XR3403D

XR3403D _____________________________ _________ ____ 1.2MHZ，14V Step-up DC/DC Converter GENERAL DESCRIPTION FEATURES The XR3403D is a high frequency, high efficiency DC to DC converter with an integrated 4A, 0.1Ω power switch capable of providing an output voltage up to 14V. The fixed 1.2MHz allows the use of small external inductions and capacitors and provides fast transient response. It integrates Soft start, Comp,. only need few components outside. It can be adjusted SW current limit by one resistor or one analog voltage.          2.3V to 6V input voltage Rangel Efficiency up to 96% 14V Boost converter with adjusted switch current 1.2Mhz fixed Switching Frequency Integrated soft-start Adjustable current limit Thermal Shutdown Under voltage Lockout SOT23-6 Package APPLICATIONS Handheld Devices GPS Receiver Digital Still Camera Portable Applications DSL Modem PCMCIA Card TFT LCD Bias Supply Figure 1. Typical Application Circuit1 XySemi Inc -1- www.xysemi.com REV 0.4 XR3403D _____________________________ _________ ____ Figure 2. Typical Application Circuit2 ORDERING INFORMATION PART NUMBER TEMP RANGE XR3403D -40°C to 85°C SWICHING OUTPUT FREQUENCY VOLTAGE (V) 1.2MHZ ADJ ILIM (A) PACKAGE PINS ADJ SOT23-6 6 PIN CONFIGURATION Figure 3. PIN Configuration XySemi Inc -2- www.xysemi.com REV 0.4 XR3403D ______________________________________ ___________________________________________________________ PIN DESCRIPTION PIN NUMBER PIN NAME 1 SW 2 GND 3 FB Feedback pin 4 EN Shutdown control input., Connect this pin to logic high level to enable the device 5 IN Input power supply pin 6 OC SW current limit setting pin, Set current limit by Rset or analog voltage PIN DESCRIPTION Switch pin Ground ABSOLUTE MAXIMUM RATINGS (Note: Do not exceed these limits to prevent damage to the device. Exposure to absolute maximum rating conditions for long periods may affect device reliability.) PARAMETER VALUE UNIT -0.3 to 6.5 V FB, EN Voltage -0.3 to VIN+0.3 V SW Voltage Operating Ambient Temperature Vin+0.3 to 15V V -40 to 85 °C Maximum Junction Temperature 150 °C -55 to 150 °C 300 °C Supply Voltage VIN Storage Temperature Lead Temperature (Soldering, 10 sec) ELECTRICAL CHARACTERISTICS (VIN = 3.6V, TA= 25C unless otherwise specified) PARAMETER Input Voltage Range SYMB OL TEST CONDITIONS MIN *VIN 2.3 Boost output voltage range *Vout 14 UVLO Threshold VUVLO VHYSTERESIS =100mV 2.1 Operating Supply Current TYP MAX UNIT 6.0 V V 2.2 2.3 VFB =1.3V，EN=Vin, ILoad =0 75 135 VEN =0V, VIN =4.2V 0.1 1 ISUPPLY Shutdown Supply Current XySemi Inc V µA -3- www.xysemi.com REV 0.4 XR3403D ______________________________________ ___________________________________________________________ Regulated Feedback Voltage VFB Inductor Current limit Peak (N-MOSFET Current limit) *Ilim Inductor Current limit Peak (N-MOSFET Current limit) *Ilim Oscillator Frequency Rds(ON) of N-channel FET Enable Threshold 1.188 1.2 1.212 V Rset=168K Vin=3.6V Vout=5V 2.1 2.6 3.1 A Rset=120K Vin=3.6V Vout=5V 1.32 1.65 1.98 A 0.9 1.2 1.5 MHz 0.1 0.2 Ohm 1 1.5 V 0.1 µA 1 uA *FOSC * ISW =-100mA VIN = 2.3V to 5.5V Enable Leakage Current 0.3 -0.1 VEN = 0V, VSW = 0V or 5V, VIN = 5V Note: * ---The parameter is guaranteed by design. SW Leakage Current Figure 4. Functional Block Diagram XySemi Inc -4- www.xysemi.com REV 0.4 XR3403D ______________________________________ ___________________________________________________________ FUNCTIONAL DESCRIPTION Because of the quasi-constant frequency behavior of the device , the XR3403D eliminates the need for an internal oscillator and slope compensation, which provides better stability for the system over a wide of input and output voltages range, and more stable and accurate current limiting operation compared to boost converters operating with a conventional PWM scheme .The XR3403D topology has also the benefits of providing very good load and line regulations, and excellent load transient response. NORMAL OPERATION The boost converter is designed for output voltage up to 14V with a switch MAX peak current limit of 4 A. The device, which operates in a current mode scheme with quasi-constant frequency, is externally 1.2MHZ and the minimum input voltage is 2.3 V. To control the inrush current at start-up a soft-start pin is available. During the on-time, the voltage across the inductor causes the current in it to rise. When the current reaches a threshold value set by the internal GM amplifier, the power transistor is turned off, the energy stored into the inductor is then released and the current flows through the Schottky diode towards the output of the boost converter. The off-time is fixed for a certain Vin and Vs, and therefore maintains the same frequency when varying these parameters. UNDERVOLTAGE LOCKOUT (UVLO) To avoid mis-operation of the device at low input voltages an under voltage lockout is included that disables the device, if the input voltage falls below 2.2V However, for different output loads, the frequency may slightly change due to the voltage drop across the Rdson of the power transistor which will have an effect on the voltage across the inductor and thus on Ton THERMAL SHUTDOWN A thermal shutdown is implemented to prevent damages due to excessive heat and power dissipation. Typically the thermal shutdown threshold is 150 ℃ .When the thermal shutdown is triggered the device stops switching until the temperature falls below typically 136 ℃ .Then the device starts switching again. ( Toff remains fixed). Some slight frequency changes might also appear with a fixed output load due to the fact that the output voltage Vs is not sensed directly but via the SW Pin, which affects accuracy. XySemi Inc -5- www.xysemi.com REV 0.4 XR3403D ______________________________________ ___________________________________________________________ APPLICATION INFORMATION INDUCTOR SELECTION In normal operation, the inductor maintains continuous current to the output. The inductor current has a ripple that is dependent on the inductance value. The high inductance reduces the ripple current. Selected inductor by actual application: Manufa Part Induct DRC Dimensions cturer Number ance(u max L*W*H(mm3) H) (Ohms ) Murata LQH44P N 2.2 0.049 3.3 0.065 4.7 0.08 10 0.16 2.2 0.030 3.3 0.044 4.7 0.058 10 0.106 2.2 0017 3.3 0.027 4.7 0.036 2.2 0.020 3.3 0.025 4.7 0.029 10 0.055 744373 24022 2.2 0.061 7447770 04 4.7 0.025 LQH5BP TDK SPM653 0T VLP6045 LT WURT H 4*4*1.7 5*5*2 7.1*6.5*3 6*6*4.5 4.4*4.05 7.3*7.3*4.5 Table 1. Recommend Surface Mount Inductors If output voltage is 5V，you can use 2.2uH~ 4.7uH, If output voltage is 12V,4.7uH~10uH is OK， Normal application: Input 3.3V (3.6V or 4.2V) to Output 5V 9V 12V ； Input 5V Output 9V 12V to Notes：Please select inductor according to Iin. The IL need to be 1.5~2*Iin. For getting higher efficiency, need to use low DRC inductors. XySemi Inc -6- www.xysemi.com REV 0.4 XR3403D ______________________________________ ___________________________________________________________ INPUT CAPACITOR SELECTION The input capacitor reduces input voltage ripple to the converter, low ESR ceramic capacitor is highly recommended. For most applications, a 22uF or 10uF capacitor is used. The input capacitor should be placed as close as possible to VIN and GND. Such as Murata GRM21BR60J226/GRM21BR60J226 or TDK C3216X5R1A226M /C3216X5R1A106M OUTPUT CAPACITOR SELECTION A low ESR output capacitor is required in order to maintain low output voltage ripple. In the case of ceramic output capacitors, capacitor ESR is very small and does not contribute to the ripple, so a lower capacitance value is acceptable when ceramic capacitors are used. A 22uF or two 10uF ceramic output capacitor is suitable for most applications. Such as Murata GRM21BR60J226 or TDK C3216X5R1A226M One 10uF for big current load application is not suitable. OUTPUT VOLTAGE PROGRAMMING In the adjustable version, the output voltage is set by a resistive divider according to the following equation: Typically choose R2=10K and determine R1 from the following equation: OC SETTING1( SETTING CURRENT LIMIT BY ANALOG VOLTAGE) XR3403D can be adjusted SW current limit by one analog volatage connected with OC pin just like Typical Application Circuit1。The setting sheet is as below( Vin=3.6V Vout=5V )---Only list the typical Ilim number，the actual data may be in +/- 20% above them because of some discrete data from IC and the analog voltage. One 0.1uF capacitor need to be placed close to OC pin. Please do not let it float. Analog Volatge（V） Ilim(typ) RMS 0.75V 3.20A 0.70V 2.75A 0.65V 2.20A 0.60V 1.75A 0.55V 1.35A 0.50V 0.95A 0.45V 0.55A 0.40V 0.20A . For 3V~4.2Vin to 5V 1A out , 0.62V~0.65V is suitable. XySemi Inc -7- www.xysemi.com REV 0.4 XR3403D ______________________________________ ___________________________________________________________ If the current limit exceeds 2A, maybe the IC will be go in to over temperature protection status without good layout. OC SETTING2( SETTING CURRENT LIMIT BY ONE RESISTOR) XR3403D can be adjusted SW current limit by one resistor connected with OC pin just like Typical Application Circuit2 。The setting sheet is as below( Vin=3.6V Vout=5V )---Only list the typical Ilim number，the actual data may be in +/- 20% above them because of some discrete data from IC and resistor. Please do not let it float. Rset （ohm） Ilim (typ) Peak Ilim (typ) RMS 168K 2.60A 2.3A 150K 2.30A 2.0A 130K 1.90A 1.60A 120K 1.65A 1.40A 100K 1.20A 0.95A Current limit (Peak) is the maxim of inductor switching current wave in one cycle Current limit (RMS) is the average of inductor switching current wave in one cycle, also it is equal to the average of input current wave. For 3V~4.2Vin to 5V 1A out , 150K~168Kohm is suitable. If the current limit RMS exceeds 2A, maybe the IC will be go in to over temperature protection status without good layout. DIODE SELECTION According to max Iout and max Vout, you can select suitable diode. Normally we select diode If=(1.5~2)*Ioutmax and VR=(1.5~2)*Voutmax. For high efficiency，suggest that you select low Vf Schottky diode. ONsemi’s MBRA210LT3 is prefer XySemi Inc -8- www.xysemi.com REV 0.4 XR3403D ______________________________________ ___________________________________________________________ TYPICAL PERFORMANCE CHARACTERISTICS (L=2.2uH 4A, CIN=22uF, COUT=22uF, if not mentioned) Rset=168K) Efficiency vs. Output Current (Vout=5V) STARTUP (3.3V IN 5V 500MA OUT) STARTUP(3.3V IN 9V 500MA OUT) SW WAVE(3.3VIN 5V 1A OUT) XySemi Inc SW WAVE(3.3VIN 5V 50MA OUT) -9- www.xysemi.com REV 0.4 XR3403D ______________________________________ ___________________________________________________________ PACKAGE OUTLINE SOT23-6 PACKAGE OUTLINE AND DIMENSIONS XySemi Inc - 10 - www.xysemi.com REV 0.4