TPS62040 TPS62042, TPS62043 TPS62044, TPS62046 www.ti.com SLVS463B − JUNE 2003 − REVISED OCTOBER 2005 1.2 A/1.25 MHz, HIGH-EFFICIENCY STEP-DOWN CONVERTER FEATURES D Up to 95% Conversion Efficiency D Typical Quiescent Current: 18 µA D Load Current: 1.2 A D Operating Input Voltage Range: 2.5 V to 6.0 V D Switching Frequency: 1.25 MHz D Adjustable and Fixed Output Voltage D Power Save Mode Operation at Light load D D D D D D D Currents 100% Duty Cycle for Lowest Dropout Internal Softstart Dynamic Output Voltage Positioning Thermal Shutdown Short-Circuit Protection 10 Pin MSOP PowerPad™ Package 10 Pin QFN 3 X 3 mm Package APPLICATIONS D PDA, Pocket PC and Smart Phones D D D D D USB Powered Modems CPUs and DSPs PC Cards and Notebooks xDSL Applications Standard 5-V to 3.3-V Conversion DESCRIPTION The TPS6204x family of devices are high efficiency synchronous step-down dc-dc converters optimized for battery powered portable applications. The devices are ideal for portable applications powered by a single Li-Ion battery cell or by 3-cell NiMH/NiCd batteries. With an output voltage range from 6.0 V down to 0.7 V, the devices support low voltage DSPs and processors in PDAs, pocket PCs, as well as notebooks and subnotebook computers. The TPS6204x operates at a fixed switching frequency of 1.25 MHz and enters the power save mode operation at light load currents to maintain high efficiency over the entire load current range. For low noise applications, the devices can be forced into fixed frequency PWM mode by pulling the MODE pin high. The TPS6204x supports up to 1.2-A load current. EFFICIENCY vs LOAD CURRENT 100 Typical Application Circuit 1.2-A Output Current VO = 1.8 V 95 VI = 2.7 V 90 C1 22 µF TPS6204x 2 VIN 3 VIN 1 EN 6 MODE 4 GND SW 8 L1 6.2 µH 7 SW 5 FB 10 PGND 9 PGND VO 0.7 V to VI /1.2 A C2 22 µF VI = 3.6 V 85 Efficiency − % VI 2.5 V to 6 V 80 VI = 5 V 75 70 65 MODE = Low 60 55 50 VI = 3.6 V MODE = High 45 40 0 0.01 0.1 1 10 100 IL − Load Current − mA 1k 10 k 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 Texas Instruments standard warranty. Production processing does not necessarily include testing of all parameters. Copyright © 2003 − 2005, Texas Instruments Incorporated TPS62040 TPS62042, TPS62043 TPS62044, TPS62046 www.ti.com SLVS463B − JUNE 2003 − REVISED OCTOBER 2005 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. ORDERING INFORMATION TA PACKAGE VOLTAGE OPTIONS PACKAGE MARKING MSOP(1) QFN(2) MSOP QFN Adjustable TPS62040DGQ TPS62040DRC BBI BBO 1.5 V TPS62042DGQ TPS62042DRC BBL BBS 1.6 V TPS62043DGQ TPS62043DRC BBM BBT 1.8 V TPS62044DGQ TPS62044DRC BBN BBU 3.3 V TPS62046DGQ TPS62046DRC BBQ BBW −40°C 40 C to 85 85°C C (1) The DGQ package is available in tape and reel. Add R suffix (DGQR) to order quantities of 2500 parts per reel. (2) The DRC package is available in tape and reel. Add R suffix (DRCR) to order quantities of 3000 parts per reel. ABSOLUTE MAXIMUM RATINGS over operating free-air temperature range unless otherwise noted(1) UNITS Supply voltage VIN (2) −0.3 V to 7 V Voltages on EN, MODE, FB, SW(2) −0.3 V to VCC +0.3 V Continuous power dissipation See Dissipation Rating Table Operating junction temperature range −40°C to 150°C Storage temperature range −65°C to 150°C Lead temperature (soldering, 10 sec) 260°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 may affect device reliability. (2) All voltage values are with respect to network ground terminal. PACKAGE DISSIPATION RATINGS RQJA(1) TA ≤ 25°C POWER RATING TA = 70°C POWER RATING TA = 85°C POWER RATING MSOP 60°C/W 1.67 W 917 mW 667 mW QFN 48.7°C/W 2.05 W 1.13 W 821 mW PACKAGE (1) The thermal resistance, RΘJA is based on a soldered PowerPAD using thermal vias. RECOMMENDED OPERATING CONDITIONS MIN TYP MAX UNIT VI Supply voltage 2.5 6.0 V VO Output voltage range for adjustable output voltage version 0.7 VI V IO Output current 1.2 A L Inductor(1) 6.2 µH CI Input capacitor(1) 22 µF capacitor(1) CO Output TA Operating ambient temperature −40 85 °C TJ Operating junction temperature −40 125 °C (1) 2 Refer to application section for further information 22 µF TPS62040 TPS62042, TPS62043 TPS62044, TPS62046 www.ti.com SLVS463B − JUNE 2003 − REVISED OCTOBER 2005 ELECTRICAL CHARACTERISTICS VI = 3.6 V, VO = 1.8 V, IO = 600 mA, EN = VIN, TA = −40°C to 85°C, typical values are at TA = 25°C (unless otherwise noted)(1) SUPPLY CURRENT PARAMETER TEST CONDITIONS VI Input voltage range I(Q) Operating quiescent current IO = 0 mA, device is not switching ISD Shutdown supply current EN = GND VUVLO Under−voltage lockout threshold MIN TYP 2.5 MAX V 35 µA 1 µA 18 0.1 1.5 UNIT 6.0 2.3 V ENABLE AND MODE VEN EN high level input voltage VEN EN low level input voltage IEN EN input bias current V(MODE) MODE high level input voltage V(MODE) MODE low level input voltage I(MODE) MODE input bias current 1.4 EN = GND or VIN V 0.01 0.4 V 1.0 µA 1.4 MODE = GND or VIN V 0.01 0.4 V 1.0 µA POWER SWITCH P-channel MOSFET on−resistance VI = VGS = 3.6 V 115 210 mΩ P-channel MOSFET on−resistance VI = VGS = 2.5 V 145 270 mΩ P-channel leakage current VDS = 6.0 V 1 µA N-channel MOSFET on−resistance VI = VGS = 3.6 V 85 200 mΩ N-channel MOSFET on−resistance VI = VGS = 2.5 V 115 280 mΩ IIkg(N) N-channel leakage current VDS = 6.0 V 1 µA IL P-channel current limit 2.5 V < VI< 6.0 V rDS(ON) Ilkg(P) rDS(ON) 1.5 Thermal shutdown 1.85 2.2 150 A °C OSCILLATOR fS VFB = 0.5 V Oscillator frequency 1 VFB = 0 V 1.25 1.5 625 MHz kHz OUTPUT VO Adjustable output voltage range Vref Reference voltage VFB Feedback voltage VO IIkg(SW) f (1) Fixed output voltage TPS62040 0.7 VIN 0.5 V V TPS62040 Adjustable VI = 2.5 V to 6.0 V; IO= 0 mA VI = 2.5 V to 6.0 V; 0 mA ≤ IO ≤ 1.2 A 0% −3% 3% 3% TPS62042 1.5V VI = 2.5 V to 6.0 V; IO = 0 mA VI = 2.5 V to 6.0 V; 0 mA ≤ IO ≤ 1.2 A 0% −3% 3% 3% TPS62043 1.6V VI = 2.5 V to 6.0 V; IO = 0 mA VI = 2.5 V to 6.0 V; 0 mA ≤ IO ≤ 1.2 A 0% −3% 3% 3% TPS62044 1.8V VI = 2.5 V to 6.0 V; IO = 0 mA VI = 2.5 V to 6.0 V; 0 mA ≤ IO ≤ 1.2 A 0% −3% 3% 3% TPS62046 3.3V VI = 3.6 V to 6.0 V; IO = 0 mA VI = 3.6 V to 6.0 V; 0 mA ≤ IO ≤ 1.2 A 0% −3% 3% 3% Line regulation(1) VI = VO + 0.5 V (min. 2.5 V) to 6.0 V, IO = 10 mA 0 %/V Load regulation(1) IO = 10 mA to 1200 mA 0 %/mA Leakage current into SW pin VI>VO, 0 V ≤ Vsw ≤ VI 0.1 1 Reverse leakage current into pin SW VI = open; EN = GND; VSW = 6.0 V 0.1 1 Short circuit switching frequency VFB = 0 V 625 µA µA kHz The line and load regulations are digitally controlled to assure an output voltage accuracy of ±3%. 3 TPS62040 TPS62042, TPS62043 TPS62044, TPS62046 www.ti.com SLVS463B − JUNE 2003 − REVISED OCTOBER 2005 PIN ASSIGNMENTS DGQ PACKAGE (TOP VIEW) EN VIN VIN GND FB NOTE: 1 10 2 9 3 8 4 7 5 6 DRC PACKAGE (TOP VIEW) PGND PGND SW SW MODE EN VIN VIN GND FB 1 10 2 9 3 8 4 7 5 6 PGND PGND SW SW MODE The PowerPAD must be connected to GND. Terminal Functions TERMINAL NAME NO. I/O DESCRIPTION EN 1 I Enable. Pulling EN to ground forces the device into shutdown mode. Pulling EN to VI enables the device. EN should not be left floating and must be terminated. VIN 2,3 I Supply voltage input GND 4 FB 5 I Feedback pin. Connect FB directly to the output if the fixed output voltage version is used. For the adjustable version an external resistor divider is connected to this pin. The internal voltage divider is disabled for the adjustable version. MODE 6 I Pulling the MODE pin high allows the device to be forced into fixed frequency operation. Pulling the MODE pin to low enables the power save mode where the device operates in fixed frequency PWM mode at high load currents and in PFM mode (pulse frequency modulation) at light load currents. SW 7,8 I/O PGND 9,10 4 Analog ground This is the switch pin of the converter and is connected to the drain of the internal power MOSFETs Power ground TPS62040 TPS62042, TPS62043 TPS62044, TPS62046 www.ti.com SLVS463B − JUNE 2003 − REVISED OCTOBER 2005 FUNCTIONAL BLOCK DIAGRAM VIN Current limit Comparator Undervoltage Lockout Bias supply + − Soft Start EN + Ref SkipComparator − V Vcomp Comparator + Saw Tooth Generator Ref MODE 1.25 MHz Oscillator I P−Channel Power MOSFET VIN S R − Control Logic SW Driver Shoot−thru Logic SW Comp High Comp Low Comp High Comp Low LoadComparator − Gm + R1 Compensation Comp Low 2 Vref = 0.5 V MODE N−Channel Power MOSFET Comp Low 2 GND + R2 − + − FB PGND PGND For the Adjustable Version the FB Pin Is Directly Connected to the Gm Amplifier 5 TPS62040 TPS62042, TPS62043 TPS62044, TPS62046 www.ti.com SLVS463B − JUNE 2003 − REVISED OCTOBER 2005 TYPICAL CHARACTERISTICS TABLE OF GRAPHS FIGURE η Efficiency vs Load current 1, 2, 3 η Efficiency vs Input voltage 4 IQ Quiescent current vs Input voltage 5, 6 fs Switching frequency vs Input voltage 7 rDS(on) P-Channel rDS(on) vs Input voltage 8 rDS(on) N-Channel rectifier rDS(on) vs Input voltage 9 Load transient response 10 PWM operation 11 Power save mode 12 Start-up 13 EFFICIENCY vs LOAD CURRENT 100 100 VO = 3.3 V 95 VI = 5 V MODE = Low 80 75 VI = 3.6 V MODE = High 70 65 60 VI = 5 V MODE = High 55 VI = 3.6 V 80 VI = 5 V 75 70 55 45 0.01 0.1 1 10 100 Figure 1 1k 10 k VI = 3.6 V MODE = High 60 45 0 MODE = Low 65 50 IL − Load Current − mA 6 85 50 40 VI = 2.7 V 90 Efficiency − % 85 VO = 1.8 V 95 VI = 3.6 V MODE = Low 90 Efficiency − % EFFICIENCY vs LOAD CURRENT 40 0 0.01 0.1 1 10 100 IL − Load Current − mA Figure 2 1k 10 k TPS62040 TPS62042, TPS62043 TPS62044, TPS62046 www.ti.com SLVS463B − JUNE 2003 − REVISED OCTOBER 2005 EFFICIENCY vs LOAD CURRENT 100 100 VO = 1.5 V 95 90 IL = 500 mA Efficiency − % VI = 3.6 V 80 VI = 5 V 75 VO = 1.8 V MODE = Low 95 VI = 2.7 V 85 Efficiency − % EFFICIENCY vs INPUT VOLTAGE 70 65 60 90 85 IL = 1000 mA IL = 1 mA 80 55 50 75 45 40 0 0.01 0.1 1 10 100 IL − Load Current − mA 1k 70 2.5 10 k 3 3.5 4 4.5 5 VI − Input Voltage − V Figure 3 QUIESCENT CURRENT vs INPUT VOLTAGE 23 7.5 MODE = Low TA = 85°C TA = 25°C 17 TA = −40°C 15 13 11 6.5 5.5 5 4.5 4 7 3.5 2.8 3.2 3.6 4 4.4 4.8 5.2 VI − Input Voltage − V Figure 5 5.6 6 TA = 25°C 6 9 5 2.4 MODE = High 7 Quisecent Current − mA Quisecent Current − µ A 19 6 Figure 4 QUIESCENT CURRENT vs INPUT VOLTAGE 21 5.5 3 2.5 3 3.5 4 4.5 5 5.5 6 VI − Input Voltage − V Figure 6 7 TPS62040 TPS62042, TPS62043 TPS62044, TPS62046 www.ti.com SLVS463B − JUNE 2003 − REVISED OCTOBER 2005 SWITCHING FREQUENCY vs INPUT VOLTAGE P-CHANNEL rDS(on) vs INPUT VOLTAGE 0.180 1.23 TA = 85°C 1.22 0.170 TA = 25°C 1.22 P−Channel r DS(on) − Ω f − Switching Frequency − MHz 1.23 1.21 1.21 TA = −40°C 1.20 1.20 TA = 85°C 0.150 TA = 25°C 0.140 0.130 0.120 0.110 1.19 0.100 1.19 TA = −40°C 0.090 1.18 1.18 2.5 0.160 2.9 3.3 3.7 4.1 4.5 4.9 VI − Input Voltage − V 5.3 5.7 6 0.080 2.5 2.9 3.3 Figure 7 3.7 4.1 4.5 4.9 VI − Input Voltage − V Figure 8 N-CHANNEL RECTIFIER rDS(on) vs INPUT VOLTAGE 0.150 N-Channel Rectifier r DS(on) − Ω 0.140 0.130 TA = 85°C 0.120 TA = 25°C 0.110 0.100 0.090 0.080 0.070 TA = −40°C 0.060 0.050 2.5 2.9 3.3 3.7 4.1 4.5 4.9 VI − Input Voltage − V Figure 9 8 5.3 5.7 6 5.3 5.7 6 TPS62040 TPS62042, TPS62043 TPS62044, TPS62046 www.ti.com SLVS463B − JUNE 2003 − REVISED OCTOBER 2005 PWM OPERATION IL 500 mA/div IO 150mA to 1.15 A VO 20 mV/div VO 100 mV/div VI = 3.6 V VO = 1.8 V PWM/PFM Operation V SW 5 V/div LOAD TRANSIENT RESPONSE 500 ns/div 50 µs/div Figure 10 Figure 11 POWER SAVE MODE V SW 5 V/div Enable 2 V/div VO 1 V/div 200 mA/div IL 500 mA/div VO 20 mV/div START-UP I IN VI = 3.6 V VO = 1.8 V IO = 1.1 A 2.5 µs/div Figure 12 200 µs/div Figure 13 9 TPS62040 TPS62042, TPS62043 TPS62044, TPS62046 www.ti.com SLVS463B − JUNE 2003 − REVISED OCTOBER 2005 DETAILED DESCRIPTION OPERATION The TPS6204x is a synchronous step-down converter operating with typically 1.25 MHz fixed frequency. At moderate to heavy load currents, the device operates in pulse width modulation (PWM), and at light load currents, the device enters power save mode operation using pulse frequency modulation (PFM). When operating in PWM mode, the typical switching frequency is 1.25 MHz with a minimum switching frequency of 1 MHz. This makes the device suitable for xDSL applications minimizing RF (radio frequency) interference. During PWM operation the converter uses a unique fast response voltage mode controller scheme with input voltage feed−forward to achieve good line and load regulation, allowing the use of small ceramic input and output capacitors. At the beginning of each clock cycle initiated by the clock signal (S) the P-channel MOSFET switch turns on and the inductor current ramps up until the comparator trips and the control logic turns off the switch. The current limit comparator also turns off the switch in case the current limit of the P-channel switch is exceeded. After the dead time preventing current shoot through, the N-channel MOSFET rectifier is turned on and the inductor current ramps down. The next cycle is initiated by the clock signal, again turning off the N-channel rectifier and turning on the P-channel switch. The Gm amplifier as well as the input voltage determines the rise time of the saw tooth generator, and therefore, any change in input voltage or output voltage directly controls the duty cycle of the converter, giving a very good line and load transient regulation. POWER SAVE MODE OPERATION As the load current decreases, the converter enters power save mode operation. During power save mode the converter operates with reduced switching frequency in PFM mode and with a minimum quiescent current maintaining high efficiency. The converter monitors the average inductor current and the device enters power save mode when the average inductor current is below the threshold. The transition point between PWM and power save mode is given by the transition current with the following equation: I transition + V I 18.66 W (1) During power save mode the output voltage is monitored with the comparator by the threshold’s comp low and comp high. As the output voltage falls below the comp low threshold set to typically 0.8% above the nominal output voltage, the P-channel switch turns on. The P-channel switch remains on until the transition current (1) is reached. Then the N-channel switch turns on completing the first cycle. The converter continues to switch with its normal duty cycle determined by the input and output voltage but with half the nominal switching frequency of 625-kHz typ. Thus the output voltage rises and as soon as the output voltage reaches the comp high threshold of 1.6%, the converter stops switching. Depending on the load current, the converter switches for a longer or shorter period of time in order to deliver the energy to the output. If the load current increases and the output voltage can not be maintained with the transition current , equation (1), the converter enters PWM again. See Figure 11 and Figure 12 under the typical graphs section and Figure 14 for power save mode operation. Among other techniques this advanced power save mode method allows high efficiency over the entire load current range and a small output ripple of typically 1% of the nominal output voltage. Setting the power save mode thresholds to typically 0.8% and 1.6% above the nominal output voltage at light load current results in a dynamic voltage positioning achieving lower absolute voltage drops during heavy load transient changes. This allows the converter to operate with small output capacitors like 22 µF and still having a low absolute voltage drop during heavy load transient. Refer to Figure 14 as well for detailed operation of the power save mode. 10 TPS62040 TPS62042, TPS62043 TPS62044, TPS62046 www.ti.com SLVS463B − JUNE 2003 − REVISED OCTOBER 2005 PFM Mode at Light Load 1.6% Comp High 0.8% Comp Low Comp Low 2 VO PWM Mode at Medium to Full Load Figure 14. Power Save Mode Thresholds and Dynamic Voltage Positioning The converter enters the fixed frequency PWM mode as soon as the output voltage falls below the comp low 2 threshold. DYNAMIC VOLTAGE POSITIONING As described in the power save mode operation sections before and as detailed in Figure 14 the output voltage is typically 0.8% (i.e., 1% on average) above the nominal output voltage at light load currents, as the device is in power save mode. This gives additional headroom for the voltage drop during a load transient from light load to full load. In the other direction during a load transient from full load to light load the voltage overshoot is also minimized by turning on the N-Channel rectifier switch to pull the output voltage actively down. MODE (AUTOMATIC PWM/PFM OPERATION AND FORCED PWM OPERATION) Connecting the MODE pin to GND enables the automatic PWM and power save mode operation. The converter operates in fixed frequency PWM mode at moderate to heavy loads and in the PFM mode during light loads, maintaining high efficiency over a wide load current range. Pulling the MODE pin high forces the converter to operate constantly in the PWM mode even at light load currents. The advantage is the converter operates with a fixed switching frequency that allows simple filtering of the switching frequency for noise sensitive applications. In this mode, the efficiency is lower compared to the power save mode during light loads (see Figure 1 to Figure 3). For additional flexibility it is possible to switch from power save mode to forced PWM mode during operation. This allows efficient power management by adjusting the operation of the TPS6204x to the specific system requirements. 100% DUTY CYCLE LOW DROPOUT OPERATION The TPS6204x offers a low input to output voltage difference while still maintaining regulation with the use of the 100% duty cycle mode. In this mode, the P−Channel switch is constantly turned on. This is particularly useful in battery powered applications to achieve longest operation time by taking full advantage of the whole battery voltage range. i.e. The minimum input voltage to maintain regulation depends on the load current and output voltage and can be calculated as: V min + V max ) I max I O O ǒrDS(on) max ) RLǓ (2) with: IO(max)= maximum output current plus inductor ripple current rDS(on)max= maximum P-channel switch tDS(on). RL = DC resistance of the inductor VOmax = nominal output voltage plus maximum output voltage tolerance 11 TPS62040 TPS62042, TPS62043 TPS62044, TPS62046 www.ti.com SLVS463B − JUNE 2003 − REVISED OCTOBER 2005 SOFTSTART The TPS6204x series has an internal softstart circuit that limits the inrush current during start up. This prevents possible voltage drops of the input voltage in case a battery or a high impedance power source is connected to the input of the TPS6204x. The softstart is implemented with a digital circuit increasing the switch current in steps of typically ILIM/8, ILIM/4, ILIM/2 and then the typical switch current limit 1.85 A as specified in the electrical parameter table. The start-up time mainly depends on the output capacitor and load current, see Figure 13. SHORT-CIRCUIT PROTECTION As soon as the output voltage falls below 50% of the nominal output voltage, the converter switching frequency as well as the current limit is reduced to 50% of the nominal value. Since the short-circuit protection is enabled during start-up, the device does not deliver more than half of its nominal current limit until the output voltage exceeds 50% of the nominal output voltage. This needs to be considered in case a load acting as a current sink is connected to the output of the converter. THERMAL SHUTDOWN As soon as the junction temperature of typically 150_C is exceeded the device goes into thermal shutdown. In this mode, the P-Channel switch and N-Channel rectifier are turned off. The device continues its operation when the junction temperature falls below typically 150°C again. ENABLE Pulling the EN low forces the part into shutdown mode, with a shutdown current of typically 0.1 µA. In this mode, the P-Channel switch and N-Channel rectifier are turned off and the whole device is in shut down. If an output voltage is present during shut down, which could be an external voltage source or super cap, the reverse leakage current is specified under electrical parameter table. For proper operation the enable (EN) pin must be terminated and should not be left floating. Pulling EN high starts up the TPS6204x with the softstart as described under the section Softstart. UNDERVOLTAGE LOCKOUT The undervoltage lockout circuit prevents device misoperation at low input voltages. It prevents the converter from turning on the switch or rectifier MOSFET with undefined conditions. 12 TPS62040 TPS62042, TPS62043 TPS62044, TPS62046 www.ti.com SLVS463B − JUNE 2003 − REVISED OCTOBER 2005 APPLICATION INFORMATION ADJUSTABLE OUTPUT VOLTAGE VERSION When the adjustable output voltage version TPS62040 is used, the output voltage is set by the external resistor divider. See Figure 15. The output voltage is calculated as: V O ǒ1 ) R1 Ǔ R2 + 0.5 V (3) with R1 + R2 ≤ 1 MΩ and internal reference voltage Vref typical = 0.5 V R1 + R2 should not be greater than 1 MΩ because of stability reasons. To keep the operating quiescent current to a minimum, the feedback resistor divider should have high impedance with R1+R2≤1 MΩ. Due to this and the low reference voltage of Vref = 0.5 V, the noise on the feedback pin (FB) needs to be minimized. Using a capacitive divider C1 and C2 across the feedback resistors minimizes the noise at the feedback, without degrading the line or load transient performance. C1 and C2 should be selected as: C1 + 2 1 10 kHz p R1 (4) with: R1 = upper resistor of voltage divider C1 = upper capacitor of voltage divider For C1 a value should be chosen that comes closest to the calculated result. C2 + R1 R2 C1 (5) with: R2 = lower resistor of voltage divider C2 = lower capacitor of voltage divider For C2, the selected capacitor value should always be selected larger than the calculated result. For example, in Figure 15 for C2 100 pF are selected for a calculated result of C2 = 88.42 pF. If quiescent current is not a key design parameter C1 and C2 can be omitted, and a low impedance feedback divider has to be used with R1 + R2 < 100 kΩ. This reduces the noise available on the feedback pin (FB) as well but increases the overall quiescent current during operation. The higher the programmed output voltage the lower the feedback impedance has to be for best operation when not using C1 and C2. VI 2.5 V to 6 V C3 10 µF TPS62040 2 SW VIN 3 SW VIN 1 FB EN 6 MODE PGND 4 GND PGND 8 7 5 10 9 VO 1.8 V / 1.2 A L1 10 µH R1 470 kΩ R2 180 kΩ C1 33 pF C4 10 µF C2 100 pF Figure 15. Adjustable Output Voltage Version 13 TPS62040 TPS62042, TPS62043 TPS62044, TPS62046 www.ti.com SLVS463B − JUNE 2003 − REVISED OCTOBER 2005 Inductor Selection The TPS6204x typically uses a 6.2-µH output inductor. Larger or smaller inductor values can be used to optimize the performance of the device for specific operation conditions. The selected inductor has to be rated for its dc resistance and saturation current. The dc resistance of the inductance directly influences the efficiency of the converter. Therefore an inductor with the lowest dc resistance should be selected for highest efficiency. Formula (7) calculates the maximum inductor current under static load conditions. The saturation current of the inductor should be rated higher than the maximum inductor current as calculated with formula (7). This is needed because during heavy load transient the inductor current rises above the value calculated under (7). DI + V L O V 1– O V I L ƒ (6) DI I max + I max ) L L O 2 (7) with ƒ = Switching frequency (1.25 MHz typical) L = Inductor value ∆IL= Peak-to-peak inductor ripple current ILmax = Maximum inductor current The highest inductor current occurs at maximum VI. Open core inductors have a soft saturation characteristic and they can usually handle higher inductor currents versus a comparable shielded inductor. A more conservative approach is to select the inductor current rating just for the maximum switch current of 2.2 A for the TPS6204x. Keep in mind that the core material from inductor to inductor differs and has an impact on the efficiency, especially at high switching frequencies. Refer to Table 1 and the typical applications and inductors selection. Table 1. Inductor Selection INDUCTOR VALUE 14 DIMENSIONS COMPONENT SUPPLIER 4.7 µH 5,0 mm × 5,0 mm × 3,0 mm Sumida CDRH4D28C-4.7 4.7 µH 5,2 mm × 5,2 mm × 2,5 mm Coiltronics SD25-4R7 5.3 µH 5,7 mm × 5,7 mm × 3,0 mm Sumida CDRH5D28-5R3 6.2 µH 5,7 mm × 5,7 mm × 3,0 mm Sumida CDRH5D28-6R2 6.0 µH 7,0 mm × 7,0 mm × 3,0 mm Sumida CDRH6D28-6R0 TPS62040 TPS62042, TPS62043 TPS62044, TPS62046 www.ti.com SLVS463B − JUNE 2003 − REVISED OCTOBER 2005 Output Capacitor Selection The advanced fast response voltage mode control scheme of the TPS6204x allows the use of small ceramic capacitors with a typical value of 22 µF without having large output voltage under and overshoots during heavy load transients. Ceramic capacitors having low ESR values have the lowest output voltage ripple and are recommended. If required, tantalum capacitors may also be used. Refer to Table 2 for component selection. If ceramic output capacitor are used, the capacitor RMS ripple current rating always meets the application requirements. Just for completeness the RMS ripple current is calculated as: I RMSCout +V O V 1– O V I L ƒ 1 2 Ǹ3 (8) At nominal load current the device operates in PWM mode and the overall output voltage ripple is the sum of the voltage spike caused by the output capacitor ESR plus the voltage ripple caused by charging and discharging the output capacitor: DV O +V O V 1– O V I L ƒ ǒ 8 1 C O ƒ Ǔ ) ESR (9) Where the highest output voltage ripple occurs at the highest input voltage, VI. At light load currents, the device operates in power save mode and the output voltage ripple is independent of the output capacitor value. The output voltage ripple is set by the internal comparator thresholds. The typical output voltage ripple is 1% of the nominal output voltage. Input Capacitor Selection Because of the nature of the buck converter having a pulsating input current, a low ESR input capacitor is required for best input voltage filtering and minimizing the interference with other circuits caused by high input voltage spikes. The input capacitor should have a minimum value of 22 µF. The input capacitor can be increased without any limit for better input voltage filtering. Table 2. Input and Output Capacitor Selection CAPACITOR VALUE CASE SIZE 22 µF 1206 Taiyo Yuden JMK316BJ226ML Ceramic 22 µF 1210 Taiyo Yuden JMK325BJ226MM Ceramic COMPONENT SUPPLIER COMMENTS 15 TPS62040 TPS62042, TPS62043 TPS62044, TPS62046 www.ti.com SLVS463B − JUNE 2003 − REVISED OCTOBER 2005 Layout Considerations 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 stability problems as well as EMI problems. Therefore, use wide and short traces for the main current paths as indicated in bold in Figure 16. These traces should be routed first. The input capacitor should be placed as close as possible to the IC pins as well as the inductor and output capacitor. The feedback resistor network should be routed away from the inductor and switch node to minimize noise and magnetic interference. To further minimize noise from coupling into the feedback network and feedback pin, the ground plane or ground traces should be used for shielding. A common ground plane or a star ground as shown below should be used. This becomes very important especially at high switching frequencies of 1.25 MHz. The Switch Node Must Be Kept as Small as Possible VI C3 22 µF TPS6204x 2 3 1 6 4 VIN VIN EN MODE GND 8 SW 7 SW FB 5 10 PGND 9 PGND L1 10 µH VO C2 22 µF Figure 16. Layout Diagram THERMAL INFORMATION One of the most influential components on the thermal performance of a package is board design. In order to take full advantage of the heat dissipating abilities of the PowerPADt packages, a board should be used that acts similar to a heat sink and allows for the use of the exposed (and solderable), deep downset pad. For further information please refer to Texas Instruments application note (SLMA002) PowerPAD Thermally Enhanced Package. The PowerPADt of the 10-pin MSOP package has an area of 1,52 mm × 1,79 mm (± 0,05 mm) and must be soldered to the PCB to lower the thermal resistance. Thermal vias to the next layer further reduce the thermal resistance. 16 TPS62040 TPS62042, TPS62043 TPS62044, TPS62046 www.ti.com SLVS463B − JUNE 2003 − REVISED OCTOBER 2005 TYPICAL APPLICATIONS VI Li-lon TPS62046 2 VIN 3 VIN 1 EN 6 MODE 4 GND C1 22 µF SW 8 L1 6.2 µH 7 SW 5 FB 10 PGND 9 PGND VO 3.3 V / 1.2 A C2 22 µF Components: C1: Taiyo Yuden JMK316BJ226ML C2: Taiyo Yuden JMK316BJ226ML L1: Sumida CDRH5D28−6R2 Figure 17. Li-Ion to 3.3 V/1.2 A Conversion VI 2.5 V to 6 V C3 22 µF Components: C1: Taiyo Yuden JMK316BJ226ML C2: Taiyo Yuden JMK316BJ226ML L1: Sumida CDRH4D28C−4R7 TPS62040 2 3 1 6 4 VIN VIN EN MODE GND 8 SW SW 7 FB 5 PGND 10 9 PGND VO 1.8 V / 1.2 A L1 4.7 µH R1 470 kΩ C1 33 pF R2 180 kΩ C2 100 pF C4 22 µF Figure 18. Li-Ion to 1.8 V/1.2 A Conversion Using the Adjustable Output Voltage Version 17 PACKAGE OPTION ADDENDUM www.ti.com 29-Jun-2011 PACKAGING INFORMATION Orderable Device Status (1) Package Type Package Drawing Pins Package Qty Eco Plan (2) Lead/ Ball Finish MSL Peak Temp (3) TPS62040DGQ ACTIVE MSOPPowerPAD DGQ 10 80 Green (RoHS & no Sb/Br) CU NIPDAUAGLevel-1-260C-UNLIM TPS62040DGQG4 ACTIVE MSOPPowerPAD DGQ 10 80 Green (RoHS & no Sb/Br) CU NIPDAUAGLevel-1-260C-UNLIM TPS62040DGQR ACTIVE MSOPPowerPAD DGQ 10 2500 Green (RoHS & no Sb/Br) CU NIPDAUAGLevel-1-260C-UNLIM TPS62040DGQRG4 ACTIVE MSOPPowerPAD DGQ 10 2500 Green (RoHS & no Sb/Br) CU NIPDAUAGLevel-1-260C-UNLIM TPS62040DRCR ACTIVE SON DRC 10 3000 Green (RoHS & no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR TPS62040DRCRG4 ACTIVE SON DRC 10 3000 Green (RoHS & no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR TPS62042DGQ ACTIVE MSOPPowerPAD DGQ 10 80 Green (RoHS & no Sb/Br) CU NIPDAUAGLevel-1-260C-UNLIM TPS62042DGQG4 ACTIVE MSOPPowerPAD DGQ 10 80 Green (RoHS & no Sb/Br) CU NIPDAUAGLevel-1-260C-UNLIM TPS62042DGQR ACTIVE MSOPPowerPAD DGQ 10 2500 Green (RoHS & no Sb/Br) CU NIPDAUAGLevel-1-260C-UNLIM TPS62042DGQRG4 ACTIVE MSOPPowerPAD DGQ 10 2500 Green (RoHS & no Sb/Br) CU NIPDAUAGLevel-1-260C-UNLIM TPS62042DRCR ACTIVE SON DRC 10 3000 Green (RoHS & no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR TPS62042DRCRG4 ACTIVE SON DRC 10 3000 Green (RoHS & no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR TPS62043DGQ ACTIVE MSOPPowerPAD DGQ 10 80 Green (RoHS & no Sb/Br) CU NIPDAUAGLevel-1-260C-UNLIM TPS62043DGQG4 ACTIVE MSOPPowerPAD DGQ 10 80 Green (RoHS & no Sb/Br) CU NIPDAUAGLevel-1-260C-UNLIM TPS62043DGQR ACTIVE MSOPPowerPAD DGQ 10 2500 Green (RoHS & no Sb/Br) CU NIPDAUAGLevel-1-260C-UNLIM TPS62043DGQRG4 ACTIVE MSOPPowerPAD DGQ 10 2500 Green (RoHS & no Sb/Br) CU NIPDAUAGLevel-1-260C-UNLIM TPS62043DRCR ACTIVE SON DRC 10 3000 Green (RoHS & no Sb/Br) Addendum-Page 1 CU NIPDAU Level-2-260C-1 YEAR Samples (Requires Login) PACKAGE OPTION ADDENDUM www.ti.com Orderable Device 29-Jun-2011 Status (1) Package Type Package Drawing Pins Package Qty Eco Plan (2) Lead/ Ball Finish MSL Peak Temp (3) TPS62043DRCRG4 ACTIVE SON DRC 10 3000 Green (RoHS & no Sb/Br) TPS62044DGQ ACTIVE MSOPPowerPAD DGQ 10 80 Green (RoHS & no Sb/Br) CU NIPDAUAGLevel-1-260C-UNLIM TPS62044DGQG4 ACTIVE MSOPPowerPAD DGQ 10 80 Green (RoHS & no Sb/Br) CU NIPDAUAGLevel-1-260C-UNLIM TPS62044DGQR ACTIVE MSOPPowerPAD DGQ 10 2500 Green (RoHS & no Sb/Br) CU NIPDAUAGLevel-1-260C-UNLIM TPS62044DGQRG4 ACTIVE MSOPPowerPAD DGQ 10 2500 Green (RoHS & no Sb/Br) CU NIPDAUAGLevel-1-260C-UNLIM TPS62044DRCR ACTIVE SON DRC 10 3000 Green (RoHS & no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR TPS62044DRCRG4 ACTIVE SON DRC 10 3000 Green (RoHS & no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR TPS62046DGQ ACTIVE MSOPPowerPAD DGQ 10 80 Green (RoHS & no Sb/Br) CU NIPDAUAGLevel-1-260C-UNLIM TPS62046DGQG4 ACTIVE MSOPPowerPAD DGQ 10 80 Green (RoHS & no Sb/Br) CU NIPDAUAGLevel-1-260C-UNLIM TPS62046DGQR ACTIVE MSOPPowerPAD DGQ 10 2500 Green (RoHS & no Sb/Br) CU NIPDAUAGLevel-1-260C-UNLIM TPS62046DGQRG4 ACTIVE MSOPPowerPAD DGQ 10 2500 Green (RoHS & no Sb/Br) CU NIPDAUAGLevel-1-260C-UNLIM TPS62046DRCR ACTIVE SON DRC 10 3000 Green (RoHS & no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR TPS62046DRCRG4 ACTIVE SON DRC 10 3000 Green (RoHS & no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR Samples (Requires Login) CU NIPDAU Level-2-260C-1 YEAR (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. Addendum-Page 2 PACKAGE OPTION ADDENDUM www.ti.com 29-Jun-2011 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 3 PACKAGE MATERIALS INFORMATION www.ti.com 20-Jul-2012 TAPE AND REEL INFORMATION *All dimensions are nominal Device Package Package Pins Type Drawing SPQ Reel Reel A0 Diameter Width (mm) (mm) W1 (mm) B0 (mm) K0 (mm) P1 (mm) W Pin1 (mm) Quadrant TPS62040DGQR MSOPPower PAD DGQ 10 2500 330.0 12.4 5.3 3.4 1.4 8.0 12.0 Q1 TPS62040DRCR SON DRC 10 3000 330.0 12.4 3.3 3.3 1.0 8.0 12.0 Q2 TPS62040DRCR SON DRC 10 3000 330.0 12.4 3.3 3.3 1.1 8.0 12.0 Q2 TPS62042DGQR MSOPPower PAD DGQ 10 2500 330.0 12.4 5.3 3.4 1.4 8.0 12.0 Q1 TPS62042DRCR SON DRC 10 3000 330.0 12.4 3.3 3.3 1.0 8.0 12.0 Q2 TPS62042DRCR SON DRC 10 3000 330.0 12.4 3.3 3.3 1.1 8.0 12.0 Q2 TPS62043DGQR MSOPPower PAD DGQ 10 2500 330.0 12.4 5.3 3.4 1.4 8.0 12.0 Q1 TPS62043DRCR SON DRC 10 3000 330.0 12.4 3.3 3.3 1.0 8.0 12.0 Q2 TPS62043DRCR SON DRC 10 3000 330.0 12.4 3.3 3.3 1.1 8.0 12.0 Q2 TPS62044DGQR MSOPPower PAD DGQ 10 2500 330.0 12.4 5.3 3.4 1.4 8.0 12.0 Q1 TPS62044DRCR SON DRC 10 3000 330.0 12.4 3.3 3.3 1.1 8.0 12.0 Q2 TPS62044DRCR SON DRC 10 3000 330.0 12.4 3.3 3.3 1.0 8.0 12.0 Q2 Pack Materials-Page 1 PACKAGE MATERIALS INFORMATION www.ti.com 20-Jul-2012 Device Package Package Pins Type Drawing SPQ Reel Reel A0 Diameter Width (mm) (mm) W1 (mm) B0 (mm) K0 (mm) P1 (mm) W Pin1 (mm) Quadrant TPS62046DGQR MSOPPower PAD DGQ 10 2500 330.0 12.4 5.3 3.4 1.4 8.0 12.0 Q1 TPS62046DRCR SON DRC 10 3000 330.0 12.4 3.3 3.3 1.0 8.0 12.0 Q2 TPS62046DRCR SON DRC 10 3000 330.0 12.4 3.3 3.3 1.1 8.0 12.0 Q2 *All dimensions are nominal Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm) TPS62040DGQR MSOP-PowerPAD DGQ 10 2500 364.0 364.0 27.0 TPS62040DRCR SON DRC 10 3000 370.0 355.0 55.0 TPS62040DRCR SON DRC 10 3000 367.0 367.0 35.0 TPS62042DGQR MSOP-PowerPAD DGQ 10 2500 364.0 364.0 27.0 TPS62042DRCR SON DRC 10 3000 370.0 355.0 55.0 TPS62042DRCR SON DRC 10 3000 367.0 367.0 35.0 TPS62043DGQR MSOP-PowerPAD DGQ 10 2500 364.0 364.0 27.0 TPS62043DRCR SON DRC 10 3000 370.0 355.0 55.0 TPS62043DRCR SON DRC 10 3000 367.0 367.0 35.0 TPS62044DGQR MSOP-PowerPAD DGQ 10 2500 364.0 364.0 27.0 TPS62044DRCR SON DRC 10 3000 367.0 367.0 35.0 TPS62044DRCR SON DRC 10 3000 370.0 355.0 55.0 Pack Materials-Page 2 PACKAGE MATERIALS INFORMATION www.ti.com 20-Jul-2012 Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm) TPS62046DGQR MSOP-PowerPAD DGQ 10 2500 364.0 364.0 27.0 TPS62046DRCR SON DRC 10 3000 370.0 355.0 55.0 TPS62046DRCR SON DRC 10 3000 367.0 367.0 35.0 Pack Materials-Page 3 IMPORTANT NOTICE Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, enhancements, improvements and other changes to its semiconductor products and services per JESD46C and to discontinue any product or service per JESD48B. Buyers should obtain the latest relevant information before placing orders and should verify that such information is current and complete. All semiconductor products (also referred to herein as “components”) are sold subject to TI’s terms and conditions of sale supplied at the time of order acknowledgment. TI warrants performance of its components to the specifications applicable at the time of sale, in accordance with the warranty in TI’s terms and conditions of sale of semiconductor products. Testing and other quality control techniques are used to the extent TI deems necessary to support this warranty. Except where mandated by applicable law, testing of all parameters of each component is not necessarily performed. TI assumes no liability for applications assistance or the design of Buyers’ products. Buyers are responsible for their products and applications using TI components. To minimize the risks associated with Buyers’ products and applications, Buyers should provide adequate design and operating safeguards. TI does not warrant or represent that any license, either express or implied, is granted under any patent right, copyright, mask work right, or other intellectual property right relating to any combination, machine, or process in which TI components or services are used. Information published by TI regarding third-party products or services does not constitute a license to use such products or services or a warranty or endorsement thereof. Use of such information may require a license from a third party under the patents or other intellectual property of the third party, or a license from TI under the patents or other intellectual property of TI. Reproduction of significant portions of TI information in TI data books or data sheets is permissible only if reproduction is without alteration and is accompanied by all associated warranties, conditions, limitations, and notices. TI is not responsible or liable for such altered documentation. Information of third parties may be subject to additional restrictions. Resale of TI components or services with statements different from or beyond the parameters stated by TI for that component or service voids all express and any implied warranties for the associated TI component or service and is an unfair and deceptive business practice. TI is not responsible or liable for any such statements. Buyer acknowledges and agrees that it is solely responsible for compliance with all legal, regulatory and safety-related requirements concerning its products, and any use of TI components in its applications, notwithstanding any applications-related information or support that may be provided by TI. Buyer represents and agrees that it has all the necessary expertise to create and implement safeguards which anticipate dangerous consequences of failures, monitor failures and their consequences, lessen the likelihood of failures that might cause harm and take appropriate remedial actions. Buyer will fully indemnify TI and its representatives against any damages arising out of the use of any TI components in safety-critical applications. In some cases, TI components may be promoted specifically to facilitate safety-related applications. With such components, TI’s goal is to help enable customers to design and create their own end-product solutions that meet applicable functional safety standards and requirements. Nonetheless, such components are subject to these terms. No TI components are authorized for use in FDA Class III (or similar life-critical medical equipment) unless authorized officers of the parties have executed a special agreement specifically governing such use. Only those TI components which TI has specifically designated as military grade or “enhanced plastic” are designed and intended for use in military/aerospace applications or environments. Buyer acknowledges and agrees that any military or aerospace use of TI components which have not been so designated is solely at the Buyer's risk, and that Buyer is solely responsible for compliance with all legal and regulatory requirements in connection with such use. TI has specifically designated certain components which meet ISO/TS16949 requirements, mainly for automotive use. Components which have not been so designated are neither designed nor intended for automotive use; and TI will not be responsible for any failure of such components to meet such requirements. Products Applications Audio www.ti.com/audio Automotive and Transportation www.ti.com/automotive Amplifiers amplifier.ti.com Communications and Telecom www.ti.com/communications Data Converters dataconverter.ti.com Computers and Peripherals www.ti.com/computers DLP® Products www.dlp.com Consumer Electronics www.ti.com/consumer-apps DSP dsp.ti.com Energy and Lighting www.ti.com/energy Clocks and Timers www.ti.com/clocks Industrial www.ti.com/industrial Interface interface.ti.com Medical www.ti.com/medical Logic logic.ti.com Security www.ti.com/security Power Mgmt power.ti.com Space, Avionics and Defense www.ti.com/space-avionics-defense Microcontrollers microcontroller.ti.com Video and Imaging www.ti.com/video RFID www.ti-rfid.com OMAP Mobile Processors www.ti.com/omap TI E2E Community e2e.ti.com Wireless Connectivity www.ti.com/wirelessconnectivity Mailing Address: Texas Instruments, Post Office Box 655303, Dallas, Texas 75265 Copyright © 2012, Texas Instruments Incorporated