Advanced Power Electronics Corp. APE2902 MICROPOWER VFM STEP-UP DC/DC CONVERTER FEATURES DESCRIPTION The APE2902 is a high efficiency VFM Step-up DC/DC converter for small, low input voltage or battery powered systems with ultra low quiescent supply current. The APE2902 accept a positive input voltage from start-up voltage to VOUT and convert it to a higher output voltage in the 2.5 to 5V range. The APE2902 combine ultra low quiescent supply current and high efficiency to give maximum battery life. The high switching frequency and the internally limited peak inductor current permits the use of small, low cost inductors. Only three external components are needed an inductor a diode and an output capacitor. The APE2902 is suitable to be used in battery powered equipment where low noise, low ripple and ultra low supply current are required. Operating shutdown function is outside controlling. If EN connects to GND, the IC was been shut down and then the supply current is lower to 1uA.The APE2902 is available in very small package: SOT-23-5L. Typical applications are pagers, cameras & video camera, cellular telephones, wireless telephones, palmtop computer, battery backup supplies, battery powered equipment. Very Low Supply Current is 22uA (typ.) Maximum Shutdown Current <1uA Output Voltage is Available form 2.5V to 5.0V by 0.1V Steps Output Voltage Accuracy ±5% Output Current up to 100mA Low Ripple and Low Noise Very Low Start-up Voltage High Efficiency (Vout = 5V TYP. 87%) Few External Components Internal Soft-Start Low Profile: SOT-23-5L Pb-Free TYPICAL APPLICATION VIN 1 L1 D1 B140 2 1 VOUT 2 47uH C1 100uF C2 0.1uF U1 NC EN Enable Input SW GND OUT C4 C3 47uF 0.1uF APE2902 ORDER/MARKING INFORMATION APE2902XX-XX Vout Package Type 22 : 2.2V Y5 : SOT-23-5L 25 : 2.5V Y5R : SOT-23-5L 26 : 2.6V 27 : 2.7V : : 50 : 5.0V Data and specifications subject to change without notice t&XYW WW : 01~26(A~Z) 27~52(A~Z) Year : 8 = 2008 A = 2010 Identification Code Identification Code see page8. 1 200907313 Advanced Power Electronics Corp. APE2902 ABSOLUTE MAXIMUM RATINGS (TA= 25 C) o VIN Supply Voltage(VIN) …………………………… 5.5 V SW Voltage(VSW ) …………………………………… 5.5 V OUT Voltage(VOUT) ………………………………… 5.5 V EN Pin Voltage(VEN) ………………………………… 5.5 V Power Dissipation(PD) ……………………………… ( TJ-TA ) / Rthja W Storage Temperature Range(TST) ………………… -40°C To 150°C Operating Junction Temperature Range(TOP) …… -20°C To + 100°C Thermal Resistance from Junction to Case(RthJC) 110°C/W Thermal Resistance from Junction to Ambient(Rth JA) 250°C/W Note : Rth JA is measured with the PCB copper area of approximately 1 in2(Multi-layer). PACKAGE INFORMATION Top View NC EN 5 4 Top View GND SW 5 4 AP2902Y5 AP2902Y5R 1 1 2 3 2 3 SW GND VOUT EN VOUT NC SOT-23-5L SOT-23-5L ELECTRICAL SPECIFICATIONS ( VIN=1.8V, IOUT=10mA, TA=25 oC, unless otherwise specified) Parameter Output Voltage Accuracy Start-up Voltage(VIN-VF)(Note 1) SYM TEST CONDITION △VOUT MIN TYP MAX UNITS -5 - 5 % VSTART-UP IOUT=1mA, VIN =rising from 0 to 2V - 0.8 1.2 V Hold-on Voltage VHOLD IOUT=1mA, VIN =falling from 2 to 0V 0.6 - - V Supply Current ISUPPLY No Load - 22 - uA ISD VEN=0V - - 1 uA ISW =150mA - 850 - mΩ VSW =4V, Forced VOUT=3.8V - - 0.5 uA - 150 - KHz - 77 - % Shutdown Current Internal Switch RDSON Internal Leakage Current RSW(DSON) ISW(leak) Maximum Oscillator Frequency FOSC Oscillator Duty On DON To be measured on SW pin VENH Driver ON 0.75 - - VENL Driver OFF - - 0.2 IENH VEN=VIN - - 0.1 IENL VEN=0V - - -0.1 Vout=2.5V~3.0V, IOUT=50mA - 82 - % Vout=3.1V~4.0V, IOUT=50mA - 83 - % Vout=4.1V~5.0V, IOUT=50mA - 87 - % Enable Input Threshold Enable Input Current EFFICIENCY η V uA Note 1: The minimum input voltage for the IC start-up is strictly a function of the VF catch diode. 2 Advanced Power Electronics Corp. APE2902 PIN DESCRIPTIONS PIN SYMBOL PIN DESCRIPTION Switch Pin. Connect External Inductor & Diode here. SW GND GND Pin OUT EN Output Voltage Chip Enable Pin BLOCK DIAGRAM + - OUT VREF SW LIMITER AMP. - + VFM CONTROL ERROR AMP. Driver Chip Enable GND EN OPERATION The APE2902 architecture is built around a VFM CONTROL logic core, switching frequency is set through a built in oscillator. TON time is fixed (Typ. 5uS) while TOFF time is determined by the error amplifier output, a logic signal coming from the comparison made by the Error Amplifier Stage between the signal coming from the output voltage divider network and the internal Band-Gap voltage reference (Vref). TOFF reaches a minimum (Typ. 1.7us) when heavy load conditions are met (Clock frequency 150KHz). An over current conditions, through the internal power switch, causes a voltage drop VSW=RDS(ON) x ISW and the VSW limiter block forces the internal switch to be off, so narrowing TON time and limiting internal power dissipation. In this case the switching frequency may be higher than the 150KHz set by the internal clock generator. VFM control ensures very low quiescent current and high conversion efficiency even with very light loads. Since the Output Voltage pin is also used as the device Supply Voltage, the versions with higher output voltage present an higher internal supply voltage that results in lower power switch RDS(ON), slightly greater output power and higher efficiency. Moreover, bootstrapping allows the input voltage to sag to 0.6V (at IOUT=1mA) once the system is started. If the input voltage exceeds the output voltage, the output will follow the input, however, the input or output voltage must not be forced above 5.5V. 3 Advanced Power Electronics Corp. APE2902 APPLICATION INFORMATION Input/Output Capacitor Selection The Output Ripple Voltage, as well as the Efficiency, is strictly related to the behavior of these elements. The output ripple voltage is the product of the peak inductor current and the output capacitor Equivalent Series Resistance (ESR). Best performances are obtained with good high frequency characteristics capacitors and low ESR. The best compromise for the value of the Output Capacitance is 47µF Tantalum Capacitor; Lower values may cause higher Output Ripple Voltage and lower Efficiency without compromising the functionality of the device. An Input Capacitor is required to compensate, if present, the series impedance between the Supply Voltage Source and the Input Voltage of the Application. Inductor Selection A 47µH inductor is recommended for most APE2902 applications. However, the inductance value is not critical, and the APE2902 will work with inductors in the 33µH to 120µH. Diode Selection Schottky diodes with higher current ratings usually have lower forward voltage drop, larger diode capacitance and fast reverse recovery, it is the ideal choices for APE2902 applications. The forward voltage drop of a Schottky diode represents the conduction losses in the system, while the diode capacitance (CT or CD) represents the switching losses. For diode selection, both forward voltage drop and diode capacitance need to be considered. PCB layout guide When laying out the PC board, the following suggestions should be taken to ensure proper operation of the APE2902. These items are also illustrated graphically in below. 1. The power traces, including the GND trace, the SW trace and the VIN trace should be kept short, direct and wide to allow large current flow. Put enough multiply-layer pads when they need to change the trace layer. 2. Do not trace signal line under inductor. 4 Advanced Power Electronics Corp. APE2902 TYPICAL PERFORMANCE CHARACTERISTICS IOUT=50mA, Output Voltage vs. Temperature TA=25℃ , Input Voltage vs. Output Voltage 3.05 3.50 VIN=2.4V 2.50 VIN=0.9V VIN=1.8V VIN=1.2V VIN=1.5 2.00 1.50 1.00 3.00 Output Vlotage (V) Output Voltage (V) 3.00 VIN=2.4V VIN=1.8V VIN=1.2V 2.95 2.90 2.85 0.50 3.10 1.0 3.00 0.9 10 0 0.1 0.0 1 50 25 0 2.30 0.3 0.2 10 0 2.40 75 IOUT=150mA IOUT=200mA IOUT=250mA Temperature (℃ ) 10 0 2.50 0.4 75 IOUT=100mA 0.5 50 IOUT=0mA 2.60 0.6 25 IOUT=50mA 2.70 0.7 10 2.80 Start-up Vlotage (V) 0.8 2.90 -2 0 75 Start-up Voltage vs. Output Current VIN=1.8V, Output Voltage vs. Temperature Output Current (mA) IOUT=1mA, Start-up Voltage vs. Temperature IOUT=1mA, Hold-On Voltage vs. Temperature 1.0 0.4 0.9 0.4 Hold-On Vlotage (V) 0.8 0.7 0.6 0.5 0.4 0.3 0.3 0.3 0.2 0.2 0.1 0.2 0.1 0.1 10 0 75 50 0 10 0 75 50 0 -2 0 25 Temperature (℃) -2 0 0.0 0.0 25 Output Vlotage (V) 50 Temperature (℃ ) Output Current (m A) Start-up Vlotage (V) 25 -2 0 25 0 22 5 20 0 17 5 15 0 12 5 10 0 75 50 25 10 0 0 2.80 0.00 Temperature (℃ ) 5 Advanced Power Electronics Corp. APE2902 TYPICAL PERFORMANCE CHARACTERISTICS Input Voltage vs. Supply Current Supply Current vs. Temperature 50 800 45 700 VIN=1.2V 35 30 APE2902-33 APE2902-30 25 20 15 APE2902-28 Supply Current (uA) 600 500 400 VIN=1.5V 300 VIN=1.8V 200 10 100 5 VIN=2.4V Maximum Oscillator Frequency vs. Temperature 90 160 80 60 40 40 30 20 75 10 0 -2 0 0 50 10 0 25 20 0 10 0 50 Temperature (℃ ) 10 0 80 60 75 100 70 50 120 25 140 0 Oscillator Duty-On (%) 100 180 Temperature (℃ ) APE2902-30, IOUT=50mA, Efficiency vs. Temperature APE2902-30, Efficiency vs. Output Current 90 90 VIN=2.4V 88 70 VIN=1.8 86 60 VIN=0.9V 50 VIN=1.2V Efficiency (%) 80 VIN=1.5V 40 30 VIN=2.4V VIN=1.8V 84 82 VIN=1.2V 80 Output Current (mA) 75 50 25 -2 0 25 0 22 5 20 0 17 5 15 0 12 5 10 0 74 75 76 0 50 10 0 78 20 25 75 Oscillator Duty-On vs. Temperature 200 -2 0 Maximum Oscillator Frequency (KHz) 50 Temperature (℃ ) Input Voltage (V) Efficiency (%) 25 -2 0 2. 4 1. 8 1. 5 1. 2 0 0 0 10 0 Supply Current (uA) 40 Temperature (℃ ) 6 Advanced Power Electronics Corp. APE2902 TYPICAL PERFORMANCE CHARACTERISTICS SW Switching Current Limit vs. Temperature VIN=1.8V, Efficiency vs. Temperature 90 900 IOUT=100mA IOUT=150mA 75 IOUT=200mA 70 IOUT=250mA 65 60 55 50 880 860 840 820 800 780 760 Temperature (℃ ) Enable Off Sequence 10 0 75 50 25 0 10 0 75 50 25 0 -2 0 740 -2 0 Efficiency (%) 80 SW Switching Current Limit (mA) IOUT=50mA 85 Temperature (℃ ) Enable On Sequence VIN VIN VOUT VOUT SW SW VEN VEN VIN=1.8V, VOUT=2.8V, IOUT=10mA, EN=5 to 0V VIN=1.8V, VOUT=2.8V, IOUT=10mA, EN=0 to 5V Ch1: VIN, 1V/div Ch1: VIN, 1V/div Ch2: VOUT, 1V/div Ch2: VOUT, 1V/div Ch3: VSW, 2V/div Ch3: VSW, 2V/div Ch4: VEN, 5V/div Ch4: VEN, 5V/div 7 ADVANCED POWER ELECTRONICS CORP. Package Outline : SOT-23-5L Millimeters SYMBOLS MIN NOM MAX A 1.00 1.10 1.30 A1 0.00 --- 0.10 A2 0.70 0.80 0.90 b 0.35 0.40 0.50 C 0.10 0.15 0.25 D 2.70 2.90 3.10 E 1.50 1.60 1.80 e --- 1.90(TYP) --- H 2.60 2.80 3.00 L 0.37 --- --- θ1 1° 5° 9° e2 --- 0.95(TYP) --- Note 1：Package Body Sizes Exclude Mold Flash Protrusions or Gate Burrs. Note 2：Tolerance ± 0.1000 mm(4mil) Unless Otherwise Spe- cified. Note 3：Coplanarity：0.1000 mm Note 4：Dimension L Is Measured in Gage plane. Part Marking Information & Packing : SOT-23 -5L Part Number : t&X (Identification Code) Date Code t&XSS Part Number Identificatio n Code Part Number Identificatio n Code APE2902Y5/Y5R-2.2V tO/tO1 APE2902Y5/Y5R-3.8V tn/tn1 APE2902Y5/Y5R-2.5V ta/ta1 APE2902Y5/Y5R-3.9V to/to1 APE2902Y5/Y5R-2.6V tb/tb1 APE2902Y5/Y5R-4.0V tp/tp1 APE2902Y5/Y5R-2.7V tc/tc1 APE2902Y5/Y5R-4.1V tq/tq1 APE2902Y5/Y5R-2.8V td/td1 APE2902Y5/Y5R-4.2V tr/tr1 APE2902Y5/Y5R-2.9V te/te1 APE2902Y5/Y5R-4.3V ts/ts1 APE2902Y5/Y5R-3.0V tf/tf1 APE2902Y5/Y5R-4.4V tt/tt1 APE2902Y5/Y5R-3.1V tg/tg1 APE2902Y5/Y5R-4.5V tu/tu1 APE2902Y5/Y5R-3.2V th/th1 APE2902Y5/Y5R-4.6V tv/tv1 APE2902Y5/Y5R-3.3V ti/ti1 APE2902Y5/Y5R-4.7V tw/tw1 APE2902Y5/Y5R-3.4V tj/tj1 APE2902Y5/Y5R-4.8V tx/tx1 APE2902Y5/Y5R-3.5V tk/tk1 APE2902Y5/Y5R-4.9V ty/ty1 APE2902Y5/Y5R-3.6V tl/tl1 APE2902Y5/Y5R-5.0V tz/tz1 APE2902Y5/Y5R-3.7V tm/tm1 8