# USRB02 Preliminary LINEAR INTEGRATED CIRCUIT

## HIGH PRECISION CC/CV PRIMARY SIDE SWITCH

Description
️· Primary controller for charger/adapter applications.
️· Primary-side sensing and regulation - eliminates opto-coupler and TL431.
️· Operates in PFM (CC mode, large load) and PWM (frequency reduction, light/medium load).
️· High precision CV/CC regulation and high power efficiency.
️· Comprehensive protection features with auto-recovery.

Features
️· ±5% constant voltage regulation.
️· Primary side control (no TL431 or opto-coupler).
️· High precision constant current regulation.
️· Programmable CV and CC regulation.
️· Eliminates loop compensation circuitry.
️· Flyback topology in DCM operation.
️· Random frequency modulation (EMI reduction).
️· Built-in power NPN.
️· Multi-mode operation for efficiency.
️· Programmable cable drop compensation.
️· Built-in leading edge blanking, primary winding/line voltage compensation.
️· Audio noise free operation.
️· Open/short/over voltage/over temperature protection.

Ordering Information
️· USRB02G-S08-R: SOP-8 package, Tape Reel packing.

Pin Configuration
️· 1: VDD (Power Supply)
️· 2: FB (Voltage Feedback)
️· 3: NC (No Connect)
️· 4: CS (Current Sense Input)
️· 5-6: C (Collector of Power NPN)
️· 7-8: GND (Ground)

Absolute Maximum Ratings
️· VDD: -0.3 to 30V
️· C: -0.3 to 700V
️· CS/FB: -0.3 to 7V
️· TJ: -40 to 150°C
️· TSTG: -55 to 150°C
️· TOPR: 260°C (10 sec)

Electrical Characteristics (TA=25°C, VDD=15V)
️· IST (Startup Current): 5-15 μA
️· IOP (Static Current): 0.72-1.0 mA
️· VTH(OFF) (Turn-off Threshold): 6.5-7.8V
️· VTH(ON) (Turn-on Threshold): 18.4-20.4V
️· VDD_OVP (VDD Over Protect): 26.5-29.5V
️· TLEB (LEB Time): 0.5μS
️· VFB (Reference Voltage): 2.475-2.525V
️· F_min (Minimum Frequency): 720-880 Hz
️· T_otp (Over Temp Protection): 165°C

Operation Description
️· Startup: Low startup current; internal circuit disabled at VTH(ON).
️· CV Operation: Regulates output voltage via auxiliary winding feedback.
️· CC Operation: Maintains fixed inductance de-magnetization time; output current adjustable via Rcs.
️· Cable Drop Compensation: Internal offset voltage compensates for cable voltage drop.
️· Protection: VDD overvoltage, output overvoltage, OTP, feedback loop open, short circuit, leading edge blanking, UVLO.

Typical Application
️· 5V/1A Charger/Adapter (BOM provided)