Bourns Inc. TIP42B-S
Full Technical Specifications
11 Parameters| Parameter / Attribute | Specification / Value |
|---|---|
| Mounting | Through Hole |
| FET type | PNP |
| Voltage - collector emitter breakdown | 80 V |
| Current - collector (Ic) | 6 A |
| Current - collector cutoff | 700µA |
| DC current gain (hFE) (Min) @ ic, vce | 15 @ 3A, 4V |
| Power - max | 2 W |
| Operating temperature | -65°C~150°C(TJ) |
| Package | Tube |
| Case | TO-220-3 |
| Vce saturation (Max) @ ib, ic | 1.5V @ 600mA, 6A |
Need Stock or a Drop-in Second-Source for TIP42B-S?
Package: TO-220AB · Pin-compatible replacements with immediate Shenzhen spot stock
The TIP41C / TIP42C pair is the general-purpose linear and switching workhorse of a generation of amplifiers, regulators and drive stages - the TO-220 answer to the classic 2N3055, with a tenth of the base drive requirements of the Darlington family and a real gain that has to be respected. The repairs that go wrong on this pair go wrong in three ways: fitted as an upgrade for a Darlington position (the base drive disappears), gain group swapped without checking (hFE 15 to 75 is a wide field), and the 2N3055 antique traded in without doing the mechanical and voltage arithmetic of the TO-3-to-TO-220 move.
Verified Pin-Compatible Replacements (3 verified alternatives)
The PNP Half of the Pair
Shenzhen Spot Stock (24-48h Dispatch)
The PNP complement: -100V / -6A with the same gain window (hFE 15-75), the same 1.5V saturation class at 6A and the same 65W body.
VCEO -100V; the A/B/C suffix ladder is the same (60 / 80 / 100V).
The 2N3055 Modernized into TO-220
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The 2N3055 die family in the TO-220 plastic body: 60V-class NPN rated 10A, substantially more current than the TIP41C with less voltage margin.
VCEO 60V class against the TIP41C 100V - check the rail before going this direction.
The Antique Original - Do the Arithmetic
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The 60V / 15A / 115W legend in the TO-3 can: more current and dissipation than the TIP41C, less voltage, and a completely different mounting world.
VCEO 60V; the classic linear-supply rating, never intended for mains-derived rails.
Buyer & Quality Checklist for Sourcing Alternatives
- Respect the gain: hFE spans 15 to 75. At the 15 floor, 6A of collector current needs about 400mA of base current - if the original circuit was designed around a Darlington (hFE over 1000) or a MOSFET, this part never saturates and dies warm. The Darlington-to-TIP41 direction is a redesign, not a swap.
- VCE(sat) 1.5V at 6A: about 9W inside the package at rated current. The 65W body rating assumes a real heatsink; the TIP41C is not a heat-free upgrade over any low-saturation part.
- The suffix is the voltage: TIP41A/B/C = 60/80/100V. The pair rule: replace NPN and PNP together (TIP41C with TIP42C) from one gain group for complementary stages.
- fT about 3MHz: linear and low-frequency switching only. In switching duty above tens of kHz the losses are the price of the old design - the modern move is a MOSFET (see the IRF540N page for the drive arithmetic).
- The TO-220 tab is the collector in both the pair and the TO-220 3055 - insulate against grounded heatsinks.
- For a real 2N3055 position, decide with the socket: restoring a TO-3 is mechanical work with better thermal credibility; fitting an MJE3055T keeps the plastic mounting but accepts 60V and the different gain curves.
Frequently Asked Technical Questions
Q: What is the difference between TIP41, TIP41B and TIP41C?
A: Voltage grade: 40V (base), 80V (B) and 100V (C) with identical 6A / 65W ratings and pinout. Higher grades substitute down safely in low-voltage circuits; lower grades replace higher ones only with the real rail and transients checked.
Q: Can a TIP41C replace a 2N3055?
A: In applications at or below 6A on 100V-class circuits, electrically yes - but the mounting world changes completely (TO-220 against the TO-3 can), and the 2N3055 position usually existed for its 15A / 115W capability. Do the current and dissipation arithmetic before substituting down.
Q: Why does a TIP41C stay cold in one board and cook in another?
A: Base drive. In saturated switching the part dissipates about 1.5V times the current; under-driven (hFE 15 at 6A, mains-derived linear duty) it dissipates the whole rail difference. Verify base resistor sizing against the actual gain group before blaming the part.