www.fairchildsemi.com FAN7315 LCD Back Light Inverter Drive IC Features Description • Wide Dimming Range Analog dimming ( 2.5 : 1 ) Burst dimming ( >100 : 1 ) • High Efficiency Single Stage Power Conversion • Wide Input Voltage Range 7.4V to 20V • Back Light Lamp Ballast and Soft Dimming • Few External Components • Precision Voltage Reference Trimmed to 2% • ZVS full-bridge topology • Soft Start • PWM Control at fixed frequency • Analog, Burst Dimming Function • Open Lamp Protection • Open Lamp Regulation • Short Lamp Protection • Thermal Protection • 20 Pin SSOP The FAN7315 provides all the control functions for a series parallel resonant converter and also contains a pulse width modulation (PWM) controller to develop a supply voltage. Typical operating frequency range is between 30kHz and 250kHz depending on the CCFL and the transformer's characteristics. 20-SSOP Rev. 1.0.1 ©2004 Fairchild Semiconductor Corporation FAN7315 Internal Block Diagram RT OUTA OSCILLATOR Output Driver OUTB Output Control Logic CT - 5.2uA S_S PGND OUTC + + Output Driver OUTD EA_OUT Thermal protection ADIM + EA_IN - Error Amp. Q Solr 240uA Sburst Q SET CLR UVLO R S - OLP 300mV + 240uA + SCP + 2V BCT Solr - OLR Voltage Reference & Internal Bias + - + 2 ENA 1.4V VIN VIN + UVLO - AGND REF Sburst BDIM 2V 2.5VREF UVLO 7.4V FAN7315 Pin Assignments SCP OUTB 20 19 OUTA VIN PGND 18 17 16 OUTC OUTD 15 14 CT RT 13 12 11 10 BCT FAN7315 1 OLP 2 3 OLR ENA 4 S_S 6 7 8 9 REF ADIM BDIM EA_IN 5 AGND EA_OUT Pin Definitions No Name 1 OLP 2 3 Function Description No Name Function Description Open Lamp Protection 11 BCT OLR Open Lamp Regulation 12 RT Timing Resistor ENA Enable Input 13 CT Timing Capacitor 4 S/S Soft Start 14 OUTD NMOSFET Drive Output D 5 AGND Analog Ground 15 OUTC PMOSFET Drive Output C 6 V25 2.5V Reference Voltage 16 PGND Power Ground Supply Voltage Burst Dimming Timing Capacitor 7 ADIM Analog Dimming Input 17 VIN 8 BDIM Burst Dimming Input 18 OUTA PMOSFET Drive Output A 9 EA_IN Error Amplifier Input 19 OUTB NMOSFET Drive Output B 10 EA_OUT Error Amplifier Output 20 SCP Short Circuit Protection 3 FAN7315 Absolute Maximum Ratings Vcc=12V, for typical values Ta=25°C, for min/max values Ta is the operating ambient temperature range with -40°C ≤ Ta ≤ 85°C and 7.4V ≤ Vcc ≤ 20V, unless otherwise specified. Characteristics Symbol Value Unit Supply Voltage VCC 7.4 ~ 20 V Operating Temperature Range Topr -40 ~ 85 °C Storage Temperature Range Tstg -65 ~ 150 °C Thermal Resistance Junction-Air (Note1,2) RθJA 112 °C/W Pd 1.1 W Power Dissipation Note: 1. Thermal resistance test board Size: 76.2mm * 114.3mm * 1.6mm(1S0P) JEDEC standard: JESD51-3, JESD51-7 2. Assume no ambient airflow 4 FAN7315 Electrical Characteristics Vcc=12V, for typical values Ta=25°C, for min/max values Ta is the operating ambient temperature range with -40°C ≤ Ta ≤ 85°C and 7.4V ≤ Vcc ≤ 20V, unless otherwise specified. Characteristics Symbol Test Condition Min. Typ. Max. Unit Load Regulation ∆V25load 0 ≤ I25 ≤ 3mA - 2 25 mV Line Regulation ∆V25line 7.4V ≤ VCC ≤ 20V REFERENCE SECTION - 2 25 mV V25 - 2.44 2.49 2.54 V Oscillation Frequency fosc Ta=25°C, Ct = 330pF, Rt = 45k 93 100 107 kHz Ct = 330pF, Rt = 45k 89 100 111 kHz CT High Voltage Vcth - - 1.95 - V CT Low Voltage Vbctl - - 0.5 - V 150 191 232 Hz 2.5V Regulation Voltage OSCILLATOR SECTION(MAIN) OSCILLATOR SECTION(BURST) Oscillation Frequency foscb Ctb = 6.8nF, Rt=45k BCT High Voltage Vbcth - - 2 - V BCT Low Voltage Vbctl - - 0.5 - V ERROR AMP SECTION Error Amp Transconductance(Note1) Gm Va = 1~2.5V 100 360 600 umho Output Sink Current lsin EA_OUT = 1V 44 73 100 uA Output Source Current lsur EA_OUT = 1V 33 50 67 uA Open Lamp Regulation Current Iolr OLR=2.5V 160 240 320 uA 2.2 2.5 2.8 V 3.5 5.2 6.9 uA EA_OUT High Volgate Vea_outh SOFT START SECTION Soft Start Current Soft Start Clamping Voltage Iss S_S=0V Vssh - 2.2 2.55 2.9 V Open Lamp Protection Voltage Volp - 245 300 425 mV Open Lamp Regulation Voltage Volr - 1.8 2 2.2 V Short Circuit Protection Voltage Vscp - 1.75 2 2.25 V Thermal Shutdown On Temp.(Note1) TSDon - 130 150 170 °C TSD Hysterisis(Note1) TSDhy - - 30 - °C Start Threshold Voltage On Vthon - 5.2 6.3 7.4 V UVLO Hysteresis Vhys - 100 300 500 mV 48 85 122 uA - - 2 mA 55 80 105 uA PROTECTION SECTION UNDER VOLTAGE LOCK OUT SECTION Start Up Current Ist VCC = Vth-0.2V Operating Supply Current Iop VCC = 12V Stand-by Current Isb VCC = 12V, ENA=0V 5 FAN7315 Electrical Characteristics (Continued) Vcc=12V, for typical values Ta=25°C, for min/max values Ta is the operating ambient temperature range with -40°C ≤ Ta ≤ 85°C and 7.4V ≤ Vcc ≤ 20V, unless otherwise specified. Characteristics Symbol Test Condition Min. Typ. Max. Unit Off State Input Voltage Voff - - - 0.7 V On State Input Voltage Von - 2.1 - - V V ON/OFF SECTION OUTPUT SECTION PMOS Gate High Voltage Vpdhv VCC =12V - Vcc - PMOS Gate Low Voltage Vpdlv VCC =12V Vcc7.25 Vcc-6.5 Vcc5.55 NMOS Gate High Voltage Vndhv VCC = 12V 5.55 6.5 7.25 NMOS Gate Low Voltage Vndlv VCC =12V PMOS Gate Voltage With UVLO Activated Vpuv VCC = Vth-0.5V Vcc-0.2 - - NMOS Gate Voltage With UVLO Activated Vnuv VCC = Vth-0.5V - - 0.2 V 0.2 V Rising Time(Note1) Tr VCC = 12V, Cload=1700pF - 100 300 ns Falling Time(Note1) Tf VCC = 12V, Cload=1700pF - 100 300 ns Min. Overlap between diagonal switches(Note1) fosc=100KHz - 0 - % Max. Overlap betwwen diagonal switches(Note1) fosc=100KHz - 100 - % PDR_A/NDR_B(Note1) fosc=100KHz, Rt=45k - 325 - ns PDR_C/NDR_D(Note1) fosc=100KHz, Rt=45k - 325 - ns Max./Min Overlap Delay Time Note: 1. These parameters, although guaranteed, are not 100% tested in production. 6 FAN7315 Mechanical Dimensions Package Dimensions in millimeters 20-SSOP 7 FAN7315 Ordering Information Product number Package Operating Temperature FAN7315G 20-SSOP -40°C ~ 85°C DISCLAIMER FAIRCHILD SEMICONDUCTOR RESERVES THE RIGHT TO MAKE CHANGES WITHOUT FURTHER NOTICE TO ANY PRODUCTS HEREIN TO IMPROVE RELIABILITY, FUNCTION OR DESIGN. FAIRCHILD DOES NOT ASSUME ANY LIABILITY ARISING OUT OF THE APPLICATION OR USE OF ANY PRODUCT OR CIRCUIT DESCRIBED HEREIN; NEITHER DOES IT CONVEY ANY LICENSE UNDER ITS PATENT RIGHTS, NOR THE RIGHTS OF OTHERS. LIFE SUPPORT POLICY FAIRCHILD’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF FAIRCHILD SEMICONDUCTOR CORPORATION. As used herein: 1. Life support devices or systems are devices or systems which, (a) are intended for surgical implant into the body, or (b) support or sustain life, and (c) whose failure to perform when properly used in accordance with instructions for use provided in the labeling, can be reasonably expected to result in a significant injury of the user. 2. A critical component in any component of a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system, or to affect its safety or effectiveness. www.fairchildsemi.com 10/6/04 0.0m 001 Stock#DSxxxxxxxx © 2002 Fairchild Semiconductor Corporation