AIC1631CS

AIC1631 2-Cell, 500mA, Step-Up DC/DC Converter FEATURES High Efficiency 90%. Adjustable Output Voltage with Two Resistors (AIC1631A) Power-Saving Shutdown Mode (7µA typical). Internal 2A Switch. 120KHz Switching Rate. Adjustable Switch Current Limit. On-Chip Low Battery Detector. DESCRIPTION The AIC1631 is a high efficiency step up DCDC converter. Only four external components are required to deliver a fixed voltage of 3V, 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 Palmtop & Notebook Computers. Pocket Organizers. Cameras. Pagers. Battery Backup Supplies. Portable Instruments. Logic-controlled shutdown mode is provided for 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 commended for most applications. re- TYPICAL APPLICATION CIRCUIT +VIN L 1N5819 D1 +VOUT (3.3V) + C2 100µF Note: VIN≥1.8V, VOUT≤7V 100Ω R1 50µH + NORMAL C1 100µF RILIM ILIM/SD VIN SW SGND VOUT LBI LBO CGND SD LOAD AIC1631 High Efficiency Step-Up DC/DC Converter Analog Integrations Corporation DS-1631-04 Dec 27, 00 4F, 9, Industry E. 9th Rd, Science Based Industrial Park, Hsinchu Taiwan, ROC TEL: 886-3-5772500 FAX: 886-3-5772510 www.analog.com.tw 1 AIC1631 ORDERING INFORMATION AIC1631 XXX 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 ORDER NUMBER AIC1631CN AIC1631-3CN AIC1631-5CN (PLASTIC DIP ) AIC1631CS AIC1631-3CS AIC1631-5CS (PLASTIC SO) AIC1631ACN (PLASTIC DIP ) AIC1631ACS (PLASTIC SO) PIN CONFIGURATION TOP VIEW ILIM/SD 1 VIN 2 SW 3 SGND 4 8 7 6 5 VOUT LBI LBO CGND TOP VIEW ILIM/SD 1 VIN 2 EXT 3 GND 4 8 7 6 5 VOUT LBI LBO FB 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 PARAMETER Input Voltage Output Voltage (VIN=3.0V, Ta=25°C, unless otherwise specified.) TEST CONDITIONS Fig. 4 in Appl. Examples ILOAD =200mA AIC1631 AIC1631-3 AIC1631-5 MIN. 1.5 3.16 2.88 4.80 TYP. MAX. 7 UNIT V V 3.3 3 5 105 3.44 3.12 5.20 140 Switch off Current No Load Current Shutdown Mode Current Shutdown Recovery Time VIN=2.5V, ILOAD =200mA AIC1631/AIC1631-3 AIC1631-5 µA µA 160 180 7 0.4 15 µA mS 2 AIC1631 ELECTRICAL CHARACTERISTICS (CONTINUED) PARAMETER Efficiency TEST CONDITIONS ILOAD =200mA AIC1631/AIC1631-3 AIC1631-5 ILOAD =100mA AIC1631, VIN=1.8 ~ 3.3V AIC1631-3, VIN=1.8 ~ 3V AIC1631-5, VIN=2.2 ~ 3.3V ILOAD =10~300mA AIC1631/AIC1631-3 AIC1631-5 MIN. TYP. 87 90 0.6 0.5 0.8 0.3 0.8 MAX. UNIT % Line Regulation %VOUT Load Regulation %VOUT Oscillator Frequency LBI Pin Trip Point FB Threshold Voltage SW “ON Resistance” LBO “ON Resistance” SW Off Leakage Input Pin Bias Current Output Pin Leakage AIC1631A AIC1631/AIC1631-3 AIC1631-5 VIN=2V 90 1.17 0.598 120 1.22 0.617 0.5 0.4 45 150 1.27 0.636 KHz V V Ω Ω 1 10 10 µA nA/Pin nA/Pin TYPICAL PERFORMANCE CHARACTERISTICS 1 Switch Voltage vs. Current Ta=25°C AIC1631/1631-3 0.58 .0.54 SW ON Resistance vs. Temperature AIC1631/1631-3 AIC1631-5 0.46 0.75 SW RDS (Ω) VSW (V) AIC1631-5 0.5 0.5 0.25 0.42 0.38 0 0 0.5 1 1.5 2 2.5 3 0.36 0 20 40 60 80 ISW (A) Temperature (°C) 3 AIC1631 TYPICAL PERFORMANCE CHARACTERISTICS 200 190 180 (CONTINUED) No Load Supply Current vs. Input Voltage Ta=25°C 210 200 190 No Load Supply Current vs. Temperature IS (µA) 170 160 AIC1631-5 AIC1631/1631-3 150 140 IS (µA) AIC1631-5 180 170 160 150 AIC1631/1631-3 0 20 40 60 80 1 1.5 2.0 2.5 VIN (V) 3.0 3.5 4.0 4.5 5.0 Temperature (°C) Shutdown Mode Supply Current vs. Input Voltage 8.2 8.0 7.8 9.4 Shutdown Mode Supply Current vs. Temperature Ta=25°C 9.0 6.6 VIN=3V IS (µA) IS (µA) 1 1.5 2 2.5 3 3.5 4 4.5 5 7.6 7.4 7.2 7.0 8.2 7.8 7.4 VIN (V) 7.0 0 20 40 60 80 Temperature (°C) Oscillator Frequency vs. Input Voltage 130 Oscillator Frequency vs. Temperature 123 110 Oscillator Frequency (KHz) Frequency (KHz) 121 Ta=25°C 90 VIN=3V 119 70 60 1 2 3 4 5 VIN (V) 117 0 20 40 60 80 Temperature (°C) 4 AIC1631 TYPICAL PERFORMANCE CHARACTERISTICS Maximum Load Current vs. Switch Current Limit Resistance Maximum Load Current (mA) (CONTINUED) Maximum Load Current vs. Switch Current Limit Resistance Maximum Load Current (mA) 600 500 400 600 500 400 300 200 100 0 AIC1631/1631-3 Ta=25°C (5% VOUT Drop) AIC1631/1631-3 Ta=25°C (5% VOUT Drop) VIN=2.7V VIN=2.2V VIN=2.5V VIN=2.0V VIN=1.8V 200 400 600 800 1000 300 VIN=2.2V 200 100 0 VIN=2.5V VIN=2.0V 0 50 100 VIN=1.8V 150 200 0 RILIM (KΩ) RILIM (KΩ) BLOCK DIAGRAM ILIM/SD Current Limit + 0.617V VOUT VIN 100mV SW A + Shutdown OSC + 1.22V LBI LBO SGND CGND 5 AIC1631 PIN DESCRIPTIONS AIC1631/ AIC1631-3 / AIC1631-5 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. 2. The AIC1631 goes in shutdown mode and consumes less than 10µA when ILIM/SD pin is pulled to ground. PIN 2: VIN PIN 3: SW Input supply. Drain of the power switch, to be connected to inductor/ diode. Ground connected to source of power switch. Ground for control circuits of the IC. It should be separated from SGND to avoid the interference. 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. The output voltage feedbacks to the IC through this pin. AIC1631A PIN 1: ILIM/SD1. 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. 2. The AIC1631A goes in shutdown mode and consumes less than 10µA when ILIM/SD pin is pulled to ground. PIN 2: VIN PIN 3: SW PIN 4: GND PIN 5: FB Input supply. Drain of the power switch, to be connected to inductor/ diode. Ground. 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. VOUT voltage is given by the following equation: PIN 4:SGND PIN 5:CGND - R1 VOUT = −1 R2 0.617 where R1 = Resistor connected 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. PIN 6:LBO - PIN 7:LBI - PIN 8:VOUT - 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 +VOUT (+3V) +VIN 22Ω R1 50µH L1 + 100µF C2 + 47µF C1 27K R2 ILIM/SD VIN SW OSCON 100µF C3 + 1N5819 D1 SGND VOUT LBI LBO CGND 75 0 100 200 300 90 VIN=3.3V Efficiency (%) 85 VIN=3.0V VIN=2.5V VIN=1.8V LOAD 80 VIN=2.2V VIN=2.0V 400 500 600 AIC1631-3 Load Current (mA) Fig. 1 3V Output Step-Up Converter +VOUT (+5V) +VIN 22Ω R1 25µH L1 95 27K R2 + 47µF C1 ILIM/SD VIN SW VOUT LBI LBO CGND 90 + 100µF C2 LOAD Efficiency (%) VIN=5.0V VIN=4.5V VIN=4.0V VIN=3.0V VIN=2.2V VIN=2.5V 85 + OSCON 100µF C3 1N5819 D1 80 VIN=2.0V SGND 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) +VOUT (+3V) 80 +VIN 100Ω R1 VIN=1.4V VIN=1.6V Efficiency (%) ILIM/SD VIN SW VOUT LBI LBO CGND 65 0 75 + LOAD 47µF L1 C1 10µF VIN=1.2V 70 VIN=1.0V 100µF C2 + 1N5819 D1 SGND AIC1631-3 2 4 6 8 10 12 Load Current (mA) Fig. 3 1-Cell Input 3V Output Step-Up Converter +VOUT (+5V) +VIN R1 100Ω + ILIM/SD VIN SW VOUT LBI LBO CGND 80 Efficiency (%) 47µH L1 LOAD 10µF C1 VIN=1.6V 75 VIN=1V VIN=1.4V VIN=1.2V + 1N5819 D1 100µF C2 70 SGND AIC1631-5 65 0 2 4 6 8 10 12 Load Current (mA) Fig. 4 1-Cell Input 5V Output Step-Up Converter 2SB1424 Q1 +VIN 100Ω R1 500µH L1 + C1 220µF + 27K R2 ILIM/SD VOUT LBI LBO CGND 20K R4 15K R5 +VOUT (+5V) 94 90 VIN=5V VIN=4V VIN=6V VIN=3V VIN=7V VIN=8V 0 50 100 150 200 250 300 350 400 C2 10µF VIN SW SGND + 100µF C4 LOAD Efficiency (%) RB 12K 62K R3 86 82 78 74 70 66 62 58 + 100µF C2 1N5819 D1 AIC1631-5 Load Current (mA) Fig. 5 4-Cell Input Step-Up / Step-Down Converter 8 AIC1631 APPLICATION EXAMPLES (CONTINUED) +VIN +VOUT (+5V) LOAD 100Ω R1 130 50µH L1 C2 47µF 1N5819 D1 + ILIM/SD VIN SW SGND VOUT LBI LBO CGND 1N4148 1M R2 15nF C4 1M R3 Total Supply Current (µA) D2 680K R4 Q1 2N3904 Q2 2N3904 VIN=2.0V VIN=1.8V VIN=2.5V VIN=3V 110 90 70 50 100µF C1 + AIC1631-5 * CTL= GND in Burst Mode CTL=VIN in Normal Mode *CTL + C3 1µF 30 10 0 10 20 30 40 Load Current (µA) Fig. 6 Low Supply Current Burst Mode Step-Up Converter +VOUT +VIN 22Ω R1 50µH L1 + 27K R2 + 47µF C1 ILIM/SD VOUT VIN SW GND LBI LBO FB R2 R1 LOAD 100µF C2 OSCON 100µF C3 + 1N5819 D1 AIC1631A Fig.7 Adjustable Output Voltage Step-Up Converter 9 AIC1631 PHYSICAL DIMENSION 8 LEAD PLASTIC SO (unit: mm) D SYMBOL A 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 A1 B C D E e A C A1 e H L L 1.27(TYP) B 8 LEAD PLASTIC DIP (unit: mm) D SYMBOL A1 E1 MIN 0.381 2.92 0.35 0.20 9.01 7.62 6.09 — 2.92 MAX — 4.96 0.56 0.36 10.16 8.26 7.12 10.92 3.81 A2 b C E D E C A2 A1 L E1 e eB L 2.54 (TYP) eB b e 10