AIC1639 3-PIN ONE-CELL STEP-UP DC/DC CONVERTER SPEC NO: DS-1639-00 05/26/00 ■ FEATURES ■ DESCRIPTION l Guaranteed Start-Up from Below 0.9 V. l High Efficiency. l Low Quiescent Current. l Few Number of External Components needed. l Low Ripple and Low Noise. l Fixed Output Voltage: 2.7, 3.0V, 3.3V, and 5V. l Driver for External Transistor. l Space Saving SOT-89 and TO-92 Packages. 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 deliver 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. ■ APPLICATIONS l Pagers. l Cameras. l Wireless Microphones. l Pocket Organizers. l Battery Backup Suppliers. l Portable Instruments. 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. ■ TYPICAL APPLICATION CIRCUIT V IN D1 V OUT + C2 47µ F L1 33 µH R1 300 EXT Q1 2SD1803 AIC1639-27 AIC1639-30 AIC1639-3 3 AIC1639-50 10nF GND VOUT + C2 100µ F 100mA Load Current Step-Up Converter ANALOG INTEGRATIONS CORPORATION www.analog.com.tw 4F, 9 Industry E. 9th Road, Science-based Industrial Park , Hsinchu, Taiwan, R.O.C. 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 ORDER NUMBER AIC1639 - X XCX AIC1639-27CX AIC1639-30CX AIC1639-33CX AIC1639-50CX (SOT-89) PACKAGE TYPE X: SOT-89 Z: TO-92 OUTPUT VOLTAGE 27: 2.7V 30: 3.0V 33: 3.3V 50: 5.0V PIN CONFIGURATION TOP VIEW 1: GND 2: VOUT 3: EXT 1 AIC1639-27CZ AIC1639-30CZ AIC1639-33CZ AIC1639-50CZ (TO-92) TOP VIEW 1: GND 2: VOUT 3: EXT 2 3 1 2 3 ■ ABSOLUATE MAXIMUM RATINGS Supply Voltage ……………………………………………………………………………….12V EXT pin Voltage …………………………………………………………….-0.3V to Vout+0.3V EXT pin Current ………………………………………………………………………….± 50mA Power Dissipation ……………………………………………………………………….500mW Operating Temperature Range ……………………………………………….-40°C to 85°C ………………………………………………… -65°C to 150 °C Storage Temperature Range Lead Temperature (Sordering 10 Sec.) …………………………………………………260°C ■ TEST CIRCUIT AIC1639 2.5V VOUT EXT F OUT GND Oscillator Test Circuit ANALOG INTEGRATIONS CORPORATION www.analog.com.tw 4F, 9 Industry E. 9th Road, Science-based Industrial Park , Hsinchu, Taiwan, R.O.C. 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 SYMBOL MIN. TYP. MAX. VOUT 2.633 2.700 2.767 VIN=1.8V 2.925 3.000 3.075 VIN=2.0V 3.218 3.300 3.382 VIN=3.0V 4.875 5.000 5.125 VIN=1.8V Input Voltage VIN Start-Up Voltage IOUT =1mA, VIN:0→2V VSTART Hold-on Voltage IOUT =1mA, VIN:2→0V VHOLD No-Load Input Current IOUT =0mA Supply Current 1 EXT at no load, VIN=VOUT x 0.5 0.8 V 8 V 0.9 V V 0.6 IIN 18 IDD1 45 µA 50 Measurement of the IC input current UNIT µA 60 80 Supply Current 2 EXT at no load, VIN=VOUT + 0.5 IDD2 7 µA Measurement of the IC input current EXT “H” On-Resistance VEXT =VOUT – 0.4V 300 REXTH 200 Ω 185 130 EXT “L” On-Resistance VEXT = 0.4V 110 REXTL 80 Ω 70 60 Oscillator Duty Cycle VIN=VOUT x 0.95 DUTY 65 75 85 % Measurement of the IC input current Max. Oscillator Freq. VIN=VOUT x 0.95 FOSC 80 105 130 KHz Measurement of the IC input current Efficiency η 80 ANALOG INTEGRATIONS CORPORATION www.analog.com.tw 4F, 9 Industry E. 9th Road, Science-based Industrial Park , Hsinchu, Taiwan, R.O.C. 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 PERFORMANCE CHARACTERISTICS Inductor (L1) : 33 µ H (Pin Type) Diode Capacitor (C1) : 47 µ F (Tantalum Type) (D1) : 1N5819 Schottky Type Transistor (Q1) : 2SD1803 AIC1639-27 Efficiency (L=33uH) 90 2.75 85 VIN=2.0V 2.70 VIN=2.0V 80 Efficiency (%) Output Voltage (V) AIC1639-27 Loading Regulation (L=33µ H) 2.80 2.65 75 VIN=1.8V 2.60 VIN=1.2V 2.55 VIN=1.8V 70 VIN=1.5V VIN=1.5V VIN=1.2V 65 60 2.50 VIN=0.9V 2.45 2.40 55 VIN=0.9V 0 50 50 100 150 200 250 300 350 400 450 500 0 50 100 150 250 300 350 400 AIC1639-30 Load Regulation (L=33µH) 3.1 3.0 85 VIN=2.0V VIN=2.0V VIN=1.5V Efficiency (%) 2.9 VIN=1.2V 500 AIC1639-30 Efficiency (L=33uH) 90 2.8 450 Output Current (mA) Output Current (mA) Output Voltage (V) 200 VIN=1.8V 2.7 VIN=0.9V 80 VIN=1.8V 75 VIN=1.5V 70 2.6 VIN=1.2V 2.5 65 2.4 60 VIN=0.9V 0 50 100 150 200 250 300 350 400 450 0 50 100 150 Output Current (mA) 200 250 300 350 400 450 Output Current (mA) AIC1639-33 Loading Regulation (L=33µH) AIC1639-33 Efficiency (L=33µH) 90 3.4 85 VIN=2.0V VIN=1.5V Efficiency (%) Output Voltage (V) 3.2 3.0 2.8 80 VIN=2.0V 75 70 VIN=1.5V VIN=1.2V 65 VIN=0.9V 2.6 60 0 50 100 150 200 250 300 350 400 2.4 0 50 100 150 200 250 300 350 400 Output Current (mA) Output Current (mA) ANALOG INTEGRATIONS CORPORATION www.analog.com.tw 4F, 9 Industry E. 9th Road, Science-based Industrial Park , Hsinchu, Taiwan, R.O.C. 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 PERFORMANCE CHARACTERISTICS (CONTINUED) AIC1639-50 Load Regulation (L=33µH) 5.25 AIC1639-50 Efficiency (L=33µH) 90 85 5.00 80 VIN=2.0V 4.50 VIN=1.5V 4.25 VIN=3.0V 75 VIN=3.0V Efficiency (%) Output Voltage (V) 4.75 4.00 VIN=1.5V 70 VIN=2.0V V IN=0.9V 65 VIN=1.2V 60 55 3.75 VIN=0.9V 3.25 50 VIN=1.2V 3.50 45 0 100 200 300 400 500 600 40 700 0 100 200 Output Current (mA) 300 400 500 600 700 Output Current (mA) AIC1639-30 Start-up & Hold-on Voltage (L=33µ H) AIC1639-27 Start-up & Hold-on Voltage (L=33µ H) 1.2 2.0 1.8 1.0 Input Voltage (V) Output Voltage (V) 1.6 1.4 Start up 1.2 1.0 0.8 0.6 Hold on 0.4 Start up 0.8 0.6 Hold on 0.4 0.2 0.2 0.0 0.0 0 20 40 60 80 100 120 140 160 180 200 0 20 40 AIC1639-33 Start-up & Hold-on Voltage (L=33µH) 1.2 60 80 100 120 140 160 140 160 Output Current (mA) Output Current (mA) 1.6 Start up AIC1639-50 Start-up & Hold-on Voltage (L=33µ H) 1.4 1.0 Start up Input Voltage (V) Input Voltage (V) 1.2 0.8 0.6 Hold on 0.4 1.0 0.8 Hold on 0.6 0.4 0.2 0.2 0.0 0 20 40 60 80 100 120 140 160 0.0 0 20 40 60 80 100 120 Output Current (mA) Output Current (mA) ANALOG INTEGRATIONS CORPORATION www.analog.com.tw 4F, 9 Industry E. 9th Road, Science-based Industrial Park , Hsinchu, Taiwan, R.O.C. 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 PERFORMANCE CHARACTERISTICS (CONTINUED) AIC1639-33 Start-up & Hold-on Voltage (L=33µH) 1.2 1.6 Start up AIC1639-50 Start-up & Hold-on Voltage (L=33µ H) 1.4 1.0 Start up Input Voltage (V) Input Voltage (V) 1.2 0.8 0.6 Hold on 0.4 1.0 0.8 Hold on 0.6 0.4 0.2 0.2 0.0 0 20 40 60 80 100 120 140 0.0 160 0 20 40 60 AIC1639 Output Voltage vs Temperature Switching Frequency (kHz) Output Voltage (V) 5.0 4.5 VOUT = 3.3V VOUT = 3.0V VOUT = 2.7V 4.0 3.5 3.0 2.5 160 VOUT = 5.0V VOUT = 3.3V VOUT = 3.0V VOUT = 2.7V 125 120 115 110 105 100 95 90 -20 0 20 40 60 80 85 -40 100 -20 0 Output Current (mA) 20 40 60 80 100 Output Current (mA) AIC1639 Supply Current vs Temperature AIC1639 Maximum Duty Cycle vs Temperature 80 75 79 VOUT = 2.7V VOUT = 3.0V VOUT = 3.3V VOUT = 5.0V 78 77 Supply Current IDD1 (µA) Maximum Duty Cycle (%) 140 130 VOUT =5.0V 76 75 74 73 72 71 70 -40 120 135 5.5 80 100 AIC1639 Switching Frequency vs Temperature 6.0 2.0 -40 80 Output Current (mA) Output Current (mA) VOUT = 5.0V VOUT = 3.3V VOUT = 3.0V VOUT = 2.7V 70 65 60 55 50 45 40 35 -20 0 20 40 60 80 100 30 -40 -20 0 Output Current (mA) 20 40 60 80 100 Temperature (° C) ANALOG INTEGRATIONS CORPORATION www.analog.com.tw 4F, 9 Industry E. 9th Road, Science-based Industrial Park , Hsinchu, Taiwan, R.O.C. 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 "H" On-Resistance AIC1639 EXT "L" On-Resistance 130 400 120 100 320 280 Resistance (Ù ) Resistance (Ù ) 110 360 VOUT = 2.7V VOUT = 3.0V VOUT = 3.3V VOUT = 5.0V 90 240 80 200 70 160 60 120 50 80 40 -40 VOUT = 2.7V VOUT = 3.0V VOUT = 3.3V VOUT = 5.0V -20 0 20 40 60 80 100 40 -40 -20 0 Temperature (° C) 20 40 60 80 100 Temperature (° C) ■ BLOCK DIAGRAM VOUT 1.25V REF . 1M - EXT + E nable GND OSC, 100KHz ■ PIN DESCRIPTIONS PIN1 : GND - Ground. Must be low impedance; sorder directly to ground plane. EXT – Push Pull driver output for external power switch. PIN2 : VOUT - IC supply pin. Connect VOUT to the regulator output. ANALOG INTEGRATIONS CORPORATION www.analog.com.tw 4F, 9 Industry E. 9th Road, Science-based Industrial Park , Hsinchu, Taiwan, R.O.C. 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 mode. Continuous conduction mode means that the inductor current does not ramp to zero during each cycle. ICs combine a switch mode regulator, push pull driver (AIC1639), precision voltage reference, and voltage VIN detector in a single monolithic device. They offer both IIN ID extreme low quescient current, high efficiency, and IOUT SW very low gate threshold voltage to ensure start-up with VOUT + EXT low battery voltage ( 0.8V typ.). Designed to maxiIsw mize battery life in protable products, and minimize Ico 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. IIN I PK 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 ISW 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 Charge Co. ID IOUT that forces inductor current through diode to the output capacitor and load. As the stored energy is depleted, the current ramp down until the diode turns off. VSW T DIS Discharge Co. At this point, inductor may ring due to residual energy t and stray capacitance. The output capacitor stores charge when current flowing through the diode is high, and release it when current is low, thereby maintain- Discontinuous Conduction Mode ing 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 www.analog.com.tw 4F, 9 Industry E. 9th Road, Science-based Industrial Park , Hsinchu, Taiwan, R.O.C. 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 where Vsw = switch drop and proportion to output current. I IN 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. ISW ID IOUT VSW t 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 Ron + Rs Vin IPK = Ton) 1 − exp( − L Ron + Rs x Vin ≅ (Ton ) 1 − L 2 Vin 1 Vin IOB = Ton (1 − x ) Vout + Vd 2 L Vin Ton L where Vd is the diode drop, ≅ x = (Ron+Rs)Ton/L. where 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 ) In the continuous mode, the switching frequency is EL = (simple lossless equation), 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 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 x Vout + Vd − Vsw x Vin − Vsw IPK = − Iout + Ton 1 − Vin − Vsw 2 2L 2 ANALOG INTEGRATIONS CORPORATION www.analog.com.tw 4F, 9 Industry E. 9th Road, Science-based Industrial Park , Hsinchu, Taiwan, R.O.C. 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. Inductance ( µH ) Resistance ( Ω ) Rated Current (A) Hieght (mm) 47 0.25 0.7 4.5 100 0.50 0.5 47 0.25 0.7 100 0.50 0.5 Hold SMT Type PM75 33 0.11 1.2 5.0 Huan Feng PIN Type V0810 33 40m 2 10.0 Power Inductor Type Sumida SMT Type CD54 Hold SMT Type PM54 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 capacitors 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 bypasss 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 4.5 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 www.analog.com.tw 4F, 9 Industry E. 9th Road, Science-based Industrial Park , Hsinchu, Taiwan, R.O.C. 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 A SYMBOL MIN MAX C A 1.40 1.60 B 0.36 0.48 C 0.35 0.44 D 4.40 4.60 D1 1.62 1.83 E 2.29 2.60 D1 H E L B e e1 l e 1.50 (TYP.) e1 3.00 (TYP.) H 3.94 4.25 L 0.89 1.20 SYMBOL MIN MAX A 4.32 5.33 SOT-89 MARKING Part No. AIC1639-27 AIC1639-30 AIC1639-33 AIC1639-50 Marking AU27 AU30 AU33 AU50 l TO-92 (unit: mm) A E L C C e1 D 0.38 (TYP.) D 4.40 5.20 E 3.17 4.20 e1 L 1.27 (TYP.) 12.7 - ANALOG INTEGRATIONS CORPORATION www.analog.com.tw 4F, 9 Industry E. 9th Road, Science-based Industrial Park , Hsinchu, Taiwan, R.O.C. TEL: (8863)577-2500 FAX:(8863)577-2510 11