By Steve Bush 19th August 2022
Diodes has introduced a 36V low-drop linear driver for strings of LEDs, with 5kV ESD protection on the input and output current adjustable up to 100mA.
The company describes AL5819, as it is known, as “ideal for 5V, 12V, and 24V LED lamps and strips”.
Vin and the top of the LED string can be the same or different – mixing and matching over 5-36V and 100mV to 36V respectively.
Current sensing is though a fixed internal low-value resistor, and current setting is via a more manageable value external resistor (diagrams) – the calculation is R=1,500/current, so 15k for 100mA, and there is a 200mA limit for values down to 0Ω.
Dimming is possible by adjusting this resistor or pulse-width modulating it using a series transistor – the data sheet shows values between 200Hz to 1kHz being used.
Drop-out is 250mV up to 60mA, and the company points out that more than one device can be paralleled for more current or power.
Heat removal is largely down the the legs of the 3 x 3mm footprint SOT26 package and, with such a tiny package, heat can easily be the limiting factor for current and voltage handling.
Local copper area will set the regulator’s power limits – on a 1 x 1inch square of 2oz FR-4 MPR substrate, said the company, junction to ambient resistance is 143°C/W.
De-rating starts at Tj=25°C and drops linearly to 145°C, with current limiting starting at 135°C. All current is stopped at +165ºC and will re-start at 145ºC. Official operating range is -40 to +125°C.
Tagged with: driver led lighting
Your email address will not be published. Required fields are marked *
Download the Elektra Awards 2022 media pack and book your sponsorship package to be part of the most prestigious awards event celebrating its 20th anniversary this year!
Get our news, blogs and comments straight to your inbox! Sign up for the Electronics Weekly newsletters: Mannerisms, Gadget Master and the Daily and Weekly roundups.
Read our special supplement celebrating 60 years of Electronics Weekly and looking ahead to the future of the industry.
Read the Electronics Weekly @ 60 supplement »
Read the first ever Electronics Weekly online: 7th September 1960. We've scanned the very first edition so you can enjoy it.
Read the very first edition »
Electronics Weekly teams up with RS Grass Roots to highlight the brightest young electronic engineers in the UK today.
Read our special supplement celebrating 60 years of Electronics Weekly and looking ahead to the future of the industry.
Read the Electronics Weekly @ 60 supplement »
Read the first ever Electronics Weekly online: 7th September 1960. We've scanned the very first edition so you can enjoy it.
Read the very first edition »
Tune into this Xilinx interview: Responding to platform-based embedded design
Tune into this podcast to hear from Chetan Khona (Director Industrial, Vision, Healthcare & Sciences at Xilinx) about how Xilinx and the semiconductor industry is responding to customer demands.
By using this website you are consenting to the use of cookies. Electronics Weekly is owned by Metropolis International Group Limited, a member of the Metropolis Group; you can view our privacy and cookies policy here.