STMicroelectronics TIP47

Overview

TIP47 from STMicroelectronics is a silicon NPN planar power transistor in TO-220 package, designed for high-voltage linear and switching applications including relay drivers and power supplies. It features 350 V collector-base voltage (VCBO), 250 V collector-emitter voltage (VCEO), 1 A continuous collector current (IC), and 40 W total power dissipation at Tcase ≤ 25 °C.

For engineers reviewing the TIP47 datasheet, TIP47 pinout, TIP47 application, or TIP47 equivalent, key selection criteria include its 250 V VCEO rating, 1 A IC capability, TO-220 thermal resistance (Rthj-case = 3.125 °C/W), and suitability for medium-power switching where ruggedness and voltage margin are critical.

Technical Context

The TIP47 operates as a general-purpose NPN bipolar junction transistor with multiepitaxial planar construction, enabling stable gain and reliable switching up to 10 MHz transition frequency (fT). Its DC current gain (hFE) ranges from 30–150 at IC = 0.3 A and drops to ≥10 at IC = 1 A, supporting both amplification and saturated switching modes.

Designed for operation up to 150 °C junction temperature, it uses a TO-220 plastic package with electrically isolated tab and thermal resistance of 3.125 °C/W junction-to-case - critical for heatsink-coupled power stage designs requiring sustained 1 A conduction without derating.

Key Specifications

Pinout & Package

Package: TO-220 (Jedec standard), plastic body with electrically isolated metal tab (pin 2), intended for mechanical mounting and thermal coupling to heatsinks.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar NPN power switching applications.

Compared with MJE13003 and BD249C, the TIP47 offers superior voltage margin (250 V VCEO) and thermal performance (3.125 °C/W) in TO-220, making it preferred for industrial relay drivers and 120 VAC-coupled power stages where robustness outweighs switching speed.

Availability

TIP47 is available at Aetrix Electronics and suitable for relay driver circuits, DC-DC converter switches, and motor control outputs requiring stable component supply and long-lifecycle availability.

Supply support for TIP47 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

STMicroelectronics is a global semiconductor leader headquartered in Geneva, designing and manufacturing analog, digital, and mixed-signal ICs and discrete devices for automotive, industrial, and power applications.

The TIP47 belongs to ST's legacy power bipolar transistor family, engineered for rugged, medium-power linear and switching applications where high-voltage tolerance and thermal reliability are prioritized over ultra-high-speed performance.

FAQ

Is the TIP47 pin-compatible with TIP48, TIP49, or TIP50?

Yes - all four devices share identical TO-220 pinout (Emitter-Collector-Base) and mechanical dimensions. However, their voltage ratings differ: TIP47 has 250 V VCEO, while TIP48, TIP49, and TIP50 offer 300 V, 350 V, and 400 V respectively. Substitution requires verifying voltage margin in the target circuit.

What is the recommended base resistor value for switching a 100 mA load?

For reliable saturation with IC = 100 mA and hFE ≥ 30, use IB ≥ 3.3 mA. With VCC = 5 V and VBE(on) ≈ 1.5 V, a 1.0 kΩ resistor delivers ~3.5 mA base current - sufficient for hard saturation while limiting drive power. Always verify VCE(sat) < 0.5 V under actual load conditions.

Can the TIP47 be used without a heatsink?

Only for intermittent operation below 0.5 A and ambient temperatures under 40 °C. At 1 A continuous, junction temperature exceeds 150 °C within seconds without heatsinking due to 40 W Ptot derating. A minimum 2°C/W heatsink is required for sustained 1 A operation at 25 °C ambient.

Does the metal tab connect internally to any pin?

Yes - the metal tab is internally connected to pin 2 (Collector) and is electrically isolated from emitter and base. When mounted to a heatsink, ensure insulating hardware (e.g., mica washer + nylon screw) is used unless the heatsink is intentionally tied to the collector potential.