SS6639

SS6639 SSC | Alldatasheet

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www.SiliconStandard.com 1 of 12 SS6639 1-Cell, 3-Pin, Step-Up DC/DC Controller n FEATURES

• Guaranteed start-up from less than 0.9 V.
• High efficiency.
• Low quiescent current.
• Fewer external components needed.
• Low ripple and low noise.
• Fixed output voltage: 2.7, 3.0V, 3.3V, and 5V.
• Driver for external transistor.
• Space-saving package: SOT-89 and TO-92. n APPLICATIONS
• Pagers.
• Cameras.
• Wireless Microphones.
• Pocket Organizers.
• Battery Backup Suppliers.
• Portable Instruments. n GENERAL DESCRIPTION The SS6639 is a high efficiency step-up DC/DC controller for applications using 1 to 4 battery cells. Only three external components are required to deliver a fixed outpu t voltage of 2.7, 3.0V, 3.3V, or 5V. The SS6639 starts up from less than 0.9V input with a 1mA load. The Pulse Frequency Modulation scheme offers optimized performance for applications with light output loading and low input voltages. The ou tput ripple an d noise are lower than with ci rcuits operating in PSM mode. The PFM control circuit operat ing up to 100 KHz switching rate results in smaller pa ssive components. The space-saving SOT-89 and TO-92 packages make the SS6639 an ideal choice of DC/DC controller for space-conscious applications, such as pagers, electronic cameras, and wireless microphones. Using an external transistor driver pin (EXT), the SS6639 is recommended for applications requiring currents from se veral tens to several hu ndreds of milliamperes. n TYPICAL APPLICATION CIRCUIT SS6639-27 SS6639-30 SS6639-33 SS6639-50 GND *Q1: Sanyo 25D1803S-TC 60V/5A/20W EXT VOUT VOUT *Q1 2SD1803 10nF 33µH VIN + C1 47µF 300 GS SS14 100µF 100mA Load Current Step-Up Converter Rev.2.01 6/26/2003

www.SiliconStandard.com 2 of 12 SS6639 n ORDERING INFORMATION n ABSOLUTE MAXIMUM RATINGS n TEST CIRCUIT FOUTEXT SS6639 2.5V VOUT GND Oscillator Test Circuit PACKING TYPE TR: TAPE & REEL BG: BAG PACKAGE TYPE X: SOT-89 Z: TO-92 OUTPUT VOLTAGE 27: 2.7V 30: 3.0V 33: 3.3V 50: 5.0V SS6639-XXCXXX EX: SS6639-27CXTR à 2.7V Version, in SOT-89 Package in Tape and Reel Packing 1 2 3 SOT-89 TOP VIEW 1: GND 2: VOUT 3: EXT TO-92 TOP VIEW 1: GND 2: VOUT 3: EXT PIN CONFIGURATION Rev.2.01 6/26/2003

www.SiliconStandard.com 3 of 12 SS6639 n ELECTRICAL CHARACTERISTICS (TA=25°C, IO=10mA, unless otherwise specified) PARAMETER TEST CONDITIONS SYMBOL MIN. TYP. MAX. UNIT Output Voltage SS6639-27 VIN=1.8V SS6639-30 VIN=1.8V SS6639-33 VIN=2.0V SS6639-50 VIN=3.0V VOUT 2.633 2.925 3.218 4.875 2.700 3.000 3.300 5.000 2.767 3.075 3.382 5.125 V Input Voltage VIN 8 V Start-Up Voltage IOUT=1mA, VIN:0→ 2V VSTART 0.8 0.9 V Hold-on Voltage IOUT=1mA, VIN:2→ 0V VHOLD 0.6 V No-Load Input Current IOUT=0mA IIN 18 µA Supply Current 1 SS6639-27 SS6639-30 SS6639-33 SS6639-50 EXT at no load, V IN=VOUT x 0.95 Measurement of the IC input current (VOUT Pin) IDD1 µA Supply Current 2 SS6639-27 SS6639-30 SS6639-33 SS6639-50 EXT at no load, V IN=VOUT + 0.95 Measurement of the IC input current (VOUT Pin) IDD2 µA EXT “H” On-Resistance SS6639-27 SS6639-30 SS6639-33 SS6639-50 V EXT=VOUT – 0.4V REXTH 300 200 185 130 Ω EXT “L” On-Resistance SS6639-27 SS6639-30 SS6639-33 SS6639-50 V EXT= 0.4V REXTL 110 Ω Rev.2.01 6/26/2003

www.SiliconStandard.com 4 of 12 SS6639 n ELECTRICAL CHARACTERISTICS (Continued) PARAMETER TEST CONDITIONS SYMBOL MIN. TYP. MAX. UNIT Oscillator Duty Cycle VIN=VOUT x 0.95 Measurement of the EXT Pin Waveform DUTY 65 75 85 % Max. Oscillator Freq. VIN=VOUT x 0.95 Measurement of the EXT Pin Waveform FOSC 80 105 130 KHz Efficiency η 80 % n TYPICAL PERFORMANCE CHARACTERISTICS Inductor (L1): 33µH (Pin Type) Capacitor (C1): 47µF (Tantalum Type) Diode (D1): 1N5819 Schottky Type Transistor (Q1): 2SD1803 0 50 100 150 200 250 300 350 400 450 500 2.40 2.45 2.50 2.55 2.60 2.65 2.70 2.75 2.80 Fig. 1 SS6639-27 Load Regulation (L=33µH) VIN =2.0 V VIN =1.8V VIN =1.5 VVIN =1.2 V VIN =0.9V Output Voltage (V) Output Current (mA) 0 50 100 150 200 250 300 350 400 450 500 Fig. 2 SS6639-27 Efficiency (L=33uH) Efficiency (%) Output Current (mA) VIN =2.0V VIN =1.8V VIN =1.5V VIN =1.2V VIN =0.9V 0 50 100 150 200 250 300 350 400 450 2.4 2.5 2.6 2.7 2.8 2.9 3.0 3.1 Fig. 3 SS6639-30 Load Regulation (L=33µH) Output Voltage (V) Output Current (mA) VIN=2.0V VIN=1.8VVIN=1.5VVIN=1.2V VIN=0.9V Output Current (mA) 0 50 100 150 200 250 300 350 400 450 Fig. 4 SS6639-30 Efficiency (L=33µH) Efficiency (%) VIN=2.0V VIN=1.8V VIN=1.5V VIN=1.2V VIN=0.9V Rev.2.01 6/26/2003

www.SiliconStandard.com 5 of 12 SS6639 n TYPICAL PERFORMANCE CHARACTERISTICS (Continued) Output Voltage (V) Output Current (mA) Fig. 5 SS6639-33 Loading Regulation (L=33µH) 0 50 100 150 200 250 300 350 400 2.4 2.6 2.8 3.0 3.2 3.4 VIN=2.0VVIN=1.5V VIN=1.2V Output Current (mA) Efficiency (%) 0 50 100 150 200 250 300 350 400 Fig. 6 SS6639-33 Efficiency (L=33µH) VIN=2.0V VIN=1.5V VIN=0.9V Output Voltage (V) Output Current (mA) Fig. 7 SS6639-50 Load Regulation (L=33µH) 0 100 200 300 400 500 600 700 3.25 3.50 3.75 4.00 4.25 4.50 4.75 5.00 5.25 VIN=3.0V VIN=2.0V VIN=1.5V VIN=0.9V VIN=1.2V Output Current (mA) 0 100 200 300 400 500 600 700 Fig. 8 SS6639-50 Efficiency (L=33µH) Efficiency (%) VIN=3.0V VIN=2.0V VIN=1.5V VIN=0.9V VIN=1.2V Output Voltage (V) Output Current (mA) 0 20 40 60 80 100 120 140 160 180 200 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 Fig. 9 SS6639-27 Start-up & Hold-on Voltage (L=33µH) Start up Hold on Output Current (mA) 0 20 40 60 80 100 120 140 160 0.0 0.2 0.4 0.6 0.8 1.0 1.2 Fig. 10 SS6639-30 Start-up & Hold-on Voltage (L=33µH) Start up Hold on Input Voltage (V) Rev.2.01 6/26/2003

www.SiliconStandard.com 6 of 12 SS6639 n TYPICAL PERFORMANCE CHARACTERISTICS (Continued) Output Current (mA) 0 20 40 60 80 100 120 140 160 0.0 0.2 0.4 0.6 0.8 1.0 1.2 Fig. 11 SS6639-33 Start-up & Hold-on Voltage (L=33µH) Input Voltage (V) Start up Hold on Output Current (mA) Input Voltage (V) Fig. 12 SS6639-50 Start-up & Hold-on Voltage (L=33uH) 0 20 40 60 80 100 120 140 160 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 Start up Hold on Output Current (mA) 0 20 40 60 80 100 120 140 160 0.0 0.2 0.4 0.6 0.8 1.0 1.2 Fig. 13 SS6639-33 Start-up & Hold-on Voltage (L=33µH) Input Voltage (V) Start up Hold on Output Current (mA) Input Voltage (V) Fig. 14 SS6639-50 Start-up & Hold-on Voltage (L=33uH) 0 20 40 60 80 100 120 140 160 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 Start up Hold on Output Current (mA) -40 -20 0 20 40 60 80 100 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 Fig. 15 SS6639 Output Voltage vs. Temperature Output Voltage (V) VOUT = 3.3V VOUT = 3.0V VOUT = 2.7V VOUT =5.0V Output Current (mA) -40 -20 0 20 40 60 80 100 100 105 110 115 120 125 130 135 Fig. 16 SS6639 Switching Frequency vs.Temperature Switching Frequency (kHz) VOUT = 5.0V VOUT = 3.3V VOUT = 3.0V VOUT = 2.7V Rev.2.01 6/26/2003

www.SiliconStandard.com 7 of 12 SS6639 n TYPICAL PERFORMANCE CHARACTERISTICS (Continued) Output Current (mA) -40 -20 0 20 40 60 80 100 Fig. 17 SS6639 Maximum Duty Cycle vs. Temperature Maximum Duty Cycle (%) VOUT = 2.7V VOUT = 3.0V VOUT = -40 -20 0 20 40 60 80 100 Fig. 18 SS6639 Supply Current vs. Temperature Supply Current IDD1 (µA) Temperature (°C) VOUT = 5.0V VOUT = 3.3V VOUT = 3.0V VOUT = 2.7V -40 -20 0 20 40 60 80 100 100 110 120 130 Fig. 19 SS6639 EXT "L" On-Resistance Resistance (O) Temperature (°C) VOUT = 2.7V VOUT = 3.0V VOUT = 3.3V VOUT = 5.0V Temperature (°C) -40 -20 0 20 40 60 80 100 120 160 200 240 280 320 360 400 Fig. 20 SS6639 EXT "H" On-Resistance Resistance (O) VOUT = 2.7V VOUT = 3.0V VOUT = 3.3V VOUT = 5.0V n BLOCK DIAGRAM GND VOUT EXT 1.25V REF. Enable OSC, 100KHz Rev.2.01 6/26/2003

www.SiliconStandard.com 8 of 12 SS6639 n PIN DESCRIPTIONS Pin 1: GND: Ground. Must be low impedance; solder directly to ground plane. Pin 2: VOUT: IC supply pin. Connect Vout to the regular output. Pin 3: EXT: Push-pull driver output for external power. Switch. n APPLICATION INFORMATION General Description The SS6639 PFM (pulse frequency modulation) controller IC combines a switch mode regulator, a push-pull driver, a precision voltage reference, and a voltage detector in a single mon olithic device. It offers extremely low quie scent current, high efficiency, and very low gate -threshold voltage to ensure start-up with low ba ttery voltage (0.8V typ.). Designed to max imize battery life in portable products, it min imizes switching losses by only switching as needed to service the load. PFM controllers transfer a discrete amount of energy per cycle and regulate the output voltage by modulating the switching frequency with a co nstant turn-on time. Switching frequency depends on load, input voltage, and inductor value and can range up to 100 KHz. When the output voltage drops, the error comparator enables the 100 kHz oscillator which turns the MOSFET on for around 7.5us and off for 2.5 µs. Turning on the MOSFET allows inductor current to ramp up, storing energy in the magnetic field. When the MOSFET turns off, the inductor forces current through the diode to the output capacitor and the load . As the stored energy is depleted, the current ramps down until the diode turns off. At this point, the inductor may ring due to residual energy and stray capacitance. The output capac itor stores charge when current flowing through the diode is high, and releases it when current is low, thereby maintaining a steady voltage across the load. As the load increases, the output capacitor discharges faster and the error comparator initiates cycles sooner, increasing the switching fr equency. The maximum duty cycle ensures ad equate time for energy transfer to the output during the second half of each cycle. Depending on the circuit, PFM controllers can operate in either discontinuous mode or continuous conduction mode. The continuous conduction mode means that the inductor current does not ramp to zero during each cycle. VIN SW VOUTEXT ID IOUT Isw Ico IIN Discontinuous Conduction Mode Rev.2.01 6/26/2003

www.SiliconStandard.com 9 of 12 SS6639 IPK IIN VEXT ISW IOUT TDIS Charge Co. VSW Discharge Co. ID t Discontinuous Conduction Mode IPK IIN VEXT ISW IOUT VSW ID t Continuous Conduction Mode At the boundary between continuous and discontinuous modes, the output current (IOB) is determined by ( ) x1*T*L V*2 1*V V VI ON IN DOUT IN OB − where VD is the diode drop, L T)R(RX ON SON ∗+ = RON= Switch turn on resistance, RS= Inductor DC resistance TON = Switch ON time In the discontinuous mode, the switching fr equency (Fsw) is )x(1* T*V )(I*)V V(V*2(L)F 2ON2IN OUTINDOUT SW +− += In the continuous mode, the switching frequency is ( ) − + − +≅ − + − + − += SWDOUT INDOUT ON SWDOUT SWIN SWDOUT INDOUT ON V V V V V V*T )]V V V V V(2 x[1* )V V(V V V V*T 1fsw where Vsw = switch drop and is proportional to output current. INDUCTOR SELECTION To operate as an efficient energy transfer el ement, the inductor must fulfill three requirements. First, the inductance must be low enough for the inductor to store adequate energy under the worst case condition of minimum input voltage and switch ON time. Second, the inductance must also be high enough so the maximum current rating of the SS6639 and the inductor are not exceeded at the other worst case condition of maximum input voltage and ON time. Lastly, the inductor must have sufficiently low DC resistance so excessive power is not lost as heat in the windings. Unfortunately this is inversely related to physical size. Rev.2.01 6/26/2003

www.SiliconStandard.com 10 of 12 SS6639 Minimum and maximum input voltage, output voltage and output current must be established before an inductor can be selected. In discontinuous mode operation, at the end of the switch ON time, peak current and energy in the inductor build according to ( ) ON IN TON IN ON SON SON IN PK T*L V x1* *L V )T*L R Rexp(1*R R VI  −  +− − (simple lossless equation), where L T)R(RX ON SON ∗+ = 2PKI*L2 1EL = Power required from the inductor per cycle must be equal to, or greater than )fsw 1(*)(I*)V V(Vf P OUTINDOUT SW L − + = in order for the converter to regulate the output. When the loading exceeds IOB, the PFM controller operates in continuous mode. Inductor peak cu rrent can be derived from  −  −+  −− − += x1*T*2L V VI * x V V V V VI ON SWIN OUT SWIN SWDOUT PK Valley current (Iv) is  −  −  −− − += x1T*2L V V* I*2 x V V V V VI *ON DEIN OUT SWIN SWDOUT V Table 1 Indicates resistance and height for each coil. Power Inductor Type Inductance ( mH ) Resistance ( Ω ) Rated Current (A) height (mm) 47 0.25 0.7 Sumida SMT Type CD54 100 0.50 0.5 4.5 47 0.25 0.7 Hold SMT Type PM54 100 0.50 0.5 4.5 Hold SMT Type PM75 33 0.11 1.2 5.0 Huan Feng PIN Type V0810 33 40m 2 10.0 CAPACITOR SELECTION A poor choice for an output capacitor can result in poor efficiency and high output ripple. Ordinary aluminum electrolytic capacitors, while inexpensive, may have unacceptably poor ESR and ESL. There are low ESR aluminum capacitors for switch mode DC -DC converters which work much better than general-purpose components. Tantalum capacitors provide still be tter performance but are more expensive. OS -CON capacitors have extremely low ESR in a small size. If the capacitance is reduced, the output ripple will increase. As most of the input supply is applied across the input bypass capacitor, the capacitor voltage rating should be at least 1.25 times greater than the maximum input voltage. DIODE SELECTION Speed, forward drop, and leakage current are thr ee main considerations in selecting a rectifier diode. The best performance is obtained with a Schottky rectifier Rev.2.01 6/26/2003

www.SiliconStandard.com 11 of 12 SS6639 diode such as the 1N5819. Motorola makes the MBR0530 for surface mount. For lower output power a 1N4148 can be used although e fficiency and start-up voltage will suffer substantially. COMPONENT POWER DISSIPATION Operating in discontinuous mode, the power loss in the winding resistance of the inductor is approximately equal to ( ) ( )OUT OUT DOUT S ON L PV V VRL TPD * * * *3 2   + where POUT=VOUT * IOUT ; RS=Inductor DC R; VD = Diode drop. The power dissipated in switching losses is OUT OUTON ON PIRL TPDsw  The power dissipated in the rectifier diode is ( )OUT OUT D D PV VPD * Rev.2.01 6/26/2003

Information furnished by Silicon Standard Corporation is believed to be accurate and reliable. However, Silicon Standard Corporation makes no guarantee or warranty, express or implied, as to the reliability, accuracy, timeliness or completeness of such information and assumes no responsibility for its use, or for infri ngement of any patent or other intellectual property rights of third parties that may result from its use. Silicon Standard reserves the right to make changes as it deems necessary to any products described herein for any reason, including without limitation enhancement in reliability, functionality or design. No license is granted, whether expressly or by implication, in relation to the use of any products described herein or to the use of any information provided herein, under any patent or other intellectual property rights of Silicon Standard Corporation or any third parties. www.SiliconStandard.com 12 of 12 SS6639 n PHYSICAL DIMENSIONS

• SOT-89 (unit: mm) SYMBOL MIN MAX A 1.40 1.60 B 0.36 0.48 C 0.35 0.44 D 4.40 4.60 D1 1.62 1.83 E 2.29 2.60 e 1.50 (TYP.) e1 3.00 (TYP.) H 3.94 4.25 Be H D A C L E L 0.89 1.20 l SOT-89 MARKING Part No. Marking SS6639-27 AU27 SS6639-30 AU30 SS6639-33 AU33 SS6639-50 AU50
• TO-92 (unit: mm) SYMBOL MIN MAX A 4.32 5.33 C 0.38 (TYP.) D 4.40 5.20 E 3.17 4.20 e1 1.27 (TYP.) A L D C E L 12.7 - Rev.2.01 6/26/2003