onsemi TIP29CTSTU

Overview

TIP29CTSTU from onsemi is an NPN silicon power transistor in TO−220 package, rated for 100 V_CEO, 1.0 A continuous collector current, and 30 W total power dissipation at T_C = 25°C. It serves as a general-purpose amplifier and switching device in linear and hard-switching applications such as power supplies, motor drivers, and relay drivers.

For engineers reviewing the TIP29CTSTU datasheet, pinout, applications, or equivalent options, key selection criteria include V_CEO = 100 V, I_C = 1.0 A, h_FE ≥ 15 (at I_C = 1.0 A), V_CE(sat) ≤ 0.7 V, and thermal resistance R_JC = 4.167 °C/W - all critical for thermal management and saturation performance in discrete power stages.

Technical Context

The TIP29CTSTU operates as a medium-power bipolar junction transistor with complementary PNP counterpart TIP30C. Its design supports both linear amplification (with h_FE = 15–75) and switching (t_r/t_f < 1 μs, E = 32 mJ unclamped inductive energy rating). Junction temperature range spans −65°C to +150°C, enabling use in industrial ambient conditions.

Thermal performance is defined by R_JC = 4.167 °C/W and R_JA = 62.5 °C/W, requiring heatsinking for sustained operation above ~1.5 W at ambient. Safe operating area (SOA) curves confirm second-breakdown-limited operation up to 100 V and 1 A under pulsed conditions (1 ms, 10% duty cycle).

Key Specifications

Pinout & Package

Package: TO−220 (Case 221A, Style 1), 4-lead, through-hole, Pb-free. Mounting tab is electrically connected to collector.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MJD2955T4G and 2N3055G, the TIP29CTSTU offers higher voltage tolerance (100 V) in a compact TO−220 package but lower current capacity; it is optimized for cost-sensitive, medium-voltage switching where thermal design targets ≤30 W dissipation.

Availability

TIP29CTSTU is available at Aetrix Electronics and suitable for power supply regulation, relay driving, and small-motor control applications requiring stable component supply, long-term manufacturability, and legacy-compatible through-hole packaging.

Supply support for TIP29CTSTU 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 focused on energy-efficient electronics, with leadership in power management, analog, sensors, and logic solutions.

The TIP29CTSTU belongs to onsemi's legacy plastic power transistor family designed for cost-effective, reliable discrete switching and amplification in industrial, consumer, and automotive auxiliary systems.

FAQ

What is the maximum collector-emitter voltage rating for TIP29CTSTU?

The TIP29CTSTU has a maximum collector-emitter sustaining voltage (V_CEO(sus)) of 100 V DC under specified test conditions (I_C = 30 mA, I_B = 0). This rating ensures safe operation in circuits with up to 80 V nominal supply rails while maintaining margin against transients and switching spikes. Exceeding this voltage risks avalanche breakdown and permanent device failure.

Is TIP29CTSTU pin-compatible with other TIP29 variants like TIP29B or TIP29A?

Yes, all TIP29x variants (TIP29, TIP29A, TIP29B, TIP29C) share identical TO−220 package pinout (Base–Collector–Emitter–Collector) and mechanical dimensions. The suffix denotes voltage rating only: TIP29CTSTU is rated for 100 V_CEO, whereas TIP29B is 80 V and TIP29A is 60 V. Electrical substitution requires verifying voltage margin in the target circuit.

Does TIP29CTSTU require a heatsink in typical operation?

Yes - the TIP29CTSTU dissipates up to 30 W at T_C = 25°C, but its R_JA = 62.5 °C/W means even 2 W of dissipation raises junction temperature by ~125°C above ambient. For reliable continuous operation above ~1.5 W, a heatsink with thermal resistance ≤10 °C/W (including interface) is required to keep T_J ≤ 150°C.

What is the DC current gain (h_FE) range for TIP29CTSTU at 1.0 A collector current?

The TIP29CTSTU exhibits h_FE ≥ 15 at I_C = 1.0 A and V_CE = 4.0 V, with typical values reaching 40–75 at lower currents (I_C = 0.2 A). Designers must size base drive to guarantee saturation across this gain spread - e.g., 125 mA I_B ensures I_C/I_B ≤ 8, well below minimum h_FE.

Can TIP29CTSTU be used in switching power supplies?

The TIP29CTSTU can be used in low-frequency (<100 kHz) switching power supplies such as flyback or forward converters where its 3.0 MHz f_T, 32 mJ unclamped inductive energy rating, and 100 V_CEO provide adequate performance. However, its relatively high V_CE(sat) and slow switching times make it less efficient than modern MOSFETs or faster BJTs in high-frequency SMPS designs.