EVALLED-ILD6150: 1A @ 48V Max, 4.5 ~ 60V in, Buck

This Application Note introduces Infineon’s Hysteritic Buck DC/DC LED driver ILD6150 for general lighting application. It describes the demo board, performance as well as design ideas for various applications. The ILD6150 offers high efficiency, various protection features, superior dimming performance & reliability for high performance lighting system.

This document is intended for users, who wish to design high efficiency, high reliability lighting system with Infineon’s ILD6150/ILD6070 DC/DC LED driver.

The ILD6150 is a hysteretic buck LED driver IC for driving high power LEDs in general lighting applications with average currents up to 1.5 A.

The ILD6150 is suitable for LED applications with a wide range of supply voltages from 4.5 V to 60 V. A multifunctional PWM input signal allows dimming of the LEDs with an analog DC voltage or an external PWM signal. To minimize color shifts of the LEDs an analog PWM voltage is converted to an internal 1.6 kHz PWM signal modulating the LED current.

The ILD6150 incorporates an undervoltage lock-out that will shut down the IC when the minimum supply voltage threshold is exceeded. The over-current protection turns off the output stage once the output current exceeds the current threshold. An integrated over-temperature protection circuit will start to reduce the LED current by internal PWM modulation once the adjustable junction temperature threshold of the IC is exceeded. Realizing a thermal coupling between LED driver and LEDs this feature eliminates the need of external temperature sensors as NTCs or PTCs.

The hysteretic concept the current control is extremely fast and always stable. A maximum contrast ratio of 3000:1 can be achieved depending of the dimensioning of the external components. The efficiency of the LED driver is remarkable high, reaching up to 98 % of efficiency over a wide range. The output current accuracy from device to device and under all load conditions and over temperature is limited to a minimum, making ILD6150 the perfect fit for LED ballasts.