OB2710

GENERAL DESCRIPTION

OB2710 is a highly integrated current mode PWM control IC optimized for high performance, low standby power and cost effective offline flyback converter applications.

At normal load condition, it operates in fixed frequency mode. When the loading goes low, it operates in PFM mode 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.

VCC low startup current and low operating current contribute to a reliable power on startup and low standby design with

OB2710 offers  Vth_oc compensation.

OB2710 offers comprehensive protection coverage with auto-recovery including Cycle-by-Cycle current limiting (OCP), over load protection (OLP), AC brownout protection,VCC under voltage lockout (UVLO), external over temperature protection (OTP), over voltage protection (OVP) and short protection(SCP).Excellent EMI performance is achieved with On-Bright proprietary frequency shuffling technique.

The tone energy at below 23KHz is minimized in the design and audio noise is eliminated ng operation.

OB2710 is offered in SOT23-6 package.

FEATURES

■   Power on soft start reducing MOSFET Vds stress

■   Multi-Mode Operation

77KHz maximum clamping frequency in QR mode @ Full Load in high line voltage

65KHz minimum clamping frequency in CCM mode @ Heavy Load in high line voltage

100KHz maximum clamping frequency in QR mode @ Full Load in low line voltage

85KHz minimum clamping frequency in CCM mode @ Heavy Load in low line voltage

Valley switching operation @ Green mode

  Burst Mode @ Light Load & No Load

■   Frequency shuffling for EMI

■   Extended burst mode control for improved efficiency and low standby power design

■   Audio noise free operation

■   Adjust Vth_oc compensation through CS pin, the compensate value can be regulated by the resister series with CS pin.

■   Comprehensive protection coverage

o    VCC Under Voltage Lockout with hysteresis (UVLO)   

o    VCC Over Voltage Protection (VCC OVP)  

o    Cycle-by-cycle over current threshold setting for constant output power limiting over universal input voltage range

o    Over Load Protection (OLP) with auto-recovery

o    Brownout protection with auto-recovery, line OVP with auto-recovery

o    Output Over Voltage Protection(Output OVP) with auto-recovery, and  the OVP triggered voltage can be adjusted by the resistors connected between auxiliary winding and ground

o    Adjust Over Temperature Protection(OTP) through CS pin with auto-recovery

o    Output diode short protection with auto-recovery

o    Output SCP Protection with auto-recovery

APPLICATIONS

Offline AC/DC flyback converter for

■   General power supply

■   Power Adapter

TYPICAL APPLICATION