This Product Selection Guide contains information to help select products in the Thyristors - SCRs category on DigiKey.com
Silicon Controlled Rectifiers (SCRs) are three-terminal devices that behave like rectifier diodes, with an added ability to block current flow in the forward direction until a control signal is applied. Most commonly used for controlling AC utility power, SCRs are also known as thyristors, though this latter term is also sometimes applied to other related devices.
SelectionCharacteristics
Specifications to determine which SCR is right for your application.
Voltage - Off State: Indicates the maximum instantaneous voltage that may be repetitively/continuously applied to a device in a non-conducting state without causing damage.
Voltage - Gate Trigger (Vgt) (Max): The maximum voltage required to produce the listed gate trigger current. Measured under manufacturer-defined test conditions.
Current - Gate Trigger (Igt) (Max): The maximum current that must be passed through a device’s gate terminal to guarantee a device will trigger into conduction. Measured under manufacturer-defined test conditions.
Voltage - On State (Vtm) (Max): Characterizes the voltage that appears across a device in an “on” state and conducting a test current of manufacturer-defined amplitude.
Current - On State (It (AV)) (Max): The maximum allowable time-averaged current flow through a device, when conducting for half of a sinusoidal AC waveform at a manufacturer-specified device temperature.
Current - On State (It (RMS)) (Max): The rated maximum RMS (root mean square) current carrying capacity of a device, typically specified for sinusoidal current waveforms at 50/60 Hz.
Current - Hold (Ih) (Max): Characterizes the minimum current flow through a device required to maintain a conductive state.
Current - Off State (Max): Maximum leakage current that flows through the device when in the off-state. Room-temp limits shown, actual values will vary significantly with device temperature.
Current - Non Rep. Surge 50, 60Hz (Itsm): The maximum current a device is rated to conduct for a single half-cycle of an AC waveform of a specified frequency. Values shown for 50 and 60 Hz, or as indicated.
SCR Type: Indicates whether or not a device is designed to be triggerable using signal levels commonly found in digital logic circuits.
Operating Temperature: Recommended operating temperature, typically given in a range or as a maximum. Exceeding these temperatures may affect performance or damage the device and other system components.
Mounting Type: Indicates how the device is attached.
Available Mounting types
Chassis Mount
Designed to be mounted to a metal chassis.
Chassis, Stud Mount
Designed to be mounted to a metal Chassis using an incorporated stud bolt.
Stud Mount
Has a stud bolt incorporated into one side for attachment.
Surface Mount
Have pins or pads that connect to solder pads on the PCB that are then soldered in place forming an electrical and mechanical connection. Number in front of SMD indicates how many pins/pads, for example a 6-SMD module has 6 pins/pads. May not use or even have all the pins/pads for example 24-SMD module, 14 leads: would fit in the space of a 24-SMD module but only has 14 pins/pads. Typically, they are smaller than the through-hole components.
There are three basic types of pins (leads) for surface mount devices.
Lead Types
Gull wing leads: Enable the most pins per inch when compared to J-lead types but they are more fragile. Easy to inspect for defects after soldering.
J-Leads: Less pins per inch than gull wing leads but they are stronger and less susceptible to breakage.
Flat Leads: Must be protectively packaged to prevent damage to leads. Leads must be formed into a gull shape prior to use with a separate piece of equipment. Due to that they are the least popular type of lead.
Through-hole
Have leads that go through a pre-drilled hole on a PCB and are soldered in place forming both an electrical and a mechanical connection.
Package / Case: Indicates the type of protective case used on an electronic component to allow easy handling, installation, and protection. This selection was determined to be the closest industry standard applicable to the suppliers device packaging. Typically it is best to check the actual dimensions from the datasheet rather than depend on this terminology when designing your circuit.
Supplier Device Package: This is what the manufacturer calls the package of this device. They are manufacturer specific. It is typically best to use the actual dimensions from the datasheets rather than to go by this terminology when designing your circuit.
ProductExamples
| MFR PART # | VS-ST380CH06C0 |
|---|---|
| DIGI-KEY PART # | VS-ST380CH06C0GI-ND |
| MANUFACTURER | Vishay General Semiconductor - Diodes Division |
| DESCRIPTION | SCR 600 V 2220 A Standard Recovery Chassis Mount TO-200AB (E-Puk) |
| DATASHEET | Click Here |
| MFR PART # | C152S |
|---|---|
| DIGI-KEY PART # | C152S-ND |
| MANUFACTURER | Powerex Inc. |
| DESCRIPTION | SCR 700 V 100 A Standard Recovery Stud Mount |
| DATASHEET | Click Here |
| MFR PART # | MCR08MT1G |
|---|---|
| DIGI-KEY PART # | MCR08MT1GOSTR-ND - Tape & Reel (TR) |
| MANUFACTURER | Littelfuse Inc. |
| DESCRIPTION | SCR 600 V 800 mA Sensitive Gate Surface Mount SOT-223 |
| DATASHEET | Click Here |
| MFR PART # | BT152-1200TQ |
|---|---|
| DIGI-KEY PART # | 1740-BT152-1200TQ-ND |
| MANUFACTURER | WeEn Semiconductors |
| DESCRIPTION | SCR 1.2 kV 31 A Standard Recovery Through Hole TO-220AB |
| DATASHEET | Click Here |
Schematic Symbol
SCR symbols courtesy of Scheme-It please use the link for more information and symbols.
MediaLinks
Videos
Littelfuse SIDACtor Thyristors
Littelfuse SJ Series Thyristors
STMicroelectronics Automotive-grade Thyristor| DigiKey
SCR Heat Sink Clamp Assembly Procedure Wakefield Thermal
Product Training Modules
AC Switches Family, Part One - STMicroelectronics
AC Switches Family Part Two - STMicroelectronics
Product Training Modules on SCRs
TechForum
Forum posts on SCRs
Forum posts on Thyristors