ME2185ASPG

ME2185 High Efficiency 2A, 1.0MHZ Synchronous Step-Up DC/DC Converter General Description Features The ME2185 is synchronous，2A，1.0MHZ step–up DC-DC Converter ， which mainly consists of a ●High efficiency.( up to 94%) ●Up to 92.5% Efficiency at IOUT=2A VOUT = 5V from reference voltage source, an oscillation circuit, an error amplifier, a phase compensation circuit, a PWM / 3.3V Input. ●Guaranteed 2.5A Output Current at VOUT = 5V from PFM switching control circuit and an adjustable output current limit circuit. With an internal low-ON-resistance N-ch Power MOS and P-ch Power MOS. 3.3V Input ●Synchronous and internal P-ch Power MOSFET This and N-ch power MOSFET, No Schottky Diode product is ideal for applications requiring high Required ●Oscillator frequency：1.0MHz efficiency and a high output current. ●Reference voltage : 1.25V（±2%） ●Input voltage range: 2.9 V to 4.4 V ● Continuous output current: 2.0A typ. (VIN=3V, VOUT=5.0V) ●Soft start function ●Shutdown function:1.0 μA max. ●UVLO (under-voltage lockout) function ●Current Limit: adjustable by the Rcs using different valve ●Thermal Shutdown Preotection:156℃ Typical Application Package  Portable charger, mobile power. ●  Digital cameras, GPS, wireless transceiver  IPad-like computers, smart phones and port- 8-pin ESOP8 able handheld devices V07 www.microne.com.cn Page 1 of 11 ME2185 Typical Application Circuit VIN 3.3V L 2.2uH VOUT 7 9 CIN 10uF LX AVDD CO3 22uF 22uF 0.1uF 5V R1 30K 6 ADJ R2 10K ME2185 EN CO2 8 PVDD 3 CO1 1 PGND Ilimit 4 RCS 30K PGND 2 AGND 5 Selection Guide ME 21 85 A XX G Environment Mark Package: E.g:SP-ESOP8 Version or Function: Product Type Product Series Microne product series product description M2185ASPG VADJ =1.25V；Package：ESOP8 NOTE: If you need other voltage and package, please contact our sales staff。 V07 www.microne.com.cn Page 2 of 11 ME2185 Pin Configuration& Pin Assignment 8 PVDD 7 AVDD 3 6 ADJ 4 5 AGND PGND 1 PGND 2 EN llimit PAD (LX) ESOP8 Pin Assignment Pin Number Pin Name Function 1 PGND Power Ground 2 PGND 3 EN 4 Ilimit Power Ground Power-enable “H” : Power-on (normal operation) “L” : Power-off (standby) Current limit External transistor 5 AGND 6 ADJ 7 AVDD IC Analog power supply pin 8 PVDD IC power supply pin 9 LX Power switching pin Analog Ground Feed Back voltage pin Block Diagram 8 PVDD UVLO&OTP EN EN 3 PMOS Reference Driver Triangle 7 AVDD UVLO Softstart 9 LX PWM NMOS EAMP PWM Control logic ADJ 6 OSC Ilimit V07 5 4 AGND Ilimit www.microne.com.cn 2 1 PGND PGND Page 3 of 11 ME2185 Absolute Maximum Ratings Parameter Symbol VDD Pin Voltage AVDD,PVDD Rating Unit -0.3～6.0 V LX Pin Voltage VLX -0.3～VDD+0.3 V ADJ Pin Voltage VADJ -0.3～VDD+0.3 V EN Pin Voltage VEN -0.3～VDD+0.3 V Power Dissipation (ESOP8) Pd 2000 mW Operating Temperature Range TOpr -40~+85 ℃ Storage Temperature Range Tstg -40~+125 ℃ External Parts List When Measuring Electrical Characteristics Element Name Symbol Value Unit Inductor L ≤2.2 uH Input capacitor CIN 10 uF Output capacitor Co1, Co2 22 uF Output capacitor Co3 0.1 uF ADJ Resistance R1,R2 30K,10K Ω Electrical Characteristics Measuring conditions：VIN=VEN= 3.3V, VOUT=5.0V,Ta=25℃。Unless otherwise specified。 Parameter Feedback voltage Input voltage Current consumption 1 Current consumption 2 Current consumption during shutdown Oscillation frequency Max. duty ratio PWM/PFM switching duty ratio High level input voltage Low level input voltage ADJ pin input current UVLO release voltage UVLO hysteresis width Soft start time V07 Symbol Condition Min Typ. Max Unit VADJ - 1.225 1.25 1.275 V VIN At switching operation, no external components ,AVDD=PVDD=VEN=3.3V,VADJ=VADJ(S)× 0.95, At switching stop, no external components, AVDD=PVDD=VEN=3.3V VADJ=VADJ(S)+ 0.5V, 2.9 - 4.4 V - 4 6 mA - 150 300 μA ISS1 ISS2 ISSS AVDD=PVDD= 3.3V, VEN=0V, no external components - - 1.0 μA Fosc - 0.8 1.0 1.2 MHz MAXDUTY VIN=VEN= 0.9V, no load 81 ﹪ PFMDUTY VIN=VEN= 3.3V,no load 18 ﹪ VSH VIN= 2.9 V to4.4V, EN pin 0.9 - - V VSL VIN= 2.9 V to 4.4 V, EN pin - - 0.2 V IADJ AVDD= PVDD= VEN =2.9 V to4.4V, ADJ pin -0.1 0 0.1 μA 2.4 V VUVLO+ VUVLOHYS tss - www.microne.com.cn 0.4 V 3 mS Page 4 of 11 ME2185 Thermal Shutdown Protection Note: Tsd 156 ℃  VADJ(S) is a setting value for ADJ voltage.  VOUT(S) is a setting value for output voltage. VOUT is the typical value of actual output voltage. VOUT(S) can be set by using the rate of VADJ and output voltage setting resistors (R1, R2). Typical Characteristics 1、Output Voltage VS. Output Current（VOUT =5.0V） Output Voltage （ V） Output Voltage VS.Out Current 5.12 5.1 5.08 5.06 5.04 Vin=3.0 Vin=3.3 Vin=3.6 Vin=3.9 Vin=4.2 V V V V 5.02 5 0 500 1000 1500 2000 2500 3000 Output Current（mA） 2、Efficiency VS. Output Current（VOUT =5.0V） Efficiency VS. Output Current Efficiency （ %） 100.0 95.0 90.0 85.0 Vin=3.0V Vin=3.3V Vin=3.6V Vin=3.9V Vin=4.2V 80.0 75.0 0 500 1000 1500 2000 2500 3000 Output Current（mA） V07 www.microne.com.cn Page 5 of 11 ME2185 3、VADJ VS. Input Voltage （IOUT=10mA） VADJ VS.Input Voltage 1.27 VADJ(V) 1.265 1.26 1.255 1.25 2 2.5 3 3.5 4 4.5 5 Input Voltage(V) 4、IIN VS. Input Voltage（system testing，No load） IIN(mA) IIN VS.Input Voltage 20 18 16 14 12 10 8 6 4 2 0 2.5 3 3.5 4 4.5 5 Input Voltage(V) 5、Oscillator Frequency VS. Input Voltage (Vin=3.3V,IOUT=500mA) Oscillator Frequency VS.Input Voltage Oscillator Frequency(KHZ) 980 970 960 950 940 930 920 910 900 2 2.5 3 3.5 4 4.5 5 Input Voltage(V) V07 www.microne.com.cn Page 6 of 11 ME2185 Application information PWM / PFM switching control The ME2185 switching regulator controller automatically switches between the pulse width modulation method (PWM) and pulse frequency modulation method (PFM) according to the load current. A low ripple power can be supplied by operating on PWM control for which the pulse width changes from 15% to 85% in the range where the output load current is large. The ME2185 operates on PFM control when the output load current is small and the fixed pulses which have the width of 15% are skipped according to the load current amount. Therefore, the oscillation circuit intermittently oscillates, reducing the self-current consumption. This avoids decreased efficiency when the output load current is small. The point at which PWM control switches to PFM control varies depending on the external element (inductor, diode, etc.), input voltage value, and output voltage value. Soft-start function The ME2185 has a soft-start circuit. The output voltage (VOUT) gradually rises after power-on or startup when the EN pin is set to high, suppressing rush current and overshooting the output voltage. The soft-start time (tss) for the ME2185 is defined as the time from startup until VOUT reaches 90% of the output set voltage value (VOUT(S)). A reference voltage adjustment method is used as the soft-start method and the reference voltage gradually rises from 0 V after soft-start. UVLO function The ME2185 has a UVLO (under voltage lockout) circuit for avoiding IC malfunctions due to power supply voltage drops. The ME2185 stops switching operation upon UVLO detection and retains the external transistor in the off state. After entering the UVLO detection status once, the soft-start function is reset. Note, however, that the other internal circuits operate normally and that the status differs from the power-off status. CURRENT LIMIT DESIGNING The ME2185 has a cycle-by-cycle current limit to maximum inductor peak current（IPK）,adjust inductor peak current limit (Ipklimit)by the Rcs with calculating the value for RCS as RCS≈ 5  1000  Ipk limit RDSON The RDSON is the ON-resistance of Nch Power MOS and the value of RDSON is about 40mΩ in this product.. When an over current condition is detected, the device reduces the output voltage accordingly. When Output Current（IOUT）increases The inductor peak current (Ipk) increases, as The inductor peak current up to Ipklimit,, the Output Current is the IOLIMIT L=2.2uH， Co1,Co2=22uF，VOUT=5V V07 www.microne.com.cn Page 7 of 11 ME2185 Table 1. Common RCS Resistor Selections VIN=3.3V RCS Ipklimit 60K 2.15A 30K 4.30A 25K 5.16A 20K 6.45A NOTE: When selecting an RCS .be careful about the influence of temperature at the RDSON and other devices , select an RCS inductor such that that Ipklimit does not exceed the allowable current External parts selection for DC/DC converter  Inductor The recommended L value of ME2185 is 2.2μH or less for 1.0 MHz products. Note the following when changing the inductance. The inductance (L) has a strong influence on the maximum output current (IOUT) and efficiency ( η). The inductor peak current (Ipk) increases when L is decreased, which improves the circuit stability and increases the IOUT users can obtain. If L is decreased further, the ability of the external transistor to drive the current becomes insufficient, reducing the efficiency and decreasing IOUT. The loss due to the Ipk of the switching transistor is decreased by increasing L and the efficiency maximizes at a certain L value. If L is increased further, the loss due to the serial resistance of the inductor increases, lowering the efficiency. Caution: When selecting an inductor, be careful about its allowable current. If a current exceeding the allowable current flows through the inductor, magnetic saturation occurs, substantially lowering the efficiency and destroying ICs due to large current. Therefore, select an inductor such that Ipk does not exceed the allowable current. 2. Capacitor (CIN, CO1, CO2) To improve efficiency, an input capacitor (CIN) lowers the power supply impedance and averages the input current. Select Cin according to the impedance of the power supply used. The recommended capacitance is 10μF for ME2185. An output capacitor (CO), which is used to smooth the output voltage, requires a capacitance larger than that of the step-down type because the current is intermittently supplied from the input to the output side in the step-up type. A 22μF ceramic capacitor is recommended for ME2185. However, a higher capacitance is recommended if the output voltage is high or the load current is large. If the output voltage or load current is low, another 22μF can be used without problems. Select CO after sufficient evaluation with actual application. V07 www.microne.com.cn Page 8 of 11 ME2185 A ceramic capacitor can be used for both the input and output. 3.Output voltage setting resistors (R1 , R2 ) For ME2185, VOUT can be set to any value by using external divider resistors. Connect the divider resistors between the VOUT and VSS pins. Because VADJ = 1.25 V typ., VOUT can be calculated by using the following equation : R1  R 2 )  1.25 R2 VOUT= (V) ( Connect divider resistors R1 and R2 as close to the IC as possible to minimize the effects of noise. The typical constants based on our evaluation are shown in the next Table: VOUT(S) (V) VIN (V) R1 (KΩ) R2 (KΩ) L (μH) Co1,Co2 (μF) 3.3 2.4 16.4 10 2.2 22 5 3.3 30 10 2.2 22 4. Precautions ● Mount external capacitors, a diode, and a coil as close as possible to the IC. ●Characteristics ripple voltage and spike noise occur in IC containing switching regulators. Moreover rush current flows at the time of a power supply injection. Because these largely depend on the inductor, the capacitor and impedance of power supply used, fully check them using an actually mounted model. ●The 0.1 μF capacitor connected between the VIN and GND pins is a bypass capacitor. It stabilizes the power supply in the IC when application is used with a heavy load, and thus effectively works for stable switching regulator operation. Allocate the bypass capacitor as close to the IC as possible, prioritized over other parts. ●Although the IC contains a static electricity protection circuit, static electricity or voltage that exceeds the limit of the protection circuit should not be applied. ●The power dissipation of the IC greatly varies depending on the size and material of the board to be connected. Perform sufficient evaluation using an actual application before designing. V07 www.microne.com.cn Page 9 of 11 ME2185 Packaging Information  Packaging Type: ESOP8 DIM Millimeters Inches Min Max Min Max A 1.3 1.75 0.0512 0.0689 A1 0 0.2 0.0000 0.0079 A2 1.25 1.65 0.0492 0.0650 A3 0.5 0.7 0.0197 0.0276 b 0.33 0.51 0.0130 0.0201 c 0.17 0.25 0.0067 0.0098 D 4.7 5.1 0.1850 0.2008 E 5.8 6.2 0.2283 0.2441 E1 3.8 4 0.1496 0.1575 e 1.27(TYP) 0.05(TYP) h 0.25 0.5 0.0098 0.0197 L 0.4 1.27 0.0157 0.0500 L1 1.04(TYP) θ 0 0.0409(TYP) 8° 0.0000 8° c1 0.25(TYP) 0.0098(TYP) D1(90*90) 2.09(TYP) 0.0823(TYP) D1(95*130) 3.1(TYP) 0.122(TYP) E2(90*90) 2.09(TYP) 0.0823(TYP) E2(95*130) 2.21(TYP) 0.087(TYP) V07 www.microne.com.cn Page 10 of 11 ME2185      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. V07 www.microne.com.cn Page 11 of 11