AT1741D

AT1741 Preliminary Product Information 2-Channel PWM Controller for CCFL Backlight Features • High-accuracy reference voltage circuit (±2%). • Built-in short-circuit protection circuit. • Built-in Undervoltage Lockout protection. • Internal 2.5V Reference supply. • Variable Dead time provides control over total Range. General Description The AT1741 is 2-channel PWM switching regulator controllers that contains an on-chip 2.5V reference, two error amplifier, an adjustable oscillator, two dead-time comparators, undervoltage lockout circuitry and 2 common-emitter output. It is idea for step-up, step-down, and inverting converter. Applications • LCD CCFL Backlight • Portable equipment Block Diagram Aimtron reserves the right without notice to change this circuitry and specifications. 2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C. Tel: 886-3-563-0878 WWW: http://www.aimtron.com.tw Fax: 886-3-563-0879 Email: service@aimtron.com.tw 1 AT1741 Preliminary Product Information 2-Channel PWM Controller for CCFL Backlight Pin Configuration Ordering Information Part number AT1741S AT1741S_GRE AT1741D Package SOP16 SOP16,Green DIP16 Marking AT1741S AT1741S, date code with one bottom line AT1741D Pin Description Pin No. Symbol I/O Description 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 CT RT NON1 INV1 FB1 DT1 OUT1 GND Vcc OUT2 DT2 FB2 INV2 NON2 SCP REF --I I O I O --O I O I I -O External timing capacitor External timing resistor Positive input for error amplifier 1 Negative input for error amplifier 1 Error amplifier 1 output Output 1 dead time / soft start setting Output 1 Ground Power supply Output 2 Output 2 dead time / soft start setting Error amplifier 2 output Negative input for error amplifier 2 Positive input for error amplifier 2 Time latch setting Reference voltage output（2.5V） 2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C. Tel: 886-3-563-0878 WWW: http://www.aimtron.com.tw Fax: 886-3-563-0879 Email: service@aimtron.com.tw 2 AT1741 Preliminary Product Information 2-Channel PWM Controller for CCFL Backlight Absolute Maximum Ratings (Ta=+250C) Parameter Power supply voltage Power dissipation Operating temperture Storage temperture Output current Output voltage ＊2 Should not exceed Pd and values. Symbol Vcc Pd Topr Tstg Io Vo Limits 28 500*1 -30~+85 -55~+125 120*2 30 Unit V mW ℃ ℃ mA V ＊1 When mounted on 70mm×70mm×1.6mm glass epoxy board. Reduced by 6.5mw for each increase in Ta of 1℃ over 25℃. Recommended Operating Conditions (Ta=+250C) Parameter Power supply voltage Output current Output voltage Error amplifier input voltage Timing capacitor Timing resistor Oscillator frequency Symbol VCC Io Vo VOM CCT RRT FOSC Min. 3.6 --0.3 100 5.1 10 Values Typ. 6.0 ------Max. 25 100 25 1.6 15000 50 800 Unit Ｖ mA V V pF kΩ kHz Timing chart 2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C. Tel: 886-3-563-0878 WWW: http://www.aimtron.com.tw Fax: 886-3-563-0879 Email: service@aimtron.com.tw 3 AT1741 Preliminary Product Information 2-Channel PWM Controller for CCFL Backlight Electrical Characteristics Parameter Output voltage Input stability Load stability Oscillation frequency Frequency deviation Threshold voltage Standby voltage Latch voltage Source current Comparator threshold voltage Input threshold voltage （fosc=10kHz） On duty cycle Input bias current Latch mode source current Latch input voltage Threshold voltage Input offset voltage Input offset current Input bias current Open circuit gain Common-mode input voltage range Common-mode rejection ratio Maximum output voltage Minimum input voltage Output sink current Output source current Input threshold voltage （fosc=10kHz） Saturation voltage Leak current Standby current Average current consumption Symbol Vref VDL1 VDLO Fosc FDV VIT VSTB VLT ISCP VCT Vt0 Vt100 DON IBDT IDT VDT VUT VIO IIO IIB AV VOM CMRR VOH VOL IOI IOO Vt0 Vt100 VSAT IREAK ICCS ICCA (unless otherwise noted, Ta=25℃, and Vcc=6V ) Condition Values Max. Unit 2.55 V 10 mV 10 mV 480 kHz -% 1.80 V 100 mV 100 mV -3.5 μA 1.2 V V V % μA μA V V mV nA nA dB V dB V Reference voltage block Triangular wave oscillator Protection circuit Min. Typ. Iref=1mA 2.45 2.5 Vcc=3.6~25V -1 Iref=0~5mA -1 RRT=10kΩ, CCT=220pF 320 400 Vcc=3.6~25V -1 -1.48 1.64 No pull up -50 No pull up -30 --1.5 -2.5 Pin 5, Pin 12 Duty cycle=0% Duty cycle=100% Divide Vref using 13 kΩ and 27 kΩ DT1, DT2=2.0V DT1, DT2=0V IDT=40μA -----Vcc=3.6~25V ---FB=1.25V FB=1.25V Duty cycle=0% Duty cycle=100% Io=75mA Vo=25V When output is off RRT=10 kΩ 0.9 1.05 1.79 1.97 2.15 1.32 1.48 1.64 60 -70 -0.1 80 -1 ---6 30 100 -1.6 --- Rest period adjustment circuit -200 -560 2.28 2.48 ----70 0.3 60 2.3 2.53 --15 85 -80 2.5 Low-voltage input miss-operation prevention circuit Error amplifier PWM comparator Output block Total device -0.7 0.9 V 3 20 -mA -45 -75 -- μA 1.79 1.97 2.15 V 1.32 1.48 1.64 V -0.8 1.2 V μA -0 5 -1.3 1.8 mA -1.6 2.3 mA 2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C. Tel: 886-3-563-0878 WWW: http://www.aimtron.com.tw Fax: 886-3-563-0879 Email: service@aimtron.com.tw 4 AT1741 Preliminary Product Information 2-Channel PWM Controller for CCFL Backlight Timing Curve 2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C. Tel: 886-3-563-0878 WWW: http://www.aimtron.com.tw Fax: 886-3-563-0879 Email: service@aimtron.com.tw 5 AT1741 Preliminary Product Information 2-Channel PWM Controller for CCFL Backlight 2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C. Tel: 886-3-563-0878 WWW: http://www.aimtron.com.tw Fax: 886-3-563-0879 Email: service@aimtron.com.tw 6 AT1741 Preliminary Product Information 2-Channel PWM Controller for CCFL Backlight Application Circuit: Step-Down converter 2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C. Tel: 886-3-563-0878 WWW: http://www.aimtron.com.tw Fax: 886-3-563-0879 Email: service@aimtron.com.tw 7 AT1741 Preliminary Product Information 2-Channel PWM Controller for CCFL Backlight Application Circuit: CCFL Inverter 2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C. Tel: 886-3-563-0878 WWW: http://www.aimtron.com.tw Fax: 886-3-563-0879 Email: service@aimtron.com.tw 8 AT1741 Preliminary Product Information 2-Channel PWM Controller for CCFL Backlight Package Outline 16-pin SOP(150mil) *Controlling dimensions are in millmeters(mm). 2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C. Tel: 886-3-563-0878 WWW: http://www.aimtron.com.tw Fax: 886-3-563-0879 Email: service@aimtron.com.tw 9 AT1741 Preliminary Product Information 2-Channel PWM Controller for CCFL Backlight Package Outline 16-pin DIP(300mil) 2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C. Tel: 886-3-563-0878 WWW: http://www.aimtron.com.tw Fax: 886-3-563-0879 Email: service@aimtron.com.tw 10