S6520 F Semiconductor LCD Back Light Inverter with Analog Dimming Description The S6520 contains all of the necessary control circuitry to implement a highly efficient cold cathode fluorescent back-light driver and provides a near sinusoidal output voltage and current waveforms for a CCFL. A specially designed integrated circuit provides all control functions for a current fed push-pull converter and contains two PWM(Pulse Width Modulation) control circuits to drive 4 CCFLs for LCD monitor. The S6520 operates at constant frequency in a PWM mode and it has feed forward control method, this function preventing lamp flickering against input voltage step changing. Therefore, even though input voltage is changed suddenly, the lamp current remains constant because of the feed back and feed forward control. Typical operating frequency ranges between 30kHz to 200kHz, dependent upon the CCFL and transformer characteristics. It provides protection functions such as OLP(Open Lamp Protection), SCP(Short Circuit Protection). Features • • • • • • • Complete Dual PWM Power Control Circuitry Internal Soft Start for Soft Lamp lgnition Enable Function to lock the output off until Out Signal is Operational Analog Dimming Function Internal Stable 5V Reference Supply Open Lamp Protection Internal Short Circuit Protection Ordering Information Type NO. S6520 Marking Package Code S6520 SOP-16 Outline Dimensions unit : mm KSI-8019-000 1 S6520 Internal Block Diagram Open Lamp Regulation Ct1 + 1 Oscillator1 + + - regulation signal to COMP1, COMP2 - 3 OLR1 14 OLR2 9 Vcc 6 ENA 7 OUT1 10 OUT2 16 REF Vref Vref Ct2 + 15 Oscillator2 Enable Switch 7V Vz - Internal bias 5V Vref Vref ena + 1.4V CMP1 5 FB1 4 ADIM 11 SS 2 FB2 Comparator 1 Amplifier 1 + + + Vref iss Amplifier 2 + + + 13 Output 1 + + Output 2 Comparator 2 + + Vref delay timer CMP2 GND 12 Shut Down Signal to Output Q S 10us R 8 + + - from FB1 from FB2 n*Vref reset signal from bias Short Circuit Protection PIN Collection Pin Number Symbol I/O Pin Function Description 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 CT1 SS OLR1 FB1 CMP1 ENA OUT1 GND VCC OUT2 ADIM CMP2 FB2 OLR2 CT2 REF I I I I I O I O I I I O Frequency Trimming Capacitor for Main Frequency Setting 1 Initial Soft Start Open Lamp Regulation 1 Feedback 1 (Error Amplifier Negative Input) Error Amplifier Output 1 ON/OFF Control Pin. TTL Signal is Applicable. Output Drive1 Ground Supply Voltage Output Drive 2 Analog Dimming Input Error Amplifier Output 2 Feedback 2 (Error Amplifier Negative Input) Open Lamp Regulation 2 Frequency Trimming Capacitor for Main Frequency Setting 2 Reference Voltage (VREF) = 5V KSI-8019-000 2 S6520 ABSOLUTE MAXIMUM RATINGS CHARACTERISTICS SYMBOL VALUE UNITS Supply Voltage VCC 22 V Power Dissipation PD 1 W Operating Temperature TOPR -25~+85 Storage Temperature TSTG -40~+125 ℃ Electrical Characteristics Ta=25℃, VCC = 10V, unless otherwise specified. Characteristic Symbol Test Condition Min. Typ. Max. Unit Vref - 4.925 5.0 5.075 V Line Regulation △Vref. LINE 8≤Vcc≤20 - 2.0 25 mV Load Regulation △Vref. LOAD 0mA≤Iref≤5mA - 1.0 15 mV Temperature Coefficient (note 1) △Vref/△T -25℃≤Ta≤85℃ - 0.01 - %/℃ Vref(EA) - 2.4 2.5 2.6 V Input Bias Current IB(EA) VCMP=2.5V - -0.1 -1.0 uA Output Sink Current ISINK VCMP=2.5V 0.3 2 - mA ISOURCE VCMP=2.5V -0.3 -2 - mA VDIM - 0 - 2.5 V Initial Soft Start Current ISS - 7.5 12.5 17 uA Soft Start Limit Voltage VSSL - 4.1 4.7 5.3 V REFERENCE SECTION Reference Voltage ERROR AMPLIFIER SECTION (EA1, EA2) Inverting Reference Voltage Output Source Current Dimming Input Voltage Range SOFT START SECTION PROTECTION SECTION (SCP1, SCP2 & OLR1, OLR2) SCP Threshold Voltage VSCP - 2.55 2.7 2.85 V OLR Threshold Voltage VOLR - 2.35 2.5 2.65 V On/Off Threshold Voltage VENA - 1.1 1.4 1.7 V FO Rt=50k, Ct=680pF 45 50 55 kHz OSCILLATOR SECTION (OSC1, OSC2) Oscillator Frequency KSI-8019-000 3 S6520 Electrical Characteristics(Continued) Ta=25℃, VCC = 10V, unless otherwise specified. Characteristic Symbol Test Condition Min. Typ. Max. P-CH Output High Voltage VPOH ISINK=10mA P-CH Output Low Voltage VPOL ISOURCE=10mA Output Rising Time (Note1) tR Output Falling Time (Note1) Unit Vcc0.9 Vcc7.5 Vcc0.7 Vcc6.0 Vcc0.4 Vcc4.5 COUT=0.5nF - 200 300 nsec tF COUT=0.5nF - 100 200 nsec Stand by Current 8V ISB8 - - 10 30 uA Stand by Current 20V ISB20 - - 20 60 uA Operating Current ICC - - 4 6 mA OUTPUT SECTION (OUT1, OUT2) V V START SECTION * Note 1. These parameters, although guaranteed, are not 100% tested in production KSI-8019-000 4 S6520 Electrical Characteristic Curves Fig. 1 VCC - ISB Fig. 2 VCC - ICC Fig. 3 VCC - Vref Fig. 4 Vref(EA) - VCMP Fig. 7 VSCP - VOUT Fig. 8 VENA - ICC KSI-8019-000 5 S6520 These AUK products are intended for usage in general electronic equipments(Office and communication equipment, measuring equipment, domestic electrification, etc.). Please make sure that you consult with us before you use these AUK products in equipments which require high quality and/or reliability, and in equipments which could have major impact to the welfare of human life(atomic energy control, airplane, spaceship, traffic signal, combustion central, all types of safety device, etc.). AUK cannot accept liability to any damage which may occur in case these AUK products were used in the mentioned equipments without prior consultation with AUK. KSI-8019-000 6