Diodes' smart lighting LED drivers ensure flicker-free dimming

     Diodes Corporation, a leading global manufacturer and supplier of high quality application-specific standard products and products for a wide range of discrete, logic and analog semiconductor markets, today announced the introduction of the AL1791/2/3/4 LED driver. These single, double, triple, and four-channel DC-constant current (DC-CC) LED driver ics provide analog and PWM dimming control and are adjustable for white color LED bulbs using smart, connected lighting applications. When used in combination with an AC-DC power conversion block and a microcontroller, these current-ratio optimized regulators provide a cost-effective, scalable and easy to implement solution for the emerging smart lighting market.

     Operating from 6.5V to 30V input voltage range, the AL1791/2/3/4 constant current regulator can drive up to four separate LED channels, up to a total drive current of 1.5A per channel or a current of 500mA for AL1792/3/4, or a maximum of 1A for AL1791. Each channel can be individually controlled down to 0.125%, with flicker-free PWM dimming at 500Hz of 10kHz or analog dimming down to 1.25%. Use the same pin as the input to ensure proper analog or PWM dimming response.

     Support for deep dimming (below 1%) is important because the human eye perceives the square root of the light intensity measured by the light, which is proportional to the dimming current. Similarly, while the human eye can only notify flickers below 120Hz, the ability to operate PWM dimming above 1kHz avoids the problem of e-flickering, which is picking up the camera, as in a smartphone, can cause dark bands or flicker images. The AL179X is capable of high frequency PWM deep dimming applications: 1.0% at 10kHz, 0.4% at 4kHz and 0.1% at 1kHz.

     The AL179x LED driver is equipped with an enable pin, low standby power consumption, internal protection for LED string open/short circuit and undervoltage lock, overtemperature protection, thermal shutdown and automatic recovery, complete failure reporting, and LED power supply - good reports. The integrated low-side current absorber topology allows users to choose between lower-cost common-anode LED connections or different anode voltages for increased energy efficiency. All devices operate in the ambient temperature range from -40 ° C to + 125 ° C and are packaged in the same 14-pin UDFN-4030 package, thus facilitating scalable LED driver design for smart, connected lighting applications.