeding this voltage risks avalanche breakdown and permanent device damage. The BD682T is therefore suited for 72 VDC bus systems and audio amplifier rails with transient headroom.

Is BD682T pin-compatible with BD682G?

Yes, BD682T is fully pin-compatible with BD682G: both use identical TO-225 package (Case 77−09, Style 1) with pin 1 = emitter, pins 2 & 4 = collector, and pin 3 = base. Electrical specifications including V_CEO, I_C, h_FE, and V_CE(sat) are identical. The "T" suffix denotes updated packaging (50-unit rail vs. 500-unit box) and reflects current production status - BD682G is marked discontinued in the official datasheet.

What is the thermal resistance junction-to-case for BD682T?

The BD682T has a thermal resistance junction-to-case (R_θJC) of 3.13 °C/W, as specified in the Thermal Characteristics table of the onsemi BD676/D datasheet. This value is measured under standardized conditions and enables accurate heatsink sizing when the device operates at elevated case temperatures. For example, at 20 W dissipation and T_C = 80 °C, junction temperature reaches approximately 142.6 °C - within the −55 to +150 °C operating range.

Does BD682T require a base resistor, and what value is typical?

Yes, BD682T requires an external base current-limiting resistor because it lacks internal base-emitter resistors. For reliable saturation at I_C = 1.5 A, the datasheet specifies I_B = 30 mA. With V_BE(on) ≈ 2.5 V and typical drive voltage of 5 V or 12 V, a 82 Ω resistor (for 5 V drive) or 330 Ω (for 12 V) ensures sufficient base current while preventing overdrive. Undersized resistors risk excessive base current and thermal runaway.

Is BD682T suitable for use in linear regulator applications?

Yes, BD682T is suitable as a series pass element in linear voltage regulators. Its 40 W power dissipation rating at T_C = 25 °C, 100 V V_CEO, and high h_FE (>750) allow efficient regulation across wide input-output differentials. Designers must ensure adequate heatsinking - using the R_θJC = 3.13 °C/W value - and verify SOA compliance under worst-case load and dropout conditions per Figure 2 in the BD676/D datasheet.