Transistors - Programmable Unijunction

Category Introduction

Programmable unijunction transistors (PUTs) are a relative of Silicon Controlled Rectifier (SCR) devices, having a characteristic behavior somewhat like a unidirectional DIAC with a user-configurable threshold voltage. While useful for creating low frequency oscillator and timing functions, SCR triggering applications, and others, alternative techniques for addressing such needs have gained greater favor.

Product List

39 Items

Mfr Part #	Quantity Available	UnitPrice	Packaging	Product Status	Voltage	Power Dissipation (Max)	Voltage - Output	Voltage - Offset (Vt)	Current - Gate to Anode Leakage (Igao)	Current - Valley (Iv)	Current - Peak	Package / Case
2N4988 SMALL SIGNAL BIPOLAR TRANSISTOR Harris Corporation	1,010	$0.57	Bulk	Active	30V	300 mW	3.5V	-	-	-	-	TO-98-3
2N2646 UNI JUNCT TRANS TO18 Solid State Inc.	243	$1.18	Box	Active	35V	300 mW	-	3 V	-	600 µA	5 µA	TO-206AA, TO-18-3 Metal Can
2N4989 SMALL SIGNAL BIPOLAR TRANSISTOR Harris Corporation	201	$1.43	Bulk	Active	30V	300 mW	-	-	-	-	-	TO-98-3
CMPP6028 TR PBFREE PROGRAMMABLE UJT SOT-23 Central Semiconductor Corp	354	$2.74	Tape & Reel (TR)	Active	40V	167 mW	6V	600 mV	10 nA	25 µA	150 nA	TO-236-3, SC-59, SOT-23-3
NTE6410 T-UNIJUNCTION SI NTE Electronics, Inc	31	$7.69	Bag	Active	-	300 mW	-	-	-	7 mA	5 µA	TO-226-3, TO-92-3 (TO-226AA)
NTE6401 T-UNIJUNCTION SI NTE Electronics, Inc	38	$9.08	Bag	Active	-	300 mW	-	-	-	6 mA	5 µA	TO-206AA, TO-18-3 Metal Can
NTE6409 T-UNIJUNCTION SI NTE Electronics, Inc	27	$9.57	Bag	Active	-	600 mW	-	-	-	18 mA	2 µA	TO-206AA, TO-18-3 Metal Can
NTE6400 T-UNIJUNCTION SI NTE Electronics, Inc	13	$59.48	Bag	Active	-	300 mW	-	-	-	8 mA	25 µA	TO-205AD, TO-39-3 Metal Can
NTE6400A T-UNIJUNCTION SI NTE Electronics, Inc	5	$55.21	Bag	Active	-	600 mW	-	-	-	8 mA	25 µA	TO-205AD, TO-39-3 Metal Can
GES6028 PNP PROGRAMMABLE UNIJUNCTION TRA Harris Corporation	208	$0.00	Bulk	Active	1.5V	300 mW	6V	1.6 V	10 nA	25 µA	150 nA	TO-226-3, TO-92-3 (TO-226AA)
NTE6402 T-PROG. UNIJUNCTION SI NTE Electronics, Inc	180	$3.03	Bag	Active	40V	300 mW	6V	1.6 V	10 nA	50 µA	2 µA	TO-226-3, TO-92-3 (TO-226AA)
CMPP6027 TR PBFREE PROGRAMMABLE UJT SOT-23 Central Semiconductor Corp	455	$1.20	Tape & Reel (TR)	Active	-	-	-	-	-	-	-	-
2N6027 PBFREE PROGRAMMABLE UJT 40V TO226-3 Central Semiconductor Corp	433	$1.21	Bulk	Active	40V	300 mW	6V	1.6 V	10 nA	50 µA	2 µA	TO-226-3, TO-92-3 (TO-226AA)
2N6028 PBFREE PROGRAMMABLE UJT 40V TO226-3 Central Semiconductor Corp	136	$1.23	Bulk	Active	40V	300 mW	6V	600 mV	10 nA	25 µA	150 nA	TO-226-3, TO-92-3 (TO-226AA)
2N2647 TO 18 UNIJUNCTION TRANSISTOR Solid State Inc.	249	$1.38	Bulk	Active	35V	300 mW	7V	-	-	18 mA	2 µA	TO-206AA, TO-18-3 Metal Can
2N1671 TO 5 UNIJUNCTION TRANSISTOR Solid State Inc.	3	$58.87	Bulk	Active	30V	450 mW	-	-	-	-	25 µA	TO-205AA, TO-5-3 Metal Can
2N1671A TO 5 UNIJUNCTION TRANSISTOR Solid State Inc.	12	$58.95	Bulk	Active	30V	450 mW	-	-	-	-	25 µA	TO-205AA, TO-5-3 Metal Can
2N1671C TO 5 UNIJUNCTION TRANSISTOR Solid State Inc.	6	$59.21	Bulk	Active	30V	450 mW	-	-	-	-	25 µA	TO-205AA, TO-5-3 Metal Can
2N6027RLRA THYRISTOR PROG UNIJUNCT 40V TO92 onsemi	476	$0.00	Cut Tape (CT)	Obsolete	40V	300 mW	11V	1.6 V	10 nA	50 µA	2 µA	TO-226-3, TO-92-3 (TO-226AA) Formed Leads
2N6028RLRA THYRISTOR PROG UNIJUNCT 40V TO92 onsemi	99	$0.00	Cut Tape (CT)	Obsolete	40V	300 mW	11V	600 mV	10 nA	25 µA	150 nA	TO-226-3, TO-92-3 (TO-226AA) Formed Leads

About Programmable Unijunction Transistors (PUTs)

What are Programmable Unijunction Transistors (PUTs)?

Programmable Unijunction Transistors (PUTs)

Programmable Unijunction Transistors (PUTs) are a type of semiconductor device that functions as a switch or amplifier in electronic circuits. Unlike traditional unijunction transistors, PUTs offer the advantage of programmability, allowing users to set the intrinsic standoff ratio through external resistors. This flexibility makes them ideal for applications requiring precise control over switching characteristics. PUTs operate by utilizing a four-layer structure (PNPN) and are triggered into conduction when the anode voltage exceeds a certain threshold, determined by the gate voltage. This makes them suitable for timing, triggering, and oscillator circuits.

Types of Programmable Unijunction Transistors (PUTs)

Standard PUTs

Standard PUTs are the most common type, used in general-purpose applications. They are characterized by their simplicity and ease of use, making them suitable for educational purposes and basic circuit designs. These PUTs are often employed in relaxation oscillators and timing circuits.

High-Voltage PUTs

High-voltage PUTs are designed to handle higher voltage levels, making them ideal for industrial applications where robust performance is required. These PUTs are used in power control circuits and high-voltage triggering applications, where they provide reliable switching capabilities.

Low-Power PUTs

Low-power PUTs are optimized for applications where energy efficiency is crucial. They consume less power and are used in battery-operated devices and low-power oscillators. Their reduced power consumption makes them suitable for portable electronics and energy-saving applications.

How to choose Programmable Unijunction Transistors (PUTs)?

When selecting a PUT, consider the following key parameters:

Voltage Rating: Ensure the PUT can handle the maximum voltage in your application.
Current Rating: Choose a PUT with a current rating that matches your circuit's requirements.
Gate Sensitivity: Select a PUT with appropriate gate sensitivity for your triggering needs.
Temperature Range: Consider the operating temperature range to ensure reliability in your environment.

Evaluate product quality by reviewing supplier certifications, customer reviews, and testing standards. Consider environmental factors such as humidity and temperature fluctuations, and ensure proper installation with adequate heat dissipation and protection against electrical noise.

Applications of Programmable Unijunction Transistors (PUTs)

Consumer Electronics

In consumer electronics, PUTs are used in timing circuits for devices like televisions and radios. They help manage power supply timing and ensure efficient operation of electronic components.

Industrial Automation

PUTs play a crucial role in industrial automation systems, where they are used in control circuits for machinery and equipment. Their ability to handle high voltages makes them suitable for robust industrial environments.

Automotive Industry

In the automotive sector, PUTs are employed in ignition systems and timing circuits. They help improve the efficiency and reliability of vehicle electronics, contributing to better performance and fuel efficiency.

Telecommunications

PUTs are used in telecommunications for signal processing and timing applications. They ensure accurate timing and synchronization in communication networks, enhancing data transmission reliability.

Medical Devices

In medical devices, PUTs are used in monitoring and diagnostic equipment. Their precise timing capabilities are essential for accurate measurements and reliable operation of medical instruments.