PWM + QR Multi-Mode Controller with Primary Side Regulation and integrated 650V N-Channel MOSFET
In order to enhance the efficiency performance, the LD9174K integrates the multi-mode PWM controller, which consists
of quasi-resonant (QR) PWM control for light load condition and continue conduction mode (CCM) for heavy load condition.
Moreover, the QR controller gains the system performance, but also brings the worse EMI capability, especially at boundary
mode in heavy load.
While the frequency swapping function of LD9174K can reduce the EMI emission of SMPS and helps the power circuit designers
to simply deal with EMI filter and saves several component and developing time.
The LD9174K includes the comprehensive protection function, such as overload protection (OLP), over voltage protection (OVP),
output short circuit protection (OSCP) and internal over temperature protection (OTP).
Furthermore, the programmable brown-in/out protection is built-in.
The IC is available in THT. LD9174K GN in DIP-8 package.
FEATURES
▲ Primay-side CCM + QR multi-mode control
▲ Built-in 650V Power MOSFET
▲ Frequency swapping for better EMI performance
▲ Ultra-low startup current (< 1.9mA)
▲ Built-in load regulation compensation
▲ 75kHz PWM switching frequency at low line
▲ Current mode control with cycle-by-cycle current limit
▲ UVLO (under voltage lock out)
▲ Bulk over voltage protection
▲ LEB (leading edge blanking) on CS pin
▲ VCC & FB OVP (over voltage protection)
▲ SDSP (secondary diode short protection)
▲ Adjustable brown-in/out on FB pin
▲ Low line ripple compensation on FB pin
▲ Internal OTP (over temperature protection)
APPLICATIONS
▲ Networking power supply
▲ Low power AC/DC adaptor
Datasheet 
