OB2646
GENERAL DESCRIPTION
OB2646 is a highly integrated current mode controller with adaptive multi-mode regulation, optimized for high performance, low EMI, low standby power consumption and wide output voltage range Quick Charger solutions, together with secondary -side controllers, such as OB2019 and OB2602 supporting HUAWEI SCP A/B and Qualcomm Quick Charge QC2.0 protocol. The controller is as well compatible with cost effective offline flyback converter applications covering a wide output range.
With On-Bright proprietary technology, OB2646 operates in QR Valley lockout operation in high line input voltage at heavy load condition. To minimize switching loss, the maximum switching frequency in QR mode is internally limited to 130 KHz. In the low line input voltage, the IC operates in fixed frequency (110 KHz) CCM mode at the heavy loading. When the loading goes low, it operates in Green mode, the switching frequency linearly decrease from 110K to about 23K. At no load or light load condition, the IC operates in extended ‘burst mode’ to minimize switching loss.
OB2646 switching frequency is specially optimized to avoid touch panel interference issue with lower CMN (Common Mode Noise) during operation.
OB2646 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.
OB2646 is offered in SSOP10 package.
FEATURES
n Multi-Mode Operation
130KHz maximum clamping frequency in 2nd valley switching mode @ Full Load in high line voltage
110KHz minimum clamping frequency in CCM mode @ Heavy Load in low line voltage
n Fast frequency reduction @ Green mode
n Burst Mode @ Light Load & No Load
n Internal boost VDD power supply, support wide voltage output
n Extended burst mode control for improved efficiency and low standby power
n Power on soft start reducing MOSFET Vds stress
n Adaptive frequency shuffling for EMI
n Low operating current at no/light load
n Audio noise free operation
n Switching frequency optimized for touch panel CMN requirement
n Comprehensive auto-recovery protection
n VDD under voltage lockout with hysteresis (UVLO)
n Cycle-by-cycle over current protection (OCP)
n Overload protection (OLP)
n Internal Over temperature protection (OTP)
n VDD over voltage protection
n Output over voltage protection
n Output short protection (SCP)
n Output diode short protection
APPLICATIONS
Offline AC/DC flyback converter for
n Quick-charging AC/DC chargers
n AC/DC Adapters with wide output range
TYPICAL APPLICATION
