UNISONIC TECHNOLOGIES CO., LTD UPSRB01 LINEAR INTEGRATED CIRCUIT HIGH PRECISION CC/CV PRIMARY SIDE SWITCHING REGULATOR 6 DESCRIPTION The UTC UPSRB01 is a primary control unit for switch mode charger and adapter applications. The controlled variable is transferred by an auxiliary winding from the secondary to the primary side. The device uses Pulse Frequency Modulation (PFM) method to build discontinuous conduction mode (DCM) flyback power supplies. The UTC UPSRB01 operates in primary-side sensing and regulation. Opto-coupler and TL431 could be eliminated. It also eliminates the need of loop compensation circuitry while maintaining stability. The UTC UPSRB01 achieves high precision CV/CC regulation and high power efficiency. It offers comprehensive protection coverage with auto-recovery features including Cycle-by-cycle current limiting, output over voltage protection, VDD over voltage protection, feedback loop open protection, short circuit protection, leading edge blanking, OTP, VDD under voltage lockout, etc. 4 1 2 3 SOT-26 FEATURES * ±5% constant voltage regulation at universal AC input * Primary side control without TL431 and opto-coupler * High precision constant current regulation at universal AC input * Programmable CV and CC regulation * Eliminates control loop compensation circuitry * Flyback topology in DCM operation * Random frequency modulation to reduce system EMI * Driver BJT switch * Programmable cable drop compensation 5 * Built-in leading edge blanking * Built-in primary winding inductance compensation * Open circuit protection * Output over voltage protection * VDD over voltage protection * Short circuit protection * Over temperature protection ORDERING INFORMATION Ordering Number UPSRB01G-AG6-R Package SOT-26 Packing Tape Reel UPSRB01G-AG6-R (1)Packing Type (1) R: Tape Reel (2)Package Type (2) AG6: SOT-26 (3)Green Package (3) G: Halogen Free and Lead Freee www.unisonic.com.tw Copyright © 2015 Unisonic Technologies Co., Ltd 1 of 7 QW-R103-078.B UPSRB01 LINEAR INTEGRATED CIRCUIT MARKING PIN CONFIGURATION PIN DESCRIPTION PIN NO. 1 2 3 4 5 6 PIN NAME GND CS BASE FB VC VDD DESCRIPTION Ground Current sense input. Base drive for power BJT. The voltage feedback from the auxiliary winding Low pass filter capacitor for cable compensation Power supply BLOCK DIAGRAM Regulator &Ref VDD 6 I_drive Por Base drive Logic core 4V FB 4 2V 3 BASE OVP + - CV controller + - 2 CS + 0.4V Tdemag detector LEB CC controller + - Drop comp UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw 5 1 VC GND 0.5V 2 of 7 QW-R103-078.B UPSRB01 LINEAR INTEGRATED CIRCUIT ABSOLUTE MAXIMUM RATING PARAMETER SYMBOL RATINGS UNIT VDD Voltage VDD -0.3~30 V VC Voltage VC -0.3~7 V BASE Voltage VBASE -0.3~7 V CS Input Voltage VCS -0.3~7 V FB Input Voltage VFB -0.3~7 V Junction Temperature TJ -40~150 °C Storage Temperature TSTG -55~150 °C Lead Temperature (Soldering, 10 secs) TOPR 260 °C Note: Absolute maximum ratings are those values beyond which the device could be permanently damaged. Absolute maximum ratings are stress ratings only and functional device operation is not implied. ELECTRICAL CHARACTERISTICS (TA=25°C, VDD=15V, if not otherwise noted) PARAMETER Supply Voltage (VDD) Section Start up Current Static Current Turn-off Threshold Voltage Turn-on Threshold Voltage VDD Over Voltage Protection Operating Voltage Current Sense Input Section LEB Time Over Current Threshold OCP Propagation Delay FB Input Section Reference Voltage for Feedback Threshold Minimum Pause Maximum Pause Maximum Cable Compensation Current BASE Drive Section Base Sourcing Maximum Current Base Sourcing Current After Pre-off Base Drive Low Side On Resistor SYMBOL MIN TYP MAX UNIT VTH(OFF) VTH (ON) VDD_OVP 6.0 11.5 25 1 300 6.8 12.5 27 3 400 7.6 13.5 29 25 μA μA V V V V TLEB VCS 420 0.5 460 500 μS mV IST IOP TD_OC TEST CONDITIONS VDD=11V VDD=15V From OCP Comparator to Base Drive nS VFB 1.98 2.00 2.02 V TPAUSE_MIN TPAUSE_MAX 8 2.0 10 12 μS mS ICABLE 23 26 29 μA IOUT(SOURCE) IOUT(PRE) RDSON_L 20 0.5 30 1 1 40 1.5 mA mA Ω UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw 100 3 of 7 QW-R103-078.B UPSRB01 LINEAR INTEGRATED CIRCUIT OPERATION DESCRIPTION The UTC UPSRB01 is a primary control unit for switch mode charger and adapter applications. It operates in primary-side sensing and regulation. Opto-coupler and TL431 could be eliminated. Proprietary built-in CV and CC control can achieve high precision CV/CC performance. It uses Pulse Frequency Modulation (PFM) method to build discontinuous conduction mode (DCM) flyback power supplies. Startup control The VDD pin of UTC UPSRB01 is connected to the line input through a resistor. A large value startup resistor can be used to minimize the power loss in application because the start current of UTC UPSRB01 is very low. When the VDD voltage reaches VTH (ON), the internal startup circuit is disabled and the IC turns on. Operating Current The Operating current of UTC UPSRB01 is as low as 400μA. Good efficiency and very low standby power can be achieved. Constant Voltage Operation The output voltage is defined by the transmission ratio between the secondary and auxiliary winding. The UTC UPSRB01 captures the auxiliary winding feedback voltage at FB pin and operates in constant-voltage (CV) mode to regulate the output voltage. The auxiliary voltage reflects the output voltage is given by: N VAUX = A ×（VO + ∆V） (1) NS Where △V indicates the drop voltage of the output diode. Figure2. Auxiliary voltage waveform Via a resistor divider connected between the auxiliary winding and FB, the VAUX is sampled at the Tsampling end and it is hold until the next sampling. The sampled voltage is compared with 2V reference voltage and the error is amplified. The error amplifier output reflects the load condition and controls the Toff time to regulate the output voltage, thus constant output voltage can be achieved. Constant Current Operation When the sampled voltage is below 2V reference voltage and the error amplifier output reaches its maximum, thus UTC UPSRB01 operates in constant-current (CC) mode. The CC point and maximum output power can be externally adjusted by external current sense resistor Rcs. The larger Rcs, the smaller CC point is, and the smaller output power becomes. UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw 4 of 7 QW-R103-078.B UPSRB01 LINEAR INTEGRATED CIRCUIT OPERATION DESCRIPTION (Cont.) Figure3. Adjustable output power by changing RCS Figure4. Secondary current waveform In CC operation, the CC loop control function of UTC UPSRB01 will keep a fixed proportion between secondary inductance de-magnetization time (Tdemag) and switching cycle time (Tsw). The fixed proportion is Tdemag 1 (2) = TSW 2 Thus the output current is given by: Iout = Tdemag 1 NP 1 NP = × ×I × × IPK × TSW 4 NS PK 2 NS (3) Programmable Cable drop Compensation UTC UPSRB01 has a built-in cable voltage drop compensation to achieve good load regulation. An offset voltage is generated at FB pin by an internal current flowing into the resistor divider. The current is inversely proportional to the voltage of VC pin. As a result, it is inversely proportional to the output load current. The voltage drop across the cable is compensated by this offset voltage at FB pin. It can also be programmed by adjusting the resistance of the divider to compensate the drop for various cable lines used. Current Sensing and Leading Edge Blanking Cycle-by-cycle current limiting is offered in UTC UPSRB01. The switch current is detected by a sense resistor into the CS pin. When the power switch is turned on, a turn-on spike will occur on this resistor. A 500ns leading-edge blanking is built in to avoid false-termination of the switching pulse so that the external RC filtering is no longer needed. UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw 5 of 7 QW-R103-078.B UPSRB01 LINEAR INTEGRATED CIRCUIT OPERATION DESCRIPTION (Cont.) Drive BJT The driver is a push pull stage with the supply voltage VDD. It provides the driving current for the external power bipolar transistor. The output signal is current-limited to IOUT(SOURCE). Protection Control Good power supply system reliability is achieved with its comprehensive protection features including output over-voltage protection, VDD over voltage protection, OTP, feedback loop open protection, Cycle-by-cycle current limiting, short circuit protection, leading edge blanking and UVLO, etc. VDD is supplied by transformer auxiliary winding output. The output of UTC UPSRB01 is shutdown when VDD drops below VTH(OFF) and the power converter enters power on start-up sequence thereafter. UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw 6 of 7 QW-R103-078.B UPSRB01 LINEAR INTEGRATED CIRCUIT TYPICAL APPLICATION CIRCUIT UTC assumes no responsibility for equipment failures that result from using products at values that exceed, even momentarily, rated values (such as maximum ratings, operating condition ranges, or other parameters) listed in products specifications of any and all UTC products described or contained herein. UTC products are not designed for use in life support appliances, devices or systems where malfunction of these products can be reasonably expected to result in personal injury. Reproduction in whole or in part is prohibited without the prior written consent of the copyright owner. The information presented in this document does not form part of any quotation or contract, is believed to be accurate and reliable and may be changed without notice. UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw 7 of 7 QW-R103-078.B