Whenever a lighting application, such as street lighting for example, requires an elevated number of LEDs, there are basically two solutions: the first is to connect all the diodes in series in a single "string"; the second is to place several strings in parallel with fewer elements in each one.

This design was developed to minimize the current spikes coming out of an electronic transformer to less than 5A, which is a typical transformer rating, when driving an LED MR16 circuit. The off the shelf LED MR16 solutions exhibit spikes that significantly exceed a transformers maximum rated output current which will degrade the reliability of the transformer and reduce its operating lifetime. T…

This design note shows a typical ZXSC310 LED driver circuit for a solar power garden light. The input voltage ranges from 1.7V to 2.5V with a maximum output current of 160mA at 2.4V input.

The ZXLD1350 is a continuous mode inductive step-down converter, designed for driving single or multiple series connected LEDs efficiently from a voltage source higher than the LED voltage.

The CAT4201 is a high efficiency step-down LED driver from Catalyst Semiconductor. This device is designed to drive high brightness LEDs up to 350mA from a power supply up to 28V. The LED brightness is controlled by a single resistor from the RSET pin to GND. Analog dimming and idle mode control are available through the CTRL input. An external circuit is provided on the CAT4201AEVB for PWM dimmin…

The L6920D is used in this flashlight application as it is a high efficiency step-up controller that realizes the conversion from battery voltage to the selected output voltage with only three external components.

L6920D has a startup voltage of 1V and its operating input voltage ranges from 0.6V to 5.5V.

Demonstration circuit 1160 is a full-featured LED driver with 2.3A switch current featuring the LT®3518. The board is optimized to drive a 330mA LED string with a total LED voltage between the input voltage and 40V in a boost topology. The high input voltage range, high efficiency low side internal 2.3A NPN power switch, low voltage floating current sense amplifier, soft-start, high side PMOS PWM…

* The eval board must be modified for 350mA output. The Transformer/Dual inductor and sense resistor(s).

This evaluation board showcases the LM3409HV PFET controller
for a buck current regulator. It is designed to drive 12
LEDs (VO = 42V) at a maximum average LED current (ILED =
1.5A) from a DC input voltage (VIN = 48V). The switching frequency
(fSW = 400 kHz) is targeted for the nominal operating
point, however fSW varies across the entire operating range.

The evaluation board is designed to display the full functionality of L5973D as a LED driver to drive one to three 1W, 3W as well as 5W LEDs at 12Vac input. The components selected for the demo board are optimized for 5W LED driver application.