onsemi TIP131

Overview

TIP131 from onsemi is an NPN Darlington power transistor designed for low-speed switching and general-purpose amplifier applications, with V_CEO(sus) = 80 Vdc (min), I_C = 8.0 Adc continuous, V_CE(sat) = 2.0 Vdc (max) at 4.0 Adc, h_FE = 2500 (typ), and TO-220AB package. It delivers high current gain and low saturation voltage in industrial relay drivers and linear power supplies.

For engineers reviewing the TIP131 datasheet, pinout, applications, or equivalent options, key selection considerations include its monolithic Darlington structure with built-in base-emitter shunt resistors, thermal resistance R_JC = 1.78 °C/W, and suitability for 70 W dissipation at T_C = 25°C in fixed-mount power stages.

Technical Context

The TIP131 integrates two NPN transistors in a monolithic Darlington configuration with internal base-emitter shunt resistors (~8.0 kΩ and ~120 Ω), enabling simplified biasing and improved turn-off behavior. Its sustaining voltage rating of 80 Vdc and 8.0 Adc collector current support robust operation in inductive load switching.

Thermal design is constrained by R_JA = 63.5 °C/W (free-air) and R_JC = 1.78 °C/W (case), requiring heatsinking for sustained >2.0 W operation. The device operates across –65 to +150°C junction temperature range and is rated for 70 W at case temperature 25°C.

Key Specifications

Pinout & Package

Package: TO-220AB (Case 221A, Style 1), through-hole, single-ended heatsink mount, Pb-free option available (TIP131G).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MJD131 and TIP121, the TIP131 uniquely combines 80 Vdc sustaining voltage, 8.0 Adc current, and through-hole TO-220AB packaging-making it irreplaceable in legacy 80 V industrial controls where SMT conversion or voltage derating is not feasible.

Availability

TIP131 is available at Aetrix Electronics and suitable for industrial relay drivers, DC motor starters, and linear power supply designs requiring stable component supply, long-term obsolescence management, and traceable sourcing.

Supply support for TIP131 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 supplier specializing in energy-efficient power, analog, sensor, and connectivity solutions for automotive, industrial, cloud, and consumer markets.

The TIP131 belongs to onsemi's legacy silicon power transistor product line, engineered for rugged, cost-effective discrete switching and amplification in non-high-frequency industrial power systems.

FAQ

What is the maximum continuous collector current for the TIP131?

The TIP131 supports a maximum continuous collector current of 8.0 Adc at case temperature T_C = 25°C. This rating assumes proper heatsinking; current must be derated linearly above 25°C per the power derating curve in Figure 2 of the official datasheet. At T_C = 100°C, the usable I_C drops to approximately 4.0 Adc. The TIP131 datasheet specifies this limit under "Maximum Ratings" and confirms it with thermal resistance R_JC = 1.78 °C/W.

Does the TIP131 have built-in base-emitter resistors?

Yes, the TIP131 features monolithic construction with built-in base-emitter shunt resistors (~8.0 kΩ and ~120 Ω), as confirmed in the "Features" section and Figure 1 of the TIP131 datasheet. These resistors ensure reliable turn-off by discharging stored charge and prevent false triggering from leakage or noise-eliminating the need for external pull-down components in most applications using the TIP131.

What is the collector-emitter saturation voltage of the TIP131 at rated current?

The TIP131 has a maximum V_CE(sat) of 2.0 Vdc at I_C = 4.0 Adc and I_B = 16 mAdc, per the "Electrical Characteristics" table. At higher current (I_C = 6.0 Adc, I_B = 30 mAdc), V_CE(sat) rises to 3.0 Vdc max. This low saturation voltage directly reduces conduction losses in the TIP131, making it suitable for linear regulation and high-current switching where efficiency matters.

Can the TIP131 replace the TIP121 in an existing design?

The TIP131 can replace the TIP121 only if the application requires ≥80 Vdc collector-emitter sustaining voltage. While both share TO-220AB packaging and similar gain/saturation specs, the TIP121 is rated for only 60 Vdc V_CEO(sus). Substituting TIP131 into a 60 V system is safe-but using TIP121 in place of TIP131 risks breakdown in 80 V applications. Always verify bus voltage margins before interchanging the TIP131 and TIP121.

Is there a Pb-free version of the TIP131 available?

Yes, the Pb-free variant is explicitly listed as TIP131G in the "Ordering Information" section of the TIP131 datasheet. It uses the same TO-220AB package (Case 221A, Style 1) and shares identical electrical and thermal specifications with the standard TIP131. The "G" suffix denotes RoHS-compliant lead finish, and both versions ship in 50-unit rails.