TIP42C Reference Tables, Pins & Specifications

Pin reference

Signal names, electrical functions and connection guidance

TO-220AB

Physical pin numbers3 pins

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TIP42C pin functions and connections
Signal	Type	Function & connection
B	Base	Current-driven control junction. Connection guidance Use the example’s 330 Ω base resistor and 10 kΩ base-emitter return. The driver must sink base current. A 3.3 V output cannot directly turn off a 12 V high-side transistor.
C	Collector	Load terminal, also connected to the metal tab. Connection guidance Connect the 100 Ω resistor load to this terminal. The exposed tab is electrically live; insulate it when required.
E	Emitter	Positive supply and base-drive reference. Connection guidance Connect emitter to +12 V. Pull base up to emitter to turn off. Front view: B1, C2, E3; tab is collector.

Archived manufacturer reference

Manufacturer-referenced values5 parameters

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Parameter	Value	Conditions / notes
Selected device	TIP42C · TO-220	onsemi TIP42C/D Rev. 2, November 2017
Polarity	PNP	Electrical values below are magnitudes
Terminals	B1 · C2 · E3	Metal tab is collector
Package drawing	TO220B03 Rev. 8	Two supplier body shapes are documented
Availability	Archived reference	Verify current sourcing separately; no unverified SMD substitute is offered

The source is explicitly retained as a legacy reference.

Individual stress limits, not operating targets

Manufacturer-referenced values5 parameters

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Parameter	Value	Conditions / notes
Collector-emitter / collector-base	100 / 100 V	C-voltage grade
Emitter-base reverse limit	5 V	Do not overdrive the reverse base junction
DC / pulse collector current	6 / 10 A	Pulse duration and safe operating area apply
Base current	2 A	Absolute maximum
Junction maximum	150°C	Storage −65 to +150°C

Thermal limits may restrict current well below the headline rating.

25°C; pulse ≤300 µs and duty ≤2%

Manufacturer-referenced values5 parameters

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Parameter	Value	Conditions / notes
hFE at IC 0.3 A	30 minimum	VCE 4 V
hFE at IC 3 A	15–75	VCE 4 V
Collector-emitter saturation	1.5 V maximum	IC 6 A; IB 600 mA
Base-emitter on voltage	2 V maximum	IC 6 A; VCE 4 V
Gain-bandwidth product	3 MHz minimum	IC 500 mA; VCE 10 V; f 1 MHz

PNP voltage and current signs are negative in the manufacturer table; magnitudes are shown here.

25°C maximum magnitudes

Manufacturer-referenced values3 parameters

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Temperature affects leakage.

Keep the boundary conditions explicit

Manufacturer-referenced values6 parameters

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Parameter	Value	Conditions / notes
Collector dissipation	65 W	Case held at 25°C
Ambient dissipation	2 W	Ambient 25°C
Safe operating area	See source curves	Check current, voltage and pulse width together
Lead pitch	2.54 mm nominal	Drawing range 2.40–2.67 mm
Lead cross-section maximum	1.00 × 0.60 mm	Below the stamped shoulder
Authored copper / hole	2.2 / 1.3 mm	Verify fabrication and mechanical clearances

The package illustration does not imply a heatsink is present.

Explicit illustrative assumptions

Manufacturer-referenced values7 parameters

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Parameter	Value	Conditions / notes
Load	100 Ω, at least 3 W	Collector to ground
Base resistor / return	330 Ω / 10 kΩ	Return resistor goes from base to emitter
Buffered driver	12 V off / 7 V on	Level-shifted; sinks base current
Assumed junctions	\|VBE\| 0.8 V; \|VCE\| 0.2 V	Teaching assumptions, not guaranteed test points
Base current	12.65 mA	(5−0.8)/330−0.8/10000
Collector current / forced ratio	118 mA / 9.33	(12−0.2)/100; IC/IB
Transistor / load loss	33.7 mW / 1.392 W	Include base contribution; allow resistor thermal margin

Inductive loads require a suitable clamp and a separate transient check.