FL7733AMX

Overview

The FL7733AMX is a highly integrated PWM controller designed for primary-side regulated (PSR) LED lighting converters with power factor correction. It utilizes TrueCurrent technology to achieve tight constant-current tolerance of less than ±1% over the universal line voltage range. The device supports Boost, Buck, and Flyback topologies with an input voltage range of 80 VAC to 308 VAC. Key electrical parameters include a high power factor greater than 0.9 and total harmonic distortion below 10%. It features an internal high-voltage startup circuit for fast start-up under 200 ms at 85 VAC. The component operates within a temperature range of -40°C to 125°C and is housed in an 8-SOIC package.

Feature Summary

• Advanced Primary-Side Regulation (PSR) technique minimizes external components by eliminating the need for input bulk capacitors and secondary feedback circuits.
• Innovative TrueCurrent technology provides precise constant-current output control without requiring optocouplers or TL431 references.
• Adaptive feedback loop control anticipates steady-state conditions during startup to prevent LED current overshoot or undershoot.
• Integrated protection mechanisms include safeguards against LED short/open, output diode short, sensing resistor faults, and over-temperature conditions.

Applications

• Low-to-mid-power LED lighting converters
• LED drivers requiring analog dimming functionality
• Single-stage PFC LED driver designs

Procurement Notes

Verify the specific ordering suffix to ensure compatibility with required packaging formats such as tape and reel or cut tape. Confirm that the component meets RoHS3 and REACH compliance standards for your target market. Check for any recent product change notices regarding pinout or electrical specifications. Ensure the supplier provides valid traceability documentation. Validate that the part number matches the exact onsemi designation to avoid counterfeit risks.

Selection Notes

Select this controller for applications prioritizing cost reduction through component count minimization. It is suitable for designs requiring high power factor and low harmonic distortion without secondary side regulation. Consider its wide input voltage range for universal AC line applications. Evaluate its thermal protection features for systems operating in constrained environments. Ensure the design can accommodate the single-channel output capability.

Part Context

The FL7733AMX belongs to the FL7733 family of LED driver ICs from onsemi. This series focuses on integrating power factor correction and primary-side regulation into a single chip. The 'MX' suffix typically denotes the tape and reel packaging variant. It serves as a direct replacement for legacy Fairchild Semiconductor parts following corporate integration, maintaining functional equivalence while updating nomenclature standards.

Replacement Considerations

Check for updated part numbers resulting from the Fairchild Semiconductor integration into onsemi. Verify if alternative suffixes are available for different packaging requirements. Ensure substitute components maintain the same 8-SOIC footprint and pin configuration. Confirm that replacement devices support the required analog dimming interface and PSR performance metrics.