onsemi TIP101

Overview

TIP101 from onsemi is an NPN silicon Darlington power transistor in TO-220AB package, rated for 8 A continuous collector current, 80 V collector-emitter sustaining voltage (V_CEO(sus)), and 80 W power dissipation at T_C = 25°C, designed for low-speed switching and general-purpose amplifier applications in industrial motor controls and relay drivers.

For engineers reviewing the TIP101 datasheet, pinout, applications, or equivalent options, this page delivers verified electrical parameters, thermal derating behavior, built-in base-emitter shunt resistors, safe operating area limits, and real-world switching performance data under defined test conditions.

Technical Context

The TIP101 integrates two monolithic NPN transistors in Darlington configuration with internal base-emitter shunt resistors (~8.0 kΩ and ~120 Ω), enabling high DC current gain (h_FE = 1000–2000 at I_C = 3.0 A) and simplified drive requirements. It operates with a typical V_BE(on) of 2.8 V at I_C = 8.0 A and supports unclamped inductive load energy up to 30 mJ.

Thermal design is constrained by R_JC = 1.56 °C/W and R_JA = 62.5 °C/W, with power derating beginning above 25°C at 0.64 W/°C when mounted on heatsink (T_C-based) or 0.016 W/°C in free-air (T_A-based). Second-breakdown-limited SOA curves apply below rated V_CEO(sus) = 80 V.

Key Specifications

Pinout & Package

TO-220AB package (Case 221A, Style 1) with 4-terminal configuration: metal tab is collector (pins 2 and 4 electrically common), pin 1 is base, pin 3 is emitter. Requires mechanical mounting to heatsink via tab; pin 1 isolated from tab.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TIP102 and MJD122G, the TIP101 offers the best balance of 80 V robustness, through-hole serviceability, and thermal performance in cost-sensitive industrial controls-without over-specifying voltage rating or sacrificing mechanical mounting versatility.

Availability

TIP101 is available at Aetrix Electronics and suitable for DC motor control, relay driver circuits, and linear power regulator designs requiring stable component supply, long-term industrial lifecycle support, and traceable sourcing from authorized channels.

Supply support for TIP101 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, sensor, and connectivity solutions for automotive, industrial, and cloud infrastructure markets.

The TIP101 belongs to onsemi's legacy plastic medium-power transistor family, engineered for ruggedized general-purpose amplification and low-speed switching in harsh industrial environments where reliability and thermal stability are prioritized over RF or high-frequency performance.

FAQ

What is the maximum continuous collector current rating for the TIP101?

The TIP101 is rated for 8.0 A continuous collector current (I_C) when operated with case temperature maintained at 25°C using an appropriate heatsink. This rating drops linearly at 0.64 W/°C above 25°C per the derating curve in Figure 2 of the official datasheet. At T_C = 100°C, the usable I_C reduces to approximately 4.4 A assuming proportional power reduction.

Does the TIP101 have built-in base-emitter resistors, and how do they affect circuit design?

Yes, the TIP101 features monolithic base-emitter shunt resistors (~8.0 kΩ and ~120 Ω) integrated into its Darlington structure. These resistors provide automatic turn-off biasing, eliminating the need for external pull-down resistors in most switching applications. This simplifies PCB layout, reduces component count, and improves reliability in industrial environments where board contamination or leakage paths may compromise discrete resistor performance.

Can the TIP101 be used in linear regulator applications, and what thermal considerations apply?

Yes, the TIP101 is commonly used as a series pass element in linear regulators. Its R_JC = 1.56 °C/W and 80 W power rating allow effective thermal management when mounted to a heatsink. Designers must calculate junction temperature using T_J = T_C + P_D × R_JC, ensuring T_J stays ≤150°C. Free-air operation is limited to 2.0 W, making heatsinking essential for >500 mW dissipation.

What is the safe operating area (SOA) limitation for the TIP101 at DC operation?

At DC (single-pulse or continuous), the TIP101's SOA is thermally limited at T_C = 25°C, with maximum allowable V_CE and I_C bounded by the "Thermally Limited" curve in Figure 6. For example, at V_CE = 40 V, the absolute maximum I_C is ~1.2 A; at V_CE = 10 V, it rises to ~7.5 A. Exceeding these boundaries risks thermal runaway or second breakdown, even if instantaneous power appears within 80 W limit.

Is there a Pb-free version of the TIP101, and how is it marked?

Yes, the Pb-free version is designated TIP101G and uses the same TO-220AB package. It is marked with the suffix "G" in the date code (e.g., "TIP101G AYWW"), where "G" explicitly indicates compliance with RoHS Directive 2011/65/EU. The soldering profile and mounting guidelines follow ON Semiconductor's SOLDERRM/D reference manual, confirming compatibility with standard lead-free reflow processes.