AIC1639

AIC1639 3-PIN ONE-CELL STEP-UP DC/DC CONVERTER SPEC NO: DS-1639-00 05/26/00 ■ FEATURES l l l l l l l l ■ DESCRIPTION The AIC1639 is a high efficiency step-up DC/DC converter for applications using 1 to 4 battery cells. Only three external components are required to d eliver a fixed output voltage of 2.7, 3.0V, 3.3V, or 5V. The AIC1639 starts up from below 0.9V input with 1mA load. Pulse Frequency Modulation scheme brings optimized performance for applications with light output loading and low input voltages. The output ripple and noise are lower compared with the circuits operating in PSM mode. The PFM control circuit operating in 100KHz (max.) switching rate results in smaller passive components. The space saving SOT-89 and TO-92 packages make the AIC1639 an ideal choice of DC/DC converter for space conscious applications, like pagers, electronic cameras, and wireless microphones. Provided with an external transistor driver pin (EXT), the AIC1639 is recommended for applications requiring current as large as several tens to several hundreds of milli-amperes. Guaranteed Start-Up from Below 0.9 V. High Efficiency. Low Quiescent Current. Few Number of External Components needed. Low Ripple and Low Noise. Fixed Output Voltage: 2.7, 3.0V, 3.3V, and 5V. Driver for External Transistor. Space Saving SOT-89 and TO-92 Packages. ■ APPLICATIONS l l l l l l Pagers. Cameras. Wireless Microphones. Pocket Organizers. Battery Backup Suppliers. Portable Instruments. ■ TYPICAL APPLICATION CIRCUIT V IN D1 V OUT L1 33 µH R1 300 AIC1639-27 AIC1639-30 AIC1639-3 3 AIC1639-50 GND + C2 47µ F Q1 2SD1803 10nF EXT VOUT + C2 100µ F 100mA Load Current Step-Up Converter ANALOG INTEGRATIONS CORPORATION 4F, 9 Industry E. 9th Road, Science-based Industrial Park , Hsinchu, Taiwan, R.O.C. www.analog.com.tw TEL: (8863)577-2500 FAX:(8863)577-2510 1 AIC1639 3-PIN ONE-CELL STEP-UP DC/DC CONVERTER SPEC NO: DS-1639-00 05/26/00 ■ ORDERING INFORMATION AIC1639 - X XCX PACKAGE TYPE X: SOT-89 Z: TO-92 OUTPUT VOLTAGE 27: 2.7V 30: 3.0V 33: 3.3V 50: 5.0V ORDER NUMBER AIC1639-27CX AIC1639-30CX AIC1639-33CX AIC1639-50CX (SOT-89) PIN CONFIGURATION TOP VIEW 1: GND 2: VOUT 3: EXT 1 2 3 AIC1639-27CZ AIC1639-30CZ AIC1639-33CZ AIC1639-50CZ (TO-92) TOP VIEW 1: GND 2: VOUT 3: EXT 1 2 3 ■ ABSOLUATE MAXIMUM RATINGS Supply Voltage EXT pin Voltage EXT pin Current Power Dissipation Operating Temperature Range Storage Temperature Range Lead Temperature (Sordering 10 Sec.) ……………………………………………………………………………….12V …………………………………………………………….-0.3V to Vout+0.3V ………………………………………………………………………….± 50mA ……………………………………………………………………….500mW ……………………………………………….-40°C to 85°C ………………………………………………… -65°C to 150 °C …………………………………………………260°C ■ TEST CIRCUIT AIC1639 2.5V VOUT GND EXT F OUT Oscillator Test Circuit ANALOG INTEGRATIONS CORPORATION 4F, 9 Industry E. 9th Road, Science-based Industrial Park , Hsinchu, Taiwan, R.O.C. www.analog.com.tw TEL: (8863)577-2500 FAX:(8863)577-2510 2 AIC1639 3-PIN ONE-CELL STEP-UP DC/DC CONVERTER SPEC NO: DS-1639-00 05/26/00 n ELECTRICAL CHARACTERISTICS specified) PARAMETER Output Voltage (AIC1639 Ta=25° C, IO=10mA, Unless otherwise TEST CONDITIONS VIN=1.8V VIN=1.8V VIN=2.0V VIN=3.0V SYMBOL MIN. 2.633 2.925 3.218 4.875 TYP. 2.700 3.000 3.300 5.000 MAX. 2.767 3.075 3.382 5.125 8 UNIT VOUT V Input Voltage Start-Up Voltage Hold-on Voltage No-Load Input Current Supply Current 1 IOUT =1mA, VIN:0→2V IOUT =1mA, VIN:2→0V IOUT =0mA EXT at no load, VIN=VOUT x 0.5 Measurement of the IC input current VIN VSTART VHOLD IIN IDD1 0.6 18 45 50 60 80 0.8 V V V µA 0.9 µA Supply Current 2 EXT at no load, VIN=VOUT + 0.5 Measurement of the IC input current IDD2 7 µA EXT “H” On-Resistance VEXT =VOUT – 0.4V REXTH 300 200 185 130 Ω EXT “L” On-Resistance VEXT = 0.4V REXTL 110 80 70 60 Ω Oscillator Duty Cycle VIN=VOUT x 0.95 Measurement of the IC input current DUTY 65 75 85 % Max. Oscillator Freq. VIN=VOUT x 0.95 Measurement of the IC input current FOSC 80 105 130 KHz Efficiency η 80 % ANALOG INTEGRATIONS CORPORATION 4F, 9 Industry E. 9th Road, Science-based Industrial Park , Hsinchu, Taiwan, R.O.C. www.analog.com.tw TEL: (8863)577-2500 FAX:(8863)577-2510 3 AIC1639 3-PIN ONE-CELL STEP-UP DC/DC CONVERTER SPEC NO: DS-1639-00 05/26/00 n TYPICAL Diode PERFORMANCE CHARACTERISTICS Capacitor (C1) : 47 µ F (Tantalum Type) Transistor (Q1) : 2SD1803 AIC1639-27 Efficiency (L=33uH) 90 85 Inductor (L1) : 33 µ H (Pin Type) (D1) : 1N5819 Schottky Type AIC1639-27 Loading Regulation (L=33µ H) 2.80 2.75 Output Voltage (V) 2.70 2.65 2.60 2.55 2.50 2.45 2.40 0 VIN=2.0V 80 VIN=2.0V Efficiency (%) 75 VIN=1.8V VIN=1.5V VIN=1.2V VIN=1.8V VIN=1.5V VIN=1.2V VIN=0.9V 70 65 60 VIN=0.9V 50 100 150 200 250 300 350 400 450 500 55 50 0 50 100 150 200 250 300 350 400 450 500 Output Current (mA) Output Current (mA) AIC1639-30 Load Regulation (L=33µH) 3.1 3.0 90 85 AIC1639-30 Efficiency (L=33uH) VIN=2.0V Output Voltage (V) 2.9 2.8 2.7 VIN=2.0V VIN=1.2V VIN=1.5V VIN=1.8V Efficiency (%) 80 VIN=1.8V 75 VIN=1.5V 70 VIN=0.9V 2.6 VIN=1.2V 2.5 2.4 65 VIN=0.9V 0 50 100 150 200 250 300 350 400 450 60 0 50 100 150 200 250 300 350 400 450 Output Current (mA) Output Current (mA) AIC1639-33 Loading Regulation (L=33µH) 3.4 90 AIC1639-33 Efficiency (L=33µH) 85 3.2 Output Voltage (V) 3.0 Efficiency (%) VIN=1.5V VIN=2.0V 80 75 VIN=2.0V 2.8 70 VIN=1.2V 65 2.6 60 2.4 0 50 100 150 200 250 300 350 400 0 50 VIN=1.5V VIN=0.9V 100 150 200 250 300 350 400 Output Current (mA) Output Current (mA) ANALOG INTEGRATIONS CORPORATION 4F, 9 Industry E. 9th Road, Science-based Industrial Park , Hsinchu, Taiwan, R.O.C. www.analog.com.tw TEL: (8863)577-2500 FAX:(8863)577-2510 4 AIC1639 3-PIN ONE-CELL STEP-UP DC/DC CONVERTER SPEC NO: DS-1639-00 05/26/00 n TYPICAL 5.25 5.00 4.75 PERFORMANCE CHARACTERISTICS (CONTINUED) AIC1639-50 Load Regulation (L=33µH) 90 85 80 AIC1639-50 Efficiency (L=33µH) VIN=3.0V VIN=1.5V VIN=2.0V V IN=0.9V VIN=1.2V Output Voltage (V) 4.50 4.25 4.00 3.75 3.50 3.25 VIN=2.0V VIN=1.5V Efficiency (%) 700 VIN=3.0V 75 70 65 60 55 VIN=0.9V VIN=1.2V 50 45 0 100 200 300 400 500 600 40 0 100 200 300 400 500 600 700 Output Current (mA) Output Current (mA) AIC1639-27 Start-up & Hold-on Voltage (L=33µ H) 2.0 1.8 1.6 AIC1639-30 Start-up & Hold-on Voltage (L=33µ H) 1.2 1.0 Output Voltage (V) 1.4 1.2 1.0 0.8 0.6 0.4 0.2 0.0 Input Voltage (V) Start up 0.8 Start up 0.6 Hold on 0.4 Hold on 0.2 0.0 0 20 40 60 80 100 120 140 160 180 200 0 20 40 60 80 100 120 140 160 Output Current (mA) Output Current (mA) 1.2 AIC1639-33 Start-up & Hold-on Voltage (L=33µH) Start up 1.6 1.4 1.2 AIC1639-50 Start-up & Hold-on Voltage (L=33µ H) 1.0 Start up Input Voltage (V) 0.8 Input Voltage (V) 1.0 0.8 0.6 0.4 0.6 Hold on 0.4 Hold on 0.2 0.2 0.0 0.0 0 20 40 60 80 100 120 140 160 0 20 40 60 80 100 120 140 160 Output Current (mA) Output Current (mA) ANALOG INTEGRATIONS CORPORATION 4F, 9 Industry E. 9th Road, Science-based Industrial Park , Hsinchu, Taiwan, R.O.C. www.analog.com.tw TEL: (8863)577-2500 FAX:(8863)577-2510 5 AIC1639 3-PIN ONE-CELL STEP-UP DC/DC CONVERTER SPEC NO: DS-1639-00 05/26/00 n TYPICAL 1.2 PERFORMANCE CHARACTERISTICS (CONTINUED) AIC1639-33 Start-up & Hold-on Voltage (L=33µH) Start up 1.6 1.4 1.2 AIC1639-50 Start-up & Hold-on Voltage (L=33µ H) 1.0 Start up Input Voltage (V) 0.8 Input Voltage (V) 1.0 0.8 0.6 0.4 0.6 Hold on 0.4 Hold on 0.2 0.2 0.0 0.0 0 20 40 60 80 100 120 140 160 0 20 40 60 80 100 120 140 160 Output Current (mA) Output Current (mA) AIC1639 Output Voltage vs Temperature 6.0 5.5 135 130 AIC1639 Switching Frequency vs Temperature VOUT =5.0V Output Voltage (V) 5.0 4.5 4.0 3.5 3.0 2.5 2.0 -40 Switching Frequency (kHz) 125 120 115 110 105 100 95 90 VOUT = 5.0V VOUT = 3.3V VOUT = 3.0V VOUT = 2.7V VOUT = 3.3V VOUT = 3.0V VOUT = 2.7V -20 0 20 40 60 80 100 85 -40 -20 0 20 40 60 80 100 Output Current (mA) Output Current (mA) 80 79 AIC1639 Maximum Duty Cycle vs Temperature VOUT = 2.7V VOUT = 3.0V VOUT = 3.3V VOUT = 5.0V AIC1639 Supply Current vs Temperature 80 75 Maximum Duty Cycle (%) 77 76 75 74 73 72 71 70 -40 -20 0 20 40 Supply Current IDD1 (µA) 78 70 65 60 55 50 45 40 35 VOUT = 5.0V VOUT = 3.3V VOUT = 3.0V VOUT = 2.7V 60 80 100 30 -40 -20 0 20 40 60 80 100 Output Current (mA) Temperature (° C) ANALOG INTEGRATIONS CORPORATION 4F, 9 Industry E. 9th Road, Science-based Industrial Park , Hsinchu, Taiwan, R.O.C. www.analog.com.tw TEL: (8863)577-2500 FAX:(8863)577-2510 6 AIC1639 3-PIN ONE-CELL STEP-UP DC/DC CONVERTER SPEC NO: DS-1639-00 05/26/00 n TYPICAL PERFORMANCE CHARACTERISTICS (CONTINUED) AIC1639 EXT "L" On-Resistance 130 120 110 400 360 AIC1639 EXT "H" On-Resistance Resistance (Ù ) 90 80 70 60 50 40 -40 -20 0 20 40 60 80 100 Resistance (Ù ) 100 VOUT = 2.7V VOUT = 3.0V VOUT = 3.3V VOUT = 5.0V 320 280 240 200 160 120 80 40 -40 VOUT = 2.7V VOUT = 3.0V VOUT = 3.3V VOUT = 5.0V -20 0 20 40 60 80 100 Temperature (° C) Temperature (° C) ■ BLOCK DIAGRAM VOUT 1M 1.25V REF . + EXT E nable GND OSC, 100KHz ■ PIN DESCRIPTIONS PIN1 : GND - Ground. Must be low impedance; sorder directly to ground plane. PIN2 : VOUT - IC supply pin. Connect VOUT to the regulator output. EXT – Push Pull driver output for external power switch. ANALOG INTEGRATIONS CORPORATION 4F, 9 Industry E. 9th Road, Science-based Industrial Park , Hsinchu, Taiwan, R.O.C. www.analog.com.tw TEL: (8863)577-2500 FAX:(8863)577-2510 7 AIC1639 3-PIN ONE-CELL STEP-UP DC/DC CONVERTER SPEC NO: DS-1639-00 05/26/00 ■ APPLICATION INFORMATION GENERAL DESCRIPTION AIC1639 PFM (pluse frequency modulation) controller ICs combine a switch mode regulator, push pull driver (AIC1639), precision voltage reference, and voltage detector in a single monolithic device. They offer both IIN VIN mode. Continuous conduction mode means that the inductor current does not ramp to zero during each cycle. extreme low quescient current, high efficiency, and very low gate threshold voltage to ensure start-up with EXT SW ID IOUT + Isw Ico VOUT low battery voltage ( 0.8V typ.). Designed to maximize battery life in protable products, and minimize switching losses by only switching as needed service the load. VEXT PFM controllers transfer a discreate amount of energy per cycle and regulate the output voltage by modulating switching frequency with the constant turn-on time. Switching frequency depends on load, input voltage, and inductor value, and it can range up to 100KHz. When the output voltage drops, the error comparator enable 100kHz oscillator that turns on the MOSFET around 7.5us and 2.5us off time. Turning on the MOSFET allows inductor current to ramp up, storing energy in a magnetic field. When MOSFET turns off that forces inductor current through diode to the output capacitor and load. As the stored energy is d epleted, the current ramp down until the diode turns off. At this point, inductor may ring due to residual energy and stray capacitance. The output capacitor stores charge when current flowing through the diode is high, and release it when current is low, thereby maintaining a steady voltage across the load. As the load increases, the output capacitor discharges faster and the error comparator initiates cycles sooner, increasing the switching frequency. The maximum duty cycle ensure adequate time for energy tranfer to output during the second half each cycle. Depending on circuit, PFM controller can operate in either discontinuous mode or continuous conduction ANALOG INTEGRATIONS CORPORATION 4F, 9 Industry E. 9th Road, Science-based Industrial Park , Hsinchu, Taiwan, R.O.C. t VSW T DIS Discharge Co. Charge Co. ID IOUT ISW IIN I PK Discontinuous Conduction Mode www.analog.com.tw TEL: (8863)577-2500 FAX:(8863)577-2510 8 AIC1639 3-PIN ONE-CELL STEP-UP DC/DC CONVERTER SPEC NO: DS-1639-00 05/26/00 VEXT ≅ 1  Vout + Vd − Vin    Ton  Vout + Vd − Vsw  I IN where Vsw = switch drop and proportion to output current. IPK INDUCTOR SELECTION To operate as an efficient energy transfer element, the inductor must fulfill three requirement. First, the inductance must be low enough for the inductor to store adquate energy under the worst case condition of minimum input voltage and switch ON time. Second, the inductance must also be high enough so maximum current rating of AIC1639 and inductor are not exceed at the other worst case cindition of maximum input voltage and ON time. Lastly, the inductor must have sufficiently low DC resistance so excessive power is not lost as heat in the windings. But unfotrunately this is inversely related to physical size. t ISW ID IOUT VSW Continuous Conduction Mode Minimum and Maximum input voltage, output voltage and output current must be established before and incuctor can be selected. In discontinuous mode operation, at the end of the switch ON time, peak current and energy in the inductor build according to At the boundry between continuous and discontinuous mode, output current (IOB) is determined by Vin   1 Vin IOB =  Ton (1 − x )   Vout + Vd  2 L where Vd is the diode drop, x = (Ron+Rs)Ton/L. Ron= Switch turn on resistance, Rs= Inductor DC resistance Ton = Switch ON time In the discontinuous mode, the switching frequency (fsw) is fsw = 2(L)(Vout + Vd − Vin)(Iout) Vin2 × Ton 2 (1 + x ) Ron + Rs  Vin    IPK =  Ton)   1 − exp( − L  Ron + Rs    x  Vin   ≅ (Ton ) 1 −  L 2   ≅ Vin Ton L (simple lossless equation), where x=(Ron+Rs)Ton/L EL = 1 L × Ipk 2 2 Power required from the inductor per cycle must be equal or greater than PL/f SW = (Vout + Vd − Vin)(Iout) ( 1 ) fsw In the continuous mode, the switching frequency is in order for the converter to regulate the output. When loading is over IOB, PFM controller operates in continuous mode. Inductor peak current can be derived from fsw= 1 (Vout + Vd − Vin) x Vin − Vsw [1 + ( )] Ton (Vout + Vd − Vsw) 2 Vout + Vd − Vsw ANALOG INTEGRATIONS CORPORATION 4F, 9 Industry E. 9th Road, Science-based Industrial Park , Hsinchu, Taiwan, R.O.C. x  Vout + Vd − Vsw x   Vin − Vsw   IPK =  − Iout +  Ton  1 −  Vin − Vsw 2 2L 2     www.analog.com.tw TEL: (8863)577-2500 FAX:(8863)577-2510 9 AIC1639 3-PIN ONE-CELL STEP-UP DC/DC CONVERTER SPEC NO: DS-1639-00 05/26/00 Valley current (Iv) is x  Vout + Vd − Vsw x   Vin − Vsw   IV =  − Iout −  Ton 1 −  Vin − Vsw 2 2L 2     Table 1 Indicates resistance and height for each coil. Power Inductor Type Sumida SMT Type CD54 Inductance ( µH ) 47 100 Hold SMT Type PM54 47 100 Hold SMT Type PM75 Huan Feng PIN Type V0810 33 33 Resistance ( Ω ) 0.25 0.50 0.25 0.50 0.11 40m Rated Current (A) 0.7 0.5 0.7 0.5 1.2 2 5.0 10.0 4.5 Hieght (mm) 4.5 CAPACITOR SELECTION A poor choice for a output capacitor can result in poor efficiency and hight output ripple. Ordinary aluminum electrolytics, while inexpensive may have unacceptably poor ESR and ESL. There are low ESR aluminum capacitors for switch mode DC-DC converters which work much better than general porpuse unit. Tantalum c apacitors provide still better performance at more expensive. OS-CON capacitors have extremely low ESR in a small size. If capacitance is reduced, output ripple will increase. Most of the input supply is supplied by the input b ypasss capacitor, the capacitor voltage rating should be at least 1.25 times greather than a maximum input voltage. DIODE SELECTION Speed, forward drop, and leakage current are the three main consideration in selecting a rectifier diode. Best performance is obtained with Schottky retifier diode such 1N5819. Motorola makes MBR0530 in surface mount. For lower output power a 1N4148 can be used although efficiency and start-up voltage will suffer substantially. COMPONENT POWER DISSIPATION Opeating in discontinuous mode, power loss in the winding resistance of inductor can be approximate equal to PD L = 2  Ton   Vout + Vd    (Rs )  (Pout ) 3 L   Vout  where Pout=Vout * Iout ; Rs=Inductor DC R; VD = Diode drop. The power dissipated in a switch loss is PDsw = 2  Ton   Vout + Vd − Vin   (Ron ) (Pout ) 3 L  Vout   The power dissipated in rectifier diode is  Vd  PDd =  (Pout )  Vout  ANALOG INTEGRATIONS CORPORATION 4F, 9 Industry E. 9th Road, Science-based Industrial Park , Hsinchu, Taiwan, R.O.C. www.analog.com.tw TEL: (8863)577-2500 FAX:(8863)577-2510 10 AIC1639 3-PIN ONE-CELL STEP-UP DC/DC CONVERTER SPEC NO: DS-1639-00 05/26/00 ■ PHYSICAL DIMENSIONS l SOT-89 (unit: mm) D D1 C A SYMBOL A B C D MIN 1.40 0.36 0.35 4.40 1.62 2.29 MAX 1.60 0.48 0.44 4.60 1.83 2.60 1.50 (TYP.) 3.00 (TYP.) H E D1 E e L e e1 B e1 H L 3.94 0.89 4.25 1.20 l SOT-89 MARKING Marking AU27 AU30 AU33 AU50 Part No. AIC1639-27 AIC1639-30 AIC1639-33 AIC1639-50 l TO-92 (unit: mm) L C E SYMBOL A C MIN 4.32 MAX 5.33 0.38 (TYP.) A e1 D D E e1 L 4.40 3.17 1.27 (TYP.) 12.7 5.20 4.20 - ANALOG INTEGRATIONS CORPORATION 4F, 9 Industry E. 9th Road, Science-based Industrial Park , Hsinchu, Taiwan, R.O.C. www.analog.com.tw TEL: (8863)577-2500 FAX:(8863)577-2510 11