PWM Controlled, Step-up DC/DC Converter in Tiny Package

1 1 FP6731fitipower integrated technology lnc. PWM Controlled, Step-up DC/DC Converter in tiny Package Pin Assignments S3 Package (SOT-23-3) S5 Package (SOT-23-5) 21345 CEVOUTNCVSSLX Figure 2. Pin Assignment of FP6731 Ordering Information SOT-23-3 Marking Part Number Product Code FP6731-30S3G T8= SOT-23-5 Marking Part Number Product Code FP6731-32S5G aX= Description The FP6731 is a high efficiency PWM DC/DC step -up Converter with internally compensated current mode controller. The 250kHz switching frequency minimizes the size of external components. The output voltage is internally set and a 1A switch is built in the IC. The FP6731 starts up below 1V input voltage with 1mA load. Due to built-in automatic PWM/PFM switch-over function, the FP6731 is able to get high efficiency during both light and heavy load.

2 The built-in current limit and thermal protection function protect the device in any over-load or over-temperature situation. The FP6731 is available in a SOT-23-3 and SOT-23-5 packages . Features (typ.) Low Start-up Voltage with 1mA Load Fixed / output Voltage 250kHz Switching Frequency Automatic PFM Mode at Light Load Low Ripple and High Efficiency Excellent Line/Load Regulation Chip Enable Control Function Current Limit Protection Thermal Overload Protection Space Saving Package : SOT-23-5 and SOT-23-3 Applications PDA MP3 DSC RF Tags Wireless Equipments Portable Equipments FP6731- G: Green TR: Tape/Real Package Type S3: SOT-23-3 S5: SOT-23-5 Output Voltage 30: 32: 2 FP6731fitipower integrated technology lnc.

3 Typical Application Circuit Figure 2. Typical Application Circuit of FP6731 Functional Pin Description Pin Name Pin Function CE Chip Enable pin H : Normal operation ( Step-up operating) L : Switch stopped (Entire circuit off) VOUT Output voltage pin and IC power supply pin NC No connection VSS Ground pin LX External inductor connection pin 3 FP6731fitipower integrated technology lnc. Block Diagram Figure 3. Block Diagram of FP6731 Absolute Maximum Ratings VOUT to GND------------------------------------- ---------------------------------------- -------------------- +6V LX, CE to GND------------------------------------- ---------------------------------------- ------------------ +6V Power Dissipation @TA=25 C, (PD) SOT-23-3 ---------------------------------------- ---------------------------------------- ------ + SOT-23-5 ---------------------------------------- ---------------------------------------- ------ + Package Thermal Resistance, ( JA)

4 SOT-23-3 ---------------------------------------- ---------------------------------------- ------ + 250 C/W SOT-23-5-------------------------------- ---------------------------------------- --------------- +250 C/W Maximum Junction Temperature----------------------------- ---------------------------------------- ----- +150 C Storage Temperature Range (TSTG)---------------------------------- ------------------------------------ -65 C to +150 C Lead Temperature (Soldering, 10sec.) (TLEAD)--------------------------------- ----------------------- +260 C Note1 Stresses beyond those listed under Absolute Maximum Ratings" may cause permanent damage to the device. Recommended Operating Conditions Operating Voltage (VOUT)---------------------------------- ---------------------------------------- --------- + to + Operating Temperature Range (TOPR)---------------------------------- --------------------------------- -40 C to +85 C 4 FP6731fitipower integrated technology lnc.

5 Electrical Characteristics (TA=25 C, unless otherwise specified.) Parameter Symbol Test Conditions Min Typ Output Voltage VOUT(S) Start-up Voltage VSTART VIN : 0 1V, IOUT=1mA No-Load Input Current INO_LOAD VIN= , VOUT= 75 A Continuous Switching CurrentISWITCH VOUT=VCE = VOUT(S) * mA Shutdown Current IOFF VOUT= , VCE=0V A LX ON Resistance (Note2) RDS-ON VIN= , VOUT= Max.

6 Duty Ratio DUTY VOUT=VCE = VOUT(S) * 85 95 % Oscillator Frequency fOSC VOUT=VCE= VOUT(S) * 250 kHz LX Leakage Current ILXL VLX=6V, VCE=0V, VOUT= A Line Regulation VLINE VIN= ~ , IL=15mA 15 30 mV Load Regulation VLOAD VIN= , IL=10 A~15mA 15 30 mV Current Limit (Note2) ILIMIT VIN= , VOUT= 1 A CE High Voltage VCEH VDD= , switch ON V CE Low Voltage VCEL VDD= , switch OFF V CE High Current ICEH VOUT = , VCE=VOUT A CE Low Current ICEL VOUT = , VCE=0V A Efficiency (Note2)

7 85 % TSD 145 C Thermal Shutdown Threshold (Note2) TSD Hysteresis 30 C Note2: Guarantee by design 5 FP6731fitipower integrated technology lnc. Typical Performance Curves CE Pin Trip Level(V)VOUT pin Operation Voltage (V)-40-20 0 Pin Trip Level (V)Temperature(OC) Figure 4. Operation Voltage vs. CE Pin Trip Level Figure 5.

8 Temperature vs. CE Pin Trip Level -100010020030040050060070080065707580859 0 VIN= (%)Output Current (mA)VIN= 0 20406080100707580859095 VIN= (%)IOUT Figure 6. Efficiency (VOUT= ) Figure 7. Efficiency (VOUT= ) Output Voltage (V)Output Current (mA)VIN= (V)VIN (V)IOUT=50mA Figure 8. Load Regulation (VOUT= ) Figure 9. Line Regulation (VOUT= ) 6 FP6731fitipower integrated technology lnc. Typical Performance Curves (Continued) -40-20 0 Start Voltage (V)Temperature(OC)no load -40-20 0 Switch Current (mA)Tempurature (OC) Figure 10. Temperature vs. Oscillator Start Voltage Figure 11. Temperature vs. Switch current (V)Tempurature (OC)IOUT=10mA -40-20 0 204060801012141618202224 Quiescent Current (uA)Temperture. (OC) Figure 12. Temperature vs. Output Voltage Fi gure 13. Temperature vs.

9 Quiescent Current -40-20 0 20406080230235240245250255260265270 Frequency (KHz)Tempurature (OC) Figure 14. Temperature vs. Frequency 7 FP6731fitipower integrated technology lnc. Typical Performance Curves (Continued) Figure 15. Output Waveform, VIN= , IOUT=10mA Figure 16. Output Waveform, VIN= , IOUT=50mA Figure 17. Output Waveform, VIN= , IOUT=100mA Figure 18. Power-on Response, VIN=0 , IOUT=50mA Figure 19. CE Pin Enable Response VIN= , VCE=0V , IOUT=50mA Figure 20. Load Transient Waveform VIN= , IOUT= 50mA VLX VOUT VLX VOUT VLX VOUT VOUT VIN VLX VCE IOUT VOUT 8 FP6731fitipower integrated technology lnc. Application Information Operation The FP6731 is designed in a current mode PFM/PWM scheme which features an automatic switch PFM/PWM mode to maintain the highest efficiency and extend battery life.

10 The quiescent current is less than 25uA at no switching status. The control loop is internally compensated reducing the amount of external components. Chip Enable The FP6731 features a chip enable input pin that allows CE control the Converter . When CE=Low, shutdown of the chip occurs and at that time almost no quiescent current (<1uA) flows. The chip enable input is TTL/CMOS compatible. Connect CE to battery for normal operation. Current Limit Protection The FP6731 provides cycle-by-cycle over-current protection. Current limit is accomplished by sensing voltage drop across the drain to source of power switch. If the current sense amplifier output voltage is larger than current-limited threshold level (typ. ), it will be immediately turned off power MOS.