UNISONIC TECHNOLOGIES CO., LTD UPSL102 Preliminary LINEAR INTEGRATED CIRCUIT HIGH PRECISION CC PRIMARY-SIDE LED CONTROLLER 3 2 1 DESCRIPTION 5 The UTC UPSL102 is a high performance offline PSR controller for LED lighting, which can achieve accurate LED current and low system cost for an isolated lighting application in a single stage converter. Consequently, opto-coupler and TL431 could be eliminated. Constant Current (CC) control is intergrated as shown in the figure below. In CC control, the current can be adjusted externally by the sense resistor RS at CS pin. The chip consumes low start up current and very low operation current (typical 350μA), it can achieve high efficiency and low standby power consumption. The UTC UPSL102 offers comprehensive protection coverage with auto-recovery features including open loop protection, short circuit protection, cycle-by-cycle current limiting, VDD over voltage protection, built-in leading edge blanking, VDD under voltage lockout (UVLO), etc. SOT-25 FEATURES * Primary-side sensing and regulation without TL431 and opto-coupler * High precision constant current regulation at universal AC input * Low system cost and high efficiency * Built-in primary winding inductance compensation * Programmable CC regulation * Drivability for BJT switch 4 * Short circuit protection * Ultra low start-up current (Typ. 1μA) * Open loop protection * Built-in leading edge blanking (LEB) * Cycle-by-cycle current limiting * VDD under voltage lockout with hysteresis * VDD over voltage protection ORDERING INFORMATION Ordering Number UPSL102G-AF5-R UPSL102G-AF5-R Package SOT-25 (1)Packing Type (1) R: Tape Reel (2)Package Type (2) AF5: SOT-25 (3)Green Package (3) G: Halogen Free and Lead Free www.unisonic.com.tw Copyright © 2014 Unisonic Technologies Co., Ltd Packing Tape Reel 1 of 6 QW-R125-028.c UPSL102 Preliminary LINEAR INTEGRATED CIRCUIT MARKING 5 4 L102G 1 2 3 PIN CONFIGURATION VDD INV 4 5 2 3 GND CS BASE PIN DESCRIPTION PIN NO. 1 2 3 4 5 1 PIN NAME GND CS BASE INV VDD DESCRIPTION Ground Current sense input. Base driver with current limit for power BJT. The voltage feedback from auxiliary winding. Power supply. BLOCK DIAGRAM VDD 5 Internal Supply OVP UVLO OSC 5V POR INV 4 CC Controller GND 1 Base Drive Logic Control OTP OCP 3 BASE 2 CS LEB UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw 2 of 6 QW-R125-028.c UPSL102 Preliminary LINEAR INTEGRATED CIRCUIT ABSOLUTE MAXIMUM RATING PARAMETER SYMBOL RATINGS UNIT VDD Voltage -0.3~30 V BASE Voltage -0.3~7 V CS Input Voltage -0.3~7 V INV Input Voltage -0.3~7 V Junction Temperature TJ -40~150 °C Storage Temperature TSTG -55~150 °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. CAL CHARACTERISTICS (VDD=15V, TA=25°C, if not otherwise noted.) PARAMETER Supply Voltage (VDD) Section Start up Current Static Current VDD Under Voltage Lockout Enter VDD Under Voltage Lockout Exit VDD Over Voltage Protection Current Sense Input Section Lead Time Over Current Threshold OCP Propagation Delay INV Input Section Maximum Pause BASE Drive Section Base Sourcing Maximum Current Base Sourcing Current After Pre-off Base Drive Low Side On Resistor SYMBOL ISTART-UP ISTATIC UVLO(ON) UVLO(OFF) VDD_OVP TEST CONDITIONS MAX UNIT 5.0 11.5 23 0.1 350 6.0 12.5 26 3 500 7.6 13.5 29 μA μA V V V 1.21 0.5 1.23 1.25 μS V From OCP Comparator to Base Drive 100 nS TPAUSE_MAX 710 765 810 μS IS_MAX 40 1.9 50 2.4 1.8 60 2.9 mA mA Ω IS_PREOFF RDSON_l UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw TYP VDD=11V VDD=15V TLEB Vth_OCP Td_OC MIN 3 of 6 QW-R125-028.c UPSL102 Preliminary LINEAR INTEGRATED CIRCUIT OPERATION DESCRIPTION The UTC UPSL102 is a cost effective PSR controller optimized for off-line LED lighting applications which can achieve accurate LED current. It operates in primary side sensing and regulation, eliminating the need of opto-coupler and TL431, which makes the solution simple, small and low cost. Proprietary built-in CC control meeting accurate LED current. Startup Current and Start up Control Startup current of UTC UPSL102 is designed to be very low so that VDD can be charged up quickly. A large value startup resistor can therefore be used to minimize the power loss in application. Operating Current The operating current of UTC UPSL102 is designed to be very low so that VDD could be charged up above UVLO threshold and starts up quickly. Good efficiency and very low standby power is achieved with the low operating current. Adjustable CC point In UTC UPSL102, the CC point can be externally adjusted by external current sense resistor RS at CS pin as illustrated in typical application diagram. The larger RS is, the smaller CC point is, and vice versa. Principle of CC Operation To support the UTC UPSL102 proprietary CC control, system needs to be designed in DCM mode for flyback system. For flyback operating in DCM, the output current Iout is given by 1 Iout = LPFSWIP2 η / Vout (1) 2 Where LP indicates the inductance of primary winding and IP is the peak current of primary winding. Refer to the equation 1, the change of the primary winding inductance results in the change of the constant output current. To compensate the change from variations of primary winding inductance, the switching frequency is locked by an internal loop such that the switching frequency is 1 FSW = (2) 2TDemag Since TDemag is inversely proportional to the inductance, as a result, the product LP and fSW is constant, thus output current will not change as primary winding inductance changes. Up to ±10% variation of the primary winding inductance can be compensated. The output LED current is 1 V Iout = N thoc (3) 4 RS Where N is the ratio of transformer between primary side winding and secondary winding. UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw 4 of 6 QW-R125-028.c UPSL102 Preliminary LINEAR INTEGRATED CIRCUIT OPERATION DESCRIPTION(Cont.) CS and LEB Cycle-by-Cycle current limiting is offered in UTC UPSL102. The switch current is detected by a sense resistor into the CS pin. An internal leading edge blanking circuit chops off the sensed voltage spike at initial power BJT on state so that the external RC filtering on sense input is no longer needed. Protection Control Good power supply system reliability is achieved with its rich protection features including Cycle-by-Cycle current limiting (OCP), VDD over voltage protection, feedback loop open protection, short circuit protection and Under Voltage Lockout on VDD (UVLO). Because of the coupling between secondary winding and auxiliary winding, the voltage at VDD pin will rise up if the output of secondary side is open-circuited, when VDD pin voltage is larger than 27V, the UTC UPSL102 will stop sending pulses to BASE pin and enter auto restart mode. If the output of secondary side is short-circuited, the VDD voltage will drop down and the system enters under voltage lockout protection. Base Drive The drive is a push pull stage with supply voltage VDD. It provides the driving current for the external power bipolar transistor. The output signal is current limit to Is_max (typical 30mA). UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw 5 of 6 QW-R125-028.c UPSL102 Preliminary LINEAR INTEGRATED CIRCUIT TYPICAL APPLICATION CIRCUIT VLED NP ~ AC + NS UTC UPSL102 GND + CO + NAUX VDD CS BASE INV RS 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 6 of 6 QW-R125-028.c