AME AME5143 1.4MHz Boost Converter With 30V Internal FET Switch General Description Typical Application The AME5143 switching regulator is current-mode boost converters operating at fixed frequency of 1.4MHz. The use of MSOP-8/PP package, made possible by the minimal power loss of the internal 1.8A switch, and use of small inductor and capacitors result in the industry's highest power density. The 30V internal switch makes these solutions perfect for boosting to voltages up to 30V. C3 10µF L1 10µH V IN 5V C1 4.7µF L2 10µH SW IN VOUT 6V D1 R1 59K CF 820pF EN AME5143 SW CS CS GND FB Rcs These parts have a logic-level shutdown pin that can be used to reduce quiescent current and extend battery life. Protection is provided through cycle-by-cycle current limiting and thermal shutdown. Internal compensation simplifies and reduces component count. Cs C2 22µF R2 15K Figure 1. 5V to 6V Boost Converter L1 4.7µH Features z z z z z z z z z 30V DMOS FET Switch 1.4MHz Switching Frequency Low RDSON DMOS FET Switch Current Up to 1.8A (CS Connects to GND) Wide Input Voltage Range (2.7V-5.5V) Low Shutdown Current (<1µA) MSOP-8/PP Package Uses Tiny Capacitors and Inductor Meet RoHS Standards VIN 3.3V D1 IN SW AME5143 R1 30K EN C1 4.7µF VOUT 5V 750mA FB GND CS R2 10K CF 820pF C2 22µF Figure 2. 3.3V to 5V Boost Converter L1 10µH VIN 5V Applications z z z z z White LED Current Source PDA's and Palm-Top Computers Digital Cameras Portable Phones and Games Local Boost Regulator D1 IN SW AME5143 EN C1 4.7µF VOUT 12V 500mA GND R1 117K FB CS R2 13.3K CF 220pF C2 10µF Figure 3. 5V to 12V Boost Converter Rev.A.01 1 AME 1.4MHz Boost Converter with 30V Internal FET Switch AME5143 Function Block Diagram EN SW IN THERMAL SHUTDOWN SHUTDOWN CIRCUITRY R5 R6 + Q1 Q2X8 - R + Gm RAMP GENERATOR FB Σ - Q R DRIVER R S RC R3 oscillator CURRENT LIMIT COMP CC + R4 - RW CS GND Figure 4. Functional Block Diagram 2 Rev.A.01 AME 1.4MHz Boost Converter With 30V Internal FET Switch AME5143 n Pin Configuration MSOP-8/PP Top View 8 7 6 5 AME5143AE2Axxx 1. IN 2. EN 3. GND AME5143 4. FB 5. SW 6. SW 7. CS 8. CS 1 2 3 4 Die Attach: Conductive Epoxy Note: The rectangular area enclosed by dashed line represents Exposed Pad and is GND. Rev.A.01 3 AME 1.4MHz Boost Converter with 30V Internal FET Switch AME5143 n Pin Description AME5143AE2A MSOP-8/PP Pin Number Pin Name Pin Description 1 IN Analog and Power input. Input Supply Pin. Place bypass capacitor as close to VIN as possible. 2 EN Enable, active high. The enable pin is an active high control. Tie this pin above 2V to enable the device. Tie this pin below 0.4V to turn off the device. 3 GND Ground. Tie directly to ground plane. Output voltage feedback input. Set the output voltage by selecting values for R1 and R2 using: 4 FB V R 1 = R 2 out − 1 1 . 23 V Connect the ground of the feedback network to a GND plane. 4 5,6 SW Power Switch input. This is the drain of the internal NMOS power switch. Minimize the metal trace area connected to this pin to minimize EMI. 7,8 CS Current sense pins Rev.A.01 AME 1.4MHz Boost Converter With 30V Internal FET Switch AME5143 n Ordering Information AME5143 x x x x xxx x Special Feature Output Voltage Number of Pins Package Type Operating Ambient Temperature Range Pin Configuration Pin Configuration A (MSOP-8/PP) Rev.A.01 1. IN 2. EN 3. GND 4. FB 5. SW 6. SW 7. CS 8. CS Operating Ambient Temperature Range Package Type Number of Output Voltage Pins E: -40OC to +85OC 2: MSOP/PP A: 8 Special Feature ADJ: Adjustable Z: Lead free 5 AME 1.4MHz Boost Converter with 30V Internal FET Switch AME5143 n Available Options Part Number Marking* Output Voltage Package Operating Ambient Temperature Range AME5143AE2AADJZ 5143 Ayww ADJ MSOP-8/PP -40OC to +85OC Note: yww represents the date code and pls refer to Date Code Rule before Package Dimension. * A line on top of the first letter represents lead free plating such as 5143. Please consult AME sales office or authorized Rep./Distributor for the availability of package type. 6 Rev.A.01 AME 1.4MHz Boost Converter With 30V Internal FET Switch AME5143 n Absolute Maximum Ratings Parameter Input Supply Voltage EN, FB Voltages SW Voltage Symbol Maximum Unit VIN 6 V VEN ,V FB VIN V VSW 30 V B* ESD Classification Caution: Stress above the listed absolute maximum rating may cause permanent damage to the device. * HBM B:2000V~3999V n Recommended Operating Conditions Parameter Symbol Rating Ambient Temperature Range TA -40 to +85 Junction Temperature Range TJ -40 to +125 Storage Temperature Range TSTG -65 to +150 Unit o C n Thermal Information Parameter Thermal Resistance* (Junction to Case) Package Die Attach MSOP-8/PP Symbol Maximum θJC 9 Unit O Thermal Resistance (Junction to Ambient) MSOP-8/PP Internal Power Dissipation MSOP-8/PP Conductive Epoxy Solder Iron (10 Sec)** θJA 142 PD 900 350 C/W mW o C * Measure θJC on backside center of molding compund if IC has no tab. ** MIL-STD-202G 210F Rev.A.01 7 AME 1.4MHz Boost Converter with 30V Internal FET Switch AME5143 n Electrical Specifications VIN = 5V, EN = VIN, TA= 25oC, I L = 0A, unless otherwise noted. Parameter Symbol Test Condition Input Voltage VIN Switch Current Limit ICL Rcs = 0 VCS ISW = 5mA Switch Current Limit Trip Volatge Point 90 TA = 25 C VFB VIN = 3V Feedback Pin Bias Current IFB VFB = 1.23V 0.6 0.5 1.205 TA = 25 C 1.255 V 60 500 nA 2 VIN = 5V 3 o TA = -40 to +85 C TA = 25oC VIN = 5V Over Temperature Protection OTP Rising Edge 500 o 2.15 VIN =2.7V to 5.5V OTP Hysteresis Temperature 1 2.35 2.55 o VIN = 3V, TA = -40 to +85oC 1 1.4 Maximum Duty Cycle DMAX VIN = 3V, TA = -40 to +85oC 86 93 ISW EN = 0V C C 0.02 0.1 TA = -40 to +85oC V 20 fSW EN Threshold µA 160 Switching Frequency EN Input Threshold (Low) (Shutdown) EN Input Threshold (High) (Enable the device) µA o 2.7V <= VIN <= 5.5V Switch Leakage 8 0.01 ∆VFB ∆VIN FB Voltage Line Regulation mA 400 EN = 0V UVP Ω 1.23 TA = -40 to +85 C Undervoltage Lockout 0.7 mV 0.8 o Shutdown Current A 0.4 TA = -40 to +85oC Feedback Pin Reference Voltage FB = 1.3V (Not Switching) V 0.7 O IQ 5.5 110 TA = -40 to +85 C FB = 1.15V (Switching) Units 100 o RDSON Max 1.8 TA = 25OC VIN = 3.3V Quiescent Current Typ 2.7 VIN = 5V Switch ON Resistance Min %V 1.65 MHz % 2 µA 0.4 V TA = -40 to +85oC 2 Rev.A.01 AME AME5143 1.4MHz Boost Converter With 30V Internal FET Switch n Detailed Description n Application Hints The AME5143 is a switching converter IC that operates at a fixed frequency (1.4MHz) for fast transient response over a wide input voltage range and incorporates pulse-bypulse current limiting protection. Operation can be best understood by referring to Figure 4. Because this is current mode control, a 40mΩ sense resistor RW in series with the switch FET is used to provide a voltage (which is proportional to the FET current) to both the input of the pulse width modulation (PWM) comparator and the current limit amplifier. We can develop an expression which allows the maximun current limit to be calculated. Selecting The External Capacitors RCS = VCS / ICL - 40mΩ At the beginning of each cycle, the S-R latch turns on the FET. As the current through the FET increases, a voltage (proportional to this current) is summed with the ramp coming from the ramp generator and then fed into the input of the PWM comparator. When this voltage exceeds the voltage on the other input (coming from the Gm amplifier), the latch resets and turns the FET off. Since the signal coming from the Gm amplifier is derived from the feedback (which samples the voltage at the output), the action of the PWM comparator constantly sets the correct peak current through the FET to keep the output voltage in regulation. Q1 and Q2 align with R3 - R6 form a bandgap voltage reference used by the IC to hold the output in regulation. The currents flowing through Q1 and Q2 will be equal, and the feedback loop will adjust the regulated output to maintain this. Because of this, the regulated output is always maintained at a voltage level equal to the voltage at the FB node "multiplied up" by the ratio of the output resistive divider. The current limit comparator feeds directly into the flipflop that drives the switch FET. If the FET current reaches the limit threshold, the FET is turned off and the cycle terminated until the next clock pulse. The current limit input terminates the pulse regardless of the status of the output of the PWM comparator. Rev.A.01 The best capacitors for use with the AME5143 are multilayer Ceramic capacitors. They have the lowest ESR (equivalent series resistance) and highest resonance frequency, which makes them optimum for use with high frequency switching Converters. When selecting a ceramic capacitor, only X5R and X7R dielectric types should be used. Other types such as Z5U and Y5F have such severe loss of capacitance due to effects of temperature variation and applied voltage, they may provide as little as 20% of rated capacitance in many typical applications. Always consult capacitor manufacturer’ s data curves before selecting a capacitor. High-quality ceramic capacitors can be obtained from Taiyo-Yuden, AVX, and Murata. Selecting The Output Capacitor A single ceramic capacitor of value 4.7µF to 10µF will provide sufficient output capacitance for most applications. If larger amounts of capacitance are desired for improved line support and transient response, tantalum capacitors can be used. Aluminum electrolytic with ultra low ESR such as Sanyo Oscon can be used, but are usually prohibitively expensive. Typical AI electrolytic capacitors are not suitable for switching frequencies above 500kHz due to significant ringing and temperature rise due to self-heating from ripple current. An output capacitor with excessive ESR can also reduce phase margin and cause instability. In general, if electrolytic are used, it is recommended that. They be paralleled with ceramic capacitors to reduce ringing, switching losses, and output voltage ripple. Selecting The Input Capacitor An input capacitor is required to serve as an energy reservoir for the current which must flow into the coil each time the switch turns ON. This capacitor must have extremely low ESR, so ceramic is the best choice. We recommend a nominal value of 4.7µF, but larger values can be used. Since this capacitor reduces the amount of voltage ripple seen at the input pin, it also reduces the amount of EMI passed back along that line to other circuitry. 9 AME 1.4MHz Boost Converter with 30V Internal FET Switch AME5143 n Application Hints Feed-Forward Compensation Shutdown Pin Operation Although internally compensated, the feed-forward capacitor Cf is required for stability. Adding this capacitor puts a zero in the loop response of the Converter. The recommended frequency for the zero fz should be approximately 6kHz. Cf can be calculated using the formula: The device is turned off by pulling the shutdown pin low. If this function is not going to be used, the pin should be tied directly to V IN. If the SHDN function will be needed, a pull-up resistor must be used to VIN (approximately 50k100k recommended). The EN pin must not be left unterminated. Cf = 1 / (2 x π x R1 x fz) Selecting Diodes The external diode used in the typical application should be a Schottky diode. A 30V diode such as the MBR0530 is recommended. The MBR05XX series of diodes are designed to handle a maximum average current of 0.5A. For applications exceeding 0.5A average but less than 1A, a Microsemi UPS5817 can be used. Thermal Consuderations At higher duty cycles, the increased ON time of the FET means the maximum output current will be determined by power dissipation within the AME5143 FET switch. The switch power dissipation from ON-state conduction is calculated by: P(SW) = D x I2IND(AVE) x RDS(ON) There will be some switching losses as well, so some derating needs to be applied when calculating IC power dissipation. Inductor Suppliers Recommended suppliers of inductors for this product include, but are not limited to Sumida, Coilcraft, Panasonic, TDK and Murata. When selecting an inductor, make certain that the continuous current rating is high enough to avoid saturation at peak currents. A suitable core type must be used to minimize core (switching) losses, and wire power losses must be considered when selecting the current rating. 10 Rev.A.01 AME 1.4MHz Boost Converter With 30V Internal FET Switch AME5143 IQ VIN(Active) vs Temperature Oscillator Frequency vs Temperature 1.60 3.50 2.50 2.00 1.50 1.00 0.50 0.00 -50 1.55 Oscillator Frequency (MHz) IQ VIN Active (mA) 3.00 -25 0 25 50 75 100 1.50 1.45 1.40 1.35 V IN=3.3V 1.30 1.25 V IN=5V 1.20 1.15 1.10 1.05 1.00 -50 125 Temperature (O C) -25 0 25 50 75 100 125 100 125 o Temperature ( C) Max. Duty Cycle vs Temperature IQ VIN (Idle) vs Temperature 95.0 500 94.0 400 VIN =3.3V IQ VIN (Idle) (µA) Max Duty Cycle (%) 94.5 93.5 93.0 VIN =5V 92.5 92.0 91.5 300 200 100 91.0 90.5 90.0 -50 -25 0 25 50 75 100 0 -50 125 -25 Feedback Voltage vs Temperature 75 Feedback Bias Current vs Temperature Feedback Bias Current (µA) Feedback Voltage (V) 50 0.04 1.24 1.23 1.22 1.21 -25 0 25 50 75 o Temperature ( C) Rev.A.01 25 O Temperature ( C) 1.20 -50 0 Temperature ( C) o 100 125 0.03 0.02 0.01 0 -50 -25 0 25 50 75 100 125 Temperature ( oC) 11 AME 1.4MHz Boost Converter with 30V Internal FET Switch AME5143 RDS(ON) vs Temperature RDS(ON) vs VIN 800 750 700 700 650 600 550 RDS(ON) (mΩ) RDS(ON) (mΩ) 600 V IN = 3.3V 500 400 VIN = 5V 300 500 450 400 350 300 250 200 200 150 100 100 50 0 -50 -25 0 25 50 75 100 0 2.5 125 3 3.5 4 4.5 o Temperature ( C) 5 5.5 6 6.5 7 7.5 8 VIN (V) Efficiency vs Iout Efficiency vs Iout 95 100 Efficiency (%) Efficiency (%) 90 90 85 80 70 60 80 VIN=3.3V VOUT=5V 75 0 100 200 300 400 500 600 700 800 VIN =5V VOUT=12V 50 40 900 0 IOUT(mA) 100 200 300 400 500 600 IOUT(mA) Start Up Waveform EN 1V/Div VOUT 2V/Div IL 500mA/Div V IN= 3.3V V OUT=5V ILOAD =700mA 12 400µS/Div Rev.A.01 AME 1.4MHz Boost Converter With 30V Internal FET Switch AME5143 n Tape and Reel Dimension MSOP-8/PP P PIN 1 W AME AME Carrier Tape, Number of Components Per Reel and Reel Size Rev.A.01 Package Carrier Width (W) Pitch (P) Part Per Full Reel Reel Size MSOP-8/PP 12.0±0.1 mm 4.0±0.1 mm 4000pcs 330±1 mm 13 AME 1.4MHz Boost Converter with 30V Internal FET Switch AME5143 n Package Dimension MSOP-8/PP TOP VIEW SIDE VIEW SYMBOLS L D1 L2 E1 E E2 1 0' FRONT VIEW D A2 A1 14 e INCHES MIN MAX MIN MAX A1 0.000 0.150 0.0000 0.0059 A2 0.750 0.950 0.0295 0.0374 b 0.220 0.380 0.0087 0.0150 E 3.000 BSC 0.1181 BSC D 3.000 BSC 0.1181 BSC e 0.650 BSC 0.0256 BSC E1 4.900 BSC 0.1929 BSC L 0.400 θ' 0 L2 b MILLIMETERS 0.800 o 8 o 0.950 REF 0.0157 0 o 0.0315 8 o 0.0374 REF E2 1.380 1.800 0.0543 0.0709 D1 1.420 1.800 0.0559 0.0709 Rev.A.01 www.ame.com.tw E-Mail: [email protected] Life Support Policy: These products of AME, Inc. are not authorized for use as critical components in life-support devices or systems, without the express written approval of the president of AME, Inc. AME, Inc. reserves the right to make changes in the circuitry and specifications of its devices and advises its customers to obtain the latest version of relevant information. AME, Inc. , March 2009 Document: 1259-DS5143-A.01 Corporate Headquarter AME, Inc. 2F, 302 Rui-Guang Road, Nei-Hu District Taipei 114, Taiwan, R.O.C. Tel: 886 2 2627-8687 Fax: 886 2 2659-2989