AIC1641-50CW

AIC1641 LOW VOLTAGE STEP-UP DC/DC CONVERTER SPEC NO: DS-1641-00 05/04/00

FEATURES ! ! ! ! ! !
DESCRIPTION The AIC1641 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 2.7V, 3.0V, 3.3V, or 5.0V. Pulse Frequency Modulation scheme brings optimized performance for applications with light output loading and low input voltage. The output ripple and noise are lower compared with the circuit operating in PSM mode. The AIC1641 starts up from below 0.9V input to boost either 2.7V, 3.0V, 3.3V, or 5.0V output with 1mA load. Some useful features include, shutdown mode for saving the life of battery. The PFM control circuit operates in 100KHz (max.) switching rate, resulting in smaller passive component size, which makes the AIC1641 an ideal choice of DC/DC converter for space conscious applications. Guaranteed Start-Up from Below 0.9 V. High Efficiency. Low Quiescent Current. Fixed Output Voltage: 2.7V, 3.0V, 3.3V, and 5V. Logic Controlled Shutdown. External Switch Driver for High Power Level Application.

APPLICATIONS ! ! ! ! ! ! Pagers. Cameras. W ireless Microphones. Pocket Organizers. Battery Backup Suppliers. Portable Instruments.
TYPICAL APPLICATION CIRCUIT VOUT + C1 47µF VOUT D1 1N5819 CB EXT CE L1 VIN
0.9V 33µH GND AIC1641 Q1 2SD1803 10nF RB 300 One Cell Step-Up DC/DC 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 AIC1641 LOW VOLTAGE STEP-UP DC/DC CONVERTER SPEC NO: DS-1641-00 05/04/00

ORDERING INFORMATION A IC1641-XXCX PACKAGE TYPE O: MSOP8 S: SMALL OUTLINE W : SOT89-5 OUTPUT VOLTAGE 27: 2.7V 30: 3.0V 33: 3.3V 50: 5.0V O RDER NUM BER AIC1641-27CS AIC1641-30CS AIC1641-33CS AIC1641-50CS (SO8) PIN CONFIGURATION VOUT 1 EXT 2 NC 3 NC 4 8 CE 7 NC 6 NC 5 GND AIC1641-27CS AIC1641-30CS AIC1641-33CS AIC1641-50CS (SO8) VOUT 1 EXT 2 NC 3 NC 4 8 CE 7 NC 6 NC 5 GND AIC1641-27CW AIC1641-30CW AIC1641-33CW AIC1641-50CW (SOT89-5) TOP VIEW GND 5 EXT 4 1 2 3 NC VOUT CE

ABSOLUATE MAXIMUM RATINGS Supply Voltage ……………………………………………………………………………….12V CE input Voltage ……………………………………………………………………………….12V EXT pin Voltage EXT pin Current Power Dissipation …………………………………………………………….-0.3V to Vout+0.3V ………………………………………………………………………….± 50mA ……………………………………………………………………….500mW Operating Temperature Range ………………………………………………….-40 °C to 85°C Storage Temperature Range ………………………………………………… -65°C to 150 °C Lead Temperature (Sordering 10 Sec.) …………………………………………………260°C

TEST CIRCUIT AIC1641 EXT FOUT GND VOUT 2.5V CE 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 AIC1641 LOW VOLTAGE STEP-UP DC/DC CONVERTER SPEC NO: DS-1641-00 05/04/00 " ELECTRICAL CHARACTERISTICS PARAMETER Output Voltage (Ta=25°C, IO=10mA, Unless otherwise specified) SYMBOL TEST CONDITIONS VIN=1.8V VIN=1.8V VIN=2.0V VIN=3.0V MIN. 2.633 2.925 TYP. 2.700 3.000 3.300 5.000 MAX. 2.767 3.075 3.382 5.125 8 UNIT VOUT 3.218 4.875 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 18 45 50 IDD1 60 80 0.8 V V V µA 0.9 0.6 µA Supply Current 2 EXT at no load, VIN=VOUT + 0.5 Measurement of the IC input current IDD2 7 µA 300 200 REXTH 185 130 Ω EXT “H” On-Resistance VEXT=VOUT – 0.4V EXT “L” On-Resistance VEXT= 0.4V REXTL 110 80 70 60 Ω Oscillator Duty Cycle VIN=VOUT x 0.95 Measure the waveform at the EXT pin DUTY 65 75 85 % Max. Oscillator Freq. VIN=VOUT x 0.95 Measure the waveform at the EXT pin FOSC 80 1.2 1.3 VCEH 1.4 2.1 V 105 130 KHz Chip Enable Pin Input High Voltage VIN=VOUT x 0.95 VCEH : 0V→2.5V Judge the oscillation at EXT pin 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 AIC1641 LOW VOLTAGE STEP-UP DC/DC CONVERTER SPEC NO: DS-1641-00 05/04/00 " ELECTRICAL CHARACTERISTICS PARAMETER Chip Enable Pin Input Low Voltage (Continued) SYMBOL TEST CONDITIONS VIN=VOUT x 0.95 VCEL : 2.5V→0V Judge the stop at EXT pin MIN. TYP. MAX. 1.1 1.2 UNIT VCEL 1.3 2.0 V CE Pin Input Current Efficiency Same as IDD1, VCE=VOUT x 0.95 η 80 0.5 µA % " TYPICAL PERFORMANCE CHARACTERISTICS Inductor (L1) : 33µH (Pin Type) Diode (D1) : 1N5819 Schottky Type AIC1641-27 Loading Regulation (L=33uH) 2.80 2.75 2.70 90 85 Capacitor (C1) : 47µF (Tantalum Type) Transistor (Q1) : 2SD1803 AIC1641-27 Efficiency (L=33uH) Vin=2.0V 80 Vin=2.0V Output Voltage (V) 2.65 2.60 2.55 2.50 2.45 2.40 0 50 100 150 200 250 300 350 400 450 500 Vin=1.5V Vin=1.2V Vin=1.8V Efficiency (%) 75 70 65 60 Vin=1.8V Vin=1.5V Vin=0.9V Vin=1.2V Vin=0.9V 55 50 0 50 100 150 200 250 300 350 400 450 500 Output Current (mA) Output Current (mA) AIC1641-30 Load Regulation (L=33uH) 3.1 90 AIC1641-30 Efficiency (L=33uH) 3.0 Vin=2.0V 85 Vin=2.0V Output Voltage (V) 2.9 2.8 Vin=1.2V Vin=0.9V Vin=1.5V Vin=1.8V Efficiency (%) 80 75 Vin=1.8V 2.7 70 2.6 Vin=1.5V Vin=0.9V Vin=1.2V 2.5 65 2.4 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) 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 AIC1641 LOW VOLTAGE STEP-UP DC/DC CONVERTER SPEC NO: DS-1641-00 05/04/00 " TYPICAL PERFORMANCE CHARACTERISTICS (CONTINUED) AIC1641-33 Loading Regulation (L=33uH) 3.6 3.4 3.2 90 85 80 AIC1641-33 Efficiency (L=33uH) Output Voltage (V) Efficiency (%) 3.0 2.8 2.6 2.4 2.2 2.0 0 50 100 150 Vin=1.5V Vin=2.0V 75 70 65 60 55 50 Vin=2.0V Vin=1.5V Vin=0.9V Vin=0.9V 200 250 300 350 400 0 50 100 150 200 250 300 350 400 Output Current (mA) Output Current (mA) AIC1641-50 Load Regulation (L=33uH) 5.5 5.0 4.5 90 85 80 AIC1641-50 Efficiency (L=33uH) Output Voltage (V) 4.0 3.5 3.0 2.5 2.0 1.5 0 100 200 300 Efficiency (%) Vin=2.0V Vin=1.5V Vin=3.0V 75 70 65 60 55 50 Vin=3.0V Vin=2.0V Vin=1.5V Vin=1.2V Vin=0.9V 0 100 200 300 400 500 600 700 Vin=1.2V Vin=0.9V 400 500 600 700 Output Current (mA) Output Current (mA) AIC1641-27 Start-up & Hold-on Voltage (L=33uH) 2.0 1.8 1.6 AIC1641-30 Start-up & Hold-on Voltage (L=33uH) 2.0 1.8 1.6 1.2 1.0 0.8 0.6 0.4 0.2 0.0 0 Start up Input Voltage (V) Input Voltage (V) 1.4 1.4 1.2 1.0 0.8 0.6 0.4 0.2 Start up Hold on Hold on 20 40 60 80 100 120 140 160 180 200 0.0 0 20 40 60 80 100 120 140 160 180 200 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 AIC1641 LOW VOLTAGE STEP-UP DC/DC CONVERTER SPEC NO: DS-1641-00 05/04/00 " TYPICAL PERFORMANCE CHARACTERISTICS (CONTINUED) AIC1641-33 Start-up & Hold-on Voltage (L=33uH) 2.0 1.8 1.6 2.0 1.8 1.6 AIC1641-50 Start-up & Hold-on Voltage (L=33uH) Start up Input Voltage (V) 1.2 1.0 0.8 0.6 0.4 0.2 0.0 0 20 Start up Input Voltage (V) 1.4 1.4 1.2 1.0 0.8 0.6 0.4 0.2 0.0 Hold on Hold on 40 60 80 100 120 140 160 180 200 0 20 40 60 80 100 120 140 160 180 200 Output Current (mA) Output Current (mA) AIC1641 Output Voltage vs Temperature 6.0 5.5 5.0 AIC1641 Switching Frequency vs Temperature 135 130 Switching Frequency (kHz) 125 120 115 110 105 100 95 90 85 -40 Output Voltage (V) 4.5 4.0 3.5 3.0 2.5 2.0 -40 -20 0 20 40 o 60 80 100 -20 0 20 40 o 60 80 100 Temperature ( C) Temperature ( C) AIC1641 Maximum Duty Cycle vs Temperature 80 79 80 75 AIC1641 Supply Current vs Temperature Maximum Duty Cycle (%) 77 76 75 74 73 72 71 70 -40 Supply Current IDD1 (uA) -20 0 20 40 o 78 70 65 60 55 50 45 40 35 60 80 100 30 -40 -20 0 20 40 o 60 80 100 Temperature ( C) 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 AIC1641 LOW VOLTAGE STEP-UP DC/DC CONVERTER SPEC NO: DS-1641-00 05/04/00 " TYPICAL PERFORMANCE CHARACTERISTICS (CONTINUED) AIC1641 EXT "L" On-Resistance 130 120 110 400 360 320 AIC1641 EXT "H" On-Resistance Resistance (
) Resistance (
) 100 90 80 70 60 50 40 -40 280 240 200 160 120 80 40 -40 -20 0 20 40 o 60 80 100 -20 0 20 40 o 60 80 100 Temperature ( C) Temperature ( C)

BLOCK DIAGRAM CE VOUT 1M 1.25V REF. Chip Enable + EXT Enable GND OSC, 100KHz

PIN DESCRIPTIONS NC Not Connected. VOUT - IC supply pin. Connect VOUT to the regulator output. CE Chip enable pin (Active High). EXT - Push pull driver output for external power switch. GND – Ground Terminal. Must be low impedance; sorder directly to ground plane. 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 AIC1641 LOW VOLTAGE STEP-UP DC/DC CONVERTER SPEC NO: DS-1641-00 05/04/00

APPLICATION INFORMATION GENERAL DESCRIPTION AIC1641 PFM (pluse frequency modulation) controller ICs combine a switch mode regulator, push pull driver, precision voltage reference, and voltage detector in a single monolithic device. They offer both extreme low quescient current, high efficiency, and very low gate threshold voltage to ensure start-up with 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. 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 7.5µs and 2.5µs 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 depleted, 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. EXT Isw VIN mode. Continuous conduction mode means that the inductor current does not ramp to zero during each cycle. IIN SW ID IOUT VOUT + Ico VEXT IIN IPK ISW Charge Co. ID TDIS Discharge Co. IOUT VSW t Discontinuous Conduction Mode www.analog.com.tw TEL: (8863)577-2500 FAX:(8863)577-2510 8 AIC1641 LOW VOLTAGE STEP-UP DC/DC CONVERTER SPEC NO: DS-1641-00 05/04/00 VEXT ≅ 1  VOUT + VD − VIN    TON  VOUT + VD − VSW  IIN where Vsw = switch drop and proportion to output current. IPK INDUCTOR SELECTION ISW ID IOUT VSW t 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 AIC1641 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. 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 VIN  RON + Rs   IPK =  TON)  1 − exp( − L  RON + Rs   x  VIN   ≅ (TON)1 −  L 2   ≅ VIN TON L (simple lossless equation), Continuous Conduction Mode t 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) VIN 2 × TON 2 (1+ x
where x=(RON+Rs)TON/L 1 L × IPK
2 Power required from the inductor per cycle must be equal or greater than PL/fSW = (VOUT + VD − VIN)(IOUT)( 1 ) fsw In the continuous mode, the switching frequency is fsw= VIN − VSW x 1 (VOUT + VD − VIN ) )] [1 + ( ON (VOUT + VD − VSW ) OUT + VD − VSW 2V T 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 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 9 AIC1641 LOW VOLTAGE STEP-UP DC/DC CONVERTER SPEC NO: DS-1641-00 05/04/00  VOUT + VD − VSW x   VIN − VSW   x − IOUT +  IPK =  TON1 −  VIN − VSW 2 2L     2 Valley current (Iv) is  VOUT + VD − VSW x   VIN − VSW   x − IOUT −  IV =  TON1 −  VIN − VSW 2 2L     2 Table 1 Indicates resistance and height for each coil. Hieght (mm) 4.5 Power Inductor Type Sumida SMT Type CD54 Inductance ( µH ) 47 100 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 Hold SMT Type PM54 47 100 4.5 Hold SMT Type PM75 Huan Feng PIN Type V0810 33 33 5.0 10.0 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. 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   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 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 AIC1641 LOW VOLTAGE STEP-UP DC/DC CONVERTER SPEC NO: DS-1641-00 05/04/00

PHYSICAL DIMENSIONS ! MSOP 8 (unit: mm) D SYMBOL A A1 H E MIN 0.76 -0.28 0.13 2.90 2.90 0.65 4.80 0.40 MAX 0.97 0.20 0.38 0.23 3.10 3.10 5.00 0.66 B C D E e A C A1 e H L L B ! 8 LEAD PLASTIC SO (unit: mm) D SYMBOL A A1 H E MIN 1.35 0.10 0.33 0.19 4.80 3.80 5.80 0.40 MAX 1.75 0.25 0.51 0.25 5.00 4.00 6.20 1.27 B C D E e A C A1 e H L L 1.27(TYP) B 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 AIC1641 LOW VOLTAGE STEP-UP DC/DC CONVERTER SPEC NO: DS-1641-00 05/04/00 ! SOT-89-5 (unit: mm) SYMBOL D b1 b A C MIN 1.40 0.32 1.40 0.30 4.40 2.40 300 (TYP) 1.50 (TYP) 4.20 0.80 MAX 1.60 0.52 1.80 0.50 4.60 2.60 A b b1 C HE E D E e e1 HE LE LE b e1 e 5.00 --- ! SOT-89-5 Marking Part No. AIC1641-27CW AIC1641-30CW AIC1641-33CW AIC1641-50CW Marking BD27 BD30 BD33 BD50 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 12