LYT2004K-TL

The LYTSwitch-2 family of ICs dramatically simplifies low power CC LED drivers by eliminating the optocoupler and secondary control circuitry. The family introduces a revolutionary control technique which provides accurate output current regulation, compensating for transformer and external component variations, and device parameter tolerances as well as input voltage variations. The device incorporates a high-voltage switching MOSFET, an ON/OFF control state-machine, a high-voltage switched current source for self-biasing, frequency jitter to reduce EMI, cycle-by-cycle current limit and hysteretic thermal shutdown circuitry into a monolithic IC. This high level of integration enables cost-effective designs with very few external components, reducing solution cost and driver size. LYTSwitch-2 parts minimize energy consumption when the output is unloaded. Practical designs can easily achieve less than 30 mW no-load consumption. The 725 V power MOSFET used in LYTSwitch-2 devices increases the circuits’ ability to withstand input surge. In addition, each package is designed to maximize the creepage distance between high-voltage pins and logic level inputs. This increased pin spacing increases driver lifetime and reliability in polluted environments. These in-built protection features also protect the entire circuit from excess temperature.

• Transformer inductance variation
• External component changes with temperature
• Input line voltage variations This enhances production yield Cost-Effective, Small Size Designs
• Eliminates the optocoupler and secondary CC control circuitry
• Eliminates control loop compensation circuitry
• Frequency-jitter greatly reduces EMI filter cost
• Programmable switching frequency reduces transformer size
• 725 V switching power MOSFET enables clampless flyback designs Advanced Protection/Safety Features
• Auto-restart protection reduces power delivered by >90% for output short-circuit and control loop faults (open and short-circuit components)
• Hysteretic thermal shutdown – with automatic recovery
• Meets high-voltage creepage requirements between DRAIN and all other pins both on the PCB and at the package