OB2633x is a highly integrated Quasi-Resonant(QR) controller with adaptive multi-mode regulation, optimized for high performance, low EMI, low standby power consumption and wide output voltage range Quick Charger(QC) solutions, together with secondary -side controllers, such as OB2004Ax and OB2603x supporting Qualcomm Quick Charge QC3.0 protocol. The controller is as well compatible with cost effective offline flyback converter applications covering a wide output range.
At normal load condition, it operates in QR mode in high line input voltage. To minimize switching loss, the maximum switching frequency in QR mode is internally limited to 92KHz. When the loading goes low, it operates in PFM 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. Additionally, in the low line input voltage, the IC operates in fixed frequency (65KHz) CCM mode at the heavy loading. As a result, high conversion efficiency can be achieved in the whole loading range.
OB2633x offers complete protection including cycle-by-cycle current limiting (OCP), over load protection (OLP), over temperature protection (OTP), output short protection (SCP), output under voltage protection (UVP), output and VDD over voltage protection. Excellent EMI performance is achieved with On-Bright proprietary frequency shuffling technique.
The tone energy at below 22KHz is minimized to avoid audio noise during operation.
OB2633x is offered in SOT23-6 package.
■ Very wide range of supply voltage
■ Multi-Mode Operation
92KHz maximum clamping frequency in QR mode @ Full Load in high line voltage
65KHz minimum clamping frequency in CCM mode @ Heavy Load in low line voltage
Valley switching operation @ Green mode
Burst Mode @ Light Load & No Load
■ Power on soft start reducing MOSFET Vds stress
■ Extended burst mode control for improved efficiency and low standby power
■ Soft Start for elimination output over shoot
■ Adaptive loop gain compensation with Iovp current detection
■ Frequency shuffling for EMI
■ Low operating current at no/light load
■ Audio noise free operation
■ Comprehensive auto-recovery protection
o VDD under voltage lockout with hysteresis (UVLO)
o Cycle-by-cycle over current protection (OCP)
o Overload protection (OLP)
o Over temperature protection (OTP)
o VDD over voltage protection
o Output over voltage protection
o Output short protection (SCP)
o Output under voltage protection (UVP)
o Output diode short protection
Offline AC/DC flyback converter for
■ Quick-charging AC/DC charges
■ AC/DC Adapters with wide output range