XL0840-AP STMicroelectronics SCR (Other) In Stock

The XL0840-AP is a sensitive-gate SCR from STMicroelectronics rated at 400 V and 800 mA, housed in a TO-92-3 through-hole package. It features a low DC gate trigger current of 0.2 mA max and gate trigger voltage of 0.8 V max. Ideal for phase control and switching applications requiring compact, reliable thyristor solutions.

OBSOLETESCRVerified Jun 2026
Package / Visual Reference
XL0840-APOther
Quick Facts
Manufacturer
STMicroelectronics
Package
Other
Pin Count
3
Lifecycle
OBSOLETE
Category
SCR
Temp Range
-40.0°C to 125.0°C
RoHS
Compliant
Lead Time
3–7 business days
Shipping
DHL Express · Worldwide

Key Features

  • Sensitive gate triggering with DC gate trigger current as low as 0.2 mA max, enabling direct interface with low-power logic circuits
  • Rated at 400 V off-state voltage with 800 mA RMS on-state current and 8 A non-repetitive peak on-state current surge capability
  • Compact TO-92-3 through-hole package with single SCR configuration for space-constrained PCB designs
  • Minimum critical rate-of-rise of off-state voltage (dV/dt) of 75 V/µs ensuring stable operation in noisy switching environments

Applications

The XL0840-AP sensitive-gate SCR is well-suited for AC power control circuits such as light dimmers, motor speed controllers, and heating element regulators where low gate trigger current is essential. Its compact TO-92-3 package and 400 V blocking voltage make it suitable for line-voltage switching and phase control in home appliances and industrial equipment. It is also used in overvoltage protection circuits and latching relay replacement designs requiring a thyristor with reliable triggering from microcontroller outputs.

Specifications

YTEOL0
ConfigurationSINGLE
Critical Rate of Rise of Off-State Voltage-Min75V/us
DC Gate Trigger Current-Max0.2mA
DC Gate Trigger Voltage-Max0.8V
Holding Current-Max5mA
JEDEC-95 CodeTO-92
JESD-30 CodeO-PBCY-T3
Non-Repetitive Pk On-state Cur8A
Number of Elements1
On-state Current-Max500A
Package Body MaterialPLASTIC/EPOXY
Package ShapeROUND
Package StyleCYLINDRICAL
RMS On-state Current-Max0.8A
Repetitive Peak Off-state Leakage Current-Max0.1 µA
Repetitive Peak Off-state Voltage400V
Surface MountNO
Terminal FormTHROUGH-HOLE
Terminal PositionBOTTOM
Trigger Device TypeSCR
PackageOther

Compliance & Regulatory

RoHS StatusCompliant
Lead-FreeYes (Pb-Free)
ECCNEAR99
HTS Code8541.30.00.80
Country of OriginMainland China

Datasheet

XL0840-AP Datasheet Download

Official datasheet from STMicroelectronics

Alternate & Equivalent Parts

Compatible alternatives and drop-in replacements for XL0840-AP:

XL0840-TR

STMicroelectronics Silicon Controlled Rectifier, 0.8A I(T)RMS, 0.5mA I(T), 400V V(DRM), 1 Element, TO-92

View Part →
XL0840

STMicroelectronics Silicon Controlled Rectifier, 0.8A I(T)RMS, 0.5mA I(T), 400V V(DRM), 1 Element, TO-92

View Part →

Frequently Asked Questions

What is the minimum gate trigger current required to turn on the XL0840-AP?

The XL0840-AP requires a maximum DC gate trigger current of 0.2 mA and a maximum gate trigger voltage of 0.8 V, making it compatible with low-power logic outputs. This sensitive-gate characteristic allows direct drive from microcontrollers without additional driver circuitry in many designs.

Can the XL0840-AP handle inrush current from capacitive loads during power-up?

The XL0840-AP supports a non-repetitive peak on-state current of 8 A, which provides margin for brief inrush events. Its steady-state on-state RMS current rating is 800 mA at the TO-92-3 package thermal limits, so sustained currents must be kept within that bound.

Which phase-control applications benefit most from the XL0840-AP's 75 V/µs dV/dt rating?

Applications such as AC light dimmers and motor speed controllers operating at 50–60 Hz line frequency benefit from the 75 V/µs minimum critical rate-of-rise of off-state voltage. This rating ensures the SCR will not accidentally trigger due to rapidly rising voltage transients on the 400 V-rated anode circuit.

How does the XL0840-AP's holding current spec affect circuit design?

The XL0840-AP has a maximum holding current of 5 mA, meaning the anode current must remain above 5 mA to keep the device latched on. Circuit designers must ensure the minimum load current exceeds 5 mA during the conduction interval, particularly in resistive-load phase-control designs at low conduction angles.

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About STMicroelectronics

STMicroelectronics is a global semiconductor leader serving customers across the spectrum of electronics applications. ST's products are found in a wide range of applications including automotive, industrial, personal electronics, and communications.

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Lead Time3-7 business days
MOQFrom 1 piece
ShippingDHL / FedEx / UPS
OriginChina (Authorized)

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Their engineering team helped us find a pin-compatible alternative when our original MCU went EOL.

MR
Marco Rossi
CTO, AutoDrive Systems, Italy