Advanced Power Electronics Corp. APE2903 Preliminary MICROPOWER VFM STEP-UP DC/DC CONVERTER FEATURES DESCRIPTION Very Low Supply Current Regulated Output Voltage Wide Range of Output Voltage is Available from 2.2V 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, SOT-89 & SOT-23-5L Pb-Free The APE2903 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 APE2903 accept a positive input voltage from start-up voltage to VOUT and convert it to a higher output voltage in the 2.2 to 5V range. The APE2903 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 APE2903 is suitable to be used in battery powered equipment where low noise, low ripple and ultra low supply current are required. The APE2903 is available in very small package: SOT-23, SOT-89 & SOT-23-5L. Typical applications are pagers, cameras & video camera, cellular telephones, wireless telephones, palmtop computer, battery backup supplies, battery powered equipment. TYPICAL APPLICATION L1 VIN 47uH C1 C4 C2 100uF 0.1uF Vout D1 B140 SW GND NC OUT APE2903 NC 0.1uF C3 47uF ORDERING INFORMATION APE2903X - XX Package Type Y5 : SOT-23-5L N : SOT-23 G : SOT-89 VOUT 22 : 2.2V 25 : 2.5V 26 : 2.6V 27 : 2.7V : 50 : 5.0V Data and specifications subject to change without notice 1 20110914pre Advanced Power Electronics Corp. APE2903 ABSOLUTE MAXIMUM RATINGS (TA= 25 o C) VIN Supply Voltage(VIN) ----------------------------------- 5.5 V SW Voltage(VSW ) -------------------------------------------- 5.5 V OUT Voltage(VOUT) ----------------------------------------- 5.5 V Power Dissipation(PD) ------------------------------------- ( TJ-TA ) / Rthja W Storage Temperature Range(T ST) ---------------------- -40°C To 150°C Operating Junction Temperature Range(T OP) ------- -20°C To + 100°C 2 Note. RthJA is measured with the PCB copper area of approximately 1 in (Multi-layer) that need connect to GND pin of the APE2903. PACKAGE INFORMATION Top View NC NC 5 4 SOT-89 SOT-23-5L 1 Top View Vout Tab is Vout 2 1 3 2 GND Vout SW SW GND VOUT o SOT-23 3 GND o Rthjc=110 C/W Rthja=250oC/W SW o Rthjc=100 C/W Rthjc=110 C/W Rthja=160oC/W Rthja=250oC/W ELECTRICAL SPECIFICATIONS ( VIN=1.8V, IOUT=10mA, TA=25 oC, unless otherwise specified) Parameter SYM OUTPUT VOLTAGE ACCURACY START-UP VOLTAGE(VIN-VF)(Note 1) HOLD-ON VOLTAGE SUPPLY CURRENT INTERNAL SWITCH R DSON MIN TYP MAX UNITS -5 - 5 % VSTART-UP IOUT=1mA, VIN =rising from 0 to 2V - 0.65 0.9 V VHOLD IOUT=1mA, VIN =falling from 2 to 0V 0.6 - - V ISUPPLY No Load - 19 - uA ILX=150mA - 850 - mΩ VLX=4V, Forced VOUT=3.8V - - 0.5 uA - 150 - KHz To be measure on SW pin - 77 - % Vout=2.2V~3.0V, IOUT=50mA - 82 - % Vout=3.1V~4.0V, IOUT=50mA - 83 - % Vout=4.1V~5.0V, IOUT=50mA - 87 - % △VOUT RLX(DSON INTERNAL LEAKAGE CURRNET ILX(leak MAXIMUM OSCILLATOR FREQUENCY FOSC OSCILLATOR DUTY ON DON EFFICIENCY TEST CONDITION η Note 1: The minimum input voltage for the IC start-up is strictly a function of the VF catch diode. PIN DESCRIPTIONS PIN SYMBOL SW PIN DESCRIPTION Switch Pin. Connect External Inductor & Diode here. GND GND Pin OUT Output Voltage 2 Advanced Power Electronics Corp. APE2903 BLOCK DIAGRAM + - OUT VREF SW LIMITER AMP. - + VFM CONTROL ERROR AMP. Driver GND OPERATION The APE2903 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 VLX=RDSON x ISW and the VLX 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 RDSON, 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. 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 47 µ H inductor is recommended for most APE2903 applications. However, the inductance value isnot critical, and the APE2903 will work with inductors in the 33 µ H to 120µH. 3 Advanced Power Electronics Corp. APE2903 APPLICATION INFORMATION 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 APE2903 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 APE2903. These items are also illustrated graphically in below. 1. The power traces, including the GND trace, the SW trace and the VCC 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. APE2903 MARKING INFORMATION SOT-23-5L Part Number : T&3 (see Identification Code) Identification Code Part Number Identification Code APE2903Y5-2.2V To3 APE2903Y5-3.8V TN3 APE2903Y5-2.5V TA3 APE2903Y5-3.9V TO3 APE2903Y5-2.6V TB3 APE2903Y5-4.0V TP3 APE2903Y5-2.7V TC3 APE2903Y5-4.1V TQ3 APE2903Y5-2.8V TD3 APE2903Y5-4.2V TR3 APE2903Y5-2.9V TE3 APE2903Y5-4.3V TS3 APE2903Y5-3.0V TH3 APE2903Y5-4.4V TT3 APE2903Y5-3.1V TG3 APE2903Y5-4.5V TU3 APE2903Y5-3.2V TF3 APE2903Y5-4.6V TV3 APE2903Y5-3.3V TI3 APE2903Y5-4.7V TW3 APE2903Y5-3.4V TJ3 APE2903Y5-4.8V TX3 APE2903Y5-3.5V TK3 APE2903Y5-4.9V TY3 APE2903Y5-3.6V TL3 APE2903Y5-5.0V TZ3 APE2903Y5-3.7V TM3 Part Number Identification Code Part Number Identification Code APE2903G-2.2V o APE2903G-3.8V N APE2903G-2.5V A APE2903G-3.9V O APE2903G-2.6V B APE2903G-4.0V P APE2903G-2.7V C APE2903G-4.1V Q APE2903G-2.8V D APE2903G-4.2V R APE2903G-2.9V E APE2903G-4.3V S APE2903G-3.0V H APE2903G-4.4V T APE2903G-3.1V G APE2903G-4.5V U APE2903G-3.2V F APE2903G-4.6V V APE2903G-3.3V I APE2903G-4.7V W APE2903G-3.4V J APE2903G-4.8V X APE2903G-3.5V K APE2903G-4.9V Y APE2903G-3.6V L APE2903G-5.0V Z APE2903G-3.7V M Identification Code Part Number Identification Code APE2903N-2.2V To3 APE2903N-3.8V TN3 APE2903N-2.5V TA3 APE2903N-3.9V TO3 APE2903N-2.6V TB3 APE2903N-4.0V TP3 APE2903N-2.7V TC3 APE2903N-4.1V TQ3 APE2903N-2.8V TD3 APE2903N-4.2V TR3 APE2903N-2.9V TE3 APE2903N-4.3V TS3 APE2903N-3.0V TH3 APE2903N-4.4V TT3 APE2903N-3.1V TG3 APE2903N-4.5V TU3 APE2903N-3.2V TF3 APE2903N-4.6V TV3 APE2903N-3.3V TI3 APE2903N-4.7V TW3 APE2903N-3.4V TJ3 APE2903N-4.8V TX3 APE2903N-3.5V TK3 APE2903N-4.9V TY3 APE2903N-3.6V TL3 APE2903N-5.0V TZ3 APE2903N-3.7V TM3 Part Number T&3SS Date Code : SS SS:2004,2008,2012… SS:2003,2007,2011… SS:2002,2006,2010… SS:2001,2005,2009… SOT-89 Part Number 2903& YWWS Output Voltage : (see Identification Code) Date Code (YWWS) Y : Year WW : Week S : Sequence SOT-23 Part Number : T&3 (see Identification Code) Part Number T&3SS Date Code : SS SS:2004,2008,2012… SS:2003,2007,2011… SS:2002,2006,2010… SS:2001,2005,2009… 5