OB2374MP

OB2374 High Performance CCM/QR mode Primary-Side Controller GENERAL DESCRIPTION FEATURES OB2374 is an excellent primary side regulation controller with CC/CV operation for medium level power AC/DC charger and adapter applications. The device directly drives a power MOSFET and operates in CCM/QR mode to provide high efficiency along with several functions of built-in protections. It removes the need for secondary feedback circuitry to lower the total bill of material cost. Proprietary Constant Voltage (CV) and Constant Current (CC) control is integrated as shown in the figure below. In CV control, the controller changes the mode of operation according to line voltage and load condition. At full loading, the controller operates in fixed frequency CCM in low line voltage and operates quasi-resonant (QR) mode in high line voltage. The primary side regulation power supplies up to high power without the efficiency limitation of DCM or audible noise. In CC control, OB2374 samples the Vcs peak current and the demagnetization pulse to regulation the output constant current. The current and output power setting can be adjusted externally by the sense resistor Rs at CS pin. OB2374 offers comprehensive protection coverage with auto-recovery feature including Cycle-by-Cycle current limiting, VDD OVP, OLP, SCP etc. OB2374 consumes less than 75mW input power at no- load condition with high line voltage. OB2374 is offered in SOT23-6 package.  Primary-side sensing and regulation operates in CCM/QR mode without TL431 and opto-coupler  High precision constant voltage and current regulation at universal AC input  Fixed frequency (65kHz) CCM mode operation with low line voltage at full load  Quasi-resonant operation for high efficiency in high line voltage  Good dynamic response  Programmable CV and CC regulation  Built-in primary winding inductance compensation  Programmable cable drop compensation  Built-in control loop compensation  External over temperature protection with latch shutdown (OTP)  Audio noise free operation  Built-in leading edge blanking (LEB)  Ultra low start-up current and low operating current  Comprehensive protection coverage with auto-recovery  VDD over voltage protection (OVP)  VDD under voltage lockout with hysteresis (UVLO)  Cycle-by-cycle current limiting  Feedback open loop protection (OLP)  Output short circuit protection (SCP) APPLICATIONS Medium level Power AC/DC offline SMPS for  Cell phone charger  Tablet PC  AC/DC adapter  Set-top box power supplies Figure.1. Typical CC/CV Curve ©On-Bright Electronics Confidential -1- Preliminary Datasheet OB_DOC_DS_237400 OB2374 High Performance CCM/QR mode Primary-Side Controller TYPICAL APPLICATION GENERAL INFORMATION Absolute Maximum Ratings Parameter Value VDD Voltage -0.3 to 30V FB Input Voltage -0.3 to 7V COMPInput Voltage -0.3 to 7V CS Input Voltage -0.3 to 7V GATE Input Voltage -0.3 to 24V Min/Max Operating Junction -40 to 150 ℃ Temperature TJ Operating Ambient -20 to 85 ℃ Temperature TA Min/Max Storage -55 to 150 ℃ Temperature Tstg Lead Temperature 260 ℃ (Soldering, 10secs) Note: Stresses beyond those listed under “absolute maximum Pin Configuration The pin map is shown as below for SOT23-6. FB 1 6 GND 2 5 CS VDD 3 4 GATE COMP Ordering Information Part Number Description OB2374MP SOT23-6, Pb-free in T&R Package Dissipation Rating Package RθJA (℃/W) SOT23-6 200 ratings” may cause permanent damage to the device. These are stress ratings only, functional operation of the device at these or any other conditions beyond those indicated under “recommended operating conditions” is not implied. Exposure to absolute maximum-rated conditions for extended periods may affect device reliability. Recommended Operating Condition Symbol Parameter Range VDD VDD Supply Voltage 9 to 22V ©On-Bright Electronics Confidential -2- Preliminary Datasheet OB_DOC_DS_237400 OB2374 High Performance CCM/QR mode Primary-Side Controller Marking Information 374YWW . ZZZ s Y:Year Code WW:Week Code(01-52) ZZZ: Lot code s: Internal code TERMINAL ASSIGNMENTS Pin Num Pin Name I/O 1 FB I The voltage feedback from auxiliary winding. Connected to resistor divider from auxiliary winding reflecting output voltage. 2 GND P Ground 3 VDD P Power Supply 4 GATE O Gate driver of power MOSFET. 5 CS I Current sense input. Connect a sense resistor from this pin to ground. 6 COMP I/O ©On-Bright Electronics Description Connected through Cap to ground for CC loop compensation. Confidential -3- Preliminary Datasheet OB_DOC_DS_237400