APW7079 Low-Supply-Current Synchronous Step-up DC-DC Converter General Description Features • • • • • 0.9V Typical Start-up Input Voltage The APW7079 is a compact, PFM mode, and step-up 11µA Typical No Load Quiescent Current DC-DC converter with low quiescent current. The internal synchronous rectifier reduces cost and PCB space PFM Operation by eliminating the need for an external Schottky diode. Low on-resistance of the internal switches improves the High Efficiency up to 92% efficiency up to 92%. The start-up voltage is guaranteed below 1V. After start-up, the device can operate with input Fixed 1.8V, 2.6V, 2.8V, 3V, 3.3V, 3.8V, 4.5V or 5V Output Voltage • • • • voltage down to 0.7V. The APW7079 is suitable for portable battery-powered applications. Consuming only 11µA 600mA Internal Switch Current quiescent current and an optimized control scheme allows the device to operate at very high efficiency over the Internal Synchronous Rectifier SOT-89 Package entire load current range. Lead Free and Green Devices Available Efficiency vs. Output Current (RoHS Compliant) 100 Applications 90 80 Toy 70 Efficiency (%) • • • Wireless Mouse Portable Instrument VIN=0.9V 60 50 VIN=1.0V 40 Pin Configuration VIN=2.4V VIN=1.2V 30 VIN=1.5V 20 10 APW7079-30 0 SOT-89 0.1 1 10 100 1000 Output Current, I OUT (mA) GND 1 VOUT 2 (TAB) LX 3 Simplified Application Circuit VIN Top View IIN L1 22µH C1 22µF APW7079 LX IOUT VOUT VOUT GND C2 47µF ANPEC reserves the right to make changes to improve reliability or manufacturability without notice, and advise customers to obtain the latest version of relevant information to verify before placing orders. Copyright ANPEC Electronics Corp. Rev. A.4 - Jun., 2009 1 www.anpec.com.tw APW7079 79 Ordering and Marking Information Package Code D : SOT-89 Operating Ambient Temperature Range I : -40 to 85oC Handling Code TR : Tape & Reel Assembly Material G : Halogen and Lead Free Device Voltage Code 18: 1.8V 26: 2.6V 28: 2.8V 33: 3.3V 38: 3.8V 45: 4.5V APW7079 Assembly Material Handling Code Temperature Range Package Code Voltage Code 30: 3.0V 50: 5.0V APW7079-18D: APW7079 XXXXX18 XXXXX - Date Code, 18: 1.8V APW7079-26D: APW7079 XXXXX26 XXXXX - Date Code, 26: 2.6V APW7079-28D: APW7079 XXXXX28 XXXXX - Date Code, 28: 2.8V APW7079-30D: APW7079 XXXXX30 XXXXX - Date Code, 30: 3.0V APW7079-33D: APW7079 XXXXX33 XXXXX - Date Code, 33: 3.3V APW7079-33D: APW7079 XXXXX38 XXXXX - Date Code, 38: 3.8V APW7079-45D: APW7079 XXXXX45 XXXXX - Date Code, 45: 4.5V APW7079-50D: APW7079 XXXXX50 XXXXX - Date Code, 50: 5.0V Note: ANPEC lead-free products contain molding compounds/die attach materials and 100% matte tin plate termination finish; which are fully compliant with RoHS. ANPEC lead-free products meet or exceed the lead-free requirements of IPC/JEDEC J-STD-020C for MSL classification at lead-free peak reflow temperature. ANPEC defines “Green” to mean lead-free (RoHS compliant) and halogen free (Br or Cl does not exceed 900ppm by weight in homogeneous material and total of Br and Cl does not exceed 1500ppm by weight). Absolute Maximum Ratings (Note 1) Symbol Parameter VOUT Output Voltage (VOUT to GND) VLX LX to GND Voltage TSTG Storage Temperature TSDR Maximum Lead Soldering Temperature, 10 Seconds Rating Unit -0.3 ~ 6 V -0.3 ~ VOUT+1 V -65 ~ 150 °C 260 °C Note 1: Absolute Maximum Ratings are those values beyond which the life of a device may be impaired. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Thermal Characteristics Symbol θJA Parameter Thermal Resistance -Junction to Ambient Typical Value Unit (Note 2) SOT-89 o 180 C/W Note 2: θJA is measured with the component mounted on a high effective thermal conductivity test board in free air. Recommended Operating Conditions (Note 3, 4) Symbol VOUT VIN Parameter Output Voltage (VOUT to GND) Converter Supply Voltage VLX LX to GND Voltage IOUT Converter Output Current TA TJ Range Unit 0.7 ~ 5.5 V 0.3 ~ VOUT+1 V -0.3 ~ VOUT+0.3 V 0 ~ 0.9 x IOUT(MAX) A Ambient Temperature -40 ~ 85 °C Junction Temperature -40 ~ 125 °C Note 3: Refer to the typical application circuit Note 4: Refer to “Application Information” for detail value. Copyright ANPEC Electronics Corp. Rev. A.4 - Jun., 2009 2 www.anpec.com.tw APW7079 Electrical Characteristics Refer to Typical Application Circuits. VIN=1.5V, RLOAD = ∞, and TA= -40 ~ 85oC, unless otherwise noted. Typical values are at TA=25oC. Symbol VIN Parameter IDD Max. 0.7 - 5.5 V - 0.9 1 V APW7079-18 1.764 1.8 1.836 APW7079-26 2.548 2.6 2.652 APW7079-28 2.744 2.8 2.856 APW7079-30 2.94 3.0 3.06 APW7079-33 3.234 3.3 3.366 APW7079-38 3.724 3.8 3.876 APW7079-45 4.41 4.5 4.59 APW7079-50 4.9 5.0 5.1 7 11 15 µA Converter Supply Voltage Start-up Voltage VOUT APW7079 Typ. Test Conditions RLOAD=3kΩ Output Voltage Supply Current VOUT = VOUT(Typ.)+0.5V Measured at VOUT No Inductor Connected Min. Unit V TOFF(MIN) Main Switch Min. Off-time 0.6 0.9 1.2 µs TON(MAX) Main Switch Max. On-time 3 4 5 µs Main Switch Max. Duty 75 - 85 % APW7079-18 - 0.5 - APW7079-26 - 0.4 - APW7079-28 - 0.4 - APW7079-30 - 0.4 - APW7079-33 - 0.4 - APW7079-38 - 0.4 - RN-FET RP-FET Main Switch on Resistance Synchronous Switch on Resistance ILX=100mA ILX=100mA APW7079-45 - 0.3 - APW7079-50 - 0.3 - APW7079-18 - 1 - APW7079-26 - 0.8 - APW7079-28 - 0.8 - APW7079-30 - 0.7 - APW7079-33 - 0.6 - APW7079-38 - 0.5 - APW7079-45 - 0.4 - APW7079-50 ILIM Ω Ω - 0.4 - 500 600 700 mA Main Switch Leakage Current - - 1 µA Synchronous Switch Leakage Current - - 1 µA Over-Temperature Shutdown - 150 - °C Over-Temperature Hysteresis - 40 - °C Main Switch Current Limit Copyright ANPEC Electronics Corp. Rev. A.4 - Jun., 2009 3 www.anpec.com.tw APW7079 Typical Operating Characteristics (Refer to the application circuit in the section “Typical Application Circuit”, VIN=1.5V, L1=22µH, TA=25oC unless otherwise noted.) Efficiency vs. Output Current Output Voltage vs. Output Current 1.84 90 1.82 80 1.80 Output Voltage, VOUT (V) 100 Efficiency (%) 70 VIN=0.9V 60 50 VIN=1.0V 40 VIN=1.2V 30 VIN=1.5V 20 1.78 1.76 VIN=0.9V 1.74 1.72 VIN=1.0V 1.70 VIN=1.2V 1.68 VIN=1.5V 1.66 10 APW7079-18 APW7079-18 1.64 0 0.1 1 10 100 0 1000 50 100 150 200 250 300 Output Current, IOUT (mA) Output Current, IOUT (mA) Efficiency vs. Output Current Output Voltage vs. Output Current 3.1 100 90 Output Voltage, VOUT (V) 80 Efficiency (%) 70 VIN=0.9V 60 50 VIN=1.0V 40 VIN=2.4V VIN=1.2V 30 20 VIN=1.5V 10 3.0 VIN=2.4V 2.9 VIN=1.5V 2.8 VIN=1.2V VIN=1.0V 2.7 VIN=0.9V APW7079-30 APW7079-30 2.6 0 0.1 1 10 100 0 1000 50 100 Output Current, IOUT (mA) 150 200 250 300 350 400 Output Current, IOUT (mA) Output Voltage vs. Output Current Output Voltage vs. Output Current 100 6 90 5 Output Voltage, VOUT (V) 80 Efficiency (%) 70 60 50 VIN=0.9V 40 VIN=3.6V VIN=1.0V 30 VIN=2.4V VIN=1.2V 20 VIN=1.5V 10 4 VIN=3.6V 3 VIN=0.9V VIN=2.4V VIN=1.0V 2 VIN=1.5V VIN=1.2V 1 APW7079-50 APW7079-50 0 0 0.1 1 10 100 1000 0 Output Current, IOUT (mA) Copyright ANPEC Electronics Corp. Rev. A.4 - Jun., 2009 4 50 100 150 200 250 Output Current, IOUT (mA) 300 350 www.anpec.com.tw APW7079 Typical Operating Characteristics (Cont.) (Refer to the application circuit in the section “Typical Application Circuit”, VIN=1.5V, L1=22µH, TA=25oC unless otherwise noted.) 1.2 1.4 Start-up/Hold-on Voltage, VST /VHOLD (V) 1.4 Start-up/Hold-on Voltage, VST /VHOLD (V) Start-up/Hold-on Voltage vs. Output Current Start-up/Hold-on Voltage vs. Output Current Start-up 1 0.8 Hold-on 0.6 0.4 0.2 APW7079-18 0 0 10 20 30 40 1.2 Start-up 1 0.8 0.6 Hold-on 0.4 0.2 APW7079-30 0 0 50 10 Output Current, IOUT (mA) Start-up/Hold-on Voltage vs. Output Current 1 0.8 Hold-on 0.6 0.4 0.2 APW7079-50 0 40 50 60 50 40 30 APW7079-50 20 10 APW7079-18 APW7079-30 0 0 0.8 Main Switch ON Resistance, RN-FET (Ω) No Load Battery Current, IIN (µA) Start-up 1.2 30 No Load Battery Current vs. Input Voltage 70 10 20 30 40 50 0 1.5 2 2.5 3 3.5 4 4.5 Main Switch ON Resistance vs. Junction Temperature Synchronous Switch ON Resistance vs. Junction Temperature 1.6 0.6 0.5 0.4 0.3 APW7079-18 0.2 APW7079-30 APW7079-50 0 -50 1 Input Voltage, VIN (V) 0.7 0.1 0.5 Output Current, IOUT (mA) Synchronous Switch ON Resistance, RP-FET (Ω) Start-up/Hold-on Voltage, VST /VHOLD (V) 1.4 20 Output Current, IOUT (mA) -25 0 25 50 75 100 Junction Temperature, TJ (oC) Copyright ANPEC Electronics Corp. Rev. A.4 - Jun., 2009 1.4 1.2 1.0 0.8 0.6 APW7079-18 0.4 APW7079-30 0.2 APW7079-50 0.0 -50 125 5 -25 0 25 50 75 100 125 Junction Temperature, TJ (oC) 5 www.anpec.com.tw APW7079 Operating Waveforms Line Transient Response Load Transient Response IOUT=10mA -> 110mA -> 10mA IOUT rise/fall time = 1µs VIN=1.5V VIN IOUT 1.5V 110mA 2 2V 10mA VOUT 3 1 VOUT 3 CH2: IOUT, 100mA/Div, DC CH3: VOUT, 50mV/Div, AC Time: 0.1ms/Div CH1: VIN, 0.5V/Div, DC CH3: VOUT, 50mV/Div, AC Time: 0.1ms/Div Heavy Load Switching Waveform IOUT=100mA, VIN=1.5V 2 ILX VOUT 3 VLX 4 CH2: ILX, 200mA/Div, DC CH3: VOUT, 50mV/Div, AC CH4: VLX, 2V/Div, DC Time: 5µs/Div Copyright ANPEC Electronics Corp. Rev. A.4 - Jun., 2009 6 www.anpec.com.tw APW7079 Pin Description PIN FUNCTION NO. NAME 1 LX 2 VOUT Converter output and control circuitry bias supply pin. 3 GND Ground. Junction of N-FET and P-FET Drains. Connect the inductor here and minimize the trace area for lowest EMI. Block Diagram VOUT 2 Zero Crossing Comparator + Thermal Shutdown 0.9µs Min. off-time Synchronous Switch Error Comparator 3 - LX + Control Logic VREF 4µs Max. on-time Gate Driver Main Switch Current Limit Comparator RSENSE + Soft start 1 GND Typical Application Circuit VIN IIN L1 22µH APW7079 LX C1 22µF Copyright ANPEC Electronics Corp. Rev. A.4 - Jun., 2009 IOUT VOUT GND 7 www.anpec.com.tw APW7079 Function Description Control Scheme The converter monitors the output voltage. When the internal feedback voltage falls below the reference voltage, the main switch turns on and the inductor current ramps up. The main switch turns off when the current reaches the peak current limit of typical 600mA. The second criterion that turns off the switch is the maximum on-time of 4µs (typical). As the main switch is turned off, the synchronous switch is turned on and delivers the current to the output. The main switch remains off for a minimum of 900ns (typical), or until the internal feedback voltage drops below the reference voltage. By the control scheme with low quiescent current of 11µA (typical), the converter gets high efficiency over a wide load range. Start-Up A startup oscillator circuit is integrated in the APW7079. When the power is applied to the device, the circuit pumps the output voltage high. Once the output voltage reaches 1.4V (typ), the main DC-DC circuitry turns on and boosts the output voltage to the final regulation point. Synchronous Rectification The internal synchronous rectifier eliminates the need for an external Schottky diode, thus, reducing cost and board space. During the cycle off-time, the P-channel MOSFET turns on and shunts the MOSFET body diode. As a result, the synchronous rectifier significantly improves efficiency without the addition of an external component. Conversion efficiency can be as high as 92%. Over-Temperature Protection The over-temperature circuit limits the junction temperature of the APW7079. When the junction temperature exceeds 150°C, a thermal sensor turns off the power MOSFETs, allowing the devices to cool. The thermal sensor allows the converter to start a start-up process and regulate the output voltage again after the junction temperature cools by 40°C. The OTP is designed with a 40°C hysteresis to lower the average TJ during continuous thermal overload conditions, increasing lifetime of the device. Copyright ANPEC Electronics Corp. Rev. A.4 - Jun., 2009 8 www.anpec.com.tw APW7079 Application Information Input Capacitor Selection The input capacitor is chosen based on the voltage rating Since the output ripple is the product of the peak inductor current and the output capacitor ESR, using low-ESR tan- and the RMS current rating. For reliable operation, it is recommended to select the capacitor voltage rating at talum capacitors for the best performance or connecting two or more filter capacitors in parallel is recommended. least 1.3 times higher than the maximum input voltage. The maximum RMS current rating of the input capacitor is Inductor Selection The inductor value determines the inductor ripple current and affects the load transient response. It is recom- calculated as the following equation: IRMS = where VIN ⋅ TON L 3 1 ⋅ mended to select the boost inductor in order to keep the maximum peak inductor current below the current limit threshold of the power switch. For example, the current limit threshold of the APW7079’s switch is 600mA. For TON = main switch max. on-time (4µs typical) VIN = input voltage choosing an inductor which has peak current passed, firstly, it is necessary to consider the output load (IOUT), L = inductor value in µH The capacitors should be placed close to the inductor and the GND. input (VIN), and output voltage (VOUT). Secondly, the desired current ripple in the inductor also needed to be Output Capacitor Selection taken into account. The current was calculated in “Output Capacitor Selection”. Since the output ripple is the prod- An output capacitor is required to filter the output and supply the load transient current. The output ripple is the sum uct of the peak inductor current and the output capacitor ESR, the larger inductor value reduces the inductor cur- of the voltages across the ESR and the ideal output capacitor. The peak-to-peak voltage of the ESR is calcu- rent ripple and output voltage ripple but typically offers a larger physical size. The inductor value also slightly affects the maximum out- lated as the following equations: ∆VESR = IPEAK x ESR IPEAK = put current. The maximum output current can be calculated as below: VOUT ⋅ IOUT VIN ⋅ TON + ≤ ILIM VIN ⋅ η 2 ⋅L IOUT (MAX ) = Where IPEAK = peak current of inductor in amp TOFF = main switch min. off-time (0.9µs typical) The peak-to-peak voltage of the ideal output capacitor is Therefore, to consider the balance of the efficiency and component size, an inductor value of 22µH to 47µH is calculated as the following equation: IOUT × TON COUT recommended in most applications. VIN For the applications using tantalum capacitors, the ∆VCOUT is much smaller than the V ESR and can be ignored. IIN ILX IOUT LX VOUT ISWP CIN Therefore, the AC peak-to-peak output voltage (∆VOUT) is shown as below: N-FET ISWN P-FET ESR COUT ∆VOUT = IPEAK x ESR Copyright ANPEC Electronics Corp. Rev. A.4 - Jun., 2009 ⋅ η where η = efficiency (0.85 typical) ∆VCOUT = VIN VOUT − VIN ILIM − TOFF VOUT 2×L 9 www.anpec.com.tw APW7079 Application Information (Cont.) ILX T J = TA + TR ILIM where TA = the ambient temperature. IPEAK The power dissipation can be calculated as below: IIN PD = POUT x (1-η)/η where POUT = Output power (VOUT x IOUT) ISWN η = Efficiency As an example, the APW7079-18 converts an input voltage 1.2V to provide a load current of 175mA at ambient temperature of 85°C. Assume the efficiency (η) is 0.75. Therefore, the power dissipated on the converter is: ISWP PD = 1.8 x 0.175 x (1-0.75)/0.75= 0.105 Watt IOUT VOUT Since the power dissipation includes the loss of external components, the actual value is slightly lower. For the IPEAK x ESR SOT-89 package, the θJA is 180°C/W. Thus, the junction temperature of the regulator is as below: VOUT TJ = 85°C + (PD)(180) = 104 °C The maximum junction temperature should be less than 125°C. Note that, the junction temperature is lower at higher output voltages due to reduced switch resistance. Thermal Consideration In most applications, the APW7079 does not dissipate much heat due to its high efficiency. However, in applications where the APW7079 is running at high ambient tem- Layout Consideration For all switching power supplies especially with high peak currents and switching frequency, the layout is an important step in the design. If the layout is not carefully done, the regulator may show noise problems and duty cycle jitter. perature with low output voltage, the heat dissipated may exceed the maximum junction temperature of the part. If the junction temperature reaches approximately 150°C, both power switches will be turned off and the LX node 1.The input capacitor should be placed close to the will become high impedance. To avoid the APW7079 from exceeding the maximum junction temperature, the user device, which can reduce copper trace resistance and effect input ripple of the IC. will need to do some thermal analysis. The goal of the thermal analysis is to determine whether the power dis- 2.The inductor should be placed as close as possible to the switch pin to minimize the switching noise. sipated exceeds the maximum junction temperature of the part. The temperature rise is given by: 3.The output capacitor should be placed closed to the VOUT and the GND. TR = (PD)(θJA) where PD is the power dissipated by the regulator and θJA is the thermal resistance from the junction of the die to the ambient temperature. The junction temperature, TJ, is given by: Copyright ANPEC Electronics Corp. Rev. A.4 - Jun., 2009 10 www.anpec.com.tw APW7079 Application Information (Cont.) Layout Consideration (Cont.) Copyright ANPEC Electronics Corp. Rev. A.4 - Jun., 2009 11 www.anpec.com.tw APW7079 Package Information SOT-89 A D1 C L H E E1 D e e1 B B1 SOT-89 S Y M B O L A MIN. MAX. MIN. MAX. 1.40 1.60 0.055 0.063 MILLIMETERS INCHES B 0.44 0.56 0.017 0.022 B1 0.36 0.48 0.014 0.019 C 0.35 0.44 0.014 0.017 0.181 D 4.40 4.60 0.173 D1 1.62 1.83 0.064 0.072 E 2.29 2.60 0.090 0.102 E1 2.13 2.29 0.084 0.090 e 1.50 BSC e1 0.059 BSC 3.00 BSC 0.118 BSC H 3.94 4.25 0.155 0.167 L 0.89 1.20 0.035 0.047 Note : Follow JEDEC TO-243 AA. Copyright ANPEC Electronics Corp. Rev. A.4 - Jun., 2009 12 www.anpec.com.tw APW7079 Carrier Tape & Reel Dimensions P0 P2 P1 A B0 W F E1 OD0 K0 A0 A OD1 B B T SECTION A-A SECTION B-B H A d T1 Application SOT-89 A H T1 C d D W E1 F 178.0±2.00 50 MIN. 12.4+2.00 -0.00 13.0+0.50 -0.20 1.5 MIN. 20.2 MIN. 12.0±0.30 1.75±0.10 5.50±0.05 P0 P1 P2 D0 D1 T A0 B0 K0 2.0±0.05 1.5+0.10 -0.00 1.5 MIN. 0.6+0.00 -0.40 4.80±0.20 4.50±0.20 1.80±0.20 4.0±0.10 8.0±0.10 (mm) Devices Per Unit Package Type Unit Quantity SOT-89 Tape & Reel 1000 Copyright ANPEC Electronics Corp. Rev. A.4 - Jun., 2009 13 www.anpec.com.tw APW7079 Taping Direction Information SOT-89 USER DIRECTION OF FEED Classification Profile Copyright ANPEC Electronics Corp. Rev. A.4 - Jun., 2009 14 www.anpec.com.tw APW7079 Classification Reflow Profiles Profile Feature Sn-Pb Eutectic Assembly Pb-Free Assembly 100 °C 150 °C 60-120 seconds 150 °C 200 °C 60-120 seconds 3 °C/second max. 3°C/second max. 183 °C 60-150 seconds 217 °C 60-150 seconds See Classification Temp in table 1 See Classification Temp in table 2 Time (tP)** within 5°C of the specified classification temperature (Tc) 20** seconds 30** seconds Average ramp-down rate (Tp to Tsmax) 6 °C/second max. 6 °C/second max. 6 minutes max. 8 minutes max. Preheat & Soak Temperature min (Tsmin) Temperature max (Tsmax) Time (Tsmin to Tsmax) (ts) Average ramp-up rate (Tsmax to TP) Liquidous temperature (TL) Time at liquidous (tL) Peak package body Temperature (Tp)* Time 25°C to peak temperature * Tolerance for peak profile Temperature (Tp) is defined as a supplier minimum and a user maximum. ** Tolerance for time at peak profile temperature (tp) is defined as a supplier minimum and a user maximum. Table 1. SnPb Eutectic Process – Classification Temperatures (Tc) Package Thickness <2.5 mm ≥2.5 mm Volume mm <350 235 °C 220 °C 3 Volume mm ≥350 220 °C 220 °C 3 Table 2. Pb-free Process – Classification Temperatures (Tc) Package Thickness <1.6 mm 1.6 mm – 2.5 mm ≥2.5 mm Volume mm <350 260 °C 260 °C 250 °C 3 Volume mm 350-2000 260 °C 250 °C 245 °C 3 Volume mm >2000 260 °C 245 °C 245 °C 3 Reliability Test Program Test item SOLDERABILITY HOLT PCT TCT HBM MM Latch-Up Method JESD-22, B102 JESD-22, A108 JESD-22, A102 JESD-22, A104 MIL-STD-883-3015.7 JESD-22, A115 JESD 78 Copyright ANPEC Electronics Corp. Rev. A.4 - Jun., 2009 15 Description 5 Sec, 245°C 1000 Hrs, Bias @ 125°C 168 Hrs, 100%RH, 2atm, 121°C 500 Cycles, -65°C~150°C VHBM≧2KV VMM≧200V 10ms, 1tr≧100mA www.anpec.com.tw APW7079 Customer Service Anpec Electronics Corp. Head Office : No.6, Dusing 1st Road, SBIP, Hsin-Chu, Taiwan, R.O.C. Tel : 886-3-5642000 Fax : 886-3-5642050 Taipei Branch : 2F, No. 11, Lane 218, Sec 2 Jhongsing Rd., Sindian City, Taipei County 23146, Taiwan Tel : 886-2-2910-3838 Fax : 886-2-2917-3838 Copyright ANPEC Electronics Corp. Rev. A.4 - Jun., 2009 16 www.anpec.com.tw