Electrovalley

MT7939 is a single-stage, primary side control AC-DC IC for LED driver with active power factor correction. MT7939 integrates on-chip PFC circuit which operates under critical conduction mode (CRM) to achieve high power factor and reduces the power MOSFET switching loss. With innovative control technique, precision LED current is achieved without secondary side sense and feedback circuit including opto-coupler. 

MT7939 provides various protections, such as input over/under-voltage protection, over-current protection (OCP), output over-voltage protection (OVP), short-circuit protection (SCP) and over-temperature regulation (OTR), etc., to improve system reliability. Moreover, MT7939 is designed with thermal regulation setting pin TADJ, which allows flexible setting of the thermal regulation threshold by connecting an external resistor to ground. 

• Single-stage active power factor correction (PF > 0.90) 

• Integrates ultra-high voltage power supply without external VDD capacitor and external power supply circuit 

• Embedded with digital integrator, no COMP capacitor needed 

• Integrates THD compensation circuit 

• Integrates odd harmonic compensation circuit for high subharmonic distortion suppression 

• Internal line voltage compensation 

• Internal demagnetization sensing, no external feedback circuit needed 

• High accurate LED current 

• Output current foldback at low input voltage 

• Good line and load regulation

Additional Information:

• Packaging Details: SPQ 4K

NE555 Timer IC Dip-8 Package.

The NE555 IC devices are precision timing circuits capable of producing accurate time delays or oscillation. In the time delay or mono-stable mode of operation, the timed interval is controlled by a single external resistor and capacitor network. In the a stable mode of operation, the frequency and duty cycle can be controlled independently with two external resistors and a single external capacitor. The threshold and trigger levels normally are two-thirds and one-third, respectively, of VCC. These levels can be altered by use of the control-voltage terminal. When the trigger input falls below the trigger level, the flip-flop is set, and the output goes high.

Features:- 

•  Timing from microseconds to hours
• Make UTC, IK, HLF
• A stable or mono-stable operation
• Adjustable duty cycle
• TTL compatible output can source or sink up to 200 mA
• Lead Free Finish/ RoHS Compliant

Additional Information:

• Packaging Details: TUBE

MT7939 is a single-stage, primary side control AC-DC IC for LED driver with active power factor correction. MT7939 integrates on-chip PFC circuit which operates under critical conduction mode (CRM) to achieve high power factor and reduces the power MOSFET switching loss. With innovative control technique, precision LED current is achieved without secondary side sense and feedback circuit including opto-coupler. 

MT7939 provides various protections, such as input over/under-voltage protection, over-current protection (OCP), output over-voltage protection (OVP), short-circuit protection (SCP) and over-temperature regulation (OTR), etc., to improve system reliability. Moreover, MT7939 is designed with thermal regulation setting pin TADJ, which allows flexible setting of the thermal regulation threshold by connecting an external resistor to ground.