W6750
Description
The Series STR-W6750 devices are hybrid integrated circuits (HICs) with a built-in power MOSFET and a control IC designed for quasi-resonant type switch-mode power supplies (SMPS).
Key Features
- Blocking (or intermittent) oscillation operation by reducing output voltage in the standby mode
- In addition to the standard quasi-resonant operation, a bottom-skip function is available for increased efficiency from light to medium load
- Soft-start operation at start-up
- Reduced switching noise (pared to conventional PWM hard-switching solution) with a step-drive function
- Built-in avalanche-energy-guaranteed power MOSFET (to simplify surge-absorption circuit; no VDSS derating is required)
- Overcurrent protection (OCP), overvoltage protection (OVP), overload protection (OLP), and maximum ON-time control circuits are incorporated
- OVP and OLP go into a latched mode
- Able to save SMPS design time with present designs and evaluation processes
- The R2 value needs to be set for more than the hold current of the latch circuit (140 µA max.) and to operate at the minimum ac input
- Figure 1 - External start-up circuit If the value of R2 is too high, the C3 charge current will be reduced
