LYT1402-1604 LYTSwitch-1 Family Single-Stage LED Driver IC with Combined PFC and Constant Current Output for Buck Topology Product Highlights M BP Single-Stage PFC + Accurate CC Output D S 3% CC regulation in single line input voltage applications Power factor >0.9 FB High efficiency >93% LYTSwitch-1 Robust 725 V MOSFET for increased line voltage surge performance Critical Conduction Mode (CrM) buck Low EMI Excellent line noise and transient rejection Design Flexibility Supports high- and low-side buck topologies Wide input (90 VAC 308 VAC) and output voltage range operation 3 family members cover power range for optimum device selection PI-7906-050316 Requires no inductor bias winding Figure 1a. High-Side Buck Typical Application Schematic. Highest Reliability Lowest component count Comprehensive protection features with auto-restart Input and output overvoltage protection (OVP) Output short-circuit protection Open-loop protection Advanced thermal control Thermal foldback ensures that light continues to be delivered at elevated temperatures LYTSwitch-1 Over-temperature shutdown provides protection during fault FB conditions S D Description BP M PI-7905-050316 The LYTSwitch-1 family is ideal for single-stage, high PF, constant current LED bulbs and tubes. Figure 1b. Low-Side Buck Typical Application Schematic. The family incorporates a high-voltage MOSFET with a variable on-time CrM controller. Extensive protection features with minimum external components provide industry leading power density and functionality. 1 Output Power Table The devices can be used in high-side or low-side non-isolated buck topology. Optimized for Smallest Components 3 Product The CrM operation results in low turn-on losses and reduces cost of 2 2 V 30 V 45 V V 55 V OUT OUT output diode (slower reverse recovery). LYT1402D 4.0 W 8.0 W LYTSwitch-1 devices are suitable for applications from 2 W to 22 W. LYT1403D 7.5 W 15 W See Table 1 for selection guidance. LYT1404D 11 W 22 W Optimized for Lowest THD 3 Product 2 2 V 30 V V 55 V OUT OUT LYT1602D 4.0 W 8.0 W LYT1603D 7.5 W 15 W Figure 2. SO-8 D Package. LYT1604D 11 W 22 W Table 1. Output Power Table (Buck Topology). Notes: 1. Maximum practical continuous power in an open frame design with adequate heat sinking, measured at 50C ambient. 2. Output power scales linearly if VOUT falls in between the specified voltages. 3. Package: SO-8 (D Package). www.power.com July 2016 This Product is Covered by Patents and/or Pending Patent Applications.LYT1402-1604 DRAIN (D) BYPASS (BP) IOVP I REGULATOR LIMIT INPUT SOA 5.25 V LINE Line Comp SENSE THERMAL OTP SHUTDOWN MULTI- FUNCTION (M) ZERO CURRENT DETECTION SOURCE OOVP (S) V OUT VOUT SS SENSE FAULT FAULT HANDLING UV 4.5 V SYSTEM CLOCK I VALLEY AC High 0.7 V FB(REF) TON CONTROL UP/DN STATE S Q R1 LOGIC COUNTER MACHINE 0 V I PK AC Valley R Q R2 FEEDBACK (FB) PI-7907-040416 Figure 3. Block Diagram. Pin Functional Description BYPASS (BP) Pin: 5.25 V supply rail. D Package (SO-8) MULTIFUNCTION (M) Pin: 1 8 Mode 1: FET OFF BP S Detection of inductor de-magnetization (ZCD) to ensure CrM. 7 2 M S Output OVP Sensing (120 % of V nominal). OUT 3 6 Steady-state operation voltage range is 1 V 2.4 V . S FB Mode 2: FET ON 4 5 D S Line OVP. FEEDBACK (FB) Pin: FET current sensing using external current sense resistor. Normal operation voltage range is V 0 V . FB(REF) PI-7908-032216 DRAIN (D) Pin: Figure 4. Pin Configuration. High-voltage internal MOSFET. SOURCE (S) Pin: Power and signal ground. 2 Rev. B 07/16 www.power.com