Contributes to improved visibility by reducing uneven brightness and color in indicators and numeric displays
ROHM has recently announced the availability of 0603-size (0.6inch × 0.3inch) / 1608-size (1.6 mm × 0.8 mm) LEDs, CSL1901 series, optimized for low-light applications for use in indicators and numeric displays in Factory Automation equipment (i.e. PLCs) and communication control equipment such as modems and routers. 
In recent years, technological advancements in LED elements have resulted in dramatically improved luminous efficiency – leading to increased brightness. At the same time, the market is demanding LEDs tailored to characteristics in the low current range. The reason: higher brightness makes it necessary to design for appropriate luminous intensity and emission wavelengths in applications where interference with adjacent light emitting parts must be considered.
ROHM has developed versatile 0603-size LEDs optimized for a low-current drive in low-light applications by leveraging in-house elemen
t technology to customize the light-emitting layer of the device.
The CSL1901 series reduces visual variations in brightness and color under low-light conditions by optimizing element characteristics of light emission at 2mA using original device technology. In general, when operating standard LEDs, which guaranteed specification at 20mA, at low currents results in brightness and color differences that vary from part to part. Compared to existing products (at 2mA), ROHM’s new LEDs reduce brightness variations by half and color sifting by 3nm, minimizing design man-hours required for light emission while improving visibility in indicators and numeric displays. Furthermore, a lineup of five colors is offered in the highly versatile 0603 size – facilitating replacement due to application and model changes.
Going forward, ROHM will continue to offer LEDs that meet customer needs while improving application design and reducing development load.
Product Lineup 
Target Applications
・ Indicators and numeric displays in a variety of applications
– FA (Factory Automation) equipment (PLC and other control devices)
– Machine tools, manufacturing/inspection equipment
– Communication control devices such as modems and routers
Sales Information
Pricing: $0.139/unit (samples, excluding tax)
Availability: Now (in mass production)
Available for purchase through online distributors Digi-Key, Mouser, and Farnell.
Terminology
PLC (Programmable Logic Controller)
A computer device that uses programs to control sequences and give commands to input/output devices. It is often utilized in automatic control equipment in factories and for various machine controls.
FA (Factory Automation)
Equipment designed for automation in factories.
Luminous Intensity
Indicates the brightness when viewed from a certain direction by specifying the amount of light per unit solid angle. The unit is cd (candela).
Emission Wavelength
In general, LEDs are expressed in terms of the wavelength corresponding to colors seen by the eye. Also referred to as the dominant wavelength, with units of nm (nanometers).
