onsemi TIP29G

Overview

TIP29G from onsemi is an NPN silicon power transistor in a TO−220 package, rated for 40 V_CEO, 1.0 A continuous collector current, and 30 W total power dissipation at T_C = 25°C. It delivers h_FE ≥ 40 at I_C = 0.2 A, V_CE = 4.0 V, and exhibits V_CE(sat) ≤ 0.7 V at I_C = 1.0 A / I_B = 125 mA - used in linear amplifier stages and medium-power switching circuits such as DC motor drivers and relay interfaces.

For engineers reviewing the TIP29G datasheet, pinout, applications, or equivalent options, key selection criteria include its 40 V V_CEO rating, TO−220 thermal performance (R_JC = 4.167 °C/W), unclamped inductive energy handling (32 mJ), and Pb-free RoHS-compliant packaging - all critical for industrial control and power interface designs requiring robust discrete gain and switching capability.

Technical Context

The TIP29G operates as a general-purpose NPN bipolar junction transistor optimized for linear amplification and hard-switching applications up to ~3 MHz f_T. Its safe operating area (SOA) is defined by second-breakdown limits at short pulses and thermal constraints at DC, with validated operation from −65°C to +150°C junction temperature.

It features low V_BE(on) ≤ 1.3 V at I_C = 1.0 A, supports peak collector current up to 3.0 A, and maintains h_FE ≥ 15 even at I_C = 1.0 A - enabling stable biasing in Class-A/B amplifier output stages and reliable saturation in low-frequency switch-mode loads.

Key Specifications

Pinout & Package

Package: TO−220 (Case 221A, Style 1), Pb-free, through-hole mounting with metal tab 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 MJD2955G and 2N3055G, the TIP29G provides optimal balance of voltage rating, thermal efficiency in TO−220, and cost for 40 V/1 A linear and switching roles - avoiding over-engineering while ensuring manufacturability and thermal margin in standard through-hole assemblies.

Availability

TIP29G is available at Aetrix Electronics and suitable for industrial motor control, audio amplifier design, and relay interface circuits requiring stable component supply and long-term obsolescence management.

Supply support for TIP29G 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 TIP29G belongs to onsemi's legacy plastic power transistor family designed for cost-sensitive, high-reliability linear amplification and medium-power switching - emphasizing ruggedness, thermal stability, and broad temperature operation in industrial and infrastructure systems.

FAQ

What is the maximum continuous collector current rating for the TIP29G?

The TIP29G has a maximum continuous collector current (I_C) rating of 1.0 A at T_C = 25°C. This value decreases with rising case temperature due to thermal derating (0.24 W/°C). At elevated temperatures or without heatsinking, actual usable current may fall below 1.0 A - always verify junction temperature using R_JC = 4.167 °C/W and ambient conditions in your final TIP29G design.

Is the TIP29G pin-compatible with other TIP29 variants like TIP29CG?

No - the TIP29G shares the same TO−220 package and pinout (Base–Collector–Emitter–Collector) with all TIP29x variants, but differs in V_CEO rating: TIP29G is rated for 40 V, whereas TIP29CG is rated for 100 V. Substituting TIP29G for TIP29CG in a 100 V circuit risks catastrophic failure; voltage rating must match system requirements, not just pinout.

Does the TIP29G require a heatsink in typical switching applications?

Yes - the TIP29G dissipates significant power during conduction (e.g., 0.7 V × 1.0 A = 0.7 W minimum in saturation). Even at moderate duty cycles, junction temperature can exceed 150°C without thermal management. A heatsink is required whenever average power exceeds ~1.5 W or when operating continuously above 25°C ambient - refer to R_JC and R_JA = 62.5 °C/W to size appropriately for your TIP29G layout.

What is the safe operating area (SOA) limitation that governs TIP29G use in inductive switching?

The TIP29G's SOA is limited by second breakdown at short pulses and thermal constraints at DC. For unclamped inductive turn-off, it is rated for 32 mJ (tested at L_C = 20 mH, V_CC = 10 V, I_C = 1.8 A). Exceeding this energy - e.g., with higher voltage, current, or inductance - risks localized junction failure. Always validate SOA boundaries using Figure 5 from the official TIP29G datasheet for your specific operating point.

Can the TIP29G be used as a direct replacement for the obsolete TIP29C in existing designs?

The TIP29G is the Pb-free, RoHS-compliant version of the legacy TIP29C, sharing identical electrical specifications, TO−220 package, and pinout. However, TIP29C has V_CEO = 100 V while TIP29G is rated for 40 V - they are not interchangeable unless the original design operates well within 40 V. Verify voltage stress margins before substituting TIP29G in any TIP29C-based circuit.