AIC3413 400mA, 1.2MHz Synchronous Step-Up Converter FEATURES DESCRIPTION The AIC3413 is a synchronous step-up DC/DC converter. There are two options for AIC3413: automatic PWM/PSM version (AIC3413), and forced PWM version (AIC3413A). The automatic PWM/PSM version enters PSM from PWM automatically when load decreases. The goal is to improve efficiency and reduce quiescent current; the forced PWM version keeps the same operating frequency even when it operates in light load. This guarantees low output ripple and noise. The AIC3413 provides a complete power supply solution for products powered by one or two Alkaline, Ni-Cd, Ni-MH or Li-Lon battery cells. It stays in operation with supply voltages down to 0.5V. The implemented boost converter uses an internal synchronous rectifier to obtain maximum efficiency. A low-EMI mode is implemented to reduce ringing and in effect lower radiated electromagnetic energy when the converter enters the discontinuous conduction mode. VIN Start Up Voltage: 0.9V Output Voltage Range: from 2.7V to 5.25V. Up to 94% Efficiency 1.2MHz Fixed Frequency Switching Built-in current mode compensation Built-in Protection: Over Current, Over Voltage, Over Temperature Optional Automatic PWM/PSM Version (AIC3413) and Forced PWM Version (AIC3413A). Logic Controlled Shutdown: < 1μA Output Disconnect by Shutdown Function Built-in Soft Start Active Anti-ringing Control Small SOT-23-6 Package APPLICATIONS Single/Dual Cells Ni-Cd/Ni-Mh/Li-Lon Type Battery Operated Products Wireless Mice PDA Digital Still Cameras Portable Equipment TYPICAL APPLICATION CIRCUITS L1 4.7uH 1.2V VIN U1 6 VIN 4 CIN 4.7uF SHDN 2 GND AIC3413 Analog Integrations Corporation SW VOUT FB 1 3.3V 5 3 VOUT R1 1M R2 600K Si-Soft Research Center COUT 4.7uF DS-3413G-P08 20110128 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 1 AIC3413 ORDERING INFORMATION PIN CONFIGURATION AIC3413XXXXXX PACKING TYPE TR: TAPE & REEL BG: BAG SOT-23-6 TOP VIEW VIN 6 PACKAGE TYPE G6: SOT-23-6 5 4 AIC3413/3413 1 SW G: Green Package Default: Automatic PWM/PSM A: Forced PWM VOUT SHDN 2 GND 3 FB Note: Pin1 is determined by orienting the package marking as shown. Example: AIC3413GG6TR Automatic PWM/PSM in SOT-23-6 Green Package and Tape & Reel Packing Type AIC3413AGG6TR Forced PWM in SOT-23-6 Green Package and Tape & Reel Packing Type ABSOLUTE MAXIMUM RATINGS Pins Voltage: LX, FB, EN, OUT, VIN Operating Ambient Temperature Range TA Operating Maximum Junction Temperature TJ Storage Temperature Range TSTG -0.3 V to 6V -40C to 85C 150C -65C to 125C Lead Temperature (Soldering 10 Sec.) 260C Thermal Resistance (Junction to Case) 115C/W Thermal Resistance (Junction to Ambient) 250C/W (Assume no Ambient Airflow, no Heatsink) Absolute Maximum Ratings are those values beyond which the life of a device may be impaired. 2 AIC3413 ELECTRICAL CHARACTERISTICS (Typical application circuit, and the ambient temperature=25C, VIN=1.2V, VOUT=3.3V, Unless otherwise specified) (Note1) PARAMETER TEST CONDITION SYMBOL MIN Output Voltage Range IOUT=0A VOUT 2.7 Minimum Start Up Voltage TYP MAX UNIT 5.25 1.1 V 0.9 0.5 V Minimum Operation Voltage Note2 Quiescent Current AIC3413 only IQ0 40 (VFB>1.23V, Non-Switching) AIC3413A only IQ0 250 Shut Down Current SHDN= 0V, (Oscillator no switching) VIN =1.1V ISD 0.3 1 μA Feedback Voltage IOUT=0 VFB 1.2 1.23 V FB Input Leakage Current VFB=1.3V IFB 1 50 nA Maximum Duty Cycle VFB=1.15V Minimum Duty Cycle VFB=1.3V 1.17 80 0.95 Frequency V 60 μA μA 88 % 0 % 1.2 1.5 MHz NMOS Switch Leakage VSW=5V 0.1 10 μA PMOS Switch Leakage VSW=5V, VOUT=0V 0.1 10 μA NMOS Switch On Resistance 350 m PMOS Switch On Resistance 450 m 0.88 SHDN High Threshold Voltage V SHDN Low Threshold Voltage SHDN Input Current SHDN= 5.25V 0.01 ISHDN 0.6 0.25 V 1.0 μA 0.9 A Over Temperature Protection 150 C Over Temperature Hysteresis 25 C NMOS Current Limit Setting Note 1: Specifications are production tested at T =25°C. Specifications over the -40°C to 85°C operating temA perature range are assured by design, characterization and correlation with Statistical Quality Controls (SQC). Note 2: Once the output is started, the IC is not dependant upon the VIN supply. 3 AIC3413 TYPICAL PERFORMANCE CHARACTERISTICS VOUT=3.3V Fig. 1 Efficiency vs. Output Current Fig. 3 Maximum Output Current vs. Supply Voltage Fig. 5 Quiescent Current vs. Supply Voltage VOUT=5.0V Fig. 2 Efficiency vs. Output Current Fig. 4 No load Battery Current vs. Supply Voltage Fig. 6 Output Voltage vs. Output Current 4 AIC3413 TYPICAL PERFORMANCE CHARACTERISTICS (Continued) Fig. 7 Frequency vs. Supply Voltage Fig. 9 Output Voltage vs. Temperature Fig. 11 Feedback Voltage vs. Temperature Fig.8 Minimum Start-up Voltage vs. Output current Fig. 10 Frequency vs. Temperature Fig. 12 Start-up Voltage Waveform 5 AIC3413 TYPICAL PERFORMANCE CHARACTERISTICS (Continued) Fig. 13 PSM Mode Operation at IOUT=0mA Fig.14 Anti-Ringing Operation at IOUT=10mA Fig.15 CCM Switching Waveform at IOUT=50mA Fig. 16 Load Transient Response Fig. 17 CCM Switching Waveform at IOUT =350mA Fig. 18 CCM Switching Waveform at IOUT =400mA 6 AIC3413 BLOCK DIAGRAM PIN DESCRIPTIONS PIN 1: SW - Power Switch Pin. This pin is tied PIN 4: SHDN - Shutdown Signal Input. Logic high to the drains of the PMOS syn- enables the IC. Logic low disables chronous rectifier and the NMOS the IC. Shutdown current is <1A. switch. PIN 2: GND - I/O Control/logic ground. PIN 3: FB - Output reference voltage is typically 1.2V PIN 5: VOUT- Power Output Pin. This pin is tied to the source of the PMOS synchronous rectifier. PIN 6: VIN - Power Supply Input. Must be closely decoupled to GND with a 4.7μF or greater ceramic capacitor. 7 AIC3413 APPLICATION INFORMATION The AIC3413 is a synchronous step-up DC-DC con- Device Shutdown verter. It is based on a slope compensated current When SHDN is set logic high, the AIC3413 is put into mode PWM control topology. It operates at a fixed active mode operation. If SHDN is set logic low, the frequency of 1.2MHz. At the beginning of each clock device is put into shutdown mode and consumes less cycle, the main switch (NMOS) is turned on and the than 1μA of current. At the shutdown mode, the syn- inductor current starts to ramp. After the maximum chronous switch will turn off and the output voltage of duty cycle or the sense current signal equals the error AIC3413 step-up converter will reduce to 0V.After amplifier (EA) output, the main switch is turned off and start-up, the internal circuitry is supplied by VOUT, the synchronous switch (PMOS) is turned on. The de- however, if shutdown mode is enabled, the internal vice can operate with an input voltage below 1V; the circuitry will be supplied by the input source again. typical start-up voltage is 0.9V. Adjustable Output Voltage Current Limit An external resistor divider is used to set the output The over current protection is to limit the switch current. voltage. The output voltage of the switching regulator The output Voltage will be dropped when over current (VOUT) is determined by the following equation: R VOUT VFB 1 1 R2 is happened. The current limit amplifier will shut the N-MOS switch off once the current exceeds its threshold. The current amplifier delay to output is about 100 Where VFB is 1.2V reference voltage. nS. Input Inductor Selection Anti-Ringing Control The inductor value determines the ripple current. The An anti-ringing circuitry is included to remove the high approximate ripple current and inductance value are frequency ringing that appears on the SW pin when the measured by the following equations: inductor current goes to zero. In this case, a ringing on ΔIL = the SW pin is induced due to remaining energy stored in parasitic components of switch and inductor. The anti-ringing circuitry clamps the voltage internally to the Where VIN D L × FSW ΔIL = inductor ripple current FSW = switch frequency battery voltage and therefore dampens this ringing. D = duty cycle, (VOUT- VIN)/ VOUT Where ΔIL is inductor ripple current, FSW is switch Zero Current Comparator frequency and D is the duty cycle. Increasing the value The zero current comparator monitors the inductor of inductance will reduce the output ripple current and current to the output and shuts off the synchronous ripple voltage. rectifier once the current is below 20 mA, This prevents the inductor current from reversing in polarity improv- Input Capacitor Selection ing efficiency at light loads. Surfaces mount 4.7μF or greater, X5R or X7R, ceramic 8 AIC3413 capacitor is suggested for the input capacitor. The in- pacitor range provides sufficient bulk capacitance to put capacitor provides a low impedance loop for the stabilize the output voltage during large load transitions edges of pulsed current drawn by the AIC3413. Low and has the low ESR and ESL characteristics neces- ESR/ESL X7R and X5R ceramic capacitors are ideal sary for low output voltage ripple. for this function. To minimize stray inductance, the capacitor should be placed as close as possible to the IC. PCB Layout Guidance This keeps the high frequency content of the input The AIC3413 typically operates at 1.2MHz. This is a current localized, minimizing EMI and input voltage considerably high frequency for DC-DC converters. ripple. Always examine the ceramic capacitor DC volt- PCB layout is important to guarantee satisfactory per- age coefficient characteristics to get the proper value. formance. It is recommended to make traces of the power loop, especially where the switching node is Output Capacitor Selection involved, as short and wide as possible. First of all, the The output capacitor limits the output ripple and pro- inductor, input and output capacitor should be as close vides holdup during large load transitions. A 4.7μF to as possible to the device. Feedback and shutdown 10μF, X5R or X7R, ceramic capacitor is suggested for circuits should avoid the proximity of large AC signals the output capacitor. Typically the recommended ca- involving the power inductor and switching node. APPLICATION CIRCUITS L1 VIN U1 6 VIN *D1 SW VOUT 1 SW1 4 CIN SHDN VOUT 5 R1 2 GND AIC3413 FB *C1 3 COUT R2 *Note: Efficiency can boost if D1 is connected. Fig.19 AIC3413 Application Circuit. 9 AIC3413 PHYSICAL DIMENSIONS SOT-23-6 A A E E1 D e e1 SEE VIEW B WITH PLATING c A A2 b S Y M B O L SECTION A-A A1 BASE METAL 0.25 A GAUGE PLANE SEATING PLANE L L1 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. SOT-23-6 MILLIMETERS MIN. MAX. 0.95 1.45 A1 0.00 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 L1 θ 0.60 0.30 0.60 REF 0° 8° 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. 10