TPS63030 TPS63031 www.ti.com.................................................................................................................................................. SLVS696A – OCTOBER 2008 – REVISED MARCH 2009 HIGH EFFICIENCY SINGLE INDUCTOR BUCK-BOOST CONVERTER WITH 1-A SWITCHES FEATURES APPLICATIONS • Up to 96% Efficiency • 800-mA Output Current at 3.3V in Step Down Mode (VIN = 3.6V to 5.5V) • Up to 500-mA Output Current at 3.3V in Boost Mode (VIN > 2.4V) • Automatic Transition Between Step Down and Boost Mode • Device Quiescent Current less than 50µA • Input Voltage Range: 1.8V to 5.5V • Fixed and Adjustable Output Voltage Options from 1.2V to 5.5V • Power Save Mode for Improved Efficiency at Low Output Power • Forced Fixed Frequency Operation and Synchronization Possible • Load Disconnect During Shutdown • Over-Temperature Protection • Available in Small 2,5-mm × 2,5-mm, QFN-10 Package • 1 2 • • • • • All Two-Cell and Three-Cell Alkaline, NiCd or NiMH or Single-Cell Li Battery Powered Products Portable Audio Players PDAs Cellular Phones Personal Medical Products White LEDs DESCRIPTION The TPS6303x devices provide a power supply solution for products powered by either a two-cell or three-cell alkaline, NiCd or NiMH battery, or a one-cell Li-Ion or Li-polymer battery. Output currents can go as high as 600 mA while using a single-cell Li-Ion or Li-Polymer Battery, and discharge it down to 2.5V or lower. The buck-boost converter is based on a fixed frequency, pulse-width-modulation (PWM) controller using synchronous rectification to obtain maximum efficiency. At low load currents, the converter enters Power Save mode to maintain high efficiency over a wide load current range. The Power Save mode can be disabled, forcing the converter to operate at a fixed switching frequency. The maximum average current in the switches is limited to a typical value of 1000 mA. The output voltage is programmable using an external resistor divider, or is fixed internally on the chip. The converter can be disabled to minimize battery drain. During shutdown, the load is disconnected from the battery. The device is packaged in a 10-pin QFN PowerPAD™ package measuring 2.5 mm × 2.5 mm (DSK). L1 1.5 µH L1 VIN 1.8 V to 5.5 V L2 VIN C1 4.7 µF VOUT VINA EN FB C2 10 µF VOUT 3.3 V up to 800 mA PS/SYNC GND PGND TPS63031 1 2 Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet. PowerPAD is a trademark of Texas Instruments. PRODUCTION DATA information is current as of publication date. Products conform to specifications per the terms of the Texas Instruments standard warranty. Production processing does not necessarily include testing of all parameters. Copyright © 2008–2009, Texas Instruments Incorporated TPS63030 TPS63031 SLVS696A – OCTOBER 2008 – REVISED MARCH 2009.................................................................................................................................................. www.ti.com These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam during storage or handling to prevent electrostatic damage to the MOS gates. AVAILABLE OUTPUT VOLTAGE OPTIONS (1) TA OUTPUT VOLTAGE DC/DC PACKAGE MARKING Adjustable CEE 3.3 V CEF –40°C to 85°C (1) (2) PART NUMBER (2) PACKAGE TPS63030DSK 10-Pin QFN TPS63031DSK Contact the factory to check availability of other fixed output voltage versions. The DSK package is available taped and reeled. Add R suffix to device type (e.g., TPS63030DSKR) to order quantities of 3000 devices per reel. Add T suffix to device type (e.g., TPS63030DSKT) to order quantities of 250 devices per reel. ABSOLUTE MAXIMUM RATINGS over operating free-air temperature range (unless otherwise noted) (1) TPS6300x Input voltage range on VIN, VINA, L1, L2, VOUT, PS/SYNC, EN, FB –0.3 V to 7 V Operating virtual junction temperature range, TJ –40°C to 150°C Storage temperature range Tstg –65°C to 150°C (1) 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-rated conditions for extended periods my affect device reliability. DISSIPATION RATINGS TABLE PACKAGE THERMAL RESISTANCE ΘJA (1) THERMAL RESISTANCE ΘJP THERMAL RESISTANCE ΘJC POWER RATING TA≤ 25°C (1) DERATING FACTOR ABOVE TA = 25°C (1) DSK 60.6°C/W 6.3°C/W 40°C/W 1650 mW 17 mW/°C (1) Thermal ratings are determined assuming a high K PCB design according to JEDEC standard JESD51-7. RECOMMENDED OPERATING CONDITIONS MIN NOM MAX UNIT Supply voltage at VIN, VINA 1.8 5.5 V Operating free air temperature range, TA –40 85 °C Operating virtual junction temperature range, TJ –40 125 °C 2 Submit Documentation Feedback Copyright © 2008–2009, Texas Instruments Incorporated Product Folder Link(s): TPS63030 TPS63031 TPS63030 TPS63031 www.ti.com.................................................................................................................................................. SLVS696A – OCTOBER 2008 – REVISED MARCH 2009 ELECTRICAL CHARACTERISTICS over recommended free-air temperature range and over recommended input voltage range (typical at an ambient temperature range of 25°C) (unless otherwise noted) DC/DC STAGE PARAMETER VI Input voltage range VI Minimum input voltage for startup VI VO TEST CONDITIONS MIN 0°C ≤ TA ≤ 85°C Iq IS V 1.9 V Minimum input voltage for startup 1.6 1.8 2.0 V TPS63030 output voltage range 1.2 5.5 V 30% TPS63030 feedback voltage PS/SYNC = VIN Oscillator frequency Frequency range for synchronization ISW UNIT 5.5 1.8 TPS63031 output voltage f MAX 1.6 Minimum duty cycle in step down conversion VFB TYP 1.8 40% 495 500 505 3.267 3.3 3.333 mV V 2200 2400 2600 kHz 2200 2400 2600 kHz 900 1000 1100 Average switch current limit VIN = VINA = 3.6 V, TA = 25°C High side switch on resistance VIN = VINA = 3.6 V 200 mΩ Low side switch on resistance VIN = VINA = 3.6 V 200 mΩ Maximum line regulation 0.5% Maximum load regulation 0.5% Quiescent current VIN and VINA IO = 0 mA, VEN = VIN = VINA = 3.6 V, VOUT = 3.3 V VOUT TPS63031 FB input impedance VEN = HIGH Shutdown current VEN = 0 V, VIN = VINA = 3.6 V 25 35 4 6 1 mA µA µA MΩ 0.1 0.9 µA 1.5 1.6 V 0.4 V CONTROL STAGE VUVLO Under voltage lockout threshold VIL EN, PS/SYNC input low voltage VIH EN, PS/SYNC input high voltage VINA voltage decreasing 1.4 1.2 EN, PS/SYNC input current Clamped on GND or VINA V 0.01 0.1 µA Overtemperature protection 140 °C Overtemperature hysteresis 20 °C Copyright © 2008–2009, Texas Instruments Incorporated Product Folder Link(s): TPS63030 TPS63031 Submit Documentation Feedback 3 TPS63030 TPS63031 SLVS696A – OCTOBER 2008 – REVISED MARCH 2009.................................................................................................................................................. www.ti.com PIN ASSIGNMENTS DSK PACKAGE (TOP VIEW) VOUT L2 PGND L1 VIN FB GND VINA PS/SYNC EN Terminal Functions TERMINAL NAME NO. I/O DESCRIPTION EN 6 I Enable input. (1 enabled, 0 disabled) FB 10 I Voltage feedback of adjustable versions, must be connected to VOUT on fixed output voltage versions GND 9 PS/SYNC 7 I Enable / disable power save mode (1 disabled, 0 enabled, clock signal for synchronization) L1 4 I Connection for Inductor L2 2 I Connection for Inductor PGND 3 VIN 5 I Supply voltage for power stage VOUT 1 O Buck-boost converter output VINA 8 I Supply voltage for control stage PowerPAD™ 4 Control / logic ground Power ground Must be soldered to achieve appropriate power dissipation. Should be connected to PGND. Submit Documentation Feedback Copyright © 2008–2009, Texas Instruments Incorporated Product Folder Link(s): TPS63030 TPS63031 TPS63030 TPS63031 www.ti.com.................................................................................................................................................. SLVS696A – OCTOBER 2008 – REVISED MARCH 2009 FUNCTIONAL BLOCK DIAGRAM (TPS63030) L1 L2 VIN VOUT Current Sensor VINA VBAT VOUT PGND PGND Gate Control _ VINA Modulator + _ + FB VREF Oscillator PS/SYNC + - Device Control EN Temperature Control PGND PGND GND FUNCTIONAL BLOCK DIAGRAM (TPS63031) L1 L2 VIN VOUT Current Sensor VINA VBAT VOUT PGND PGND Gate Control FB _ VINA Modulator + + _ Oscillator PS/SYNC + - VREF Device Control EN Temperature Control PGND PGND GND Copyright © 2008–2009, Texas Instruments Incorporated Product Folder Link(s): TPS63030 TPS63031 Submit Documentation Feedback 5 TPS63030 TPS63031 SLVS696A – OCTOBER 2008 – REVISED MARCH 2009.................................................................................................................................................. www.ti.com TYPICAL CHARACTERISTICS TABLE OF GRAPHS DESCRIPTION FIGURE Maximum output current Efficiency Output voltage Waveforms vs Input voltage (TPS63030, VOUT = 2.5 V / VOUT = 4.5 V) 1 vs Input voltage (TPS63031, VOUT = 3.3V) 2 vs Output current (TPS63030, Power Save Enabled, VOUT = 2.5 V / VOUT = 4.5 V) 3 vs Output current (TPS63030, Power Save Disabled, VOUT = 2.5V / VOUT = 4.5V) 4 vs Output current (TPS63031, Power Save Enabled, VOUT = 3.3V) 5 vs Output current (TPS63031, Power Save Disabled, VOUT = 3.3V) 6 vs Input voltage (TPS63030, Power Save Enabled, VOUT = 2.5V, IOUT = {10; 100; 500 mA}) 7 vs Input voltage (TPS63030, Power Save Enabled, VOUT = 4.5V, IOUT = {10; 100; 500 mA}) 8 vs Input voltage (TPS63030, Power Save Disabled, VOUT = 2.5V, IOUT = {10; 100; 500 mA}) 9 vs Input voltage (TPS63030, Power Save Disabled, VOUT = 4.5V, IOUT = {10; 100; 500 mA}) 10 vs Input voltage (TPS63031, Power Save Enabled, VOUT = 3.3V, IOUT = {10; 100; 500 mA}) 11 vs Input voltage (TPS63031, Power Save Disabled, VOUT = 3.3V, IOUT = {10; 100; 500 mA}) 12 vs Output current (TPS63030, VOUT = 2.5 V) 13 vs Output current (TPS63030, VOUT = 4.5 V) 14 vs Output current (TPS63031, VOUT = 3.3V) 15 Load transient response (TPS63031, VIN < VOUT, Load change from 40% to 60% of max) 16 Load transient response (TPS63031, VIN > VOUT, Load change from 40% to 60% of max) 17 Line transient response (TPS63031, VOUT = 3.3V, Iout = 300 mA) 18 Startup after enable (TPS63031, VOUT = 3.3V, VIN = 2.4V, Iout = 300mA) 19 Startup after enable (TPS63031, VOUT = 3.3V, VIN = 4.2V, Iout = 300mA) 20 MAXIMUM OUTPUT CURRENT vs INPUT VOLTAGE MAXIMUM OUTPUT CURRENT vs INPUT VOLTAGE 1200 1100 TPS63030 1000 TPS63031 VO = 2.5 V 1000 Maximum Output Current - mA Maximum Output Current - mA 900 800 700 VO = 4.5 V 600 500 400 300 200 VO = 3.3 V 800 600 400 200 100 0 1.8 2.2 2.6 3 3.4 3.8 4.2 4.6 VI - Input Voltage - V 5 5.4 0 1.8 2.2 2.6 Figure 1. 6 Submit Documentation Feedback 3 3.4 3.8 4.2 4.6 VI - Input Voltage - V 5 5.4 Figure 2. Copyright © 2008–2009, Texas Instruments Incorporated Product Folder Link(s): TPS63030 TPS63031 TPS63030 TPS63031 www.ti.com.................................................................................................................................................. SLVS696A – OCTOBER 2008 – REVISED MARCH 2009 EFFICIENCY vs OUTPUT CURRENT EFFICIENCY vs OUTPUT CURRENT 100 100 80 80 70 70 60 VI = 2.4 V, VO = 4.5 V VI = 3.6 V, VO = 4.5 V 50 VI = 2.4 V, VO = 2.5 V 40 60 40 30 20 20 TPS63030 Power Save Enabled 100 1 10 100 IO - Output Current - mA 0 0.1 1000 1000 10 100 IO - Output Current - mA Figure 4. EFFICIENCY vs OUTPUT CURRENT EFFICIENCY vs OUTPUT CURRENT 100 VI = 3.6 V, VO = 3.3 V 80 80 Efficiency - % 50 40 60 40 30 20 20 TPS63031 Power Save Enabled VI = 2.4 V, VO = 3.3 V 50 30 100 1 10 IO - Output Current - mA VI = 3.6 V, VO = 3.3 V 70 VI = 2.4 V, VO = 3.3 V 60 0 0.1 1 Figure 3. 90 10 TPS63030 Power Save Disabled 10 90 70 VI = 2.4 V, VO = 4.5 V 50 30 0 0.1 VI = 3.6 V, VO = 2.5 V VI = 2.4 V, VO = 2.5 V VI = 3.6 V, VO = 4.5 V 10 Efficiency - % 90 Efficiency - % Efficiency - % 90 VI = 3.6 V, VO = 2.5 V TPS63031 Power Save Disabled 10 1000 0 0.1 Figure 5. 1 10 100 IO - Output Current - mA 1000 Figure 6. Copyright © 2008–2009, Texas Instruments Incorporated Product Folder Link(s): TPS63030 TPS63031 Submit Documentation Feedback 7 TPS63030 TPS63031 SLVS696A – OCTOBER 2008 – REVISED MARCH 2009.................................................................................................................................................. www.ti.com EFFICIENCY vs INPUT VOLTAGE 100 100 IO = 100 mA VO = 2.5 V VO = 4.5 V 90 90 80 80 IO = 10 mA 70 IO = 500 mA 60 50 40 20 100 2.2 2.6 3 3.4 3.8 4.2 4.6 VI - Input Voltage - V 5 0 1.8 5.4 2.2 2.6 Figure 8. EFFICIENCY vs INPUT VOLTAGE EFFICIENCY vs INPUT VOLTAGE VO = 2.5 V 100 IO = 100 mA VO = 4.5 V 5 5.4 IO = 100 mA 90 80 IO = 500 mA 70 Efficiency - % 70 60 50 IO = 10 mA 40 60 IO = 10 mA 40 30 20 20 TPS63030 Power Save Disabled 2.2 2.6 3 3.4 3.8 4.2 4.6 VI - Input Voltage - V 5 IO = 500 mA 50 30 10 TPS63030 Power Save Disabled 10 5.4 0 1.8 2.2 2.6 Figure 9. 8 3 3.4 3.8 4.2 4.6 VI - Input Voltage - V Figure 7. 80 0 1.8 TPS63030 Power Save Enabled 10 90 Efficiency - % 40 20 TPS63030 Power Save Enabled IO = 500 mA 50 30 0 1.8 IO = 10 mA 60 30 10 IO = 100 mA 70 Efficiency - % Efficiency - % EFFICIENCY vs INPUT VOLTAGE Submit Documentation Feedback 3 3.4 3.8 4.2 4.6 VI - Input Voltage - V 5 5.4 Figure 10. Copyright © 2008–2009, Texas Instruments Incorporated Product Folder Link(s): TPS63030 TPS63031 TPS63030 TPS63031 www.ti.com.................................................................................................................................................. SLVS696A – OCTOBER 2008 – REVISED MARCH 2009 EFFICIENCY vs INPUT VOLTAGE 100 100 IO = 100 mA VO = 3.3 V 90 90 80 80 IO = 500 mA 70 IO = 10 mA 60 50 40 40 20 TPS63031 Power Save Enabled 2.575 2.6 3 3.4 3.8 4.2 4.6 VI - Input Voltage - V 5 TPS63031 Power Save Disabled 10 0 1.8 5.4 2.2 2.6 3 3.4 3.8 4.2 4.6 VI - Input Voltage - V Figure 11. Figure 12. OUTPUT VOLTAGE vs OUTPUT CURRENT OUTPUT VOLTAGE vs OUTPUT CURRENT 5 5.4 4.635 VO = 2.5 V VO = 4.5 V 4.59 VO - Output Voltage - V 2.55 VO - Output Voltage - V IO = 10 mA 20 2.2 IO = 500 mA 50 30 0 1.8 IO = 100 mA 60 30 10 VO = 3.3 V 70 Efficiency - % Efficiency - % EFFICIENCY vs INPUT VOLTAGE 2.525 VI = 3.6 V 2.5 2.475 2.45 4.545 VI = 3.6 V 4.5 4.455 4.41 TPS63031 Power Save Disabled TPS63031 Power Save Disabled 4.365 2.425 1 10 100 IO - Output Current - mA 1000 1 Figure 13. 10 100 IO - Output Current - mA 1000 Figure 14. Copyright © 2008–2009, Texas Instruments Incorporated Product Folder Link(s): TPS63030 TPS63031 Submit Documentation Feedback 9 TPS63030 TPS63031 SLVS696A – OCTOBER 2008 – REVISED MARCH 2009.................................................................................................................................................. www.ti.com OUTPUT VOLTAGE vs OUTPUT CURRENT LOAD TRANSIENT RESPONSE 3.399 VI = 2.4 V, IL = 175 mA to 265 mA VO = 3.3 V Output Voltage 50 mV/div, AC VO - Output Voltage - V 3.366 VI = 3.6 V 3.333 3.3 Output Current 50 mA/div 3.267 3.234 TPS63031, VO = 3.3 V TPS63031 Power Save Disabled 3.201 1 10 100 IO - Output Current - mA Time - 1 ms/div 1000 Figure 15. Figure 16. LOAD TRANSIENT RESPONSE LINE TRANSIENT RESPONSE VI = 4.2 V, IL = 340 mA to 500 mA VI = 3 V to 3.6 V, IL = 300 mA Output Voltage 50 mV/div, AC Input Voltage 500 mV/div, AC Output Current 100 mA/div Output Voltage 20 mV/div, AC TPS63031, VO = 3.3 V TPS63031, VO = 3.3 V Time 1 ms/div Time 2 ms/Div Figure 18. Figure 17. 10 Submit Documentation Feedback Copyright © 2008–2009, Texas Instruments Incorporated Product Folder Link(s): TPS63030 TPS63031 TPS63030 TPS63031 www.ti.com.................................................................................................................................................. SLVS696A – OCTOBER 2008 – REVISED MARCH 2009 STARTUP AFTER ENABLE Enable 5 V/div, DC STARTUP AFTER ENABLE Enable 5 V/div, DC Output Voltage 1 V/div, DC Output Voltage 1 V/div, DC Inductor Current 200 mA/div, DC Inductor Current Voltage at L1 200 mA/div, DC 5 V/div, DC Voltage at L2 5 V/div, DC TPS63031, VO = 3.3 V TPS63031, VO = 3.3 V VI = 2.4 V, RL = 11 W VI = 4.2 V, RL = 11 W Time 100 ms/div Time 200ms/div Figure 19. Figure 20. PARAMETER MEASUREMENT INFORMATION L1 L1 VIN L2 VIN VINA C1 C3 R1 EN C2 FB PS/SYNC GND VOUT VOUT R2 PGND TPS6303X List of Components REFERENCE DESCRIPTION MANUFACTURER TPS6303 0 / 1 Texas Instruments L1 1.5 µH, 3 mm x 3 mm x 1.5 mm LPS3015-152, Coilcraft C1 10 µF 6.3V, 0603, X7R ceramic GRM188R60J106KME84D, Murata C2 2 × 10 µF 6.3V, 0603, X7R ceramic GRM188R60J106KME84D, Murata C3 0.1 µF, X7R ceramic R1, R2 Depending on the output voltage at TPS63030, not used at TPS63031 Copyright © 2008–2009, Texas Instruments Incorporated Product Folder Link(s): TPS63030 TPS63031 Submit Documentation Feedback 11 TPS63030 TPS63031 SLVS696A – OCTOBER 2008 – REVISED MARCH 2009.................................................................................................................................................. www.ti.com DETAILED DESCRIPTION CONTROLLER CIRCUIT The controlling circuit of the device is based on an average current mode topology. The average inductor current is regulated by a fast current regulator loop which is controlled by a voltage control loop. The controller also uses input and output voltage feedforward. Changes of input and output voltage are monitored and immediately can change the duty cycle in the modulator to achieve a fast response to those errors. The voltage error amplifier gets its feedback input from the FB pin. At adjustable output voltages a resistive voltage divider must be connected to that pin. At fixed output voltages FB must be connected to the output voltage to directly sense the voltage. Fixed output voltage versions use a trimmed internal resistive divider. The feedback voltage will be compared with the internal reference voltage to generate a stable and accurate output voltage. The controller circuit also senses the average input current as well as the peak input current. With this, maximum input power can be controlled as well as the maximum peak current to achieve a safe and stable operation under all possible conditions. To finally protect the device from overheating, an internal temperature sensor is implemented. Synchronous Operation The device uses 4 internal N-channel MOSFETs to maintain synchronous power conversion at all possible operating conditions. This enables the device to keep high efficiency over a wide input voltage and output power range. To avoid ground shift problems due to the high currents in the switches, two separate ground pins GND and PGND are used. The reference for all control functions is the GND pin. The power switches are connected to PGND. Both grounds must be connected on the PCB at only one point ideally close to the GND pin. Due to the 4-switch topology, the load is always disconnected from the input during shutdown of the converter. Buck-Boost Operation To be able to regulate the output voltage properly at all possible input voltage conditions, the device automatically switches from step down operation to boost operation and back as required by the configuration. It always uses one active switch, one rectifying switch, one switch permanently on, and one switch permanently off. Therefore, it operates as a step down converter (buck) when the input voltage is higher than the output voltage, and as a boost converter when the input voltage is lower than the output voltage. There is no mode of operation in which all 4 switches are permanently switching. Controlling the switches this way allows the converter to maintain high efficiency at the most important point of operation; when input voltage is close to the output voltage. The RMS current through the switches and the inductor is kept at a minimum, to minimize switching and conduction losses. Switching losses are also kept low by using only one active and one passive switch. Regarding the remaining 2 switches, one is kept permanently on and the other is kept permanently off, thus causing no switching losses. Power Save Mode and Synchronization The PS/SYNC pin can be used to select different operation modes. To enable power save, PS/SYNC must be set low. Power save mode is used to improve efficiency at light load. If power save mode is enabled, the converter stops operating if the average inductor current gets lower than about 100 mA and the output voltage is at or above its nominal value. If the output voltage decreases below its nominal value, the device ramps up the output voltage again by starting operation using a programmed average inductor current higher than required by the current load condition. Operation can last for one or several pulses. The converter again stops operating once the conditions for stopping operation are met again. The power save mode can be disabled by programming high at the PS/SYNC. Connecting a clock signal at PS/SYNC forces the device to synchronize to the connected clock frequency. Synchronization is done by a PLL, so synchronizing to lower and higher frequencies compared to the internal clock works without any issues. The PLL can also tolerate missing clock pulses without the converter malfunctioning. The PS/SYNC input supports standard logic thresholds. 12 Submit Documentation Feedback Copyright © 2008–2009, Texas Instruments Incorporated Product Folder Link(s): TPS63030 TPS63031 TPS63030 TPS63031 www.ti.com.................................................................................................................................................. SLVS696A – OCTOBER 2008 – REVISED MARCH 2009 Device Enable The device is put into operation when EN is set high. It is put into a shutdown mode when EN is set to GND. In shutdown mode, the regulator stops switching, all internal control circuitry is switched off, and the load is disconnected from the input. This also means that the output voltage can drop below the input voltage during shutdown. During start-up of the converter, the duty cycle and the peak current are limited in order to avoid high peak currents flowing from the input. Softstart and Short Circuit Protection After being enabled, the device starts operating. The average current limit ramps up from an initial 400mA following the output voltage increasing. At an output voltage of about 1.2 V, the current limit is at its nominal value. If the output voltage does not increase, the current limit will not increase. There is no timer implemented. Thus the output voltage overshoot at startup, as well as the inrush current, is kept at a minimum. The device ramps up the output voltage in a controlled manner even if a very large capacitor is connected at the output. When the output voltage does not increase above 1.2 V, the device assumes a short circuit at the output and keeps the current limit low to protect itself and the application. At a short at the output during operation the current limit also will be decreased accordingly. At 0 V at the output, for example, the output current will not exceed about 400 mA. Undervoltage Lockout An undervoltage lockout function prevents device start-up if the supply voltage on VINA is lower than approximately its threshold (see electrical characteristics table). When in operation, the device automatically enters the shutdown mode if the voltage on VINA drops below the undervoltage lockout threshold. The device automatically restarts if the input voltage recovers to the minimum operating input voltage. Overtemperature Protection The device has a built-in temperature sensor which monitors the internal IC temperature. If the temperature exceeds the programmed threshold (see electrical characteristics table) the device stops operating. As soon as the IC temperature has decreased below the programmed threshold, it starts operating again. There is a built-in hysteresis to avoid unstable operation at IC temperatures at the overtemperature threshold. Copyright © 2008–2009, Texas Instruments Incorporated Product Folder Link(s): TPS63030 TPS63031 Submit Documentation Feedback 13 TPS63030 TPS63031 SLVS696A – OCTOBER 2008 – REVISED MARCH 2009.................................................................................................................................................. www.ti.com APPLICATION INFORMATION DESIGN PROCEDURE The TPS6303x dc/dc converters are intended for systems powered by one-cell Li-Ion or Li-Polymer battery with a typical voltage between 2.3 V and 4.5 V. They can also be used in systems powered by a double or triple cell Alkaline, NiCd, or NiMH battery with a typical terminal voltage between 1.8 V and 5.5 V . Additionally, any other voltage source with a typical output voltage between 1.8 V and 5.5 V can power systems where the TPS6303x is used. PROGRAMMING THE OUTPUT VOLTAGE Within the TPS6303X family there are fixed and adjustable output voltage versions available. To properly configure the fixed output voltage devices, the FB pin is used to sense the output voltage. This means that it must be connected directly to VOUT. At the adjustable output voltage versions, an external resistor divider is used to adjust the output voltage. The resistor divider must be connected between VOUT, FB and GND. When the output voltage is regulated properly, the typical value of the voltage at the FB pin is 500mV. The maximum recommended value for the output voltage is 5.5V. The current through the resistive divider should be about 100 times greater than the current into the FB pin. The typical current into the FB pin is 0.01 µA, and the voltage across the resistor between FB and GND, R2, is typically 500 mV. Based on those two values, the recommended value for R2 should be lower than 500kΩ, in order to set the divider current at 1µA or higher. It is recommended to keep the value for this resistor in the range of 200kΩ. From that, the value of the resistor connected between VOUT and FB, R1, depending on the needed output voltage (VOUT), can be calculated using Equation 1: R 1 + R2 ǒ VOUT V FB Ǔ *1 (1) L1 L1 VIN L2 VIN VINA C1 C3 R1 EN C2 FB PS/SYNC GND VOUT VOUT R2 PGND TPS6303X Figure 21. Typical Application Circuit for Adjustable Output Voltage Option INDUCTOR SELECTION To properly configure the TPS6303X devices, an inductor must be connected between pin L1 and pin L2. To estimate the inductance value Equation 2 and Equation 3 can be used. μs L1 = (VIN1 - VOUT ) × 0.5 × A (2) μs L2 = VOUT × 0.5 × A (3) In Equation 2 the minimum inductance value, L1 for step down mode operation is calculated. VIN1 is the maximum input voltage. In Equation 3 the minimum inductance, L2, for boost mode operation is calculated. The recommended minimum inductor value is either L1 or L2 whichever is higher. As an example, a suitable inductor for generating 3.3V from a Li-Ion battery with a battery voltage range from 2.5V up to 4.2V is 2.2 µH. The recommended inductor value range is between 1.5 µH and 4.7 µH. In general, this means that at high voltage conversion rates, higher inductor values offer better performance. 14 Submit Documentation Feedback Copyright © 2008–2009, Texas Instruments Incorporated Product Folder Link(s): TPS63030 TPS63031 TPS63030 TPS63031 www.ti.com.................................................................................................................................................. SLVS696A – OCTOBER 2008 – REVISED MARCH 2009 With the chosen inductance value, the peak current for the inductor in steady state operation can be calculated. Equation 4 shows how to calculate the peak current I1 in step down mode operation and Equation 5 shows how to calculate the peak current I2 in boost mode operation. VOUTǒV IN1 * V OUTǓ I I 1 + OUT ) 0.8 2 V IN1 f L V I OUT VIN2 I 2 + OUT ) 2 0.8 V IN2 (4) ǒV OUT * V IN2Ǔ VOUT f L (5) In both equations f is the minimum switching frequency. VIN2 is the minimum input voltage. The critical current value for selecting the right inductor is the higher value of I1 and I2. It also needs to be taken into account that load transients and error conditions may cause higher inductor currents. This also needs to be taken into account when selecting an appropriate inductor. The following inductor series from different suppliers have been used with TPS6303x converters: Table 1. List of Inductors VENDOR INDUCTOR SERIES LPS3015 Coilcraft EPL3010 Murata LQH3NP Tajo Yuden NR3015 CAPACITOR SELECTION Input Capacitor At least a 4.7 µF input capacitor is recommended to improve transient behavior of the regulator and EMI behavior of the total power supply circuit. A ceramic capacitor placed as close as possible to the VIN and PGND pins of the IC is recommended. Bypass Capacitor To make sure that the internal control circuits are supplied with a stable low noise supply voltage, a capacitor can be connected between VINA and GND. Using a ceramic capacitor with a value of 0.1µF is recommended. The value of this capacitor should not be higher than 0.22µF. Output Capacitor For the output capacitor, it is recommended to use small ceramic capacitors placed as close as possible to the VOUT and PGND pins of the IC. If, for any reason, the application requires the use of large capacitors which can not be placed close to the IC, using a smaller ceramic capacitor in parallel to the large one is recommended. This small capacitor should be placed as close as possible to the VOUT and PGND pins of the IC. To get an estimate of the recommended minimum output capacitance, Equation 6 can be used. mF C OUT + 5 L mH (6) A capacitor with a value in the range of the calculated minimum should be used. This is required to maintain control loop stability. There are no additional requirements regarding minimum ESR. There is also no upper limit for the output capacitance value. Larger capacitors will cause lower output voltage ripple as well as lower output voltage drop during load transients. Copyright © 2008–2009, Texas Instruments Incorporated Product Folder Link(s): TPS63030 TPS63031 Submit Documentation Feedback 15 TPS63030 TPS63031 SLVS696A – OCTOBER 2008 – REVISED MARCH 2009.................................................................................................................................................. www.ti.com LAYOUT CONSIDERATIONS As for all switching power supplies, the layout is an important step in the design, especially at high peak currents and high switching frequencies. If the layout is not carefully done, the regulator could show stability problems as well as EMI problems. Therefore, use wide and short traces for the main current path and for the power ground tracks. The input capacitor, output capacitor, and the inductor should be placed as close as possible to the IC. Use a common ground node for power ground and a different one for control ground to minimize the effects of ground noise. Connect these ground nodes at any place close to one of the ground pins of the IC. The feedback divider should be placed as close as possible to the control ground pin of the IC. To lay out the control ground, it is recommended to use short traces as well, separated from the power ground traces. This avoids ground shift problems, which can occur due to superimposition of power ground current and control ground current. THERMAL INFORMATION Implementation of integrated circuits in low-profile and fine-pitch surface-mount packages typically requires special attention to power dissipation. Many system-dependent issues such as thermal coupling, airflow, added heat sinks and convection surfaces, and the presence of other heat-generating components affect the power-dissipation limits of a given component. Three basic approaches for enhancing thermal performance are listed below. • Improving the power dissipation capability of the PCB design • Improving the thermal coupling of the component to the PCB by soldering the PowerPAD • Introducing airflow in the system For more details on how to use the thermal parameters in the dissipation ratings table please check the Thermal Characteristics Application Note (SZZA017) and the IC Package Thermal Metrics Application Note (SPRA953). 16 Submit Documentation Feedback Copyright © 2008–2009, Texas Instruments Incorporated Product Folder Link(s): TPS63030 TPS63031 PACKAGE OPTION ADDENDUM www.ti.com 16-Apr-2009 PACKAGING INFORMATION Orderable Device Status (1) Package Type Package Drawing Pins Package Eco Plan (2) Qty TPS63030DSKR ACTIVE SON DSK 10 3000 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM TPS63030DSKRG4 ACTIVE SON DSK 10 3000 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM TPS63030DSKT ACTIVE SON DSK 10 250 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM TPS63030DSKTG4 ACTIVE SON DSK 10 250 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM TPS63031DSKR ACTIVE SON DSK 10 3000 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM TPS63031DSKRG4 ACTIVE SON DSK 10 3000 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM TPS63031DSKT ACTIVE SON DSK 10 250 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM TPS63031DSKTG4 ACTIVE SON DSK 10 250 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM Lead/Ball Finish MSL Peak Temp (3) (1) The marketing status values are defined as follows: ACTIVE: Product device recommended for new designs. LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect. NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design. PREVIEW: Device has been announced but is not in production. Samples may or may not be available. OBSOLETE: TI has discontinued the production of the device. (2) Eco Plan - The planned eco-friendly classification: Pb-Free (RoHS), Pb-Free (RoHS Exempt), or Green (RoHS & no Sb/Br) - please check http://www.ti.com/productcontent for the latest availability information and additional product content details. TBD: The Pb-Free/Green conversion plan has not been defined. Pb-Free (RoHS): TI's terms "Lead-Free" or "Pb-Free" mean semiconductor products that are compatible with the current RoHS requirements for all 6 substances, including the requirement that lead not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, TI Pb-Free products are suitable for use in specified lead-free processes. Pb-Free (RoHS Exempt): This component has a RoHS exemption for either 1) lead-based flip-chip solder bumps used between the die and package, or 2) lead-based die adhesive used between the die and leadframe. The component is otherwise considered Pb-Free (RoHS compatible) as defined above. Green (RoHS & no Sb/Br): TI defines "Green" to mean Pb-Free (RoHS compatible), and free of Bromine (Br) and Antimony (Sb) based flame retardants (Br or Sb do not exceed 0.1% by weight in homogeneous material) (3) MSL, Peak Temp. -- The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder temperature. Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is provided. TI bases its knowledge and belief on information provided by third parties, and makes no representation or warranty as to the accuracy of such information. Efforts are underway to better integrate information from third parties. TI has taken and continues to take reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on incoming materials and chemicals. TI and TI suppliers consider certain information to be proprietary, and thus CAS numbers and other limited information may not be available for release. In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI to Customer on an annual basis. Addendum-Page 1 PACKAGE MATERIALS INFORMATION www.ti.com 10-Mar-2009 TAPE AND REEL INFORMATION *All dimensions are nominal Device Package Package Pins Type Drawing TPS63030DSKR SON DSK 10 SPQ Reel Reel Diameter Width (mm) W1 (mm) A0 (mm) B0 (mm) K0 (mm) P1 (mm) W Pin1 (mm) Quadrant 3000 179.0 8.4 2.73 2.73 0.8 4.0 8.0 Q2 TPS63030DSKT SON DSK 10 250 179.0 8.4 2.73 2.73 0.8 4.0 8.0 Q2 TPS63031DSKR SON DSK 10 3000 179.0 8.4 2.73 2.73 0.8 4.0 8.0 Q2 TPS63031DSKT SON DSK 10 250 179.0 8.4 2.73 2.73 0.8 4.0 8.0 Q2 Pack Materials-Page 1 PACKAGE MATERIALS INFORMATION www.ti.com 10-Mar-2009 *All dimensions are nominal Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm) TPS63030DSKR SON DSK 10 3000 195.0 200.0 45.0 TPS63030DSKT SON DSK 10 250 195.0 200.0 45.0 TPS63031DSKR SON DSK 10 3000 195.0 200.0 45.0 TPS63031DSKT SON DSK 10 250 195.0 200.0 45.0 Pack Materials-Page 2 IMPORTANT NOTICE Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, modifications, enhancements, improvements, and other changes to its products and services at any time and to discontinue any product or service without notice. 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