VISUAL SOLUTIONS

High-Power Mini LED Driver is Easy to Use

Requiring just a single external resistor to set its output current very accurately, the ZXLD1350 from Zetex Semiconductors dramatically simplifies high-power LED driving. Operating from an input supply of between 7V and 30V, the driver can produce an adjustable output current of up to 350mA, to support an LED chain of up to eight 1W LEDs.



This new switching regulator uses a 2.9mm x 2.8mm footprint TSOT23 five-pin package and features a high level of component integration, allowing it to fit even the most space-constrained application. By integrating a 30V NDMOS switch, and a high-side current sensing circuit yielding a typical ±4% precision current control, the ZXLD1350 needs the support of just four external circuit components.

Through careful selection of external components, designers can create an LED driving solution with extremely high overall efficiency. Using Zetex’ ZLLS1000 high-temperature, low-leakage Schottky diode for example, the whole system can achieve efficiency as high as 95%, depending on input voltage and load conditions. This, combined with the ZXLD1350’s very low typical shutdown current of only 15µA, ensures the device offers good power economy and extended battery life.

With an operating temperature range from –40ºC to +105ºC, the ZXLD1350 can also tolerate temperatures more than 20% higher than alternative solutions. In addition, its ability to support a continuous supply voltage of 30V and surge voltages of 40V makes it suitable for even the most demanding industrial and automotive applications.

Where LED lighting applications require dimming and more complex control attributes, the ZXLD1350 also offers designers a wealth of alternative control strategies. The high-side current-setting resistor can be varied to dim the LED. The device’s multi-function control pin provides the ability to finely regulate the output current in a number of ways: by applying a resistor; a DC voltage; a low frequency PWM; or a high-frequency PWM. The high-frequency PWM filter components are on-chip.

By adding a capacitor between the control pin and ground, the LED driver’s inherent soft-start time can be extended, and the application of a logic low signal to the pin enables the device output to be turned off.

Features

• Switching regulator for LED drives
• Input supply 7V to 30V
• 350mA drive current
• Can drive up to eight daisy-chained LEDs
• Integrated 30V NDMOS switch and high-side current sensing
• System solution can be realised with as few as four external components
• Typical ±4% precision current control
• 15µA shutdown current
• Up to 95% system efficiency
• 40V surge resistance
• Multi-function control pin allows dimming and complex control
• Tiny (2.9mm x 2.8mm) five-pin TSOT23 package
• Temperature range -40ºC to +105ºC

Applications

• Low-voltage halogen replacement LEDs
• Automotive lighting
• Low-voltage industrial lighting
• LED back-up lighting
• Illuminated signs

For further information, including details of how to obtain Zetex Product Samples, please click here