AT1796 Preliminary Product Information 150kHz, 3A Step-Down Switching Regulator Features Description ․3.3V and 5V output versions ․Guaranteed 3A output load current ․Requires small number ofexternal components ․Excellent line and load regulation ․150kHz fixed frequency internal oscillator ․Built-in TTL On/Off Control ․Low power standby mode, IQ typically 80uA ․Built-in current limit protection ․Built-in thermal shutdown circuit. ․Operating voltage: 4.5V~25V ․TO-265 package The AT1796 series of regulators are step-down (buck) DC/DC converter, capable of driving a 3A load with excellent line and load regulation. Requiring a minimum number of external components, these regulators are simple to use . The AT1796 series operates at a switching frequency of 150kHz.Available in a standard 5-lead TO-263 surface mount package. It include a guaranteed ±4% tolerance on output voltage under specified input voltage and output load conditions, and ±15% on the oscillator frequency. Applications High-efficiency step-down regulator TFT Scalar Board On-card switching regulators Block Diagram 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 2/15/2006 REV : 1.1 Email: [email protected] 1 AT1796 Preliminary Product Information 150kHz, 3A Step-Down Switching Regulator Pin Configuration Ordering Information Part number AT1796-50 AT1796-50_PBF AT1796-33 AT1796-33_PBF AT1796-ADJ AT1796-ADJ_PBF Package TO-265(5.0V version) TO-265(5.0V version),PB-Free TO-265(3.3V version) TO-265(3.3V version),PB-Free TO-265(ADJ version) TO-265(ADJ version),PB-Free Marking AT1796-50A AT1796-50A,date code with one bottom line AT1796-33A AT1796-33A,date code with one bottom line AT1796-ADJ AT1796-ADJ,date code with one bottom line *For more marking information, contact our sales representative directly Pin Description Symbol VCC OUT GND FB SHDN Pin No. 1 2 3 4 5 Descript Power Supply Switch Node Connection to Inductor Power ground Output Feedback ON/OFF Control 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 2/15/2006 REV : 1.1 Email: [email protected] 2 AT1796 Preliminary Product Information 150kHz, 3A Step-Down Switching Regulator Absolute maximum ratings Parameter Power supply voltage SHDN pin input voltage Power dissipation Operating Junction Temperature Storage temperature Thermal Resistance from Junction to Ambient Thermal Resistance from Junction to Case Lead Temperagture(Soldering, 5sec.) ESD Susceptibility *2 Symbol VCC VSHDN Pd TJ Tstg θJA θJC HBM MM Limits 30 -0.3~+25 Internally Limited -30~+125 -65~+150 19.4 7.7 260 2 200 unit V V W o C o C o C/W o C/W o C KV V 1. 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. 2. Device are ESD sensitive . Handling precaution recommended. The Human Body model is a 100pF capacitor discharged through a 1.5KΩ resistor into each pin. 3. θJA is measured with the component mounted on an evaluation PC board in free air that required area of copper is 2.5in2 (1 oz.)or larger. the Recommended operating conditions (TA = 25oC) Parameter Power supply voltage SHDN pin input voltage Symbol VCC VSHDN Limits 4.5~28 0~+20 unit V V 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 2/15/2006 REV : 1.1 Email: [email protected] 3 AT1796 Preliminary Product Information 150kHz, 3A Step-Down Switching Regulator Electrical characteristics (VCC = 12V , Ta =+25℃ , unless otherwise noted. ) Parameter Symbol Quiescent Current IOC Stand-by quiescent Current ISQC SHDN pin logic input voltage threshold SHDN pin logic input current Condition Values Unit Min. Typ. Max. -- 5 10 mA SHDN = 5V -- 80 200 µA VIL VIH Active mode Standby mode -2.0 --- 0.6 -- V V IIL IIH Active mode Standby mode --- 0.02 5 5 15 µA µA 3.168 3.3 3.432 V Vin = 12V , ILOAD = 3A 73 -- -- % 4.75≦Vcc≦28V 0.2A≦ILOAD≦3A 4.8 5.0 5.2 V Vin = 12V , ILOAD = 3A -- 80 -- % 1.193 1.230 1.267 V -- 73 -- % -- 1.15 1.5 V 127 150 173 kHz <AT1796-3.3V> Output voltage Efficiency VOUT η 4.75≦Vcc≦28V 0.2A≦ILOAD≦3A <AT1796-5.0V> Output voltage Efficiency VOUT η <AT1796-ADJ> FB voltage VFB Efficiency η 4.75≦Vcc≦28V 0.2A≦ILOAD≦3A Vin = 12V , ILOAD = 3A , VOUT = 3V <Device parameters> Saturation voltage VSAT Oscillator frequency FOSC Maximum duty cycle DMAX FB = 0V -- 100 -- % Minimum duty cycle DMIN FB = 3.3V or 5V -- 0 -- % ICL Peak current 3.6 4.5 5.0 A IL1 No diode . capacitor , inductor FB = 12V , Switching OFF , OUT = 0V -- 50 -- µA IL2 Vcc =28V -- 2 30 mA Current limit Output leakage current ILOAD = 3A 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 2/15/2006 REV : 1.1 Email: [email protected] 4 AT1796 Preliminary Product Information 150kHz, 3A Step-Down Switching Regulator CH1:SHDN CH2:5V Output CH3:OUT CH4:IIN Fig1. 5V/2A Output Fig2. 5V/3A Output 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 2/15/2006 REV : 1.1 Email: [email protected] 5 AT1796 Preliminary Product Information 150kHz, 3A Step-Down Switching Regulator Typical Performance Characteristics: Continuous mode switching waveforms Discontinuous mode switching waveforms VIN=20V，VOUT=5V，ILOAD=2A，L=33µH VIN=20V，VOUT=5V，ILOAD=90mA，L=33µH COUT=220µF，COUT ESR=50mΩ COUT=220µF，COUT ESR=50mΩ Load transient response for continuous mode VIN=20V，VOUT=5V，ILOAD=500mA to 2A L=33µH，COUT=220µF，COUT ESR=50mΩ 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 2/15/2006 REV : 1.1 Email: [email protected] 6 AT1796 Preliminary Product Information 150kHz, 3A Step-Down Switching Regulator Adjustable Output Application Example : VOUT = V FB (1 + R2 ) R1 V FB = 1.23V 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 2/15/2006 REV : 1.1 Email: [email protected] 7 AT1796 Preliminary Product Information 150kHz, 3A Step-Down Switching Regulator 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 2/15/2006 REV : 1.1 Email: [email protected] 8 AT1796 Preliminary Product Information 150kHz, 3A Step-Down Switching Regulator 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 2/15/2006 REV : 1.1 Email: [email protected] 9 AT1796 Preliminary Product Information 150kHz, 3A Step-Down Switching Regulator Application Data : Quick Design Component Selection Table Input/Output Condition Output Voltage (V) 5 Load Current (A) 3 Max. Input Voltage (V) 8 15 25 9 15 25 5 12 25 6 12 25 2 3.3 Inductor 3 2 Inductance (µH) Current (A) 22 33 47 22 68 68 22 22 33 22 33 47 3.5 3.5 3.5 3.1 3.1 3.1 3.5 3.5 3.5 3.1 3.1 3.1 Output Capacitor(µF/V) Through Hole electrolytic Surface Mount Tantalum Nichicon Panasonic Sprague AVX TPS PL Series HFQ Series 595D Series Series 560/25 330/35 270/35 560/16 180/35 180/35 560/16 560/25 470/35 470/35 330/35 270/50 560/25 330/35 330/35 470/25 180/35 180/35 470/25 560/35 680/35 470/25 330/35 330/35 330/10 330/10 330/10 330/10 270/10 270/10 390/6.3 390/6.3 390/6.3 390/6.3 390/6.3 330/10 220/10 220/10 220/10 220/10 100/10 100/10 330/6.3 330/6.3 330/6.3 330/6.3 330/6.3 220/10 Quick Design Component Selection Table for Adjustable Output Output Voltage (V) 2 4 6 9 12 15 24 Through Hole Output Capacitor Panasonic HFQ Series (µF/V) 820/35 560/35 470/25 330/25 330/25 220/35 220/35 Nichicon PL Series (µF/V) 820/35 470/35 470/25 330/25 330/25 220/35 150/35 Surface Mount Output Capacitor Feedforward Capacitor 33nF 10nF 3.3nF 1.5nF 1nF 680pF 560pF Panasonic HFQ Series (µF/V) 330/6.3 330/6.3 220/10 100/16 100/16 68/20 33/25 Nichicon PL Series (µF/V) 470/4 390/6.3 330/10 180/16 180/16 120/20 33/25 Feedforward Capacitor 33nF 10nF 3.3nF 1.5nF 1nF 680pF 220pF Diode Selection Table VR(V) 20 3A Diode Surface Mount Schottky SK32 30 30WQ03 SK33 40 SK34 MBRS340 30WQ04 50 SK35 MBRS360 30WQ05 MURS320 30WF10 Through Hole Schottky 1N5820 SR302 MBR320 1N5821 MBR330 31DQ03 1N5822 SR304 MBR340 31DQ04 SR305 MBR350 31DQ05 MUR320 4~6A Diode Surface Mount Through Hole Schottky Schottky 1N5823 SR502 SB520 50WQ03 1N5824 SR503 SB530 50WQ04 1N5825 SR504 SB540 50WQ05 50WF10 SB550 50SQ080 MUR620 HER601 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 2/15/2006 REV : 1.1 Email: [email protected] 10 AT1796 Preliminary Product Information 150kHz, 3A Step-Down Switching Regulator Package outlines: TO-265 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 2/15/2006 REV : 1.1 Email: [email protected] 11 AT1796 Preliminary Product Information 150kHz, 3A Step-Down Switching Regulator Reflow Profiles Profile Feature 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 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 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 2/15/2006 REV : 1.1 Email: [email protected] 12