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Home > Products > Discrete Semiconductor Products > Transistors > Bipolar (BJT) > Single Bipolar Transistors

STMicroelectronics TIP112

Name: TIP112
Brand: STMicroelectronics
SKU: TIP112
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: TIP112

Manufacturer:: STMicroelectronics

Category:: Single Bipolar Transistors

Package:: TO-220-3

Datasheet:: TIP112.pdf

Description:: TRANS NPN DARL 100V 2A TO-220

Quantity:: RFQ Add To RFQ list

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Inventory:3,263

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Product details

Overview

TIP112 from STMicroelectronics is a silicon NPN power Darlington transistor in monolithic configuration, designed for medium-power linear and switching applications such as motor drivers and power supplies. It features 100 V V_CEO, 2 A continuous collector current, integrated antiparallel collector-emitter diode, 2.5 V V_CE(sat) at I_C = 2 A / I_B = 8 mA, and 50 W total dissipation at T_case ≤ 25 °C.

For engineers reviewing the TIP112 datasheet, TIP112 pinout, TIP112 application, or TIP112 equivalent, key selection factors include its Darlington gain (h_FE ≥ 500 at I_C = 2 A), built-in freewheel diode, TO-220 thermal resistance (R_thj-case = 2.5 °C/W), and safe operating area suitability for inductive load switching.

Technical Context

The TIP112 implements a monolithic Darlington pair with internal base resistors (R1 ≈ 7 kΩ, R2 ≈ 230 Ω) enabling direct TTL/CMOS drive without external biasing. Its integrated antiparallel collector-emitter diode provides inherent flyback protection for inductive loads.

Designed for DC and low-frequency switching up to ~10 kHz, it operates with V_BE ≈ 2.8 V at I_C = 2 A and supports pulsed I_C up to 4 A (300 µs, 1.5% duty cycle), with maximum junction temperature of 150 °C and storage range from –65 °C to +150 °C.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	100 V - Maximum collector-emitter voltage before breakdown under open-base condition; defines safe DC bus voltage headroom.
I_C (continuous)	2 A - Continuous collector current rating at T_case ≤ 25 °C; sets baseline load-handling capability.
V_CE(sat)	2.5 V @ I_C=2 A, I_B=8 mA - Saturation voltage determines conduction loss and heatsink sizing in switching mode.
h_FE	≥500 @ I_C=2 A, V_CE=4 V - High DC current gain reduces required base drive current and simplifies driver design.
P_tot	50 W @ T_case ≤ 25 °C - Total power dissipation limit; combined with R_thj-case = 2.5 °C/W, defines thermal margin.
Integrated Diode	Antiparallel C–E diode - Enables self-contained flyback path for relay/motor coils; eliminates need for external freewheel diode.
R_thj-case	2.5 °C/W - Junction-to-case thermal resistance; enables accurate heatsink thermal calculation for sustained operation.

Pinout & Package

Package: JEDEC TO-220 plastic package with metal tab (collector-connected). Mounting hole centered on tab, pin 1 = base, pin 2 = collector (tab), pin 3 = emitter.

Pin/Terminal	Circuit Role	Design Meaning
Pin 1 (Base)	Control input	Accepts TTL/CMOS-compatible drive current (I_B ≤ 50 mA); internal R1/R2 enable single-resistor biasing.
Pin 2 (Collector / Tab)	Main power output	Electrically connected to metal tab; must be electrically isolated from heatsink unless circuit ground reference permits.
Pin 3 (Emitter)	Power return path	Serves as low-side switch return; polarity defines NPN topology-load connects between V_CC and collector.

Key Features

Feature	Design Value
Monolithic Darlington structure	Single-die integration of driver and output transistors ensures matched thermal behavior and eliminates interconnect parasitics.
Integrated antiparallel diode	Eliminates discrete flyback diode in relay/motor control, reducing BOM count and PCB footprint.
Internal base resistors	R1 ≈ 7 kΩ and R2 ≈ 230 Ω allow direct logic-level drive without external bias network.
TO-220 mechanical standard	Industry-standard outline with 2.5 °C/W R_thj-case supports drop-in replacement and heatsink compatibility.
150 °C max junction temperature	Enables reliable operation in industrial enclosures with ambient temperatures up to 85 °C when properly heatsinked.

Applications

DC Motor Control

Relay Driver Circuit

Use Scenario: Driving 24 V, 1.5 A brushed DC motors in industrial actuators with PWM speed control.

IC Role / Device Role / Timing Role: NPN Darlington switch controlling motor current path from supply rail to ground.

Use Value: Integrated freewheel diode clamps inductive kickback during PWM off-time, preventing voltage spikes >100 V.

Use Scenario: Solid-state replacement for electromechanical relays in PLC output modules switching 120 VAC solenoids.

IC Role / Device Role / Timing Role: Medium-power switching element interfacing microcontroller GPIO to high-current AC load.

Use Value: 100 V V_CEO and 2 A I_C support direct control of 120 VAC loads via external triac/diode bridge.

Linear Regulator Pass Element

Switch-Mode Power Supply (SMPS) Output Stage

Use Scenario: Series pass transistor in adjustable 5–30 V, 1.2 A linear regulators for lab bench supplies.

IC Role / Device Role / Timing Role: Voltage-controlled current source regulating output by dissipating excess input-output differential.

Use Value: 50 W P_tot and 2.5 °C/W R_thj-case enable stable 1.2 A operation with ≤15 °C/W heatsink at 30 V dropout.

Use Scenario: Low-frequency (≤10 kHz) output switch in flyback or forward converter auxiliary supplies.

IC Role / Device Role / Timing Role: Primary-side switching device turning on/off transformer energy transfer cycles.

Use Value: Darlington gain ≥500 allows direct drive from UC384x controller outputs without gate driver IC.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
MJD112G	TO-263 surface-mount package; lower R_thj-amb (40 °C/W vs. 62.5 °C/W), same V_CEO/I_C/h_FE.	Requires rework for SMT assembly; better suited for compact, thermally constrained PCBs.	Select for automated production where board space and thermal performance outweigh through-hole serviceability.
TIP122	Same TO-220 package; higher h_FE (min. 1000 vs. 500), identical V_CEO/I_C/V_CE(sat).	Lower base drive requirement; may reduce driver stage complexity in low-power control systems.	Select when minimizing base current (e.g., battery-powered controllers) is critical and higher gain does not compromise stability.

Compared with MJD112G and TIP122, the TIP112 offers optimal balance of through-hole serviceability, proven thermal derating in legacy industrial designs, and sufficient gain for direct microcontroller drive-making it preferred for field-serviceable equipment and retrofit upgrades.

Availability

TIP112 is available at Aetrix Electronics and suitable for DC motor control, relay driving, linear regulator pass elements, and low-frequency SMPS output stages requiring stable component supply across long-lifecycle industrial programs.

Supply support for TIP112 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

STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, specializing in automotive, industrial, and power management solutions with vertical manufacturing and broad analog/mixed-signal IP.

The TIP112 belongs to ST's legacy power bipolar transistor family, engineered specifically for robust, cost-effective medium-power switching and linear regulation in industrial control, automation, and power conversion equipment.

FAQ

Is the TIP112 pin-compatible with the TIP122?

Yes-both use identical TO-220 package with base-collector-emitter pinout (pin 1 = base, pin 2 = collector/tab, pin 3 = emitter). However, the TIP122 has minimum h_FE = 1000 versus 500 for the TIP112, which may affect base drive requirements in low-current control circuits.

Does the integrated diode connect between collector and emitter terminals?

Yes-the internal antiparallel diode is connected anode-to-emitter and cathode-to-collector, providing automatic flyback path during inductive turn-off. This diode is rated for 2 A continuous forward current and matches the transistor's thermal profile.

Can the TIP112 be used in parallel for higher current?

No-Darlington transistors exhibit positive thermal feedback and unequal current sharing due to h_FE variation and V_BE mismatch. Parallel operation requires individual emitter resistors and matched devices, which ST does not recommend or characterize for the TIP112.

What is the maximum safe switching frequency for the TIP112?

The TIP112 is characterized for DC and low-frequency switching up to 10 kHz. Above this, storage time (t_s) and fall time (t_f) increase significantly-measured at ~1.5 µs t_s and ~1.2 µs t_f-leading to excessive switching losses and thermal stress.

TIP112 Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Series:: -

Package/Case:: TO-220-3

Packaging:: Tube

Product Status:: Active

Transistor Type:: NPN - Darlington

Current - Collector (Ic) (Max):: 2 A

Voltage - Collector Emitter Breakdown (Max):: 100 V

Vce Saturation (Max) @ Ib, Ic:: 2.5V @ 8mA, 2A

Current - Collector Cutoff (Max):: 2mA

DC Current Gain (hFE) (Min) @ Ic, Vce:: 1000 @ 1A, 4V

Power - Max:: 2 W

Frequency - Transition:: -

Operating Temperature:: 150°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: TO-220

TIP112 FAQ

1.How can I place an order for TIP112 through Aetrix?

Please submit a Request for Quotation (RFQ) for TIP112 on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.

2.Are the price and stock information for TIP112 reliable?

The price and inventory of TIP112 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TIP112 is usually 5 days.

3.What payment methods are accepted for TIP112?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TIP112 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for TIP112?

TIP112 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your TIP112 order is processed, you will receive an email with the shipment details and tracking number.

Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.

5.How can I obtain technical support or documentation for TIP112?

For technical support, including TIP112 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TIP112 requirements.

6.How does Aetrix verify that TIP112 is sourced from the original manufacturer or authorized distributors?

All TIP112 products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that TIP112 meets industry standards.

7.What is the process for return or replacement of TIP112?

All TIP112 units undergo pre-shipment inspection (PSI). If there is an issue with TIP112, returns or replacements are accepted under the following conditions:

1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.

2.The issue is reported within 90 days of delivery.

3.The TIP112 part is unused and in its original packaging.

Return procedure for TIP112:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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