Techcode® ÓÉ Foxit PDF Editor ±à¼°æȨËùÓÐ (c) by Foxit Software Company, 2004 ½öÓÃÓÚÆÀ¹À¡£ DATASHEET High Efficiency 1.5MHz, Step Up Regulator TD8210 汪工 ＴＥＬ：１３８２８７１９４１０ ＱＱ：１９２９７９４２３８ General Description Features The TD8210 is a fixed switching frequency (1.5MHz typical), z z z z z z z z z z z z z current-mode, step-up regulator with an integrated N-channel MOSFET. The device allows the usage of small inductors and output capacitors for portable devices. The current-mode control scheme provides fast transient response and good output voltage accuracy. The TD8210 includes under-voltage lockout, currentlimit,and over-temperature shutdown preventing damage in the event of an output overload. Wide 2.7V to 6V Input Voltage Range Built‐in 0.2W N‐Channel MOSFET Built‐in Soft‐Start High Efficiency up to 90% <1mA Quiescent Current During Shutdown Current‐Mode Operation Stable with Ceramic Output Capacitors Fast Transient Response Current‐Limit Protection Over‐Temperature Protection with Hysteresis Available in a TSOT‐23‐5A and TDFN2x2‐6 Package Lead Free and Green Devices Available (RoHS Compliant) Applications z z z z Cell Phone and Smart Phone PDA, PMP, MP3 Digital Camera Boost Regulators Package Types SOT235 Figure 1. Package Types of TD8210 October, 20, 2011. Techcode Semiconductor Limited www.techcodesemi.com 1 Techcode® DATASHEET High Efficiency 1.5MHz, Step Up Regulator TD8210 Pin Configurations Figure 2 Pin Configuration of TD8210(Top View) Pin Description Pin Name Description 1 LX Switch pin. Connect this pin to inductor/diode here. 2 GDN GND 3 FB Feedback Input. The device senses feedback voltage via FB and regulate the voltage at 1.23V. Connecting FB wi th a resistor‐divider from the output that sets the output voltage. Pin Number 4 EN Enable Control Input. Forcing this pin above 1.0V enables the device. Forcing this pin below 0.4V to shut it down. In shutdown, all functions are disabled to decrease the supply current below 1μA. Do not left this pin floating. 5 IN Main Supply Pin. Must be closely decoupled to GND with a 2.2μF or greater ceramic capacitor. Ordering Information TD8210 □ □ Circuit Type Packing: Blank：Tube T: R:Type and Reel SOT23-5 October, 20, 2011. Techcode Semiconductor Limited www.techcodesemi.com 2 Techcode® DATASHEET High Efficiency 1.5MHz, Step Up Regulator TD8210 Function Block Figure 3 Function Block Diagram of TD8210 October, 20, 2011. Techcode Semiconductor Limited www.techcodesemi.com 3 Techcode® DATASHEET TD8210 High Efficiency 1.5MHz, Step Up Regulator Absolute Maximum Ratings Note1: Stresses beyond those listed under "absolute maximum ratings" may cause permanent damage to the device. These are stress ratings only and functional operation of the device at these or any other conditions beyond those indicated under "recommended operating conditions" is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability Recommended Operating Conditions Thermal Characteristics Symbol θJA θJC Parameter Junction-to-Ambient Resistance in Free Air Junction-to-Case Resistance Typical 220 120 Value Unit C/W o C/W o October, 20, 2011. Techcode Semiconductor Limited www.techcodesemi.com 4 Techcode® DATASHEET TD8210 High Efficiency 1.5MHz, Step Up Regulator Electrical Characteristics Symbol Parameter VIN Input Voltage TA=‐40~85 C TJ=-40~120 C TD8210 Min. Typ. 2.7 IDD1 VFB=1.3V,no switching ‐ 300 ‐ uA IDD2 ISD VREF Input DC Bias Current UVLO Threshold Voltage UVLO Hysteresis Voltage VFB=1.1V, switching EN=GND VIN Rising VIN Falling Regulated Feedback Voltage VIN=2.7V~6V, TA = 25 oC VIN=2.7V~6V, TA = -40 ~ 85 oC IFB FSW RON FB Input Current Power Switch On Resistance 2 ‐ 2.2 100 1.23 1.5 0.2 5 1 2.4 150 1.248 1.255 50 1.75 mA µA V mV V ‐ ‐ 2.0 50 1.212 1.205 ‐50 1.25 ILIM DMAX TSS VTEN ILEN TOTP Power Switch Current Limit LX Leakage Current VEN = 0V, VLX = 0V or 6V, VIN = 6V LX Maximum Duty Cycle VEN Rising 2.2 ‐1 92 0.4 95 2 0.7 0.1 150 40 1 98 3 1 A uA % ms Switching Frequency Soft‐Start Duration EN Voltage Threshold Test Conditions o o EN Voltage Hysteresis EN Leakage Current VEN=5V, VIN = 5V Over‐Temperature Protection Over‐Temperature Protection TJ Rising TJ Falling ‐1 Max. 6 Unit V 1 nA MHz Ω V V uA o C o C October, 20, 2011. Techcode Semiconductor Limited www.techcodesemi.com 5 Techcode® DATASHEET TD8210 High Efficiency 1.5MHz, Step Up Regulator Typical Performance Characteristics October, 20, 2011. Techcode Semiconductor Limited www.techcodesemi.com 6 Techcode® DATASHEET TD8210 High Efficiency 1.5MHz, Step Up Regulator Typical Performance Characteristics(Cont.) October, 20, 2011. Techcode Semiconductor Limited www.techcodesemi.com 7 Techcode® DATASHEET TD8210 High Efficiency 1.5MHz, Step Up Regulator Operating Waveforms October, 20, 2011. Techcode Semiconductor Limited www.techcodesemi.com 8 Techcode® DATASHEET High Efficiency 1.5MHz, Step Up Regulator TD8210 Operating Waveforms(Cont.) October, 20, 2011. Techcode Semiconductor Limited www.techcodesemi.com 9 Techcode® DATASHEET High Efficiency 1.5MHz, Step Up Regulator TD8210 Typical Application Circuit Figure 1. Typical 5V to 12V Supply Figure 2. Standard 3.3V to 5V Supply October, 20, 2011. Techcode Semiconductor Limited www.techcodesemi.com 10 Techcode® DATASHEET High Efficiency 1.5MHz, Step Up Regulator TD8210 Typical Application Circuit(Cont.) Figure 3. Multiple Output for TFTLCD Power Supply October, 20, 2011. Techcode Semiconductor Limited www.techcodesemi.com 11 Techcode® DATASHEET High Efficiency 1.5MHz, Step Up Regulator TD8210 Function Description Main Control Loop Over-Temperature Protection (OTP) The TD8210 is a constant frequency and current-mode switching The over-temperature circuit limits the junction temperature of the regulator. In normal operation, the internal Nchannel power TD8210. When the junction temperature exceeds 150oC, a thermal MOSFET is turned on each cycle when the oscillator sets an sensor turns off the power MOSFET allowing the devices to cool. internal RS latch, and then turned off when an internal comparator The thermal sensor allows the converters to start a soft-start (ICMP) resets the latch. The peak inductor current at which ICMP process and regulates the output voltage again after the junction resets the RS latch is controlled by the voltage on the COMP node temperature cools by 40oC. The OTP is designed with a 40oC which is the output of the error amplifier (EAMP). An external hysteresis to lower the average Junction Temperature (TJ) during resistive divider connected between VOUT and ground allows the continuous thermal overload conditions increasing the lifetime of EAMP to receive an output feedback voltage VFB at FB pin. When the device. the load current increases, it causes a slightly to decrease in VFB Enable/Shutdown associated with the 1.23V reference,which in turn, it causes the Driving EN to the ground places the TD8210 in shutdown mode. COMP voltage to increase until the average inductor current When in shutdown, the internal power MOSFET turns off, all matches the new load current. internal circuitry shuts down, and the quiescent supply current VIN Under-Voltage Lockout (UVLO) reduces to 1μA maximum. The Under-Voltage Lockout (UVLO) circuit compares the input voltage at VIN with the UVLO threshold to ensure the input voltage is high enough for reliable operation.The 100mV (typ) hysteresis prevents supply transients from causing a restart. Once the input voltage exceeds the UVLO rising threshold, startup begins. When the input voltage falls below the UVLO falling threshold, the controller turns off the converter. Soft-Start The TD8210 has a built-in soft-start to control the output voltage rise during start-up. During soft-start, an internal ramp voltage, connected to the one of the positive inputs of the error amplifier, raises up to replace the reference voltage (1.23V typical) until the ramp voltage reaches the reference voltage. Current-Limit Protection The TD8210 monitors the inductor current, flows through the N-channel MOSFET, and limits the current peak at current-limit level to prevent loads and the TD8210 from damaging during overload or short-circuit conditions. October, 20, 2011. Techcode Semiconductor Limited www.techcodesemi.com 12 Techcode® DATASHEET High Efficiency 1.5MHz, Step Up Regulator TD8210 Application Information Input Capacitor Selection The input capacitor (CIN) reduces the ripple of the input current drawn from the input supply and reduces noise injection into the IC. The reflected ripple voltage will be smaller when an input The peak inductor current is calculated as the following equation: capacitor with larger capacitance is used. For reliable operation, it is recommended to select the capacitor with maximum voltage rating at least 1.2 times of the maximum input voltage. The capacitors should be placed close to the VIN and the GND. Inductor Selection Selecting an inductor with low dc resistance reduces conduction losses and achieves high efficiency. The efficiency is moderated whilst using small chip inductor which operates with higher inductor core losses. Therefore, it is necessary to take further consideration while choosing an adequate inductor. Mainly, the inductor value determines the inductor ripple current: larger inductor value results in smaller inductor ripple current and lower conduction losses of the converter. However, larger inductor value generates slower load transient response. A reasonable design rule is to set the ripple current, ΔIL, to be 30% to 50% of the maximum average inductor current,IL(AVG). The inductor value can be obtained as below, where VIN = input voltage VOUT = output voltage FSW = switching frequency in MHz Output Capacitor Selection IOUT = maximum output current in amp. The current-mode control scheme of the TD8210 allows the usage η = Efficiency of tiny ceramic capacitors. The higher capacitor value provides good load transients response. Ceramic capacitors with low ESR ΔIL /IL(AVG) = inductor ripple current/average current values have the lowest output voltage ripple and are (0.3 to 0.5 typical) recommended. If required,tantalum capacitors may be used as To avoid the saturation of the inductor, the inductor should be well. The output ripple is the sum of the voltages across the ESR rated at least for the maximum input current of the converter plus and the ideal output capacitor. the inductor ripple current. The maximum input current is calculated as below: October, 20, 2011. Techcode Semiconductor Limited www.techcodesemi.com 13 Techcode® DATASHEET TD8210 High Efficiency 1.5MHz, Step Up Regulator Application Information(Cont.) I Output Capacitor Selection (Cont.) 3. Since the feedback pin and network is a high impedance circuit the feedback network should be routed away from the inductor. The feedback pin and feedback network should be shielded with a ground plane or trace to minimize noise coupling into this circuit. 4. A star ground connection or ground plane minimizes ground where IPEAK is the peak inductor current. shifts and noise is recommended. For ceramic capacitor application, the output voltage ripple is dominated by the ΔVCOUT. When choosing the input and output ceramic capacitors, the X5R or X7R with their good temperature and vol tage charac ter is t ic s are recommended. Output Voltage Setting The output voltage is set by a resistive divider. The external resistive divider is connected to the output which allows remote voltage sensing as shown in “Typical Application Circuits”. A suggestion of the maximum value of R1 is 2MΩ and R2 is 200kΩ for keeping the minimum current that provides enough noise rejection ability through the resistor divider. The output Optimized TD8210 Layout voltage can be calculated as below: Diode Selection To achieve the high efficiency, a Schottky diode must be used. The current rating of the diode must meet the peak current rating of the converter. Layout Consideration For all switching power supplies, the layout is an important step in the design especially at high peak currents and switching frequencies. If the layout is not carefully done, the regulator might show noise problems and duty cycle jitter. 1. The input capacitor should be placed close to the VIN and the GND without any via holes for good input voltage filtering. 2. To minimize copper trace connections that can inject noise into the system, the inductor should be placed as close as possible to the LX pin to minimize the noise coupling into other circuits. October, 20, 2011. Techcode Semiconductor Limited www.techcodesemi.com 14 Techcode® DATASHEET High Efficiency 1.5MHz, Step Up Regulator TD8210 Package Information TSOT235 Package Outline Dimensions October, 20, 2011. Techcode Semiconductor Limited www.techcodesemi.com 15 Techcode® DATASHEET High Efficiency 1.5MHz, Step Up Regulator TD8210 Design Notes October, 20, 2011. Techcode Semiconductor Limited www.techcodesemi.com 16