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Selective Catalytic Reduction (SCR)

Tools and Software
HW Evaluation Tools
Key Products
Selective catalytic reduction (SCR) is a chemical process converting nitrogen oxides (NOx) into diatomic nitrogen and water as well as a small amount of carbon dioxide. This process is facilitated by the addition of automotive-grade urea – known as Diesel Exhaust Fluid (DEF) or commercial brands like AdBlue and Bluetech – to convert hazardous NOx emissions from diesel engines into harmless nitrogen and water.

How the SCR block works

The SCR block controls a pump that draws DEF from its tank and injects it, with an appropriate dosing valve, into the diesel exhaust gases. To optimize fuel efficiency, a gas sensor is located after the catalytic reduction process and its information is fed to the diesel engine ECU that combines this information with the engine status and give to the SCR unit accurate information regarding the right amount of DEF liquid to release.

Our products and solutions

We have a range of three-phase gate drivers and Power MOSFETs for the commonly used brushless DC (BLDC) motors, as well as SPC5 32-bit microcontrollers and dedicated power management ICs with voltage regulators and CAN and LIN Interface ICs to simplify the design of high-efficiency solutions.


eDesignSuite is a comprehensive set of easy-to-use design-aid utilities ready to help you streamline the system development process with a wide range of ST products.

Thermal-electrical Simulators for Components

Power Management Design Center

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AC Switches Simulator

Select ratings and application waveforms
Get junction temperature and blocking voltage graphs
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Rectifier Diodes Simulator

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Estimate power losses
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Supports long mission profiles
Provides power loss and temperature graphs
Helps define heatsink thermal properties

Twister Sim

Help select the right ViPOWER Automotive power device
Supports load-compatibility, wiring harness optimization, fault condition impact and diagnostic analysis
Supports various PCB configurations

TVS Simulator

Specify system ratings and surge waveform
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Power Supply Design Tool

SMPS design, by topology, by type and by product
PFC design with analog and digitial control
Supports various PCB configurations
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Solar Battery Charger

LED Lighting Design Tool

Handles AC-DC and DC-DC design in common topologies
Displays interactive and annotated schematic
Provides current/voltage graphs, Bode plots, efficiency curves and power-loss data
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Digital Power Workbench

Provides a step-by-step optimized design of power section and control loop
Generates the STM32Cube embedded software package for custom applications and allows firmware project generation, compatible with multiple STM32 IDEs

Power Tree Designer

Specify input/output power for each node in the tree
Check for consistency
Design each individual node