OB5283 is a highly integrated current mode PWM control IC with high voltage startup, optimized for high performance, low standby power consumption and cost effective offline flyback converter applications. The controller‘s HV pin is used for high voltage startup, AC off detection, and X-cap Voltage discharge , this structure allows the brownout detection as well.
At full loading, the IC operates in fixed frequency (65KHz) mode. When the loading goes low, it operates in Green mode with valley switching for high power conversion efficiency. When the load is very small, the IC operates in ‘Extended Burst Mode’ to minimize the standby power loss. As a result, high conversion efficiency can be achieved in the whole loading range.
High voltage startup is implemented in OB5283, which features with short startup time and low standby power loss.
OB5283 offers complete protection coverage including cycle-by-cycle current limiting (OCP), over load protection (OLP), over temperature protection (OTP), output short(SCP), output and VDD over voltage protection. Excellent EMI performance is achieved with On-Bright proprietary frequency shuffling technique.
The tone energy at below 25KHz is minimized to avoid audio noise during operation.
OB5283 is offered in SOP8 package.
High voltage startup
Power on soft start reducing MOSFET Vds stress
Frequency shuffling for EMI
125KHz max frequency mode @ Peak Load
65KHz fix frequency mode @ Full Load
Valley switching operation @ Green mode
Burst Mode @ Light Load & No Load
Audio noise free operation
Peak power delivery for peak load
Tighten and programmable output over current protection
Comprehensive protection coverage
VDD under voltage lockout with hysteresis (UVLO)
Cycle-by-cycle over current protection (OCP) with auto-recovery
Overload protection (OLP) with auto-recovery
Over temperature protection (OTP) with latch shut down
VDD over voltage protection with latch shut down
Output over voltage protection with latch shut down
Output short protection (SCP) with auto-recovery
Brownout protection with auto-recovery
Output diode short protection with latch shut down
Intelligent AC off detection with X-CAP discharge function
Offline AC/DC flyback converter for
PK Load Application