APW7134 Dual 1.5MHz, 600mA Synchronous Step-Down Converter Features * * * * * * * * * * * * * General Description The APW7134 contains two independent 1.5MHz constant frequency, current mode, and PWM step-down 600mA Output Current on Each Channel 2.5V to 5.5V Input Voltage Range converters. Each converter integrates a main switch and a synchronous rectifier for high efficiency without an ex- 1.5MHz Constant Frequency Operation Low Dropout Operation at 100% Duty Cycle ternal Schottky diode. The APW7134 is ideal for powering portable equipment that runs from a single cell Lithium- Synchronous Topology 0.6V Low Reference Voltage Ion (Li+) battery. Each converter can supply 600mA of load current from a 2.5V to 5.5V input voltage. The output volt- Typically 0.1 A Shutdown Current Current Mode Operation age can be regulated as low as 0.6V. The APW7134 can also run at 100% duty cycle for low dropout applications. Over-Temperature Protection Over-Current Protection Pin Configuration Up to 94% Efficiency Internally Compensated APW7134 DFN3x3-10 (Top View) Lead Free and Green Devices Available (RoHS Compliant) EN1 1 Applications * * TV Tuner/Box 10 SW1 FB1 2 9 GND1 IN2 3 8 IN1 GND2 4 7 FB2 SW2 5 6 EN2 Portable Instrument Exposed Pad on Backside Ordering and Marking Information Package Code QA : DFN3x3-10 Temperature Range I : -40 to 85 oC Handling Code TR : Tape & Reel Assembly Material G : Halogen and Lead Free Device APW7134 Assembly Material Handling Code Temperature Range Package Code APW7134 QA: APW 7134 XXXXX XXXXX - Date Code 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-020D 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). 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 - Aug., 2010 1 www.anpec.com.tw APW7134 Absolute Maximum Ratings Symbol (Note 1) Parameter VIN1/IN2 Input Supply Voltage (IN1/IN2 to GND1/GND2) Rating Unit -0.3 ~ 6 V VFB1/FB2 Voltage on FB1 and FB2 -0.3 ~ VIN1/IN2+0.3 V VEN1/EN2 Voltage on EN1 and EN2 -0.3 ~ VIN1/IN2+0.3 V VSW1/SW2 Voltage on SW1 and SW2 -0.3 ~ VIN1/IN2+0.3 V ISW_PEAK Peak SW Current 1.3 A TJ Junction Temperature 150 C TSTG Storage Temperature -65 ~ 150 C TSDR Maximum Lead Soldering temperature, 10 Seconds 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 Parameter Symbol JA Junction-to-Ambient Resistance in Free Air Typical Value Unit 50 C/W (Note 2) DFN3x3-10 Note 2: JA is measured with the component mounted on a high effective thermal conductivity test board in free air. The exposed pad of package is soldered directly on the PCB. Recommended Operating Conditions Symbol (Note 3) Parameter Range Unit 2.5 ~ 5.5 V VIN1/IN2 Input Supply Voltage (IN1/IN2 to GND1/GND2) R2/R4 Feedback Resistance ~ 200 k Output Current ~ 600 mA IOUT TA Operating Ambient Temperature -40 ~ 85 C TJ Operating Junction Temperature -40 ~ 125 C Note 3: Please refer to the typical application circuit. Electrical Characteristics The * denotes the specifications that apply over TA = -40C ~ 85C, otherwise specifications are at TA=25C. Symbol Parameter VIN1/IN2 Each Converter Input Voltage Range IFB1/FB2 Each Converter Feedback Current VFB1/FB2 Each Converter Regulated Feedback Voltage VFB1/FB2 Each Converter Reference Voltage Line Regulation VIN1/IN2=2.5V to 5.5V Each Converter Peak Inductor Current VIN1/IN2=3V, VFB=0.5V or VOUT=90%, Duty cycle < 35% IPK Copyright ANPEC Electronics Corp. Rev. A.4 - Aug., 2010 APW7134 Test Conditions VFB1/FB2=0.6V 2 Unit Min. Typ. Max. * 2.5 - 5.5 V * -30 - 30 nA * 0.588 0.6 0.612 V * - 0.04 0.4 %/V 0.75 1 1.25 A www.anpec.com.tw APW7134 Electrical Characteristics (Cont.) The * denotes the specifications that apply over TA = -40C ~ 85C, otherwise specifications are at TA=25C. Symbol VLOADR Parameter APW7134 Test Conditions Each Converter Load Regulation Unit Min. Typ. Max. - 0.5 - % Each Converter Quiescent Current Duty Cycle=0; VFB=1.5V - 300 400 A IQ-SD Each Converter Quiescent Current in Shutdown VEN1/EN2=0V, VIN=4.2V - 0.1 1 A fOSC Each Converter Oscillator Frequency VFB=0.6V 1.2 1.5 1.8 MHz fOSC_FFB Each Converter Frequency Foldback VFB=0V - 210 - kHz RDS-P Each Converter On Resistance of PMOSFET ISW =100mA - 0.4 0.5 RDS-N Each Converter On Resistance of NMOSFET ISW =-100mA - 0.35 0.45 ILSW Each Converter SW Leakage Current VEN1=0V,VSW =0V or 5V, VIN=5V - 0.01 1 A IQ VEN1/EN2 Each Converter Enable Threshold * 0.3 1 1.5 V IEN1/EN2 EN1/EN2 Leakage Current * - 0.01 1 A Copyright ANPEC Electronics Corp. Rev. A.4 - Aug., 2010 3 www.anpec.com.tw APW7134 Typical Operating Characteristics Oscillator Frequency 0.615 1800 0.610 1700 VIN=5.5V 0.605 Frequency (kHz) Reference Voltage (V) Reference Voltage VIN=2.5V 0.600 0.595 1600 VIN=3.6V 1500 1400 1300 0.590 0.585 -50 -25 0 25 50 75 1200 -50 100 125 -25 0 Temperature (o C) Oscillator Frequency vs. Supply Voltage 100 125 VIN=2.7V 600 ON Resistance (m) 1700 Frequency (kHz) 75 700 TA=25oC 1600 1500 1400 1300 VIN=3.6V VIN=4.2V 500 400 300 200 NMOS PMOS 100 2 3 4 5 Supply Voltage (V) 0 -50 6 -25 0 25 50 75 Temperature (o C) 100 125 Efficiency vs. Output Current RDS(ON) vs. Input Voltage 600 100 90 500 VOUT=1.2V TA=25oC 80 PMOS VIN=2.7V VIN=3.6V 70 400 300 Efficiency (%) ON Resistance (m) 50 RDS(ON) vs. Temperature 1800 1200 25 Temperature (o C) NMOS 200 60 VIN=4.2V 50 40 30 20 100 10 0 0 1 2 3 4 5 0 0.1 6 Input Voltage (V) Copyright ANPEC Electronics Corp. Rev. A.4 - Aug., 2010 4 1.0 10.0 100.0 Output Current (mA) 1000.0 www.anpec.com.tw APW7134 Typical Operating Characteristics (Cont.) Efficiency vs. Output Current Efficiency vs. Output Current 100 100 90 80 90 70 60 VIN=4.2V 50 40 VIN=2.7V 70 VIN=4.2V 50 40 30 20 20 10 10 1.0 10.0 100.0 Output Current (mA) VIN=3.6V 60 30 0 0.1 VOUT=2.5V TA=25oC 80 VIN=3.6V Efficiency (%) Efficiency (%) VIN=2.7V VOUT=1.5V TA=25oC 0 0.1 1000.0 Efficiency vs. Input Voltage 95 85 IOUT=600mA Efficiency (%) Efficiency (%) 85 80 75 IOUT=10mA 70 IOUT=100mA 90 IOUT=100mA 90 65 IOUT=600mA 80 75 IOUT=10mA 70 65 60 60 V VOUT=1.5V TA=25oC 55 2 3 4 Input Voltage (V) 5 =1.8V 55 T OUT =25oC A 50 2 6 3 4 Input Voltage (V) 5 6 Dynamic Supply Current vs. Supply Voltage Efficiency vs. Input Voltage 100 400 IOUT=100mA 380 Dynamic Supply Current (A) 95 90 Efficiency (%) 1000.0 Efficiency vs. Input Voltage 95 85 IOUT=600mA 80 75 IOUT=10mA 70 65 60 VOUT=2.5V TA=25oC 55 50 10.0 100.0 Output Current (mA) 100 100 50 1.0 2 3 4 Input Voltage (V) Copyright ANPEC Electronics Corp. Rev. A.4 - Aug., 2010 5 360 340 320 300 280 260 240 220 200 6 5 2 3 4 5 Supply Voltage (V) 6 www.anpec.com.tw APW7134 Typical Operating Characteristics (Cont.) PMOSFET Leakage vs. Temperature NMOSFET Leakage vs. Temperature 800 300 VIN=5.5V VIN=5.5V 750 NMOSFET Leakage(nA) PMOSFET Leakage(nA) 250 200 150 100 650 600 550 50 0 -50 700 -25 0 25 50 75 100 500 -50 125 Temperature (o C) -25 0 25 50 75 100 125 Temperature (o C) Pin Description PIN FUNCTION NO. NAME 1 EN1 Channel 1 Enable Control Input. Drive EN1 above 1.5V to turn on the Channel 1. Drive EN1 below 0.3V to turn it off. In shutdown situation, all functions are disabled to decrease the supply current below 1A. There is no pull high or pull low ability inside. 2 FB1 Channel 1 Feedback Input. Connect FB1 to the center point of the external resistor divider. The feedback voltage is 0.6V. 3 IN2 Channel 2 Supply Input. Bypass to GND with a 4.7F or greater ceramic capacitor. 4 GND2 Ground 2. Connected the exposed pad to GND2. 5 SW2 Channel 2 Power Switch Output. Inductor connection to drains of the internal PMOSFET and NMOSFET switches. 6 EN2 Channel 2 Enable Control Input. Drive EN2 above 1.5V to turn on the Channel 2. Drive EN2 below 0.3V to turn it off. In shutdown situation, all functions are disabled to decrease the supply current below 1A. There is no pull high or pull low ability inside. 7 FB2 Channel 2 Feedback Input. Connect FB2 to the center point of the external resistor divider. The feedback voltage is 0.6V. 8 IN1 Channel 1 Supply Input. Bypass to GND with a 4.7F or greater ceramic capacitor. 9 GND1 Ground 1. Connected the exposed pad to GND1. 10 SW1 Channel 1 Power Switch Output. Inductor connection to drains of the internal PMOSFET and NMOSFET switches. Copyright ANPEC Electronics Corp. Rev. A.4 - Aug., 2010 6 www.anpec.com.tw APW7134 Typical Application Circuit VIN1/IN2 CIN1 4.7F 8 R5 100k IN1 1 OFF ON L1 2.2H VOUT1 1.8V 600mA R1 300k COUT1 10F 3 10 2 IN2 EN1 SW1 EN2 APW7134 FB1 SW2 FB2 GND1 GND2 R2 150k 9 CIN2 4.7F R6 100k 4 6 5 7 OFF ON L2 2.2H VOUT2 3.3V 600mA R3 680k COUT2 10F R4 150k Block Diagram Slop Compensation ICOMP Oscillator Frequency Shift IN1/IN2 RSENSE FB1/FB2 EA QSENS E 0.6V R Q Control Logic S Q EN1/EN2 QP SW1/SW2 QN Shutdown IRCMP GND1/GND2 Diagram Represents 1/2 of the APW7134 Copyright ANPEC Electronics Corp. Rev. A.4 - Aug., 2010 7 www.anpec.com.tw APW7134 Function Description Main Control Loop rent have to restrict to protect the electrical circuit in the short situation. The APW7134 has dual independent constant frequency current mode PWM step-down converters. All the main Dropout Operation and synchronous switches are internal to reduce the external components. During normal operation, the inter- An important detail to remember is that on resistance of PMOSFET switch will increase at low input supply voltage. Therefore, the user should calculate the power dissipa- nal PMOSFET is turned on, however, it is turned off when the inductor current at the input of ICOMP to reset the RS tion when the APW7134 is used at 100% duty cycle with low input voltage. latch. When the load current increases, it causes a slight to decrease in the feedback voltage, which in turn, it causes the EA's output voltage to increase until the average inductor current matches the new load current. While Slope Compensation Slope compensation provides stability in constant fre- the internal power PMOSFET is off, the internal power NMOSFET is turned on until the inductor current starts to quency current mode architecture by preventing sub-harmonic oscillations at high duty cycle. It is accomplished reverse, as indicated by the current reversal comparator IRCMP, or the beginning of next cycle. When the NMOSFET internally by adding a compensating ramp to the inductor current signal at duty cycle in excess of 40%. Normally, is turned off by IRCMP, it operates in the discontinuous this results in a reduction of maximum inductor peak current for duty cycles greater than 40%. In the APW7134, the conduction mode. reduction of inductor peak current is recovered by a special skill at high duty ratio. This allows the maximum in- Pulse Skipping Mode Operation At light load with a relative small inductance, the inductor current may reach zero. The internal power NMOSFET is ductor peak current to maintain a constant level through all duty ratio. turned off by the current reversal comparator, IRCMP, and the switching voltage will ring. This is discontinuous mode operation and normal behavior for the switching regulator. At very light load, the APW7134 will automatically skip some pulses in the pulse skipping mode to maintain the output regulation. The skipping process modulates smoothly depend on the load. Short Circuit Protection In the short circuit situation, the output voltage is almost zero volts. Output current is limited by the ICOMP to prevent the damage of electrical circuit. In the normal operation, the two straight lines of the inductor current ripple have the same height, it means the volts-seconds product is the same. When the short circuit operation occurs, the output voltage down to zero leads to the voltage across the inductor maximum in the on period and the voltage across the inductor minimum in the off period. In order to maintain the volts-seconds balance, the off-time must be extended to prevent the inductor current run away. Frequency decay will extend the switching period to provide more times to the off-period, and then the inductor cur- Copyright ANPEC Electronics Corp. Rev. A.4 - Aug., 2010 8 www.anpec.com.tw APW7134 Application Information IL Inductor Selection IOUT Due to the high switching frequency as 1.5MHz, the inductor value of the application field of APW7134 is usually IIN 0A from 1H to 4.7H. The criteria for selecting a suitable inductor depend on the worst current ripple throughout the inductor. The worst current ripple is defined as 40% of the fully load capability. In the APW7134 applications, I(CIN) IIN 0A the worst value of current ripple is 240mA, the 40% of 600mA. Evaluate L by equation (1): L= (VIN - VOUT ) VOUT VIN 1 IL fS (1) 0A where fS is the switching frequency of APW7134 and IL is I(COUT) the value of the worst current ripple, it can be any value of current ripple that smaller than the worst value you can I(Q1) accept. In order to perform high efficiency, selecting a low DC resistance inductor is a helpful way. Another impor- IOUT tant parameter is the DC current rating of the inductor. The minimum value of DC current rating is equal to the 0A full load value of 600mA plus the half of the worst current ripple, 120mA. Choosing inductors with suitable DC cur- D*TS 0A Input Capacitor Selection Figure 2. The input capacitor must be able to support the maxi- Observe the waveform of I(CIN), the RMS value of I(CIN) is mum input operating voltage and maximum RMS input current. The Buck converter absorbs current from input in I (CIN ) = (IOUT - IIN )2 D + IIN 1 - D 2 pulses. D= I(CIN) Q1 L VIN CIN Q2 2 (2) Replace D and IIN by following relation: I(Q1) IIN PWM (1-D)*TS rent rating to ensure the inductors' operation in the saturation. VOUT VIN (3) IIN = D IOUT I(COUT) I(L) COUT (4) The RMS value of input capacitor current equal: IOUT I (CIN ) = IOUT D(1 - D) (5) When D=0.5, the RMS current of input capacitor will be maximum value. Use this value to choose the input ca- PWM pacitor with suitable current rating. Figure 1. Figure 1 shows a schematic of a Buck structure. The waveforms is shown as Figure 2. Copyright ANPEC Electronics Corp. Rev. A.4 - Aug., 2010 9 www.anpec.com.tw APW7134 Application Information (Cont.) Output Capacitor Selection Thermal Consideration The output voltage ripple is a significant parameter to estimate the performance of a convertor. There are two APW7134 is a high efficiency switching converter, it means less power loss transferred into heat. Due to the on re- discrete components that affect the output voltage ripple bigger or smaller. It is recommended to use the criterion sistance difference between internal power PMOSFET and NMOSFET, the power dissipation in the high convert- has mentioned above to choose a suitable inductor. Then, based on this known inductor current ripple condition, ing ratio is greater than the low converting ratio. The worst case is the mainly conduction loss dissipate on the inter- the output voltage ripple consists of two portions; one is the product of ESR and inductor current ripple, and the nal power PMOSFET in the dropout operation. The power dissipation nearly is defined as below: [ other is the function of the inductor current ripple and the output capacitance. Figure 3 shows the waveforms to explain the part decided by the output capacitance. IL 0A ] PD = (IOUT )2 RDS_ONP D + RDS_ONN (1 - D) (9) APW7134 has internal over-temperature protection. When the junction temperature reaches 150 centigrade, APW7134 will turn off both internal power PMOSFET and NMOSFET. The estimation of the junction temperature, I(COUT) TJ, defined as below: TJ = PD JA 0.5TS VOUT1 (10) where the JA is the thermal resistance of the package utilized by APW7134. VOUT Output Voltage Setting APW7134 has the adjustable version for output voltage setting by the users. A suggestion of maximum value of Figure 3. R2 is 200k for keeping the minimum current that provides enough noise rejection ability through the resistor Output Capacitor Selection Evaluate the VOUT1 by the ideal of energy equalization. divider. The output voltage programmed by the following equation: According to the definition of Q, Q= 1 1 1 IL TS = COUT VOUT1 2 2 2 (6) VOUT = 0.6 1 + where TS is the inverse of switching frequency and the IL is the inductor current ripple. Move the COUT to the left side R1 R2 (11) VOUT to estimate the value of VOUT1 as the following equation: IL TS 8 COUT (7) APW7134 As mentioned above, one part of output voltage ripple is the product of the inductor current ripple and ESR of out- FB VOUT1 = put capacitor. The equation (8) explains the output voltage ripple estimation. VOUT = IL ESL + TS 8 COUT Copyright ANPEC Electronics Corp. Rev. A.4 - Aug., 2010 R1 R2 (8) 10 www.anpec.com.tw APW7134 Application Information (Cont.) Layout Consideration The high current paths (GND1/GND2, IN1/IN2, and SW1/ SW2) should be placed very close to the device with short, direct, and wide traces. Input capacitors should be placed as close as possible to the respective IN and GND pins. The external feedback resistors should be placed next to the FB pins. Keep the switching nodes SW1/SW2 short and away from the feedback network. Copyright ANPEC Electronics Corp. Rev. A.4 - Aug., 2010 11 www.anpec.com.tw APW7134 Package Information DFN3x3-10 D E A Pin 1 A1 D2 A3 L K E2 Pin 1 Corner e S Y M B O L DFN3x3-10 MILLIMETERS INCHES MIN. MAX. MIN. MAX. A 0.80 1.00 0.031 0.039 A1 0.00 0.05 0.000 0.002 0.30 0.007 0.012 0.122 A3 b 0.20 REF 0.18 0.008 REF D 2.90 3.10 0.114 D2 2.20 2.70 0.087 0.106 E 2.90 3.10 0.114 0.122 1.75 0.055 0.069 E2 1.40 e 0.50 BSC L 0.30 K 0.20 0.020 BSC 0.012 0.50 0.020 0.008 Note : 1. Followed from JEDEC MO-229 VEED-5. Copyright ANPEC Electronics Corp. Rev. A.4 - Aug., 2010 12 www.anpec.com.tw APW7134 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 DFN3x3-10 A H T1 C d D W E1 F 3302.00 50 MIN. 12.4+2.00 -0.00 13.0+0.50 -0.20 1.5 MIN. 20.2 MIN. 12.00.30 1.750.10 5.50.05 P0 P1 P2 D0 D1 T A0 B0 K0 2.00.05 1.5+0.10 -0.00 1.5 MIN. 0.6+0.00 -0.40 3.300.20 3.300.20 1.30 0.20 4.00.10 8.00.10 (mm) Devices Per Unit Package Type Unit Quantity DFN3x3-10 Tape & Reel 3000 Copyright ANPEC Electronics Corp. Rev. A.4 - Aug., 2010 13 www.anpec.com.tw APW7134 Taping Direction Information DFN3x3-10 USER DIRECTION OF FEED Classification Profile Copyright ANPEC Electronics Corp. Rev. A.4 - Aug., 2010 14 www.anpec.com.tw APW7134 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. 3C/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 5C 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 (Tp)* package body Temperature Time 25C 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) 3 Package Thickness <2.5 mm Volume mm <350 235 C Volume mm 350 220 C 2.5 mm 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 - Aug., 2010 15 Description 5 Sec, 245C 1000 Hrs, Bias @ Tj=125C 168 Hrs, 100%RH, 2atm, 121C 500 Cycles, -65C~150C VHBM2KV VMM200V 10ms, 1tr100mA www.anpec.com.tw APW7134 Customer Service Anpec Electronics Corp. Head Office : No.6, Dusing 1st Road, SBIP, Hsin-Chu, Taiwan 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 - Aug., 2010 16 www.anpec.com.tw