INTRODUCTION FEATURES

Transcription

1 Adjustable High Output Voltage High Efficiency Step-Up DC/DCC Converter INTRODUCTION The is a CMOS step-up switching DC/DC converter, which allows the duty ratio to be automatically switched according to the FEATURES Low volt voltage at 0.8V Duty rat tage operation: Oscillation start tio: 50/75%, built-in auto switching load (light load: 50%, highh output current: Externa l parts: Coil, capacitor, diode, NMOS 75%) ), enabling products with a low ripple over a wide range, high efficiency, and high output current. With the, a step-up switching DC/DC converte can be configured by using an external coil, capacitor, diode and NMOS. This feature, along with the mini package and low current consumption, makes the High eff Output v Providin Power Switches Zero Sh 6µA Qu Current iciency:85%(typ.) voltage Adjustable ng Flexibility for Using External hutdown Mode Supply Current iescent (Switch-off) Supply ideal for applications such as the power Small S OT-23-5,SOT-89-5 Package supply unit of portable equipment. APPLICATIONS P D PDA DSC LCD Panel R RF-Tags Portable Instrument Wireless Equipment BLOCK DIAGRAM ODERING INFORMATION DESIGNATOR SYMBOL A B Integer M P DESCRIPTION Output Voltage Adj, EXT Output Voltage Adj, EXT, EN FB, Voltage EXP: V FB =1.25V, Number125 EXP: V FB =3.3V,Number nothing Package:SOT-23-5 Package:SOT-89-5 V2.5 1(10)

2 PIN CONFIGURATION PIN NUMBER PIN (SOT-23-5) NAME A B FUNCTION 1 1 FB Feedback Input Pin 2 2 V DD IC power supply pin - 3 EN Chip Enable (Active High) 3 - NC No Connection 4 4 V SS Ground 5 5 EXT External transistor connection pin PIN NUMBER PIN (SOT-89-5) NAME A B FUNCTION - 1 EN Chip Enable (Active High) 1 - NC No Connection 2 2 V DD IC power supply pin 3 3 FB Feedback Input Pin 4 4 EXT External transistor connection pin 5 5 V SS Ground ABSOLUTE MAXIMUM RATINGS (Unless otherwise specified, Ta= 25 ) PARAMETER SYMBOL RATINGS UNITS VDD pin voltage V DD V SS -0.3 ~ V SS +8 V EN pin voltage EN V SS -0.3 ~ V SS +8 V Power SOT mw PD dissipation SOT mw Operating temperature T opr -40 ~+85 Storage temperature T stg -40 ~+125 Soldering Temperature & Time T solder 260, 10s V2.5 2(10)

3 ELECTRICAL CHARACTERISTICS (Unless otherwise specified, Ta = 25 ) PARAMETER SYMBOL CONDTIONS MIN TYP MAX UNITS Feedback Voltage V FB - V FB(s) 0.98 V FB V FB(s) 1.02 Input voltage V IN V Oscillation start voltage Current consumption 1 V ST I SS1 No external parts, voltage applied to V OUT LX pulled up to V OUT via 300Ω resistor VDD=5V, FB=V SS, Continuously Switching V 0.8 V µa Current consumption 2 I SS2 VDD=5V, FB=V DD, No Switching µa Shutdown Current I SSS V DD =5V,V EN =0 V µa Line regulation V OUT1 V IN = 0.4 V OUT ~0.6 V OUT (V OUT =5V) mv Load regulation V OUT2 I OUT = 10 µa ~ 50mA(V OUT =5V) mv Oscillation frequency f OSC 100 KHz Duty ratio 1 Duty ratio 2 Duty1 Duty2 V OUT = 0.95 V OUT, measure waveform at LX pin Measure waveform at LX pin with light load % % Efficiency EFFI 85 % Shutdown pin input voltage Shutdown pin input current V SH V SL1 V OUT =0.95 V OUT, judge oscillation at EXT pin V OUT = 0.95 V OUT, judge stop at EXT pin V V I SH V EN =8V µa I SL V EN =0V µa Remark:1 V IN =V OUT(S) 0.6 applied, I OUT = V OUT(S) / 250 Ω 2 Shutdown function built-in type: EN pin is connected to V OUT 3 V OUT(S) specified above is the set output voltage value, and V OUT is the typical value of the actual output voltage. V2.5 3(10)

4 STANDARD CIRCUITS Component: Inductor:22uH(Sumida) Diode:IN5817 IN5819 Capacitor:47uF (Tantalum type) MOS:CE2312 XP151 XP161 R FB :Set up so that R FB1 /R FB2 =(V OUT -V FB )/V FB (V OUT =set-up output voltage), Please use with R FB1 +R FB2 2M Ω C FB :Set up that Fzfb=1/(2 π C FB R FB1 ) is within the Adjustments necessary in respect of L,C L. 1 Circuits 1:(3V V IN 8V) 2 Circuits 2:(V IN 3V) 3 Circuits 3:(V IN 8V) NOTE: Pin VDD can be connected to some other power supply (3V~8V) V2.5 4(10)

5 TYPICAL PERFORMANCE CHARACTERISTICS 1. V OUT vs. I OUT :(V OUT =5.5V) 2. Efficiency vs. I OUT :(V OUT =5.5V) V2.5 5(10)

6 3. V OUT vs. I OUT :(V OUT =12V) 4. Efficiency vs. I OUT :(V OUT =12V) V2.5 6(10)

7 5. V OUT vs. I OUT :(V OUT =18V) 6. Efficiency vs. I OUT :(V OUT =18V) V2.5 7(10)

8 Package information SOT Symbol Dimensions In Millimeters Dimensions In Inches Min Max Min Max A A A b c D E E e 0.950(BSC) 0.037(BSC) e L θ V2.5 8(10)

9 SOT Symbol Dimensions in Millimeters Min TYP Max A b b b C D E 4.25 E e L 0.80 V2.5 9(10)

10 Nanjing Chipower Electronics Inc. Chipower cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Chipower product. No circuit patent license, copyrights or other intellectual property rights are implied. Chipower reserves the right to make changes to their products or specifications without notice. Customers are advised to obtain the latest version of relevant information to verify, before placing orders, that information being relied on is current and complete. V2.5 10(10)