ISL1904FAZ-T7A Renesas

DATASHEET ISL1904 FN8286 Rev 1.00 Dimmable AC Mains LED Driver with PFC and Primary Side Regulation September 20, 2012 The ISL1904 is a high-performance, critical conduction mode Features (CrCM), flyback controller used for single-stage conversion of Excellent LED current regulation over line, load, and the AC mains to a constant current source with power factor temperature correction (PFC). The controller regulates the output current by monitoring the primary side switching current so the feedback 0 - 100% dimming with leading-edge (triac) and signal does not cross the isolation barrier. Operation in CrCM trailing-edge dimmers allows near zero-voltage quasi-resonant switching (ZVS) for Power factor correction for up to 0.995 power factor and improved efficiency while maximizing magnetic core less than 20% harmonic content utilization. The ISL1904 LED driver provides all of the features Critical conduction mode (CrCM) operation for required for high-performance dimmable LED ballast designs quasi-resonant high efficiency performance and supports AC or DC input, isolated or non-isolated flyback and boost topologies. This advanced BiCMOS controller Supports universal AC mains input features all of the functions required to design low cost low Configurable for PWM or DC current dimming control of parts count LED driver. LEDs Monitors FET switching current for load regulation Supports isolated and non-isolated boost and flyback topologies Closed loop soft-start for no overshoot OFFREF feature to set dimming off-point to improve fixture performance matching -40C to +125C operation Pb-free (RoHS compliant) Applications Industrial and commercial LED lighting Retrofit LED lamps with triac dimming Universal AC mains input LED retrofit lamps AC or DC Input LED ballasts 850 800 1 5 VDD CS+ 750 14 DHC 12 AC OUT 16 700 ISL1904 4LEDs EMI Filter 8 OC 6 DELADJ 5LEDs 650 13 GND VERR 9 6LEDs 3 VREF FB 7 600 RAMP IOUT 10 4 AC Mains 550 180 190 200 210 220 230 240 250 260 270 LINE VOLTAGE (V ) RMS FIGURE 1A. TYPICAL APPLICATION FIGURE 1B. LED CURRENT vs LINE VOLTAGE FIGURE 1. TYPICAL APPLICATION PERFORMANCE FN8286 Rev 1.00 Page 1 of 21 September 20, 2012 NOT RECOMMENDED FOR NEW DESIGNS NO RECOMMENDED REPLACEMENT contact our Technical Support Center at 1-888-INTERSIL or www.intersil.com/tsc Dimmer LED CURRENT (mA)ISL1904 FN8286 Rev 1.00 Page 2 of 21 September 20, 2012 Functional Block Diagram - ISL1904 VREF BIAS AND VDD REFERENCE GENERATOR UVLO + - OTP SHUTDOWN BG 150C TO 170 C GND BIAS/UVLO/OTP DHC DUTY CYCLE TO VOLTAGE REFERENCE OUT CONVERTER LOW PASS FILTER DIMMING PWM TRIANGLE WAVE GENERATOR CLK MASTER - CLK PWMOUT OSCILLATOR + REFINBUFF PEAK REF AC-PRESENT DETECTO AC DETECTION - AC R + MINIMUM DIMMING OUT LEVEL CONTROL OFFREF + - PRIMARY CURRENT IOUT SENSE PROCESSOR INHIBIT INHIBIT CS+ + IOUT - REFERENCE SS + + ISENSE OVP + REFERENCE SS - 1.50 V BUFFER DELADJ SS - QUASI-ZVS 300ms SOFT-START + DELAY ENABLE CRCM VERR CLAMP DETECTOR F F MAX MIN CLAMP CLAMP PWM - S Q LEADING EDGE + OC + BLANKING 600mV - PRIMARY OC R Q SS LOW PWM + 0.25V RAMP + LATCH - - 200mV - PWM VERR/5 SS/5 COMPARATOR SS 1/5 1/5 FAULT LATCH S Q REFINBUFF + EA1 - R Q VERR CRCM OSCILLATOR/PWM/ERROR AMPLIFIERS SOFT-START/POR/ OVP VERR FB1