AIC1896 1. 4MHz Thin Package Current-Mode Step-Up DC/DC Converter FEATURES DESCRIPTION Fixed Frequency 1.4MHz Current-Mode PWM AIC1896 is a current-mode pulse-width modulation Operation. (PWM), step-up DC/DC Converter. The built-in high Adjustable Output Voltage up to 30V. voltage N-channel MOSFET allows AIC1896 for Guaranteed 13V/ 200mA Output with 5V Input. step-up applications with up to 30V output voltage, 2.5V to 10V Input Range. as well as for Single Ended Primary Inductance Maximum 0.1µA Shutdown Current. Converter (SEPIC) and other low-side switching Programmable Soft-Start. DC/DC converter. Tiny Inductor and Capacitors are allowed. Space-Saving SOT-23-6 and TSOT-23-6 The high switching frequency (1.4MHz) allows the Package. use of small external components. The Soft-Start function is programmable with an external capacitor, APPLICATIONS which sets the input current ramp rate. White LED Backlight. OLED Driver. The AIC1896 is available in a space-saving LCD Bias SOT-23-6 and TSOT-23-6 package. TYPICAL APPLICATION CIRCUIT L D1 3.3V or 4.2V 86 CH521S-30 C1 C3 ZD1 4.7µF AIC1896 6 OFF ON 4 IN LX SHDN FB SS GND 5 1 3 2 R2 ILED 1KΩ R1 C2 84 1µF BZV55-B12 11.8V~12.2V 62 0.033µF 82 Efficiency (%) VIN 80 VIN=4.2V 78 VIN=3.3V 76 74 72 L: GTSK-51-150M (15µH) L: GTSK-51-100M (10µH) 70 68 2 4 6 8 10 12 14 16 18 20 LED Current (mA) Fig. 1 Li-Ion Powered Driver for three white LEDs Analog Integrations Corporation Si-Soft Research Center 3A1, No.1, Li-Hsin Rd. I, Science Park, Hsinchu 300, Taiwan, R.O.C. TEL: 886-3-5772500 FAX: 886-3-5772510 www.analog.com.tw DS-1896G-01 121208 1 AIC1896 L D1 4.2V 80 CH521S-30 C1 ZD1 4.7µF 23.5V~24.5V AIC1896 OFF ON 4 LX IN SHDN FB SS GND 1 3 R2 ILED 1KΩ 2 5 76 1µF BZV55-B24 6 78 C3 R1 C2 62 0.033µF Efficiency (%) VIN 3.6V or 74 72 VIN=4.2V 70 VIN=3.6V 68 66 64 L: GTSK-51-150M (15µH) L: GTSK-51-100M (10µH) 62 60 2 4 6 8 10 12 14 16 18 20 LED Current (mA) Fig. 2 Li-Ion Powered Driver for six white LEDs ORDERING INFORMATION AIC1896XXXX PIN CONFIGURATION PACKING TYPE TR: TAPE & REEL BG: BAG PACKAGE TYPE G: SOT-23-6 K: TSOT-23-6 P: LEAD FREE COMMERCIAL G: GREEN PACKAGE Example: AIC1896PKTR SOT-23-6 / TSOT-23-6 FRONT VIEW 6 5 4 1: LX 2: GND 3: FB 1896/1896P 4: SHDN 5: SS 2 1 3 6: IN Note: Pin1 is determined by orienting the package marking as shown. in Lead Free TSOT-23-6 Package & Tape & Reel Packing Type AIC1896PGTR in Lead Free SOT-23-6 Package & Tape & Reel Packing Type TSOT-23-6 Marking Part No. Marking AIC1896PK 896PK AIC1896GK 896GK SOT-23-6 Marking Part No. Marking AIC1896PG 1896P AIC1896GG 1896G 2 AIC1896 ABSOLUTE MAXIMUM RATINGS LX to GND -0.3V to +33V FB to GND -0.3V to +6V IN, SHDN -0.3V to +11V SS to GND -0.3V to +6V 0.6A LX Pin RMS Current Continuous Power Dissipation 727mW Operating Temperature Range -40°C to 85°C 125°C Junction Temperature Storage Temperature Range -65°C to 150°C Lead Temperature (soldering, 10s) 260°C Absolute Maximum Ratings are those values beyond which the life of a device may be impaired. TEST CIRCUIT D1 L1 VIN 2.5V to 10V + C1 10µF/16V VOUT GTSK-51-100M(10uH) U1 AIC1896 6 4 SHDN IN LX SHDN FB SS SS14 C3 R1 1 C4 10µF C5 1µF 3 GND 5 C2 0.033µF + 2 R2 62 3 AIC1896 ELECTRICAL CHARACTERISTICS (VIN=V SHDN =3V, FB=GND, SS=Open, TA=25°°C, unless otherwise specified) (Note 1) PARAMETER Input Supply Range SYMBOL CONDITIONS VIN VOUT VIN Undervoltage Lockout UVLO VIN rising, 50mV hysteresis IIN Shutdown Supply Current TYP 2.5 Output Voltage Adjust Range Quiescent Current MIN MAX UNITS 10 V 30 V 2.2 VFB = 1.3V, not switching V 0.1 0.2 1 5 V SHDN = 0, TA = +25°C 0.01 0.5 µA V SHDN = 0 0.01 10 µA 1.23 1.255 V 21 80 nA 0.05 0.20 %/V 1800 KHz VFB = 1.0V, switching mA ERROR AMPLIFIER Feedback Regulation Set Point VFB FB Input Bias Current IFB Line Regulation 1.205 VFB = 1.24V 2.6V < VIN < 5.5V OSCILLATOR Frequency fOSC 1000 1400 Maximum Duty Cycle DC 82 86 % POWER SWITCH Steady State Output Current Io Refer to Fig. 13 On-Resistance RDS(ON) Vin = 5V Leakage Current ILX(OFF) A VLX = 30V, TA = +25°C 1 1.4 0.1 1 Ω µA VLX = 30V 10 Reset Switch Resistance Guaranteed By Design 100 Ω Charge Current VSS = 1.2V 7.0 µA 0.3 V SOFT-START 1.5 4 CONTROL INPUT Input Low Voltage VIL V SHDN , VIN = 2.5V to 10V Input High Voltage VIH V SHDN , VIN = 2.5V to 10V SHDN Input Current I SHDN V SHDN = 1.8V V SHDN = 0 1.0 V 25 50 0.01 0.1 µA Note 1: Specifications are production tested at TA=25°C. Specifications over the -40°C to 85°C operating temperature range are assured by design, characterization and correlation with Statistical Quality Controls (SQC). 4 AIC1896 TYPICAL PERFORMANCE CHARACTERISTICS 1.50 TA=25°C 1.45 VIN=3.6V Frequency (MHz) Switching Frequency (MHz) 1.50 1.40 1.35 1.30 1.45 1.40 1.35 1.25 1.20 1.30 -40 -20 0 20 40 60 80 100 2 3 4 5 6 7 8 Temperature (°C) 10 11 10 11 Fig. 4 Frequency vs. Supply Voltage 5.50 1.7 1.6 VIN=3.6V Output Voltage (V) 1.5 RDS(ON) (Ω) 9 Supply Voltage (V) Fig. 3 Switching Frequency vs. Temperature 1.4 1.3 1.2 1.1 1.0 5.25 5.00 4.75 0.9 0.8 4.50 2 3 4 5 6 7 8 9 10 11 1 10 100 Output Current (mA) Supply Voltage (V) Fig. 6 Load Regulation (L1=10 Fig. 5 RDSON vs. Supply Voltage μH) 12.5 2.4 VIN=3.6V 12.0 11.5 11.0 FB=1.0V SHDN=1.0V 2.2 Supply Current (mA) Output Voltage (V) 2.0 1.8 1.6 1.4 1.2 1.0 0.8 0.6 10.5 1 10 Output Current (mA) 100 μ Fig. 7 Load Regulation (L1=22 H) 2 3 4 5 6 7 8 9 Supply Voltage (V) Fig. 8 Switching Current 5 AIC1896 TYPICAL PERFORMANCE CHARACTERISTICS (Continued) 1.25 Supply Current ( μ Feedback Voltage (V) A) 90 85 FB=1.3V SHDN=1.0V 80 75 70 65 2 3 4 5 6 7 8 9 10 1.24 1.23 1.22 1.21 VIN=3.6V 1.20 -50 11 -25 Supply Voltage (V) Fig. 9 Non-Switching Current 25 50 75 100 90 VIN=4.2V VIN=3.6V VIN=3.3V VIN=2.7V VIN=2.5V 80 85 Efficiency (%) 85 Efficiency (%) 0 Temperature (°C) Fig. 10 Feedback Pin Voltage 90 75 70 VOUT=5.0V L1: GTSK-51-100M 65 VIN=4.2V 80 VIN=5.0V VIN=3.6V 75 VIN=3.3V 70 VOUT=12V L1: SLF6025-220MR 65 60 60 0 100 200 300 400 500 600 0 Output Current (mA) Fig. 11 Efficiency vs. Output Current (L1=10µH, test circuit refer to p.3) 50 100 150 200 Output Current (mA) Fig. 12 Efficiency vs. output current (L1=22µH, test circuit refer to p.3) 350 Maximum Output Current (mA) 800 Maximum Output Current (mA) 700 VOUT=13V VOUT=5V 600 VOUT=9V 500 VOUT=15V 400 300 200 Maximum output current defined at 90% of no load output voltage 100 2 3 4 5 6 7 8 9 10 Supply Voltage (V) Fig. 13(a) Maximum Output current vs. Supply Voltage (L1: 10µH, test circuit refer to p.3) 300 VOUT=20V 250 VOUT=25V 200 150 VOUT=30V 100 Maximum output current 50 defined at 90% of no load output voltage 0 3 4 5 6 7 8 9 10 11 Supply Voltage (V) Fig. 13(b) Maximum Output Current vs. Supply Voltage (L1:22µH, test circuit refer to p.3) 6 AIC1896 TYPICAL PERFORMANCE CHARACTERISTICS (Continued) VLX VSW VOUT VOUT ILX ILX Fig. 14 Operation Wave Form (VIN=5V; VOUT=12V, L1=22µH; R1=105K; R2=12K;C3=1nF;IOUT=200mA, test circuit refer to p.3) Fig. 15 Operation Wave Form (VIN=3V;VOUT=5V;L1=10µH;R1=36K;R2=12K; C3=39pF;IOUT=200mA, test circuit refer to p.3) VOUT VOUT ILX ILX Fig. 16 Load Step Response (VIN=3.3V; VOUT=5V;L1=10µH;IOUT=5mA to 200mA, test circuit refer to p.3) Fig. 17 Load Step Response (VIN=5V ; VOUT=12V ;L1=22µH;IOUT=5mA to 150mA, test circuit refer to p.3) SHDN VOUT ILX Fig. 18 Start-Up from Shutdown (VIN=3.3V ;VOUT=13V ;RLOAD=300Ω, test circuit refer to p.3) 7 AIC1896 BLOCK DIAGRAM VIN Control PWM/PFM I9 R3 Soft Start R4 Error Amp - + - + Q1 Q2 FB 1 8 R1 Control Logic SHDN Driver RC CC 1.4MHz Oscillator R2 LX x1 Slope Compensation Current AMP x 5 + x20 RS - SS 4µA PWM Comparator GND PIN DESCRIPTIONS PIN 1: LX - Power Switching Connection. Connect LX to inductor and output rectifier. Keep the distance between the components as close to LX as possible. PIN 2: GND - Ground. PIN 3: FB Feedback Input. Connect a resistive voltage-divider from the output to FB to set the output voltage. - PIN 4: SHDN - Shutdown Input. Drive SHDN low to turn off the converter. To automatically start the converter, connect SHDN to IN. Drive SHDN with a slew rate of 0.1V/µs or greater. Do not leave SHDN unconnected. SHDN draws up to 50µA. PIN 5: SS - Soft-Start Input. Connect a soft-start capacitor from SS to GND in order to soft-start the converter. Leave SS open to disable the soft-start function. PIN 6: IN - Internal Bias Voltage Input. Connect IN to the input voltage source. Bypass IN to GND with a capacitor sitting as close to IN as possible. 8 AIC1896 APPLICATION INFORMATION Inductor Selection accurate LED current, precision resistors are A 15µH inductor is recommended for most preferred (1% recommended). The formula for R1 AIC1896 applications. Although small size and selection is shown below. high efficiency are major concerns, the inductor (1) R1 = 1.23V/ILED should have low core losses at 1.4MHz and low Open-Circuit Protection DCR (copper wire resistance). In the cases of output open circuit, when the LEDs Capacitor Selection are disconnected from the circuit or the LEDs fail, The small size of ceramic capacitors makes them the feedback voltage will be zero. AIC1896 will ideal for AIC1896 applications. X5R and X7R then switch to a high duty cycle resulting in a high types are recommended because they retain their output voltage, which may cause SW pin voltage capacitance over wider ranges of voltage and to exceed its maximum 30V rating. A zener diode temperature than other types, such as Y5V or can be used at the output to limit the voltage on Z5U. A 4.7µF input capacitor and a 1µF output SW pin (Fig. 20). The zener voltage should be capacitor larger than the maximum forward voltage of the are sufficient for most AIC1896 applications. LED string. The current rating of the zener should be larger than 0.1mA. Diode Selection Schottky diodes, with their low forward voltage Dimming Control drop and fast reverse recovery, are the ideal There are three different types of dimming control choices for AIC1896 applications. The forward circuits as follows: voltage drop of a Schottky diode represents the 1. Using a PWM signal conduction losses in the diode, while the diode PWM brightness control provides the widest capacitance (CT or CD) represents the switching dimming range by pulsing LEDs on and off at full losses. For diode selection, both forward voltage and zero current, repectively. The change of drop be average LED current depends on the duty cycle of considered. Schottky diodes with higher current the PWM signal. Typically, a 0.1kHz to 10kHz ratings usually have lower forward voltage drop PWM signal is used. Two applications of PWM and larger diode capacitance, which can cause dimming with AIC 1896 are shown in Fig 21. significant 1.4MHz as fig. 21(a), uses PWM signal to drive SHDN switching frequency of AIC1896. A Schottky diode pin directly for dimming control. The other, as fig. rated at 100mA to 200mA is sufficient for most 21(b), employs PWM signal AIC1896 applications. resistor to drive FB pin. If the SHDN pin is used, and diode capacitance switching losses at need the to One, going through a the increase of duty cycle results in LED LED Current Control brightness enhancement. If the FB pin is used, on LED current is controlled by feedback resistor (R1 the contrary, the increase of duty cycle will in Fig. 1). The feedback reference is 1.23V. The decrease its brightness. In this application, LEDs LED current is 1.23V/R1. In order to have 9 AIC1896 are dimmed by FB pin and turned off completely by the FB pin bias current. With a VDC ranging from SHDN . 0V to 5V, the selection of resistors in Fig. 22 results in dimming control of LED current from 2. Using a DC Voltage 20mA to 0mA, respectively. For some applications, the preferred method of a dimming control uses a variable DC voltage to 3. Using a Filtered PWM Signal adjust LED current. A dimming control using a DC Filtered PWM signal can be considered as an voltage is shown as Fig. 22. As DC voltage adjustable DC voltage. It can be used to replace increases, the voltage drop over R2 increases and the variable DC voltage source in dimming control. the voltage drop over R1 decreases. The circuit is shown in Fig. 23. Cautiously selecting R2 and R3 is essential so that the current from the variable DC source is much smaller than the LED current and much larger than L1 10µH VIN 3.3V to 4.2V D1 SS0540 SLF6025-100M1R0 C3 C1 4.7µF ZD1 1µF BZV55-B24 U1 OFF AIC1896 23.5V~24.5V 6 IN LX 1 4 SHDN FB 3 ON SS GND 5 2 R2 IOUT=ILED=20mA 1KΩ R1 62Ω C2 0.033µF Fig. 19 White LED Driver with Open-Circuit Protection ZD1 AIC1896 IN LX IN LX R2 PWM SHDN FB R2 GND Ω SHDN ON 1K SS ZD1 AIC1896 R1 62 FB 1K OFF SS Ω GND R1 R3 30K C2 C2 0.033µF 0.033µF 62 PWM (a) (b) Fig. 20 Dimming Control Using a PWM Signal 10 AIC1896 ZD1 AIC1896 ZD1 AIC1896 IN IN SHDN R2 SHDN FB OFF ON GND R3 20mA~0mA Ω Ω C2 0.033µF 0.033µF R1 Ω 82 3.3K Ω Ω R4 4K C1 0.1µF VDC 0V~5V Fig. 21 Dimming Control Using a DC Voltage GND R3 R1 82 Ω 1K SS 3.3K C2 FB OFF ON Ω 1K SS LX R2 LX PWM Fig. 22 Dimming Control Using a Filtered PWM Signal APPLICATION EXAMPLES L1 VIN 3V to 4.2V C1 4.7µF 10µH D1 SLF6025-100M1R0 SS0504 C3 BZV55-B24 23.5V~24.5V U1 AIC1896 OFF ON 1µF ZD1 6 IN LX 1 4 SHDN FB 3 GND SS 5 2 R2 1KΩ IOUT=ILED=20mA C2 0.033µF Fig. 23 R1 62Ω R3 62Ω 1-Cell Li-Ion Powered Driver for eight White LEDs with Open-Circuit Protection 11 AIC1896 * L1 AIC1896 Vin C1 33uF IN + D1 LX SS14 Vout + /SHDN FB * R2 C4 10u/25V SS GND C3 100p R1 12k C2 0.033uF C5 0.1uF Vout *R2 *L1 5V 9V 36K 10uH 75k 10uH 12V 105k 18V 160k 10uH 22uH 24V 220k 22uH Fig. 24 Typical Step up Application Circuit VOUT2 D2 BAT54S -15V/5mA C2 L1 VIN 3V to 4.2V C1 1µF 22uH 1µF/16V SLF6025-220MR73 C4 4.7µF/6.3V AIC1896 6 LX IN 4 SHDN FB SS GND OFF ON 5 2 SS0540 D1 1 +15V/5mA R2 3 135k R1 12k C6 VOUT1 C3 1µF/16V 100pF C5 0.033µF Fig. 25 1-Cell Li-Ion to ±15V/5mA Dual Output Converter for LCD Bias VOUT=40V/10mA D2 BAT54S C4 0.1uF C3 0.01u L1 5VIN C1 4.7uF D1 SS054 U1 22uH IN SW SHDN FB GND SS C5 0.01u R1 3M R2 AIC1896 C2 10nF 91k Fig. 26 High 40V Output Voltage for Electrophoretic Display (EPD) Application 12 AIC1896 Q2 MMBT2907A D3 C6 C7 1uF 1uF BAT54WS C11 1uF R3 2.2K Vout3=-7V D5 7.7V D2 C8 Vout2=20V C9 1uF 1uF L1 Vin BAT54WS 22uH C1 4.7uF D1 SS14 AIC1896 IN SW LX /SHDN FB SS GND R2 12K Vout1=10V R1 85K C3 100pF C4 10uF/25V + C5 0.1uF C2 0.033uF Fig. 27 Three output voltage for LCD 13 AIC1896 PHYSICAL DIMENSIONS (unit: mm) TSOT-23-6 D S Y M B O L 1 E A A e1 E e SEE VIEW B b WITH PLATING 2 A c A BASE METAL 1 A SECTION A-A L1 MILLIMETERS MIN. MAX. A - 1.00 A1 0 0.10 A2 0.70 0.90 b 0.30 0.50 c 0.08 0.22 D 2.80 3.00 E 2.60 3.00 E1 1.50 1.70 e 0.95 BSC e1 1.90 BSC L 0.60 0.30 L1 5 2 . 0 L TSOT-23-6 θ 0.60 REF 0° 8° GAUGE PLANE SEATING PLANE θ VIEW B Note : 1. Refer to JEDEC MO-193AA. 2. Dimension "D" does not include mold flash, protrusions or gate burrs. Mold flash, protrusion or gate burrs shall not exceed 6 mil per side. 3. Dimension "E1" does not include inter-lead flash or protrusions. 4. Controlling dimension is millimeter, converted inch dimensions are not necessarily exact. 14 AIC1896 SOT-23-6 D 1 E A A e1 S Y M B O L E e SEE VIEW B b WITH PLATING 2 A c A BASE METAL 1 A SECTION A-A L1 MILLIMETERS MIN. MAX. A 0.95 1.45 A1 0.05 0.15 A2 0.90 1.30 b 0.30 0.50 c 0.08 0.22 D 2.80 3.00 E 2.60 3.00 E1 1.50 1.70 e 0.95 BSC e1 L 1.90 BSC θ 0.60 0.30 L1 5 2 . 0 L SOT-23-6 0.42 REF 0° 8° GAUGE PLANE SEATING PLANE θ VIEW B Note : 1. Refer to JEDEC MO-178AB. 2. Dimension "D" does not include mold flash, protrusions or gate burrs. Mold flash, protrusion or gate burrs shall not exceed 10 mil per side. 3. Dimension "E1" does not include inter-lead flash or protrusions. 4. Controlling dimension is millimeter, converted inch dimensions are not necessarily exact. Note: Information provided by AIC is believed to be accurate and reliable. However, we cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in an AIC product; nor for any infringement of patents or other rights of third parties that may result from its use. We reserve the right to change the circuitry and specifications without notice. Life Support Policy: AIC does not authorize any AIC product for use in life support devices and/or systems. Life support devices or systems are devices or systems which, (I) are intended for surgical implant into the body or (ii) support or sustain life, and whose failure to perform, when properly used in accordance with instructions for use provided in the labeling, can be reasonably expected to result in a significant injury to the user. 15