ME3103AM5G

ME3103 1A Step-Down DC-DC Converter ME3103 General Description Features The ME3103 is a step-down current-mode, DC-DC ● Efficiency up to 96% converter. At heavy load, the constant-frequency PWM ● Only 40μA (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 ME3103 provides a power-saving ● 1.5MHz Switching Frequency pulse -Skipping Modulation (PSM) mode to reduce ● Soft Start quiescent current under light load operation to save ● Under-Voltage Lockout power. ● Short Circuit Protection ● Thermal Shutdown The ME3103 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 Applications is adjustable from 0.6V to the input voltage, while the ● Cellular Phone part number suffix ME3103 indicates pre-set output ● Portable Electronics voltage of 3.3V, 2.8V, 2.5V, 1.8V, 1.5V, 1.2V or ● Wireless Devices adjustable. All versions employ internal power switch ● Cordless Phone and synchronous rectifier for to minimize external part ● Computer Peripherals count and realize high efficiency. During shutdown, the ● Battery Powered Widgets input is disconnected from the output and the ● Electronic Scales shutdown current is less than 0.1μA. Other key ● Digital Frame features include under-voltage lockout to prevent deep Package battery discharge. ● 5-pin SOT23-5 ● 6-pin DFN2*2-6L V05 www.microne.com.cn Page 1 of 14 ME3103 Typical Application Fig1. Fixed Output Voltage R1   VO  0.6  1    R2  Fig2. Adjustable Output Voltage V05 www.microne.com.cn Page 2 of 14 ME3103 Selection Guide ME 3103X X X G Environment mark Package: M5-SOT23-5 N6-DFN2*2-6L Function:A Product Type Product Series Microne product series product description ME3103AM5G VFB=0.6V；Package：SOT23-5 ME3103AN6G VFB=0.6V； Package：DFN2*2-6L Pin Configuration Pin information Pin Number（SOT23-5） Pin Number （DFN2*2-6L） Name Function 1 3 EN Chip Enable 2 6 GND Ground 3 1 SW Switch 4 5 VIN Input 5 4 FB Feedback 2 NC No Connect V05 www.microne.com.cn Page 3 of 14 ME3103 Block Diagram Absolute Maximum Ratings Parameter Symbal Rating Unit VIN -0.3～6.0 V VEN,VFB -0.3～VIN V voltage at SW Pin VSW -0.3～VIN + 0.3 V Internal Power Dissipation, （SOT23-5） PD 300 mW Operating Ambient Temperature Topr -40~+150 °C Storage Temperature Tstg -40~+150 °C Tsolder 260°C, 10S °C Power supply voltage, VIN voltage at EN、FB Pin Soldering temperature and time V05 www.microne.com.cn Page 4 of 14 ME3103 Electrical Characteristics （VIN = VEN=3.6V, VO=1.8V, CIN =10μF, CO =22μF, L=4.7μH, CFW =100pF ,TA =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 Reference Voltage Line Regulation △VFB - 0.3 - %/V Regulated Output Voltage Accuracy VO -3 - +3 % Peak Inductor Current IPK - 1.5 - A IO =100mA VIN = VEN =3V,VFB =0.5V or Vo=90% Output Voltage Line Regulation LNR VIN =VEN= 2.5V to 5V,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 - 40 70 μA Shutdown Current ISD VEN=0V - 0.1 1 μA 1.2 1.5 1.8 MHz VO=100% Oscillator Frequency FOSC VFB=0V or VO=0V 500 KHz PMOS - 0.3 0.45 Ω NMOS - 0.35 0.5 Ω ILSW - ±0.01 1 μA η - 96 - % EN Threshold High VEH 1.5 - - V EN Threshold Low VEL - - 0.3 V EN Leakage Current IEN - ±0.01 1 μA Over Temperature Protection OTP - 160 - °C OTP Hysteresis OTH - 40 - °C Drain-Source On-State Resistance SW Leakage Current High Efficiency V05 RDS(ON) IDS=100mA www.microne.com.cn Page 5 of 14 ME3103 Typical Performance Characteristics 1. Efficiency VS Output Current (VO=1.8V) Efficiency VS Output Current Efficiency VS.Output Current (VO=3.3V) Efficiency VS.Output Current 100 100 80 70 VIN=2.5V VIN=4.2V 60 VIN=3.6V 50 90 Efficiency (%) Efficiency (%) 90 80 70 VIN=5V 60 50 VIN=3.6V VIN=4.2V 40 40 30 30 1 10 100 200 300 400 500 600 700 1 800 900 1000 10 100 200 2. Efficiency VS Input Voltage (VO=1.8V) 90 80 90 Efficiency(%) Efficiency(%) 100 IO=800mA 50 40 700 800 900 1000 80 70 IO=10mA 60 IO=100mA IO=800mA 50 40 30 30 2.5 3 3.5 4 4.5 5 3.5 5.5 3.75 4 4.25 4.5 4.75 5 5.25 5.5 Input Voltage(V) Input Voltage(V) 3. VFB VS Input Voltage 4. VFB VS Output Current VFB VS Input Voltage VFB VS Output Current 0.608 0.61 0.608 0.606 0.604 0.604 VFB (V) VFB (V) 600 Efficiency VS.Input Voltage 100 IO=100mA 500 Efficiency VS Input Voltage (VO=3.3V) Efficiency VS.Input Voltage IO=10mA 400 Output Current(mA) Output Current (mA) 70 60 300 0.602 0.6 0.598 0.596 0.594 IO=800mA IO=100mA IO=600mA 0.6 0.596 VIN=2.5V 0.592 VIN=3.6V VIN=4.2V 0.588 0.584 2.5 3 3.5 4 4.5 5 5.5 Input Voltage(V) V05 0 200 400 600 800 Output Current(mA) www.microne.com.cn Page 6 of 14 1000 ME3103 5. Output Voltage VS Output Current(VO=1.8V) 6. VFB VS Temperature VFB VS Temperature Output Voltage (V) 1.825 1.82 1.815 1.81 1.805 1.8 1.795 1.79 1.785 VIN=2.5V VFB ( V) Output Voltage VS Output Current VIN=4.2V VIN=5V VIN=3.6V 10 100 200 300 400 500 600 700 800 0.608 0.606 0.604 0.602 0.6 0.598 0.596 0.594 0.592 -25 900 1000 0 25 75 100 125 7. Dynamic Supply Current VS Input Voltage (VO=1.8V) 8. Dynamic Supply Current VS Temperature (VIN=3.6V，VO=1.8V) Dynamic Supply Current VS Temperature Dynamic Supply Current VS Input Voltage 50 45 40 35 30 25 20 15 10 Dynamic Supply Current(uA ) 60 50 40 30 20 10 0 2.5 3 3.5 4 4.5 5 5.5 0 20 40 60 80 100 120 Temperature(℃) Input Voltage(V) 9. Oscillator Frequency VS Input Voltage Oscillator Frequency VS Input Voltage Oscillator Frequency (MHz) 150 Temperature(℃) Output Current(mA) Supply Current(uA) 50 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) V05 www.microne.com.cn Page 7 of 14 140 ME3103 Application Information The basic ME3103 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 1μH 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). I L =  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 1.4A rated inductor should be enough for most applications (1A + 400mA). For better efficiency, choose a low DC-resistance inductor. VO 1.2V 1.5V 1.8V 2.5V 3.3V L 2.2μH 2.2μH 4.7μH 4.7μH 4.7μH CIN and COUT Selection In continuous mode, the source current of the top MOSFET is a square wave of duty cycle VOUT/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 I RMS  I OMAX VOUT VIN  VOUT  1 2 VIN 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  I L  ESR  8fCOUT     Where f = operating frequency, COUT=output capacitance and ΔIL= ripple current in the inductor. For a fixed output V05 www.microne.com.cn Page 8 of 14 ME3103 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. Thermal consideration Thermal protection limits power dissipation in the PAM2305. When the junction temperature exceeds 150°C, the OTP (Over Temperature Protection) starts the thermal shutdown and turns the pass transistor off. The pass transistor resumes operation after the junction temperature drops below 120°C. For continuous operation, the junction temperature should be maintained below 125°C. The power dissipation is defined as: PD  I O 2 VO RDSONH  VIN  VO RDSONL  t S W FS I O  I Q VIN VIN IQ is the step-down converter quiescent current. The term tSW is used to estimate the full load step-down converter switching losses. For the condition where the step-down converter is in dropout at 100% duty cycle, the total device dissipation reduces to: PD  I O RDSONH  I QVIN 2 Since RDS(ON), quiescent current, and switching losses all vary with input voltage, the total losses should be investigated over the complete input voltage range. The maximum power dissipation depends on the thermal resistance of IC package, PCB layout, the rate of surrounding airflow and temperature difference between junction and ambient. The maximum power dissipation can be calculated by the following formula: PD  TJ MAX   TA  JA Where TJ(max) is the maximum allowable junction temperature 125°C.TA is the ambient temperature and θJA is the thermal resistance from the junction to the ambient. Based on the standard JEDEC for a two layers thermal test board, the thermal resistance θJA of SOT23-5 package is 250°C/W. The maximum power dissipation at TA = 25°C can be calculated by following formula: P =(125°C-25°C)/250°C/W=0.4W V05 www.microne.com.cn Page 9 of 14 ME3103 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  I LOAD RDSON  RL  where RDSON= P-channel switch ON resistance, ILOAD= Output current , RL= Inductor DC resistance UVLO and Soft-Start The reference and the circuit remain reset until the VIN crosses its UVLO threshold. The ME3103 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. The soft-start acts as a digital circuit to increase the switch current in several steps to the P-channel current limit (1500mA). Short Circuit Protection The switch peak current is limited cycle-by-cycle to a typical value of 1500mA. In the event of an output voltage short circuit, the device operates with a frequency of 400KHz and minimum duty cycle, therefore the average input current is typically 200mA. Thermal Shutdown When the die temperature exceeds 150°C, a reset occurs and the reset remains until the temperature decrease to 120°C, at which time the circuit can be restarted. V05 www.microne.com.cn Page 10 of 14 ME3103 PCB Layout Check List When laying out the printed circuit board, the following checklist should be used to ensure proper operation of the ME3103. 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. V05 www.microne.com.cn Page 11 of 14 ME3103 Package Information ● Package type:SOT23-5 Dimension (mm) Character DIM V05 Min Max Min Max A 0.9 1.45 0.0354 0.0570 A1 0 0.15 0 0.0059 A2 0.9 1.3 0.0354 0.0511 B 0.2 0.5 0.0078 0.0196 C 0.09 0.26 0.0035 0.0102 D 2.7 3.10 0.1062 0.1220 E 2.2 3.2 0.0866 0.1181 E1 1.30 1.80 0.0511 0.0708 e 0.95REF 0.0374REF e1 1.90REF 0.0748REF L 0.10 0.60 0.0039 0.0236 a0 00 300 00 300 www.microne.com.cn Page 12 of 14 ME3103 ● Package type:DFN2*2-6L Dimension (mm) DIM Min Typ Max A 0.70 0.75 0.80 A1 0.00 0.02 0.05 A2 0.203(Typ.) b 0.20 0.25 0.30 D 1.95 2.00 2.05 D1 1.20 1.30 1.40 E 1.95 2.00 2.05 0.80 0.90 E1 0.70 e L V05 0.65bsc 0.30 0.35 K 0.20 min N 6 aaa 0.08 bbb 0.10 www.microne.com.cn 0.40 Page 13 of 14 ME3103      V05 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 14 of 14