AT1780 Preliminary Product Information 640kHz/1.2MHz,Low-Noise Step-Up Current-Mode PWM Controller Features General Description • 1.6A,0.21Ω,14V Power MOSFET • Operating input voltage:+2.6V to +5.5V • Adjustable Output from VIN to 12V • 640kHz /1.2MHz pin selectable switching Frequency • 0.1μA shutdown Current • Built-in Soft-Start function • Small 8-Pin MSOP Package The AT1780 is a current-mode step-up DC/DC converter with a 1.6A, 0.21Ω power MOSFET. The soft-start function is programmed with an external capacitor, which sets the input current ramp rate. It is ideal for generating bias voltages for LCD panels. Pin selectable frequency 640KHz or 1.2MHz operation results in a low noise output that is easy to filter and faster loop performance. An external compensation pin provides the user flexibility in determining loop dynamics, allowing the use of small, low equivalent series resistance (ESR) ceramic output capacitors. Applications • LCD Displays • Digital Cameras • Portable Applications • Hand-Held Devices *Protected by U.S. Patent # 6,791,368 Block Diagram COMP VIN SHDN Reference 1.24V Power ON/OFF SOFTSTART BIAS 4uA SS Enable + Error Amplifier FB Comparator gm 1.24V LX - + R + Clock Q N S GND FSLC Oscillator Ramp Generator + + CURRENT SENSE Aimtron reserves the right without notice to change this circuitry and specifications. 7F, No.9, PARK AVENUE II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C. Tel: 886-3-563-0878 Fax: 886-3-563-0879 WWW: http://www.aimtron.com.tw 3/24/06 REV 1.1 Email: [email protected] 1 AT1780 Preliminary Product Information 640kHz/1.2MHz,Low-Noise Step-Up Current-Mode PWM Controller Pin Configuration 8 7 6 5 1780 1 2 3 4 Ordering Information Part number AT1780M_GRE Package MSOP8,Green Marking 1780,data code with one bottom line *For more marking information, contact our sales representative directly Pin Description Pin No. Symbol I/O 1 2 3 4 5 6 7 8 COMP FB /SHDN GND LX VIN FSLC SS I I O I — Description Compensation network connection. Output voltage feedback input Shutdown control input, active low Ground Switch Pin. Power supply pin. Frequency select input. Ground=640KHz, VIN=1.2MHz Soft-Start control pin. 7F, No.9, PARK AVENUE II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C. Tel: 886-3-563-0878 Fax: 886-3-563-0879 WWW: http://www.aimtron.com.tw 3/24/06 REV 1.1 Email: [email protected] 2 AT1780 Preliminary Product Information 640kHz/1.2MHz,Low-Noise Step-Up Current-Mode PWM Controller Absolute Maximum Ratings Parameter Condition LX to GND IN, /SHDN, FREG, FB to GND SS, COMP to GND RMS LX pin current Continuous power dissipation Operating temperature Junction temperature Storage temperature Lead temperature — — — — 8pin μMAX（TA=+70℃） — — — — Rated Value Min. Max. -0.3 +14 -0.3 +6 -0.3 VIN+0.3 — 1.2 — 330 -30 +85 — +150 -40 +150 — +300 Unit V V V A 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 SS pin capacitance Phase compensation capacitance Phase compensation capacitance Phase compensation resistance Oscillation frequency Operating temperature Symbol VIN CPE CCOMP1 CCOMP2 RCOMP fOSC1 fOSC2 TOP Values Min. 2.6 ----540 1000 -30 Typ. -0.033 470 18 30 640 1220 +25 Unit Max. 5.5 ----740 1500 +85 Ｖ μＦ pＦ pＦ KΩ kHz kHz °C 7F, No.9, PARK AVENUE II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C. Tel: 886-3-563-0878 Fax: 886-3-563-0879 WWW: http://www.aimtron.com.tw 3/24/06 REV 1.1 Email: [email protected] 3 AT1780 Preliminary Product Information 640kHz/1.2MHz,Low-Noise Step-Up Current-Mode PWM Controller Electrical Characteristics (VIN = SHDN = 3V, FREQ = GND, TA =0℃ to +85℃, unless otherwise noted. Typical values are at TA = +25℃.) Parameter Symbol Condition Values Unit Min. Typ. Max. Input Supply Range VIN VIN Undervoltage UVLO Lockout Entire device Quiescent Current Error amplifier Sawtooth wave oscillator (OSC) N-CHANNEL SWITCH SOFT-START CONTROL INPUTS IIN Shutdown Supply Current IIN Feedback Voltage VFB FB Input Bias Current IFB Feedback-Voltage Line Regulation Transconductance Voltage Gain gm Av Frequency fosc Maximum Duty Cycle DC Current Limit ILIM On-Resistance RON Leakage Current Current-Sense Transresistance Reset Switch Resistance Charge Current ILXOFF VIL Input High Voltage VIH IFSLC ISHDN 2.1 Level to produce 1.222 VCOMP = 1.24V VFB = 1.25V Level to produce VCOMP = 1.24V, 2.6V < VIN < 5.5V ΔI = 5µA -FSLC = GND 540 FSLC = IN 1050 FSLC = GND 79 FSLC = IN VFB = 1V, duty cycle = 1.2 65% ILX = 1.2A VLX = 12V 0.3 VSS = 1.2V /SHDN, FREQ; VIN = 2.6V to 5.5V /SHDN, FREQ; VIN = 2.6V to 5.5V SHDN, FREQ 2.3 5.5 V 2.5 V 0.218 0.35 /SHDN = GND RCS Input Low Voltage Hysteresis FSLC Pull-Down Current /SHDN Input Current 2.6 VIN rising, typical hysteresis is 40mV,LX remains off below this level VFB = 1.3V, not switching VFB = 1.0V, switching 1.5 2.045 5 0.1 10 1.24 1.258 0 40 mA μA V nA 0.05 0.15 %/V μmhos 140 500 V/V 640 740 kHz 1200 1350 91.3 92 % 82.1 1.6 2.3 A 0.21 0.5 0.01 20 Ω μA 0.45 0.65 V/A 4 100 Ω 7 μA 0.4 V 1.6 V 100 mV 1.5 5 9 μA 0.001 1 μA 7F, No.9, PARK AVENUE II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C. Tel: 886-3-563-0878 Fax: 886-3-563-0879 WWW: http://www.aimtron.com.tw 3/24/06 REV 1.1 Email: [email protected] 4 AT1780 Preliminary Product Information 640kHz/1.2MHz,Low-Noise Step-Up Current-Mode PWM Controller Typical Characteristics (VIN = 3.3V, FREQ = GND, TA=25℃, unless otherwise noted.) Efficiency vs. Output current Efficiency vs. Output current 90 90 85 85 Efficiency Eff (%) Efficiency Eff (%) AT1780 95 AT1780 95 80 75 80 70 75 70 Vin=3.3V Vout=10V fosc=640kHz L=10uH 65 1 10 100 Output current Iout (mA) Vin=3.3V Vout=10V fosc=1.2MHz L=4.7uH 65 1000 1 10 100 Output current Iout (mA) Output voltage vs. Output current Output voltage vs. Output current AT1780 10.05 Output voltage Vout (V) 10.05 10.00 9.95 9.90 9.85 9.80 9.75 Vin=3.3V Vout=10V fosc=640kHz L=10uH 9.70 9.65 0 40 80 120 160 200 Output current Iout (mA) CH1:Output voltage,100mV/div/AC CH4:Output current,100mA/div/DC Vout=10V,fosc=640kHz,L=10uH R1=100k,C1=470PF,C2=18PF 240 AT1780 10.10 10.10 Output voltage Vout (V) 1000 10.00 9.95 9.90 9.85 9.80 9.75 Vin=3.3V Vout=10V fosc=1.2MHz L=4.7uH 9.70 9.65 0 40 80 120 160 200 Output current Iout (mA) 240 CH1:Output voltage,100mV/div/AC CH4:Output current,100mA/div/DC Vout=10V,fosc=1.2MHz,L=4.7uH R1=100k,C1=470PF,C2=18PF 7F, No.9, PARK AVENUE II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C. Tel: 886-3-563-0878 Fax: 886-3-563-0879 WWW: http://www.aimtron.com.tw 3/24/06 REV 1.1 Email: [email protected] 5 AT1780 Preliminary Product Information 640kHz/1.2MHz,Low-Noise Step-Up Current-Mode PWM Controller Typical Characteristics (continuted) CH1:LX voltage,5V/div/DC CH4:Inductor current,500mA/div/DC Vout=10V,fosc=640kHz,L=10uH CH1:LX voltage,5V/div/DC CH4:Inductor current,500mA/div/DC Vout=10V,fosc=1.2MHz,L=4.7uH CH1:LX voltage,5V/div/DC CH2:Vin and /SHDN voltage,2V/div/DC CH3:SS voltage,2V/div/DC CH4:Iin current,500mA/div/DC Vout=10V,Iout=100mA, fosc=640kHz,L=10uH CH1:LX voltage,5V/div/DC CH2:Vin and /SHDN voltage,2V/div/DC CH1:SS voltage,2V/div/DC CH4:Iin current,500mA/div/DC Vout=10V,Iout=100mA, fosc=1.2MHz,L=4.7uH 7F, No.9, PARK AVENUE II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C. Tel: 886-3-563-0878 Fax: 886-3-563-0879 WWW: http://www.aimtron.com.tw 3/24/06 REV 1.1 Email: [email protected] 6 AT1780 Preliminary Product Information 640kHz/1.2MHz,Low-Noise Step-Up Current-Mode PWM Controller Typical Application Circuit Vin 2.6V to 5.5V Vout D1 L1 Cin Cout Aimtron 6 3 C1 0.1UF 1 4 LX /SHDN FB COMP FLSC 5 2 7 R2 8 SS Rcomp Cout AT1780 VIN GND R1 Css Ccomp1 Ccomp Figure 1.Typical application circuit Vin 3.0V to 3.6V CRS01 4.7UH VAA 10V/150mA 22UF 10UF 6 3 C1 0.1UF 1 4 Aimtron LX /SHDN FB COMP FLSC SS 5 47K 2 D2 7 0.1UF 8 D5 0.1UF 30K 18PF 10UF AT1780 VIN GND 332K 0.033UF D3 1UF D4 VGH 30V/5mA 1UF 470PF 0.1UF D7 D6 VGL -10V/10mA 4.7UF Figure 2.TFT panel power supply application circuit 7F, No.9, PARK AVENUE II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C. Tel: 886-3-563-0878 Fax: 886-3-563-0879 WWW: http://www.aimtron.com.tw 3/24/06 REV 1.1 Email: [email protected] 7 AT1780 Preliminary Product Information 640kHz/1.2MHz,Low-Noise Step-Up Current-Mode PWM Controller Small Outline 8-pin Plastic µMAX D S 8 7 6 5 E 1 2 3 5 5 7 8 4 3 2 1 H 4 A α A1 C B e SYMBOL A A1 B C D e E H L α S INCHES MIN MAX 0.037 0.043 0.002 0.006 0.010 0.014 0.005 0.007 0.116 0.120 0.0256 BSC 0.116 0.120 0.188 0.198 0.016 0.026 0° 6° 0.207 BSC L MILLIMETERS MIN MAX 0.94 1.10 0.05 0.15 0.25 0.36 0.13 0.18 2.95 3.05 0.65 BSC 2.95 3.05 4.78 5.03 0.41 0.66 0° 6° 0.525 BSC NOTES - 7F, No.9, PARK AVENUE II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C. Tel: 886-3-563-0878 Fax: 886-3-563-0879 WWW: http://www.aimtron.com.tw 3/24/06 REV 1.1 Email: [email protected] 8 AT1780 Preliminary Product Information 640kHz/1.2MHz,Low-Noise Step-Up Current-Mode PWM Controller Reflow Profiles Profile Feature Average ramp-up rate (TL to TP) Preheat -Temperature Min(Tsmin) -Temperature Max (Tsmax) -Time (min to max)(ts) Tsmax to TL -Ramp-up Rate Time maintained above: -Temperature (TL) -Time (tL) Peak Temperature(TP) Time within 5°C of actual Peak Temperature (tP) Ramp-down Rate Time 25°C to Peak Temperature Sn-Pb Eutectic Assembly Large Body Small Body Pkg. thickness Pkg. thickness <2.5mm or Pkg. ≥2.5mm or Pkg. 3 volume ≥350mm3 volume <350mm 3°C/second max. Pb-Free Assembly Large Body Small Body Pkg. thickness Pkg. thickness ≥2.5mm or Pkg. ≥2.5mm or Pkg. volume ≥350mm3 volume ≥350mm3 3°C/second max. 100°C 150°C 60-120 seconds 150°C 200°C 60-180 seconds 3°C/second max. 183°C 60-150 seconds 217°C 60-150 seconds 225+0/-5°C 10-30 seconds 240+0/-5°C 10-30 seconds 6°C/second max. 6 minutes max. 245+0/-5°C 10-30 seconds 250+0/-5°C 20-40 seconds 3°C/second max. 8 minutes max. *All temperatures refer to topside of the package, measured on the package body surface. 7F, No.9, PARK AVENUE II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C. Tel: 886-3-563-0878 Fax: 886-3-563-0879 WWW: http://www.aimtron.com.tw 3/24/06 REV 1.1 Email: [email protected] 9