ZD850 1.5A High Power LED Driver Zywyn ZD850 1.5A High Power LED Driver Features General Description • • • • • • • The ZD850 is a constant off-time, high power LED driver IC using a Buck Converter Topology that is capable of driving up to 1.5A of output current. It operates from an input voltage range of 4VAC to 16VAC or 5VDC to 24VDC and generates a regulated programmable constant output current for high power LEDs. A patent pending design technique with AC/ DC bridge rectifier, linear regulator and internal high voltage NDMOS power switch has been designed on-chip to reduce component count by eliminating the need for an external power switch and diode bridge. Based on high efficient PFM control design, the minimum Off-Time in the controlled frequency range is set at a typical 1.5μs, allowing a good LED current regulation over a wide range of supply voltage with respect to using conventional transformers or E-transformers. Built-in thermal and over-voltage circuitry protects the power transistors from excessive power dissipation. 4~16VAC on VAC1 and VAC2 with current up to 350mA 5~24VDC on HVCC and PGND with current up to 1.5A For One to Five High-Power LEDs in series per string High Efficiency Output Design Over-Temperature Thermal Protection Over-Voltage Circuit Protection Thermally Enhanced 16-Lead Exposed TSSOP Green Package Applications • • • • • • Offline LED Lamps and Fixtures DC/DC LED Driver Decorative Lighting MR16 Lighting Industrial Lighting Automotive Lighting The ZD850 is available in a thermally enhanced 16-pin exposed TSSOP green package. Ordering Information Pin Configuration 15 VAC1 NC 3 VDD 5 NC 6 Temperature Range Package Type ZD850LEY –40°C to +85°C ZD850EVB n/a Blank EVB 16-Pin TSSOP ZD850MR n/a Evaluation Board ZD850KIT n/a ZD850MR + 1Wx3 LEDs + E-Transformer 16 VAC1 VAC2 1 VAC2 2 PGND 4 Part Number 14 NC ZD850 13 HVCC 12 SW 11 RLIM SGND 7 10 SENSEP PGND 8 9 SENSEN Please contact the factory for pricing and availabiliy on Tape-on-Reel option. Typical Application 16-Pin Exposed TSSOP RAC 2Ω 4~16VAC 5~24VDC VAC1 HVCC VAC2 SW C2† 4.7μF High Power LEDs ZD850 VDD RLIM D1 SENSEP C1 1μF R1 SGND SENSEN L1 PGND † C2 = 4.7μF for DC applications and C2= 470μF for AC applications. Figure 1. ZD850 driving High Power LEDs up to 1.5A Zywyn Specifications subject to change without notice 1 • Email [email protected] • www.zywyn.com Zywyn Corporation • Tel (408) 733-3225 • Fax (408) 733-3206 June 2008 rev. 1.6