DC1816B Analog Devices

DEMO MANUAL DC1816B LT3799-1 Offline Isolated Flyback LED Driver with PFC Description Demonstration circuit 1816B is an off-line isolated flyback without using an opto-coupler. Open- and shorted-LED LED driver featuring LT 3799-1. The demo board provides protection ensures long term reliability. a single constant current output of 3A over an LED string The LT3799-1 is available in a low profile, thermally- voltage from 22V to 38V. It is optimized to operate over enhanced 16-lead MSOP package. a wide AC input voltage range (90VAC to 305VAC, 47Hz The LT3799-1 data sheet gives a complete description to 63Hz). LED current typically stays within 5% over the of the device, operation and application information. The whole input voltage range. It provides a high power factor data sheet must be read in conjunction with this quick (>0.9) enabling a single design to be used worldwide. It start guide for demo circuit 1816B. is also designed to comply with the IEC 61000-3-2 Class C harmonics standard and the EN55015B conducted EMI Design files for this circuit board are available at standard. DEMO MANUAL DC1816B Quick s p D IMPORTANT NOTE TO CUSTOMERS for proper measurement equipment setup and follow the procedure below: HIGH VOLTAGES ARE PRESENTED ON THE DEMO CIRCUIT, AND CAN LEAD TO LETHAL INJURIES TO HUMAN BODY. 1. Connect a 3A LED string with forward voltage less + ONLY QUALIFIED PERSONNEL SHOULD OPERATE IT. IT than 38V, but greater than 22V, between LED and IS STRONGLY RECOMMENDED TO USE SAFETY GLASSES LED terminals. AND AN ISOLATION TRANSFORMER. 2. With power off, connect the input power supply to line NOTE. IMPROPER COMPONENTS REPLACEMENT ON THE (L) input and neutral (N) input. DEMO CIRCUIT CAN CAUSE PERFORMANCE DETERIORA- 3. Turn on the power at the input. TIONS, CIRCUIT MALFUNCTION, PROPERTY DAMAGE, NOTE. Make sure that the input voltage does not exceed AND EVEN LIFE-THREATENING INJURIES. CONTACT the maximum input voltage (305VAC). LINEAR TECHNOLOGY APPLICATIONS ENGINEERS FOR PROPER COMPONENT REPLACEMENT. 4. Check for the proper output current. Demonstration circuit 1816B is easy to set up to evalu- Once the proper output currents are established, adjust the ate the performance of the LT3799-1. Refer to Figure 1 input voltage and/or the load and observe the output current regulation, efficiency, power factor and other parameters. Figure 1. Proper Measurement Equipment Setup dc1816bfc 2 ure roce tart