AT1743 2-Channel PWM Controller for LCD Display Features General Description • High-accuracy reference voltage circuit (±1%). • Built-in short-circuit protection circuit. • Built-in Undervoltage Lockout protection. • Internal 2.5V Reference supply. • Variable Dead time provides control over total Range. The AT1743 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 Display • Portable equipment Block Diagram 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: [email protected] 1 AT1743 2-Channel PWM Controller for LCD Display Pin Configuration Ordering Information Part number AT1743 - Package TSSOP16 - Marking AT1743P - Pin Description Pin No. Symbol I/O 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 Vref --I I O I O --O I O I I -O Description 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: [email protected] 2 AT1743 2-Channel PWM Controller for LCD Display Absolute Maximum Ratings (Ta=+250C) Parameter Power supply voltage Power dissipation Operating temperture Storage temperture Output current Output voltage Symbol Limits Vcc Pd Topr Tstg Io Vo 30 450*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℃. ＊2 Should not exceed Pd and values. 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 Values Min. 3.6 --0.3 100 5.1 10 Typ. 6.0 ------- Unit Max. 25 100 25 1.6 15000 50 800 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: [email protected] 3 AT1743 2-Channel PWM Controller for LCD Display Electrical Characteristics Parameter Reference voltage block Triangular wave oscillator Protection circuit Rest period adjustment circuit Low-voltage input miss-operation prevention circuit Error amplifier PWM comparator Output block Total device (unless otherwise noted, Ta=25℃, and Vcc=6V ) Symbol Condition Values Unit 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） Vref VDL1 VDLO Fosc FDV VIT VSTB VLT ISCP Min. Typ. Iref=1mA 2.48 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 VCT Pin 5, Pin 12 0.9 1.2 V Vt0 Vt100 1.79 1.97 2.15 1.32 1.48 1.64 V V On duty cycle DON Input bias current Latch mode source current Latch input voltage IBDT Duty cycle=0% Duty cycle=100% Divide Vref using 13 kΩ and 27 kΩ DT1, DT2=2.0V IDT VDT Threshold voltage VUT -- -- 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 VIO IIO IIB AV ----- VOM 1.05 Max. 2.53 V 10 mV 10 mV 480 kHz -% 1.80 V 100 mV 100 mV 3.5 μA 45 55 65 % -- 0.1 1 μA DT1, DT2=0V 200 560 -- μA IDT=40μA 2.28 2.48 -- V 2.53 -- V ---70 --15 85 6 30 100 -- mV nA nA dB 0.3 -- 1.6 V Vcc=3.6~25V CMRR -- 60 80 -- dB VOH -- 2.3 2.5 -- V VOL IOI IOO Vt0 Vt100 VSAT IREAK ICCS -FB=1.25V FB=1.25V Duty cycle=0% Duty cycle=100% Io=75mA Vo=25V When output is off ICCA RRT=10 kΩ -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: [email protected] 4 AT1743 2-Channel PWM Controller for LCD Display 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: [email protected] 5 AT1743 2-Channel PWM Controller for LCD Display 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: [email protected] 6 AT1743 2-Channel PWM Controller for LCD Display 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: [email protected] 7 AT1743 2-Channel PWM Controller for LCD Display Package Outline 16-pin TSSOP SYMBOL A A1 A2 b C D E E1 L e y θ MILLIMETERS MIN TYP MAX 1.05 1.10 1.20 0.05 0.10 0.15 1.00 1.05 0.20 0.25 0.28 0.127 4.90 5.075 5.10 6.20 6.40 6.60 4.30 4.40 4.50 0.50 0.60 0.70 0.65 0.076 0° 8° MIN 0.041 0.002 0.008 0.193 0.244 0.170 0.020 0° INCHES TYP 0.043 0.004 0.039 0.010 0.005 0.1998 0.252 0.173 0.024 0.026 - MAX 0.047 0.006 0.041 0.011 0.200 0.260 0.177 0.028 0.003 8° 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: [email protected] 8 AT1743 2-Channel PWM Controller for LCD Display Reflow Condition (IR/Convection or VPR Reflow) Reference JEDEC Standard J-STD-020A Classification Reflow Profiles Convection or IR/Convction Average Heating Rate(180°C to peak) 5°C/second max. 120 seconds max. Preheat Temperature(125±20°C) 10~150 seconds Temperature maintained above 180°C Time within 5°C of actual Peak 10~20 seconds Temperature Peak Temperature Range(Note 1) 219~225°C or 235~240°C Cooling Rate 6°C /second max. 6 minutes max. Time 25°C to Peak Temperature VPR 10°C/second max. 60 seconds 219~225°C or 235~240°C 10°C/second max. *1 The maximum peak temperatures for IR and VP reflow are depending on package dimensions. Package Reflow Conditions Pkg. Thickness ≥2.5mm Pkg. Thickness <2.5mm Pkg. Thickness <2.5mm and and and all bags Pkg. Volume ≥350 mm3 Pkg. Volume <350 mm3 Convection 219~225°C VPR 219~225°C IR/Convection 219~225°C Convection 235~240°C VPR 235~240°C IR/Convection 235~240°C 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: [email protected] 9