ADVANCED INFORMATION ® SP6649 Ultra-low Quiescent Current, High Efficiency Boost DC-DC Regulator FEATURES ■ Ultra-low 12µA Quiescent Current ■ 700mA Output Current at 2.6VIN, 3.3VOUT ■ 94% Efficiency Possible ■ Wide Input Voltage Range: 0.85V to 4.5V ■ 3.3V Fixed Output and adjustable 2.5V to 5.0V Output Range ■ Internal Synchronous Rectifier for High Efficiency ■ 0.3 Charging Switch, 0.3 Synchronous Rectifier ■ Anti-Ringing Inductor Switch ■ Programmable Inductor Peak Current ■ Logic Shutdown Control ■ Under Voltage Lock-Out, 0.62V ■ Programmable Low Battery Detect ■ Small 10 pin MSOP Package VBATT 1 LBI 2 LBON 3 RLIM 4 SHDN Top View 10 pin MSOP 10 VOUT 9 LX 8 PGND 7 GND 6 FB Tja=113°C/W 5 APPLICATIONS ■ Digital Still Cameras ■ MP3 Players ■ PDA's ■ Pagers ■ Handheld Portable Devices ■ Medical Monitors DESCRIPTION The SP6649 is an ultra-low quiescent current, high efficiency step-up DC-DC converter ideal for single and dual cell alkaline, or Li-Ion battery applications such as digital still cameras, PDA’s, MP3 players, and other portable devices. The SP6649 combines the high delivery associated with PWM control, and the low quiescent current and excellent light-load efficiency of PFM control. The SP6649 features 12µA quiescent current, synchronous rectification, a 0.3 charging switch, anti-ringing inductor switch, programmable low battery detect, under-voltage lockout and programmable inductor peak current. The device can be controlled by a 1nA active LOW shutdown pin. VBATT L1 10uH + C1 3.3Vout 1 47uF LBI LBON 2 3 4 SHDN 5 VBATT LBI VOUT SP6649 LX LBON PGND RLIM GND SHDN FB 10 9 8 C4 1uF 7 R1 205K C3 + C2 47pF 47uF TBD 6 RLIM 1.87K R2 124K C1 = C2 = Kemet T49C476K010AS, L1 = Sumida CDRH5D28-100 R1 = 374K for 5VOUT Figure 1. Typical Application Circuit Rev:001 Date:11/20/03 Figure 2. Maximum Load Current in Operation SP6649 Ultra-low Quiescent Current, High Efficiency Boost DC-DC Regulator 1 © Copyright 2002 Sipex Corporation LX, Vo, VBATT , LBON, FB to GND pin ................................. -0.3 to 6.0V SHDN, LBI ............................................................ -0.3V to VBATT +0.5V Vo, GND, LX Current .................................................................... 1.3A Reverse VBATT Current ............................................................... 220mA Forward VBATT Current ............................................................... 500mA Storage Temperature .................................................. -65 °C to 150°C Operating Temperature ................................................ -40°C to +85°C Lead Temperature (Soldering, 10 sec) ....................................... 300 °C ESD Rating ........................................................................... 2kV HBM ABSOLUTE MAXIMUM RATINGS ADVANCED INFORMATION These are stress ratings only and functional operation of the device at these ratings or any other above those indicated in the operation sections of the specifications below is not implied. Exposure to absolute maximum rating conditions for extended periods of time may affect reliability. SPECIFICATIONS VBATT=VSHDN = 1.3V, VFB=0V, ILOAD = 0mA, TAMB= -40°C to +85°C, VOUT = +3.3V, typical values at 27°C unless otherwise noted. PARAMETER MIN Input Voltage Operating Range, VBATT 0.7 TYP MAX UNITS 4.5 V CONDITIONS After Startup Under Voltage Lock-out/UVLO 0.62 Start-up Input Voltage, VBATT 0.85 0.9 V RLOAD = 3k 3.30 3.44 V 3.3V VO preset Output Voltage, VO 3.16 V Quiescent Current into VO, IQO 12 22 µA VOUT = 3.3V, VFB = 1.5V, Toggle SHDN Quiescent Current into VBATT, IQB 20 500 nA VOUT = 3.3V, VFB = 1.5V Shutdown Current into VO, ISDO 1 500 nA VSHDN = 0V Shutdown Current into VBATT, ISDB 200 500 nA VSHDN = 0V, VBATT = 2.6V Efficiency, RLIM = 4.0K 85 91 % % VBATT = 1.3V, IOUT = 50mA VBATT = 2.6V, IOUT = 100mA Efficiency, RLIM = 1.87K 85 92 % % VBATT = 1.3V, IOUT = 100mA VBATT = 2.6V, IOUT = 200mA A RLIM = 1.17k , I Inductor Current Limit, IPK 1.0 1.2 1.4 PK = 1400/RLIM 250 700 mA mA VBATT = 1.3V, RLIM = 1.17k VBATT = 2.6V, RLIM = 1.17k 150 400 mA mA VBATT = 1.3V, RLIM = 1.87k VBATT = 2.6V, RLIM = 1.87k Minimum Off-Time Constant KOFF 1.1 V*µs tOFF K OFF / (VOUT- VBATT) Maximum On-Time Constant KON 3.3 V*µs tON K ON / VBATT NMOS Switch Resistance 0.30 0.6 PMOS Switch Resistance 0.30 0.6 1.25 1.30 V External feedback 1 100 nA VFB =1.3V 0.625 0.656 Output Current FB Set Voltage, VFB 1.20 FB Input Current LBI Falling Trip Voltage 0.594 LBI Hysteresis 25 INMOS = 100mA IPMOS = 100mA V mV Low Output Voltage for LBON, VOL 0.4 V Leakage current for LBON 500 nA SHDN Input Voltage SHDN Input Current VIL VIH VIL VIH 0.25 1.0 V 0.5 2.0 1 100 VBATT = 1.3V, Isink = 1mA VBATT = 1.3V, VLBON = 3.3V VBATT = 1.3V VBATT = 1.3V VBATT = 2.6V VBATT = 2.6V nA Rev:001 Date:11/20/03 SP6649 Ultra-low Quiescent Current, High Efficiency Boost DC-DC Regulator 2 © Copyright 2002 Sipex Corporation ADVANCED INFORMATION PIN DESCRIPTION PIN NUMBER PIN NAME 1 VBATT 2 LBI 3 LBON 4 RLIM Resistor Programmable Inductor Peak Current. By connecting a resistor RLIM from this pin to ground the inductor peak current is set by IPEAK=1400/RLIM. The range for RLIM is 4.0K (for 350mA) to 1.17K (for 1.2A). 5 SHDN Shutdown Not. Tie this pin to VBATT for normal operation. Tie this pin to ground to disable all circuitry inside the chip. In shutdown the output voltage will float down to a diode drop below the battery potential. 6 FB External Feedback pin. Connect this pin to GND for fixed +3.3V operation. Connect this pin to a resistor voltage divider between VOUT and GND for adjustable output operation. 7 GND Ground pin for the internal regulator bias currents. 8 PGND Switch ground pin. The inductor charging current flows out of this pin. 9 LX Inductor switching node. Connect one terminal of the inductor to the positive terminal of the battery. Connect the second terminal of the inductor to this pin. The inductor charging current flows into LX, through the internal charging N-channel FET, and out the GND pin. 10 VOUT Output Voltage pin. The inductor current flows out of this pin during the off-time. It is also the internal regulator voltage supply, and minimum off-time one shot input. Kelvin connect this pin to the positive terminal of the output capacitor. Rev:001 Date:11/20/03 DESCRIPTION Battery Voltage pin. The startup circuitry runs off of this pin. The operate circuit also uses this voltage to regulate the off-time [tOFF = KOFF/ (VOUT - VBATT)]. When the battery voltage drops below 0.62V after a successful startup the SP6649 goes into an undervoltage lockout mode (UVLO). Low Battery Input pin. LBI below 0.61V causes the LBON pin to pull down to ground. Use a resistor divider to program the low voltage threshold for each battery configuration. Low Battery Output Not pin. Open drain NMOS output that sinks current to ground when LBI is below 0.625V. SP6649 Ultra-low Quiescent Current, High Efficiency Boost DC-DC Regulator 3 © Copyright 2002 Sipex Corporation VBATT LX QKILL charge end IUC VO VBATT undercurrent comparator - SHDN SDI 0.61V + c + TOFF Min Toff - c INTERNAL Vbatt INTERNAL SUPPLY UVLO VOUT QKILL R switch buffer Q PMOS VO VBATT CHARGE NMOS VO Max Ton n Ref Block SDI IBIAS 1.25V REF FB 0.61V + - + - c VOLOW S LX Qn current reference VO ADVANCED INFORMATION BLOCK DIAGRAM c - LOAD c overcurrent comparator FB Rlim + SWITCH GROUND Ipkset LBI current control current reference PGND INTERNAL GROUND 0.61V + GND LBON c SP6649 THEORY OF OPERATION Detailed Desctiption: Control Scheme: The SP6649 is a step-up DC-DC converter that starts up with input voltages as low as 0.85V (typically) and operates with input voltages down to 0.62V. The ultra low quiescent current of 12µA provides excellent efficiencies. In addition to the 0.3 internal MOSFET the SP6649 has an internal synchronous rectifier eliminating the need for an external diode. An internal inductive-damping switch significantly reduces inductive ringing. If the supply voltage drops below 0.62V the SP6649 goes into under voltage lock-out opening up the internal switches. An externally programmable low battery detector with open drain output provides the user the ability to monitor the supply voltage. The inductor peak current is externally programmable to allow for a range of inductors. A minimum off-time, current limited pulse frequency modulation (PFM) control scheme combines the high output power and efficiency of a pulse width modulation (PWM) device with the ultra low quiescent current of the traditional PFM. At low to moderate output loads the PFM control provides a higher efficiencies than traditional PWM converters are capable of delivering. At these loads the switching frequency is determined by a minimum off-time (tOFF, MIN) and a maximum on-time (tON, MAX) where: tOFF K tON K OFF ON / (VOUT - VBATT) and / VBATT with KOFF = 1.1Vµs and KON = 3.3Vµs. Rev:001 Date:11/20/03 SP6649 Ultra-low Quiescent Current, High Efficiency Boost DC-DC Regulator 4 © Copyright 2002 Sipex Corporation At light loads (plot A in Figure 3) the charge cycle will take tON, MAX µs. For a 1V battery this would be: Inductor Current vs. Load llim Ton Max. tON, MAX = KON / VBATT = 3.3Vµs / 1V = 3.3µs Toff Min. E. Iripple=Toff* (Vo - Vi)/L ADVANCED INFORMATION llim The current built up in the coil during the charge cycle gets fully discharged (discontinuous conduction mode, DCM) When the current in the coil has reached zero the synchronous rectifier switch is opened and the voltage across the coil (from VBATT to LX) is shorted internally to eliminate inductive ringing. Ton Max. Toff Min. D. Toff*= (Vo - Vi)/L<Iripple<Ton*Vi/L llim Ton Max. Toff Min. C. Iripple=Ton*Vi/L llim Ton Max. With increasing load (plot B in Figure 3) this inductor damping time becomes shorter (because the output will drop quicker below its regulation point due to the heavier load) up to the point where it becomes zero. If the load increases further the SP6649 enters continuous conduction mode (CCM) where there is always current in the inductor. The charge time is still tON,MAX as long as the inductor peak current limit is not reached (plot C in Figure 3). the inductor peak current limit can be programmed by trying a resistor RLIM from the RLIM pin to ground where: Toff Min. B. Iripple=Ton*Vi/L llim Ton Max. Toff Min. A. Iripple=Ton*Vi/L Figure 3. Inductor Current vs. Load In (plot D of Figure 3) the current reaches the peak current limit during the charge cycle but full load is still not reached becuse at the end of the minimum off-time VOUT was still not below its regulation point. Finally in plot E the maximum load is reached where the discharge time has shrunk to its minimum allowed value tOFF,MIN. IPEAK = 1400 / RLIM with a maximum recommended IPEAK of 1.2A (or a minimum RLIM of 1.17K ). When the peak current limit is reached the charge time is short-cycled. Rev:001 Date:11/20/03 SP6649 Ultra-low Quiescent Current, High Efficiency Boost DC-DC Regulator 5 © Copyright 2002 Sipex Corporation PERFORMANCE CHARACTERISTICS 3.3V out, refer to the Circuit in Figure 1, TAMB=+25°C. 100 90 85 Vi=3.0V Vi=2.6V Vi=2.0V Vi=1.3V Vi=1.0V 80 75 70 VOUT (V) Efficiency (%) ADVANCED INFORMATION 95 60 1.0 10.0 100.0 Vi=3.0V Vi=2.6V Vi=2.0V Vi=1.3V Vi=1.0V 3.240 3.220 3.200 65 0.1 3.400 3.380 3.360 3.340 3.320 3.300 3.280 3.260 0 1000.0 100 200 300 400 500 ILOAD(mA) Iload (mA) Figure 5. Line/Load Rejection vs. Load Current Figure 4. Efficiency vs. Load Current 100 400 350 80 300 Io (mA) Iin (uA) 60 40 250 200 150 100 20 50 0 0 1.0 1.5 2.0 2.5 3.0 1.0 1.5 Vin (V) 2.0 2.5 3.0 Vin (V) Figure 6. No Load Battery Current Figure 7. Maximum Resistive Load Current in Startup Figure 8. Output Ripple, VIN=2.6V, ILOAD=80mA Figure 9. Output Ripple, VIN=2.6V, ILOAD=200mA Rev:001 Date:11/20/03 SP6649 Ultra-low Quiescent Current, High Efficiency Boost DC-DC Regulator 6 © Copyright 2002 Sipex Corporation PERFORMANCE CHARACTERISTICS 5V out, refer to the Circuit in Figure 1, TAMB=+25°C, R1=374K. 100 5.100 5.080 5.060 85 80 75 Vout (V) Vi=4.2V Vi=3.2V Vi=2.6V Vi=2.0V Vi=1.6V 90 Efficiency (%) ADVANCED INFORMATION 95 70 65 60 0.1 1.0 10.0 100.0 5.040 5.020 5.000 4.980 4.960 4.940 4.920 4.900 Vi=4.2V Vi=3.2V Vi=2.6V Vi=2.0V Vi=1.6V 0 1000.0 100 200 Figure 10. SP6649 5V Efficiency vs. Load Current 250 Io (mA) Iin (uA) 200 150 100 50 0 1.5 2.0 400 500 Figure 11. SP6649 5V Line/Load Rejection vs. Load Current 300 1.0 300 Iload (mA) Iload (mA) 2.5 3.0 3.5 4.0 4.5 500 450 400 350 300 250 200 150 100 50 0 1.0 1.5 2.0 Vin (V) 2.5 3.0 Vin (V) 3.5 4.0 4.5 Figure 12. SP6649 5V No Load Battery Current Figure 13. SP6649 5V Maximum Resistive Load Current in Startup Figure 14. SP6649 5V Output Ripple, Vin=2.6V, Iload=80mA Figure 15. SP6649 5V Output Ripple, Vin=2.6V, Iload=200mA Rev:001 Date:11/20/03 SP6649 Ultra-low Quiescent Current, High Efficiency Boost DC-DC Regulator 7 © Copyright 2002 Sipex Corporation PACKAGE: 10-PIN MSOP ADVANCED INFORMATION (ALL DIMENSIONS IN MILLIMETERS) D e1 Ø1 E/2 R1 R E1 E Gauge Plane L2 Ø1 Seating Plane Ø L L1 1 2 e Pin #1 indentifier must be indicated within this shaded area (D/2 * E1/2) Dimensions in (mm) 10-PIN MSOP JEDEC MO-187 (BA) Variation MIN NOM MAX A - - 1.1 A1 0 - 0.15 A2 0.75 b 0.17 - 0.27 c 0.08 - 0.23 0.85 D 3.00 BSC E 4.90 BSC 0.95 E1 3.00 BSC e 0.50 BSC e1 2.00 BSC WITH PLATING c L 0.4 0.60 0.80 L1 - 0.95 - L2 - 0.25 - N - 10 - R 0.07 - - R1 0.07 - Ø 0º Ø1 0º (b) BASE METAL D A2 - A 8º - b 15º A1 1 Rev:001 Date:11/20/03 SP6649 Ultra-low Quiescent Current, High Efficiency Boost DC-DC Regulator 8 © Copyright 2002 Sipex Corporation ORDERING INFORMATION Part Number Operating Temperature Range Package Type ADVANCED INFORMATION SP6649EU .................................................. -40°C to +85°C ........................................................ 10 Pin MSOP SP6649EU/TR ............................................ -40°C to +85°C ................................ (Tape & Reel) 10 Pin MSOP Corporation SIGNAL PROCESSING EXCELLENCE Sipex Corporation Headquarters and Sales Office 233 South Hillview Drive Milpitas, CA 95035 TEL: (408) 934-7500 FAX: (408) 935-7600 Sales Office 22 Linnell Circle Billerica, MA 01821 TEL: (978) 667-8700 FAX: (978) 670-9001 e-mail: [email protected] Sipex Corporation reserves the right to make changes to any products described herein. Sipex does not assume any liability arising out of the application or use of any product or circuit described herein; neither does it convey any license under its patent rights nor the rights of others. Rev:001 Date:11/20/03 SP6649 Ultra-low Quiescent Current, High Efficiency Boost DC-DC Regulator 9 © Copyright 2002 Sipex Corporation