AIC1631 2-Cell, 500mA, Step-Up DC/DC Converter DESCRIPTION FEATURES High Efficiency 90%. Adjustable Output Voltage with Two Resistors (AIC1631A) The AIC1631 is a high efficiency step up DCDC converter. Only four external components are required to deliver a fixed voltage of 3V, Power-Saving Shutdown Mode (7µA typical). Internal 2A Switch. 120KHz Switching Rate. Adjustable Switch Current Limit. On-Chip Low Battery Detector. 3.3V, or 5V. The output voltage can be externally set to an arbitrary value below breakdown voltage of the power switch for AIC1631A. Efficiency beyond 87% can be easily achieved at 100mA load with 2.2V to 3V input voltages. APPLICATIONS Logic-controlled shutdown mode is provided for Palmtop & Notebook Computers. Pocket Organizers. Cameras. Pagers. Battery Backup Supplies. Portable Instruments. power saving. Switch current limit can be programmed with a resistor. The low battery detector can be configured as a linear regulator or a burst mode controller performing an extremely low supply current operation. 120KHz switching rate reduces the inductor size. Inductors of 25µH to 50µH inductance are re- commended for most applications. TYPICAL APPLICATION CIRCUIT 100Ω +VIN R1 L 1N5819 D1 +VOUT (3.3V) LOAD 50µH NORMAL + C1 100µF RILIM SD + C2 100µF ILIM/SD LBI SW LBO SGND Note: VIN≥1.8V, VOUT≤7V VOUT VIN CGND AIC1631 High Efficiency Step-Up DC/DC Converter Analog Integrations Corporation 4F, 9, Industry E. 9th Rd, Science Based Industrial Park, Hsinchu Taiwan, ROC DS-1631-04 Dec 27, 00 TEL: 886-3-5772500 FAX: 886-3-5772510 www.analog.com.tw 1 AIC1631 ORDERING INFORMATION AIC1631 XXX PIN CONFIGURATION ORDER NUMBER AIC1631CN AIC1631-3CN AIC1631-5CN (PLASTIC DIP ) PACKAGE TYPE N: PLASTIC DIP S: SMALL OUTLINE TEMPERATURE RANGE C=0°C~+70°C OUTPUT VOLTAGE DEFAULT: 3.3V 3: 3.0V 5: 5.0V A: Adjustable TOP VIEW AIC1631CS AIC1631-3CS AIC1631-5CS (PLASTIC SO) AIC1631ACN (PLASTIC DIP ) VOUT ILIM/SD 1 8 VIN 2 7 LBI SW 3 6 LBO SGND 4 5 CGND ILIM/SD 1 8 VOUT VIN 2 7 LBI EXT 3 6 LBO GND 4 5 FB TOP VIEW AIC1631ACS (PLASTIC SO) ABSOLUTE MAXIMUM RATINGS Supply Voltage ......................................…………....................…………....................... 7.0V Operating Temperature Range.....................……..............………................... -20°C ~ 80°C Storage Temperature Range .......................………...................………....... -65°C ~ 150°C TEST CIRCUIT Refer to Typical Application Circuit. ELECTRICAL CHARACTERISTICS (V IN=3.0V, PARAMETER TEST CONDITIONS Input Voltage Fig. 4 in Appl. Examples Output Voltage ILOAD =200mA AIC1631 AIC1631-3 AIC1631-5 Switch off Current No Load Current AIC1631/AIC1631-3 AIC1631-5 Shutdown Mode Current Shutdown Recovery Time Ta=25°°C, unless otherwise specified.) MIN. TYP. MAX. UNIT 7 V 3.3 3 5 3.44 3.12 5.20 V 105 140 µA 1.5 3.16 2.88 4.80 7 VIN=2.5V, ILOAD =200mA µA 160 180 0.4 15 µA mS 2 AIC1631 ELECTRICAL CHARACTERISTICS (CONTINUED) PARAMETER TEST CONDITIONS Efficiency Line Regulation Load Regulation MIN. TYP. MAX. UNIT ILOAD =200mA AIC1631/AIC1631-3 AIC1631-5 87 90 % ILOAD =100mA AIC1631, VIN=1.8 ~ 3.3V AIC1631-3, VIN=1.8 ~ 3V AIC1631-5, VIN=2.2 ~ 3.3V 0.6 0.5 0.8 %VOUT ILOAD =10~300mA AIC1631/AIC1631-3 AIC1631-5 0.3 0.8 %VOUT Oscillator Frequency LBI Pin Trip Point 90 120 150 KHz 1.17 1.22 1.27 V 0.598 0.617 0.636 V FB Threshold Voltage AIC1631A SW “ON Resistance” AIC1631/AIC1631-3 AIC1631-5 0.5 0.4 Ω LBO “ON Resistance” VIN=2V 45 Ω SW Off Leakage 1 µA Input Pin Bias Current 10 nA/Pin Output Pin Leakage 10 nA/Pin TYPICAL PERFORMANCE CHARACTERISTICS Switch Voltage vs. Current 1 SW ON Resistance vs. Temperature 0.58 AIC1631/1631-3 Ta=25°C .0.54 AIC1631/1631-3 AIC1631-5 SW RDS (Ω) VSW (V) 0.75 0.5 0.5 AIC1631-5 0.46 0.42 0.25 0.38 0 0 0.5 1 1.5 ISW (A) 2 2.5 3 0.36 0 20 40 60 80 Temperature (°C) 3 AIC1631 TYPICAL PERFORMANCE CHARACTERISTICS (CONTINUED) No Load Supply Current vs. Input Voltage 200 Ta=25°C 190 No Load Supply Current vs. Temperature 210 200 180 IS (µA) 190 IS (µA) AIC1631-5 170 160 AIC1631-5 180 170 AIC1631/1631-3 140 AIC1631/1631-3 160 150 1 1.5 2.0 2.5 3.0 VIN (V) 3.5 4.0 4.5 5.0 150 0 9.4 7.8 6.6 IS (µA) IS (µA) 9.0 7.6 7.8 7.2 7.4 1 1.5 2 2.5 3 VIN (V) 3.5 4 4.5 7.0 0 5 Oscillator Frequency (KHz) Ta=25°C 90 70 3 VIN (V) 40 60 80 123 110 2 20 Oscillator Frequency vs. Temperature Oscillator Frequency vs. Input Voltage 1 VIN=3V Temperature (°C) 130 Frequency (KHz) Shutdown Mode Supply Current vs. Temperature 8.2 7.4 60 80 Ta=25°C 8.0 7.0 60 Temperature (°C) Shutdown Mode Supply Current vs. Input Voltage 8.2 40 20 4 5 121 VIN=3V 119 117 0 20 40 60 80 Temperature (°C) 4 AIC1631 TYPICAL PERFORMANCE CHARACTERISTICS (CONTINUED) Maximum Load Current vs. Switch Current Limit Resistance 600 Maximum Load Current (mA) Maximum Load Current (mA) Maximum Load Current vs. Switch Current Limit Resistance AIC1631/1631-3 Ta=25°C (5% VOUT Drop) 500 400 300 VIN=2.2V 200 VIN=2.5V VIN=2.0V VIN=1.8V 100 0 0 200 400 600 800 600 400 VIN=2.7V 300 VIN=2.2V VIN=2.5V 200 VIN=2.0V 100 0 1000 AIC1631/1631-3 Ta=25°C (5% VOUT Drop) 500 0 VIN=1.8V 50 RILIM (KΩ) 100 150 200 RILIM (KΩ) BLOCK DIAGRAM ILIM/SD - Current Limit VOUT + VIN 100mV SW 0.617V + LBI - Shutdown A + 1.22V LBO OSC SGND CGND 5 AIC1631 PIN DESCRIPTIONS AIC1631/ AIC1631-3 / AIC1631-5 AIC1631A PIN 1: ILIM/SD- 1. Connected to VIN pin through a resistor to set the switch peak current. It serves to protect IC and inductor, as well as to improve efficiency and output ripples. However, supply capability of the AIC1631 is limited by the current limit resistor. (See typical performance characteristics). The ILIM/SD pin should be shorted to VIN pin if limiting on switch peak current is not intended. PIN 1: ILIM/SD- PIN 2: VIN - Input supply. PIN 3: SW - Drain of the power switch, to be connected to inductor/ diode. PIN 4: GND - Ground. PIN 5: FB - Output voltage can either be internally set to 5 volt by grounding FB pin, or be externally set to an arbitrary voltage by applying to FB pin the divider voltage of two divider resistors. - Input supply. PIN 3: SW - Drain of the power switch, to be connected to inductor/ diode. PIN 4:SGND - Ground connected to source of power switch. PIN 5:CGND - Ground for control circuits of the IC. It should be separated from SGND to avoid the interference. PIN 7:LBI - 2. The AIC1631A goes in shutdown mode and consumes less than 10µA when ILIM/SD pin is pulled to ground. 2. The AIC1631 goes in shutdown mode and consumes less than 10µA when ILIM/SD pin is pulled to ground. PIN 2: VIN PIN 6:LBO 1. Connected to VIN pin through a resistor to set the switch peak current. It serves to protect IC and inductor, as well as to improve efficiency and output ripples. However, supply capability of the AIC1631A is limited by the current limit resistor. (See typical performance characteristics). The ILIM/SD pin should be shorted to VIN pin if limiting on switch peak current is not intended. VOUT voltage is given by the following equation: R1 VOUT = −1 R2 0.617 where R1 = Resistor connected Open drain output of the battery low detector, with 45Ω “ON resistance” at VIN=2V. It is pulled low when the voltage on LBI pin is below 1.22V. - The noninverting input of the battery low detector, of which the inverting input is internally connects to 1.22V voltage reference. PIN 8:VOUT - The output voltage feedbacks to the IC through this pin. between FB pin and VOUT pin. R2= Resistor connected between FB pin and ground. VOUT=Output voltage to be set. PIN 6: LBO - Open drain output of the battery low detector, with 45Ω “ON resistance” at VIN=2V. It is pulled low when the voltage on LBI pin is below 1.22V. 6 AIC1631 AIC1631A (continued) PIN 7: LBI - The noninverting input of the battery low detector, of which the inverting input is internally connects to 1.22V voltage reference. PIN 8: VOUT- The output voltage feedbacks to the IC through this pin. If output voltage was externally set, the VOUT pin can be tied to any low impedance node with voltage between the external power switch threshold and 7V APPLICATION EXAMPLES OSCON 100µF C3 + 100µF C2 VIN=3.3V 27K R2 + ILIM/SD 47µF C1 + VIN LBI SW LBO SGND 1N5819 D1 VOUT Efficiency (%) 22Ω R1 50µH L1 LOAD 90 +VIN +VOUT (+3V) VIN=3.0V 85 VIN=2.5V VIN=1.8V VIN=2.2V 80 VIN=2.0V CGND AIC1631-3 75 0 100 200 400 300 500 600 Load Current (mA) Fig. 1 3V Output Step-Up Converter 27K R2 + 100µF C2 + 47µF C1 ILIM/SD OSCON 100µF C3 1N5819 D1 VOUT VIN LBI SW + VIN=5.0V VIN=4.5V VIN=4.0V 90 LBO SGND Efficiency (%) 22Ω R1 25µH L1 LOAD 95 +VIN +VOUT (+5V) VIN=3.0V 85 VIN=2.2V 80 VIN=2.5V VIN=2.0V CGND AIC1631-5 75 0 100 200 300 400 500 600 700 Load Current (mA) Fig. 2 5V Output Step-Up Converter 7 AIC1631 APPLICATION EXAMPLES (CONTINUED) 80 + VIN=1.6V C1 10µF 47µF L1 LOAD VIN=1.4V 100Ω R1 +VIN ILIM/SD VOUT VIN LBI SW 1N5819 D1 + 100µF C2 Efficiency (%) +VOUT (+3V) LBO SGND 75 VIN=1.2V VIN=1.0V 70 CGND AIC1631-3 65 0 2 4 6 8 10 12 Load Current (mA) Fig. 3 1-Cell Input 3V Output Step-Up Converter +VOUT (+5V) R1 100Ω +VIN 80 ILIM/SD 10µF C1 VIN=1.6V VOUT VIN Efficiency (%) + 47µH L1 LBI LOAD SW + 1N5819 D1 LBO SGND 100µF C2 CGND AIC1631-5 75 VIN=1V VIN=1.4V VIN=1.2V 70 65 0 2 4 6 8 10 12 Load Current (mA) Fig. 4 1-Cell Input 5V Output Step-Up Converter 2SB1424 Q1 27K R2 + 100µF C2 + ILIM/SD + C1 220µF 1N5819 D1 C2 10µF 94 VOUT VIN LBI SW LBO SGND CGND AIC1631-5 VIN=5V 90 R5 62K R3 RB 12K + 100µF C4 20K R4 VIN=4V 86 LOAD Efficiency (%) 100Ω R1 500µH L1 +VOUT (+5V) 15K +VIN 82 VIN=3V VIN=6V 78 74 VIN=7V 70 66 VIN=8V 62 58 0 50 100 150 200 250 300 350 400 Load Current (mA) Fig. 5 4-Cell Input Step-Up / Step-Down Converter 8 AIC1631 APPLICATION EXAMPLES (CONTINUED) +VIN 100Ω R1 50µH L1 LOAD 100µF C1 C2 47µF ILIM/SD + VOUT VIN LBI SW LBO 1M R2 1N4148 1M R3 15nF 1N5819 D1 + VIN=2.0V 130 D2 SGND Q1 2N3904 C4 CGND AIC1631-5 + C3 1µF *CTL * CTL= GND in Burst Mode CTL=VIN in Normal Mode 680K R4 Q2 2N3904 Total Supply Current (µA) +VOUT (+5V) 110 VIN=2.5V VIN=1.8V 90 VIN=3V 70 50 30 10 0 10 20 30 40 Load Current (µA) Fig. 6 Low Supply Current Burst Mode Step-Up Converter +VOUT +VIN LOAD OSCON 100µF C3 50µH L1 22Ω R1 + 100µF C2 27K R2 + 47µF C1 ILIM/SD VOUT VIN LBI SW LBO GND + 1N5819 D1 R1 FB AIC1631A R2 Fig.7 Adjustable Output Voltage Step-Up Converter 9 AIC1631 PHYSICAL DIMENSION 8 LEAD PLASTIC SO (unit: mm) D H E e MIN MAX A 1.35 1.75 A1 0.10 0.25 B 0.33 0.51 C 0.19 0.25 D 4.80 5.00 E 3.80 4.00 e A A1 C B SYMBOL 1.27(TYP) H 5.80 6.20 L 0.40 1.27 SYMBOL MIN MAX A1 0.381 — A2 2.92 4.96 b 0.35 0.56 C 0.20 0.36 D 9.01 10.16 E 7.62 8.26 E1 6.09 7.12 L 8 LEAD PLASTIC DIP (unit: mm) D E1 E A2 A1 C L eB b e e 2.54 (TYP) eB — 10.92 L 2.92 3.81 10