ME3102AM5G

ME3102 1A Step-Down DC-DC Converter ME3102 General Description Features The ME3102 is a step-down current-mode, DC-DC  Efficiency up to 96% converter. At heavy load, the constant-frequency PWM  Only 45μA (TYP.) Quiescent Current control performs excellent stability and transient  Output Current: Up to 1A response. To ensure the longest battery life in portable  Internal Synchronous Rectifier applications, the ME3102 provides a power-saving  1.75MHz/1.4MHz Switching Frequency pulse -Skipping Modulation (PSM) mode to reduce  Soft Start quiescent current under light load operation to save  Short Circuit Protection power. The ME3102 supports a range of input voltages from 2.5V to 5.5V, allowing the use of a single Li+/Li-polymer cell, multiple Alkaline/NiMH cell, USB, and other standard power sources. The output voltage is adjustable from 0.6V to the input voltage, while the part number suffix ME3102 indicates pre-set output voltage of 3.3V, 2.8V, 2.5V, 1.8V, 1.5V, 1.2V or adjustable. All versions employ internal power switch and synchronous rectifier for to minimize external part count and realize high efficiency. During shutdown, the input is disconnected from the output and the shutdown current is less than 0.1μA. Other key features include under-voltage lockout to prevent deep battery discharge. Typical Applications Package  Cellular Phone  5-pin SOT23-5  Portable Electronics  6-pin DFN2*2-6  Wireless Devices  Cordless Phone  Computer Peripherals  Battery Powered Widgets  Electronic Scales  Digital Frame V06 www.microne.com.cn Page 1 of 12 ME3102 Typical Application L 0.6uH-4.7uH VIN C1A 22uF VO VIN C1B 0.1 uF SW ME3102 CFW CO 100pF 22uF R1 GND FB R2 EN Vo=0.6x(1+R1/R2) Selection Guide ME 31 02 X X G Environment mark Package M5:SOT23-5 N6A:DFN2*2-6 Version or Function Product Type Product Series Microne product series product description ME3102AM5G VFB=0.6V；Fosc=1.75MHz；Package：SOT23-5 ME3102BM5G VFB=0.6V；Fosc=1.4MHz；Package：SOT23-5 ME3102BN6AG VFB=0.6V； Fosc=1.4MHz；Package：DFN2*2-6 ME3102CN6AG VFB=0.6V； Fosc=1.4MHz；Package：DFN2*2-6；Different Pin Assignment NOTE: V06 If you need other voltage and package, please contact our sales staff。 www.microne.com.cn Page 2 of 12 ME3102 Pin Configuration 5 4 1 2 1 6 2 5 3 4 3 SOT23-5 DFN2*2-6 Pin Assignment Pin Number （SOT23-5） Pin Number（DFN2*2-6L） Name Function ME3102A/B ME3102B ME3102C 1 3 4 EN Chip Enable 2 2 6 GND Ground 3 1 1 SW Switch 4 5 5 VIN Input 5 4 3 FB Feedback 6 2 NC No Connect Block Diagram V06 www.microne.com.cn Page 3 of 12 ME3102 Absolute Maximum Ratings Parameter Power supply voltage, VIN voltage at EN、FB Pin voltage at SW Pin Symbal Rating Unit VIN 6.0 V VEN,VFB 6.0 V VSW -0.3～VIN V 0.6 mW 1.3 mW SOT23-5 Internal Power Dissipation PD DFN2*2-6 SOT23-5 210 θJA Thermal resistance DFN2*2-6 ºC/W 95 Operating Ambient Temperature Topr -40~+85 °C Storage Temperature Tstg -55~+150 °C Tsolder 260(10S) °C Soldering temperature and time Electrical Characteristics VIN=3.6V, VO=1.8V, CIN =22μF//0.1uF, CO =22μF, L=2.2μH,T A =25 °C, unless otherwise noted. Parameter Symbol Test condition Min Typ. Max Unit Input voltage range VIN 2.5 - 5.5 V Regulated Feedback Voltage VFB 0.588 0.6 0.612 V Regulated Output Voltage Accuracy VO IO =100mA -3 - +3 % Output Voltage Line Regulation LNR VIN = 2.5V to5V,Io=10mA - 0.2 0.5 %/V Output Voltage Load Regulation LDR Io=1.0mA to 800mA - 0.5 1.5 % Quiescent Current IQ No load - 45 70 μA Shutdown Current ISD VEN=0V - 0.1 1 μA Current limiting protection Ilimit SW Leakage Current ILSW 1.6 -1 VO=100% Oscillator Frequency FOSC A 1 ME3102A 1.45 1.75 2.1 ME3102B/C 1.2 1.4 1.8 VFB=0V or ME3102A 600 VO=0V ME3102B/C 500 μA MHz KHz P MOSFET - 0.3 0.6 Ω N MOSFET - 0.3 0.6 Ω η - 96 - % EN Threshold High VEH 1.5 - - V EN Threshold Low VEL - - 0.3 V Drain-Source On-State Resistance High Efficiency V06 RDS(ON) IDS=100mA www.microne.com.cn Page 4 of 12 ME3102 Typical Performance Characteristics 1. Efficiency VS Output Current (VO=1.8V) Efficiency VS Output Current (VO=3.3V) Efficiency VS.Output Current (Vo=3.3V) Efficiency VS.Output Current (Vo=1.8V) 100 100 90 80 Efficiency (%) Efficiency (%) 90 70 VIN =4.2V 60 VIN =2.5V VIN =3.6 50 80 VIN=3.6 70 VIN=4.2V 60 VIN =5V 50 40 40 30 30 1 1 10 100 200 300 400 500 600 700 800 900 1000 10 100 200 2. Efficiency VS Input Voltage (VO=1.8V) 100 90 90 Efficiency(%) 100 Efficiency(%) 600 700 800 900 1000 Efficiency VS.Input Voltage (Vo=3.3V) 80 70 IO=800 IO=100 50 40 80 70 IO=10mA IO=100m IO=800m 60 50 40 30 30 2.5 3 3.5 4 4.5 5 5.5 3.6 3.75 4 4.25 3. VFB VS Input Voltage 4.75 5 5.25 5.5 4. VFB VS Output Current VFB VS Output Current VFB VS Input Voltage 0.606 0.604 0.602 0.6 0.598 0.596 0.594 0.592 0.59 0.588 4.5 Input Voltage(V) Input Voltage(V) 0.608 0.604 VFB(V) VFB(V) 500 Efficiency VS Input Voltage (VO=3.3V) Efficiency VS.Input Voltage (Vo=1.8V) IO=10m 400 Output Current(mA) Output Current (mA) 60 300 IO=100mA 3.5 4 4.5 5 5.5 VIN =3.6V 0 200 400 600 VIN=4.2V 800 Output Current(mA) Input Voltage(V) V06 0.592 0.584 IO=600mA 3 0.596 0.588 IO=800mA 2.5 VIN =2.5V 0.6 www.microne.com.cn Page 5 of 12 1000 ME3102 5. Output Voltage VS Output Current (VO=1.8V) 6. VFB VS Temperature VFB VS Temperature 1.83 0.608 1.82 0.606 0.604 1.81 V FB ( V) Output Voltage (V) Output Voltage VS Output Current (Vo=1.8V) 1.8 1.79 0.602 0.6 0.598 0.596 1.78 VIN=2.5V VIN=5V VIN=3.6 VIN=4.2 0.594 1.77 0.592 10 100 200 300 400 500 600 700 800 900 1000 -25 0 25 50 75 100 Temperature(℃) Output Current(mA) 7. Dynamic Supply Current VS Input Voltage (VO=1.8V) 8. Dynamic Supply Current VS Temperature (V IN=3.6V，VO=1.8V) Supply Current VS Input Voltage 50 Supply Current(uA) 45 40 35 30 25 20 15 10 2.5 3 3.5 4 4.5 5 5.5 Input Voltage(V) 9. Oscillator Frequency VS Input Voltage Oscillator Frequency (MHz) Oscillator Frequency VS Input Voltage 2 1.9 1.8 1.7 1.6 1.5 1.4 1.3 1.2 2.5 3 3.5 4 4.5 5 5.5 6 Input Voltage(V) V06 www.microne.com.cn Page 6 of 12 125 150 ME3102 Application Information The basic ME3102 application circuit is shown as up figures. External component selection is determined by the load requirement, selecting L first and then CIN and COUT 。It is better to use the patch ceramic capacitors at COUT.. Inductor Selection For most applications, the value of the inductor will fall in the range of 0.6μH to 4.7μH. Its value is chosen based on the desired ripple current. Large value inductors lower ripple current and small value inductors result in higher ripple currents. Higher VIN or VOUT also increases the ripple current as shown in equation 1. A reasonable starting point for setting ripple current is △IL=400mA (40% of 1A). IL =  V  1 VOUT  1  OUT  f L VIN   The DC current rating of the inductor should be at least equal to the maximum load current plus half the ripple current to prevent core saturation. Thus, a 2A rated inductor should be enough for most applications. For better efficiency, choose a low DC-resistance inductor. VO 0.6V 1.2V 1.5V 1.8V/2.5V/2.8V/3.3V L 0.6uH 1.2μH 1.5μH 2.2μH/3.3μH/4.3μH CIN and COUT Selection In continuous mode, the source current of the top MOSFET is a square wave of duty cycle V OUT/VIN. To prevent large voltage transients, a low ESR input capacitor sized for the maximum RMS current must be used. The maximum RMS capacitor current is given by: CIN required IRMS  IOMAX  VOUT  VIN  VOUT   VIN 1 2 This formula has a maximum at VIN=2VOUT, where IRMS=IOUT/2. This simple worst-case condition is commonly used for design because even significant deviations do not offer much relief. Note that the capacitor manufacturer's ripple current ratings are often based on 2000 hours of life. This makes it advisable to further derate the capacitor, or choose a capacitor rated at a higher temperature than required. Consult the manufacturer if there is any question. The selection of COUT is driven by the required effective series resistance (ESR). Typically, once the ESR requirement for COUT has been met, the RMS current rating generally far exceeds the IRIPPLE (P-P) requirement. The output ripple △VOUT is determined by:  1  VOUT  IL  ESR   8fCOUT   Where f = operating frequency, COUT=output capacitance and ΔIL= ripple current in the inductor. For a fixed output V06 www.microne.com.cn Page 7 of 12 ME3102 voltage, the output ripple is highest at maximum input voltage since ΔI increases with input voltage. Using Ceramic Input and Output Capacitors Higher values, lower cost ceramic capacitors are now becoming available in smaller case sizes. Their high ripple current, high voltage rating and low ESR make them ideal for switching regulator applications. Using ceramic capacitors can achieve very low output ripple and small circuit size. When choosing the input and output ceramic capacitors, choose the X5R or X7R dielectric formulations. These dielectrics have the best temperature and voltage characteristics of all the ceramics for a given value and size. Setting the Output Voltage The internal reference is 0.6V (Typical). The output voltage is calculated as below: R1   VO  0.6   1  R2   The output voltage is given by Table 1. Table 1: Resistor selection for output voltage setting VO (V) R1 (KΩ) R2 (KΩ) 1.2 100 100 1.5 150 100 1.8 200 100 2.5 380 120 3.3 540 120 100% Duty Cycle Operation As the input voltage approaches the output voltage, the converter turns the P-channel transistor continuously on. In this mode the output voltage is equal to the input voltage minus the voltage drop across the P- channel transistor: VOUT  V  ILOAD RDSON  RL  where RDSON= P-channel switch ON resistance, ILOAD= Output current , RL= Inductor DC resistance Soft-Start The ME3102 has an internal soft-start circuit that limits the in-rush current during start-up. This prevents possible voltage drops of the input voltage and eliminates the output voltage overshoot. Short Circuit Protection The switch peak current is limited cycle-by-cycle to a typical value of 1600mA. In the event of an output voltage short circuit, the device operates with a frequency of 600KHz and minimum duty cycle, therefore the average input current is typically 200mA. V06 www.microne.com.cn Page 8 of 12 ME3102 PCB Layout Check List VIA TO VIN VIA TO VOUT VIA TO VIN VIA TO VOUT When laying out the printed circuit board, the following checklist should be used to ensure proper operation of the ME3102. 1. The power traces, consisting of the GND trace, the SW trace and the VIN trace should be kept short, direct and wide. 2. Does the VFB pin connect directly to the feedback resistors? The resistive divider R1/R2 must be connected between the (+) plate of COUT and ground. 3. Does the (+) plate of CIN connect to VIN as closely as possible? This capacitor provides the AC current to the internal power MOSFETs. 4. Keep the switching node, SW, away from the sensitive VFB node. 5. Keep the (–) plates of C and COUT as close as possible. V06 www.microne.com.cn Page 9 of 12 ME3102 Package Information  Package type:SOT23-5 DIM Millimeters Inches Min Max Min Max A 1.05 1.45 0.0413 0.0571 A1 0 0.15 0.0000 0.0059 A2 0.9 1.3 0.0354 0.0512 A3 0.6 0.7 0.0236 0.0276 b 0.25 0.5 0.0098 0.0197 c 0.1 0.23 0.0039 0.0091 D 2.82 3.05 0.1110 0.1201 e1 1.9(TYP) 0.0748(TYP) E 2.6 3.05 0.1024 0.1201 E1 1.5 1.75 0.0512 0.0689 e L 0.95(TYP) 0.25 L1 θ c1 V06 0.0374(TYP) 0.6 0.0098 0.59(TYP) 0 0.0236 0.0232(TYP) 8° 0.2(TYP) 0.0000 8° 0.0079(TYP) www.microne.com.cn Page 10 of 12 ME3102  Package type:DFN2*2-6 DIM Millimeters Inches Min Max Min Max A 0.7 0.8 0.0276 0.0315 A1 0 0.05 0 0.002 A2 0.203(TYP) 0.008(TYP) b 0.2 0.35 0.0078 0.0138 D 1.9 2.1 0.0748 0.0827 E 1.9 2.1 0.0748 0.0827 E1 0.5 0.9 0.0197 0.0354 e 0.65(TYP) 0.0256(TYP) L 0.25 0.426 0.0098 0.0168 K 0.2 一 0.0079 一 D1 1 1.45 0.0393 0.0571 V06 www.microne.com.cn Page 11 of 12 ME3102      V06 The information described herein is subject to change without notice. Nanjing Micro One Electronics Inc is not responsible for any problems caused by circuits or diagrams described herein whose related industrial properties, patents, or other rights belong to third parties. The application circuit examples explain typical applications of the products, and do not guarantee the success of any specific mass-production design. Use of the information described herein for other purposes and/or reproduction or copying without the express permission of Nanjing Micro One Electronics Inc is strictly prohibited. The products described herein cannot be used as part of any device or equipment affecting the human body, such as exercise equipment, medical equipment, security systems, gas equipment, or any apparatus installed in airplanes and other vehicles, without prior written permission of Nanjing Micro One Electronics Inc. Although Nanjing Micro One Electronics Inc exerts the greatest possible effort to ensure high quality and reliability, the failure or malfunction of semiconductor products may occur. The user of these products should therefore give thorough consideration to safety design, including redundancy, fire-prevention measures, and malfunction prevention, to prevent any accidents, fires, or community damage that may ensue. www.microne.com.cn Page 12 of 12