AT1731 Preliminary 2-Channel PWM Controller for LCD Bias Features • Low input voltage: 2.5V to 7V • 2-Channels PWM Control: 1 Boost Controller(CH1) 1 Inverting Controller (CH2) • Adjustable Soft start time and maximum duty cycle • Built-in timer latch for short circuit protection: Delay time=216/(Switching frequency) • Built-in under-voltage lockout, thermal shutdown. • High operating frequency: 100kHz to 1MHz General Description The AT1731 is a PWM DC/DC converter control IC with 2 channel outputs that can directly drive power MOSFET. This IC ia suitable for very small DC/DC converters because of their small and thin package(1.1 mm max.), and high operation frequency (up to 1.0 MHz). Applications • LCD Displays Bias • Power Supply for general 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 AT1731 Preliminary 2-Channel PWM Controller for LCD Bias Pin Configuration Ordering Information Part number AT1731 Package TSSOP16 Marking AT1731P - Pin Description Symbol Pin No. Descript Symbol Pin No. Descript FB1 1 CH1 error amplifier output OUT1 9 IN1 2 10 NC 3 CH1 inverting input to OUT2 error amplifier Don’t connect NC 11 CH1 output for NchMOSFET CH2 output for PchMOSFET Don’t connect GND 4 Control blocks ground VCC 12 Power Supply PGND 5 Power blocks ground REG 13 Regulated voltage output GND 6 Control blocks ground CT 14 IN2 7 CS2 15 FB2 8 CH2 inverting input to error amplifier CH2 error amplifier output Oscillator timing capacitor Sotf-start for CH2 CS1 16 Soft-star for CH1 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 AT1731 Preliminary 2-Channel PWM Controller for LCD Bias Absolute Maximum Ratings Parameter Condition Power Supply Voltage Source Average Current of OUT1 OUT2 Sink Average Current of OUT1 OUT2 Input Voltage to Error Amplifier Continuous power dissipation Operating temperature Junction temperature Storage temperature Lead temperature — — Rated Value Min. Max. +8 -50 Unit V mA — - 50 mA — TSSOP16（Ta=+25℃） — — — — -30 -40 - 6.5 500 +85 +125 +150 +300 V mW 0 C 0 C 0 C 0 C Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Recommended Operating Conditions (Ta=+250C) Parameter Power supply voltage Oscillation frequency Operating temperature Symbol VCC fOSC TOP Values Min. 2.5 100 -30 Typ. -500 +25 Unit Max. 7 1000 +85 Ｖ KHz °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] 3 AT1731 Preliminary 2-Channel PWM Controller for LCD Bias Electrical Characteristics (VCC = 3V,Ta =+25℃, unless otherwise noted.) Parameter Symbol Condition Values Unit Min. Typ. Max. Input Supply Range 7.0 V UVLO 1.95 2.05 2.15 V Reference Voltage VREF 0.98 1.00 1.02 V Reference Voltage line-regulation VREF-Line 1 5 mV 0.5 1.5 % 3.0 3.8 mA 10 mV -160 -120 -80 μA 2.0 3.0 mA 20 % 20 % VCC Lockout Entire device VCC Undervoltage Operating Current ICC Input Offset Voltage Source Current (CH1,2) Sink Current(CH1,2) Source current Variation with temperature Sink current Variation with temperature Unity Gain Bandwidth Common Mode Input Voltage Range DC Open Loop Gain VIO Frequency VCC=2.5V to 7.0V Ta =-30℃ to +85℃ Rference Variation with Temperature Error amplifier 2.5 IOH IOL Duty=50%, fOSC=500KHz VFB = VREG -0.5V VFB = 0.5V Ta =-30℃ to +85℃ -- 2.5 Ta =-30℃ to +85℃ fT 2.0 VCOM 0.2 AV fosc High Level Voltage Sawtooth wave Oscillator (OSC) Low Level Voltage Variation with Power Supply Variation with Temperature Regulated Voltage Variation with Power Regulated Voltage Supply for internal Control Variation with Block Temperature Source Current VREG Soft-Start and Duty Charge Current of Section CS1(Source) ICS1_2 CT =150pF 480 1.5 80 550 V dB 620 kHz CT =150pF 1.0 V CT =150pF 0.5 V Vcc=2.5V to 7V 2 Ta =-30℃ to +85℃ 7 CO =0.1μF Vcc=2.5V to 7V % % 2.16 2.20 2.24 V 1.5 % 1.5 % -15 mA Ta =-30℃ to +85℃ IREG MHz -40 -1.0 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 AT1731 Preliminary 2-Channel PWM Controller for LCD Bias Charge Current of CS2(Sink) Max. Duty of CH1 Max. Duty of CH2 Invalid TL threshold voltage of CS1 Invalid TL threshold voltage of CS2 Threshold Voltage of FB1 Timer Latch Section Threshold Voltage of (TL) FB2 Start up count Start up time Thermal Shuntdown Threshold Temperature Section Output Section ICS3 fOSC=500KHz fOSC=500KHz 80 80 87 86 mA 90 90 % % 0.3 V 1.32. V VTLTH1 1.32 V VTLTH2 0.3 V Count TTL 216 119 105 TOH Rise time of OUT1 tr1 Rise time of OUT3 Tr2 Fall time of OUT1 tf1 Fall time of OUT2 tf2 High Level on Resistance of OUT1 Low Level on Resistance of OUT1 High Level on Resistance of OUT2 Low Level on Resistance of OUT2 1.0 R1AH R1AL R2AH R2AL 137 0 140 CO =1000pF OUT1-GND CO =1000pF VCC-OUT2 CO =1000pF OUT1-GND CO =1000pF VCC-OUT2 IOUT1=-150mA between ms C 20 25 35 ns 20 25 35 ns 20 25 35 ns 20 25 35 ns 2.5 4.0 5.5 Ω IOUT1=150mA 2.5 4.0 5.5 Ω IOUT2=-150mA 2.5 4.0 5.5 Ω IOUT2=150mA 2.5 4.0 5.5 Ω between between between 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 AT1731 Preliminary 2-Channel PWM Controller for LCD Bias Typical Application Circuit 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 AT1731 Preliminary 2-Channel PWM Controller for LCD Bias 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] 7 AT1731 Preliminary 2-Channel PWM Controller for LCD Bias 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 10~20 seconds Time within 5°C of actual Peak 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 3 Pkg. Volume ≥350 mm 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] 8