HV9861ADB1 Supertex inc. 21-Watt, Universal, AC LED Driver Demoboard with Accurate Average-Mode, Constant Current Control General Description PWM dimming can be achieved by applying a pulse-width- The HV9861ADB1 demoboard is a high-brightness LED driver modulated square wave signal between the PWMD and GND employing the patented average-mode, constant current pins. control scheme by Supertex Inc. The power conversion stage of the HV9861ADB1 consists of a diode bridge rectiefi r followed The HV9861ADB1 features protection from an output short by a buck converter operating with fixed off-time of 20s. circuit condition. Open LED protection is inherent, since the output ltfi er capacitor can accept the full rated rectiefi d AC line The HV9861ADB1 LED driver features tight regulation of the voltage. LED current within a few milliamps over the entire range of the input AC line and the output LED string voltage. The LED Please, note that the demoboard is not CISPR15 compliant. current accuracy is almost insensitive to the passive component An additional input EMI lfi ter circuit is required to make the tolerances, such as the output ltfi er inductance or the timing board meet conducted electro-magnetic emission limits. Also, resistor. The accuracy of the LED current is mainly determined note that: by the internal 270mV 3% reference voltage of the HV9861A control IC and by the external current sense resistor tolerance. NO SAFETY ISOLATION OF THE LED LOAD FROM THE AC MAINS VOLTAGE IS PROVIDED (Note, that the linear dimming input of the HV9861A disables switching, when its voltage falls below a 200mV threshold. Expect the LED driver to shut off when the LED current falls below 50 ~ 55mA.) Connection Diagram Silk Screen 20-60V 350mA 0 -1.5V for LD function or leave open 90-265VAC 50/60Hz WARNING Do not connect earth-grounded test instruments. Doing so No galvanic isolation. Dangerous voltages are present will short the AC line, resulting in damage to the instrument when connected to the AC line. and/or the HV9861ADB1. Use floating high voltage differ - ential probes or isolate the demoboard by using an isolat- ing transformer. Connections 1. Connect the input AC voltage between the AC IN 3. Connect the PWMD terminal to the VDD terminal terminals as shown in the connection diagram. using the jumper provided to enable the LED driver. 2. Connect the LED string between LED+ (anode of 4. The current level can be adjusted by applying 0 - 1.5V between LD and GND. Leave LD floating to LED string) and LED- (cathode of LED string). use the internal current setting. Doc. DSDB-HV9861ADB1 Supertex inc. A032713 www.supertex.comJ3.1 R1 VIN 464k VDD RT J3.3 HV9861A Q1 R2 LD GATE STD5NM50 100k C8 2.2F PWMD CS 16V GND R4 0 R5 C7 C6 R6 1k (not used) R6a 0.1F 0.82 15 J3.2 J3.4 HV9861ADB1 PWM Dimming 3.8k The HV9861ADB1 is capable of being PWM dimmed by apply- VDD ing a square wave TTL compatible signal between PWMD and 5.0V GND terminals. However, since there is no galvanic isolation square on the board, care must be taken to prevent damage to the wave signal PWM dimming source and/or the HV9861ADB1. One simple (<1.0kHz) way is to isolate the LED driver from the AC line using an isola- PWMD tion transformer. Another approach is to use an opto-isolator to Opto-isolator (e.g. LTV-814 from Lite-On) drive the PWMD pin as shown in the following figure. Specifications Parameter Value Condition Input voltage 90~265VAC, 50/60Hz --- Output voltage 20~60V --- Nominal output current 350mA4% --- 15% Output current ripple 120VAC, 60V/350mA (typical, depending on the type of LED) 92% 120VAC, 60V/350mA Full load efficiency 91% 240VAC, 60V/350mA 0.56 120VAC, 60V/350mA Power factor 0.50 240VAC, 60V/350mA Maximum input current 0.27A (RMS) 90VAC, 60V/350mA 29kHz 120VAC, 60V/350mA Switching frequency 38kHz 240VAC, 60V/350mA (variable, T = 20s) OFF 40kHz 120VAC, 20V/350mA 43kHz 240VAC, 20V/350mA Open LED protection YES --- Output short circuit protection YES --- Dimensions 68.6mm X 49.6mm --- Schematic F1 RT1 J1 U1 CL-140 J2 2.0A 250VAC C3 C1 1 AC1 POS 1 C5 47F 0.47F C4 D1 0.47F 400V 400V 0.1F STTH2R06U 400V 2 AC2 NEG 2 305VAC L1 1 2 4.7mH RL-1292-4700 Doc. DSDB-HV9861ADB1 Supertex inc. A032713 2 www.supertex.com