TPS62000-HT www.ti.com .......................................................................................................................................................... SLVS917A – MARCH 2009 – REVISED JUNE 2009 HIGH-EFFICIENCY STEP-DOWN LOW POWER DC-DC CONVERTER FEATURES 1 • • • • • • • • • • • • High-Efficiency Synchronous Step-Down Converter With Greater Than 95% Efficiency 2 V to 5.5 V Operating Input Voltage Range Adjustable Output Voltage Range From 0.8 V to VI Synchronizable to External Clock Signal up to 1 MHz Up to 300 mA Output Current Pin-Programmable Current Limit High Efficiency Over a Wide Load Current Range in Power Save Mode 100% Maximum Duty Cycle for Lowest Dropout Low-Noise Operation Antiringing Switch and PFM/PWM Operation Mode Internal Softstart 50-µA Quiescent Current (TYP) Evaluation Module Available for Commercial Temperature Range APPLICATIONS • • Down-Hole Drilling High Temperature Environments SUPPORTS EXTREME TEMPERATURE APPLICATIONS • • • • • • • • (1) Controlled Baseline One Assembly/Test Site One Fabrication Site Available in Extreme (–55°C/210°C) Temperature Range (1) Extended Product Life Cycle Extended Product-Change Notification Product Traceability Texas Instruments high temperature products utilize highly optimized silicon (die) solutions with design and process enhancements to maximize performance over extended temperatures. Custom temperature ranges available DESCRIPTION The TPS62000 device is a low-noise synchronous step-down dc-dc converter that is ideally suited for systems powered from a 1-cell Li-ion battery or from a 2- to 3-cell NiCd, NiMH, or alkaline battery. The TPS62000 operates typically down to an input voltage of 1.8 V, with a specified minimum input voltage of 2 V. 1 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. 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 © 2009, Texas Instruments Incorporated TPS62000-HT SLVS917A – MARCH 2009 – REVISED JUNE 2009 .......................................................................................................................................................... www.ti.com EFFICIENCY vs LOAD CURRENT 10 mH VI = 2 V to 5.5 V 100 10 mF VIN L EN FB † PGND 80 70 Efficiency − % 10 mF TPS6200x 90 VO = 0.8 V to VI SYNC GND SYNC = Low FC 60 SYNC = High 50 0.1 mF 40 † 30 With VO ≥1.8 V; Co = 10 mF, VO <1.8 V; Co = 47 mF 20 VI = 3.6 V, VO = 2.5 V 10 0 0.1 1 10 100 IO − Load Current − mA 1000 Figure 1. Figure 2. Typical Application Circuit for Fixed Output Voltage Option DESCRIPTION (CONTINUED) The TPS62000 is a synchronous current-mode PWM converter with integrated N- and P-channel power MOSFET switches. Synchronous rectification is used to increase efficiency and to reduce external component count. To achieve the highest efficiency over a wide load current range, the converter enters a power-saving pulse-frequency modulation (PFM) mode at light load currents. Operating frequency is typically 750 kHz, allowing the use of small inductor and capacitor values. The device can be synchronized to an external clock signal in the range of 500 kHz to 1 MHz. For low-noise operation, the converter can be operated in the PWM mode and the internal antiringing switch reduces noise and EMI. In the shutdown mode, the current consumption is reduced to less than 1 µA. The TPS62000-HT is available in the 10-pin (HKK). The dvice operates a free-air temperature range of –55°C to 210°C. HKK PACKAGE (TOP VIEW) VIN FC GND NC FB 1 10 2 9 3 8 4 7 5 6 PGND L EN SYNC NC AVAILABLE OPTIONS (1) TA VOLTAGE OPTIONS –55°C to 210°C (1) (2) 2 Adjustable PACKAGE (2) ORDERING PART NUMBER KGD TPS62000SKGD1 HKK TPS62000SHKK For the most current package and ordering information, see the Package Option Addendum at the end of this document, or see the TI web site at www.ti.com. Package drawings, thermal data, and symbolization are available at www.ti.com/packaging. Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): TPS62000-HT TPS62000-HT www.ti.com .......................................................................................................................................................... SLVS917A – MARCH 2009 – REVISED JUNE 2009 FUNCTIONAL BLOCK DIAGRAM FC (See Note B) Undervoltage Lockout Bias Supply VIN 10 Ω EN + _ R1 PFM/PWM Comparator _ + Soft Start + PFM/PWM Control Logic Current Limit Logic Driver Shoot-Through Logic N-Channel Power MOSFET EN + _ L Compensation R2 R1 + R2 ≈ 1 MΩ P-Channel Power MOSFET PFM/PWM Mode Select Error Amplifier _ FB (See Note A) Current Sense Slope Compensation Power Good Vref = 0.45 V Sync + Oscillator Load Comparator + _ Current Sense + Offset PGND Antiringing FB GND SYNC A. The adjustable output voltage version does not use the internal feedback resistor divider. The FB pin is directly connected to the error amplifier. B. Do not connect the FC pin to an external power source PIN FUNCTIONS PIN NAME I/O DESCRIPTION EN I Enable. A logic high enables the converter, logic low forces the device into shutdown mode reducing the supply current to less than 1 µA. FB I An external resistive divider is connected to FB. The internal voltage divider is disabled. Supply bypass pin. A 0.1 µF coupling capacitor should be connected as close as possible to this pin for good high frequency input voltage supply filtering. FC GND L Ground. I/O PGND Connect the inductor to this pin. L is the switch pin connected to the drain of the internal power MOSFETS. Power ground. Connect all power grounds to PGND. SYNC I Input for synchronization to external clock signal. Synchronizes the converter switching frequency to an external clock signal with CMOS level: SYNC = HIGH: Low-noise mode enabled, fixed frequency PWM operation is forced. SYNC = LOW (GND): Power save mode enabled, PFM/PWM mode enabled. VIN I Supply voltage input. Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): TPS62000-HT 3 TPS62000-HT SLVS917A – MARCH 2009 – REVISED JUNE 2009 .......................................................................................................................................................... www.ti.com BARE DIE INFORMATION DIE THICKNESS BACKSIDE FINISH BACKSIDE POTENTIAL BOND PAD METALLIZATION COMPOSITION 15 mils. Silicon with backgrind GND Al-Si-Cu (0.5%) Origin a c b d Bond Pad Coordinates in Microns - Rev A 4 DESCRIPTION PAD NUMBER a b c d FB 1 142.15 92.40 227.15 177.40 Do not use 2 142.15 194.40 227.15 279.40 Do not use 3 907.35 104.05 983.35 180.05 Do not use 4 1001.35 104.05 1077.35 180.05 Do not use 5 1095.35 104.05 1171.35 180.05 Do not use 6 1189.35 104.05 1265.35 180.05 Do not use 7 1296.85 90.60 1381.85 175.60 SYNC 8 1296.85 192.60 1381.85 277.60 EN 9 1296.85 835.10 1381.85 920.10 L 10 1128.20 1194.55 1213.20 1279.55 L 11 1128.20 1296.55 1213.20 1381.55 Do not use 12 1350.50 1806.50 1435.50 1891.50 PGND 13 1350.50 1908.50 1435.50 1993.50 PGND 14 1350.50 2010.50 1435.50 2095.50 Vin 15 92.40 1956.85 177.40 2041.85 Vin 16 92.40 1854.85 177.40 1939.85 Do not use 17 92.40 1687.70 177.40 1772.70 FC 18 92.40 1529.00 177.40 1614.00 GND 19 90.60 1295.70 175.60 1380.70 Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): TPS62000-HT TPS62000-HT www.ti.com .......................................................................................................................................................... SLVS917A – MARCH 2009 – REVISED JUNE 2009 1524 mm FB SYNC EN 2184 mm L L GND FC PGND PGND Vin Vin Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): TPS62000-HT 5 TPS62000-HT SLVS917A – MARCH 2009 – REVISED JUNE 2009 .......................................................................................................................................................... www.ti.com DETAILED DESCRIPTION Operation The TPS62000 is a step down converter operating in a current mode PFM/PWM scheme with a typical switching frequency of 750 kHz. At moderate to heavy loads, the converter operates in the pulse width modulation (PWM) and at light loads the converter enters a power save mode (pulse frequency modulation) to keep the efficiency high. In the PWM mode operation, the part operates at a fixed frequency of 750 kHz. At the beginning of each clock cycle, the high side P-channel MOSFET is turned on. The current in the inductor ramps up and is sensed via an internal circuit. The high side switch is turned off when the sensed current causes the PFM/PWM comparator to trip when the output voltage is in regulation or when the inductor current reaches the current limit (set by ILIM). After a minimum dead time preventing shoot through current, the low side N-channel MOSFET is turned on and the current ramps down again. As the clock cycle is completed, the low side switch is turned off and the next clock cycle starts. In discontinuous conduction mode (DCM), the inductor current ramps to zero before the end of each clock cycle. In order to increase the efficiency the load comparator turns off the low side MOSFET before the inductor current becomes negative. This prevents reverse current flowing from the output capacitor through the inductor and low side MOSFET to ground that would cause additional losses. As the load current decreases and the peak inductor current does not reach the power save mode threshold of typically 120 mA for more than 15 clock cycles, the converter enters a pulse frequency modulation (PFM) mode. In • • • the PFM mode, the converter operates with: Variable frequency Constant peak current that reduces switching losses Quiescent current at a minimum Thus maintaining the highest efficiency at light load currents. In this mode, the output voltage is monitored with the error amplifier. As soon as the output voltage falls below the nominal value, the high side switch is turned on and the inductor current ramps up. When the inductor current reaches the peak current of typical: 150 mA + 50 mA/V × (VI – VO), the high side switch turns off and the low side switch turns on. As the inductor current ramps down, the low side switch is turned off before the inductor current becomes negative which completes the cycle. When the output voltage falls below the nominal voltage again, the next cycle is started. The converter enters the PWM mode again as soon as the output voltage can not be maintained with the typical peak inductor current in the PFM mode. The control loop is internally compensated reducing the amount of external components. The switch current is internally sensed and the maximum current limit can be set to typical 600 mA by connecting ILIM to ground; or, to typically 1.2 A by connecting ILIM to VIN. 100% Duty Cycle Operation As the input voltage approaches the output voltage and the duty cycle exceeds typical 95%, the converter turns the P-channel high side switch continuously on. In this mode, the output voltage is equal to the input voltage minus the voltage drop across the P-channel MOSFET. Synchronization, Power Save Mode and Forced PWM Mode If no clock signal is applied, the converter operates with a typical switching frequency of 750 kHz. It is possible to synchronize the converter to an external clock within a frequency range from 500 kHz to 1000 kHz. The device automatically detects the rising edge of the first clock and is synchronizes immediately to the external clock. If the clock signal is stopped, the converter automatically switches back to the internal clock and continues operation without interruption. The switch over is initiated if no rising edge on the SYNC pin is detected for a duration of four clock cycles. Therefore, the maximum delay time can be 8 µs in case the internal clock has a minimum frequency of 500 kHz. In case the device is synchronized to an external clock, the power save mode is disabled and the device stays in forced PWM mode. 6 Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): TPS62000-HT TPS62000-HT www.ti.com .......................................................................................................................................................... SLVS917A – MARCH 2009 – REVISED JUNE 2009 Connecting the SYNC pin to the GND pin enables the power save mode. The converter operates in the PWM mode at moderate to heavy loads and in the PFM mode during light loads maintaining high efficiency over a wide load current range. Connecting the SYNC pin to the VIN pin forces the converter to operate permanently in the PWM mode even at light or no 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). It is possible to switch from forced PWM mode to the power save mode during operation. The flexible configuration of the SYNC pin during operation of the device allows efficient power management by adjusting the operation of the TPS62000 to the specific system requirements. Low Noise Antiringing Switch An antiringing switch is implemented in order to reduce the EMI radiated from the converter during discontinuous conduction mode (DCM). In DCM, the inductor current ramps to zero before the end of each switching period. The internal load comparator turns off the low side switch at that instant thus preventing the current flowing backward through the inductance which increases the efficiency. An antiringing switch across the inductor prevents parasitic oscillation caused by the residual energy stored in the inductance (see Figure 12). NOTE: The antiringing switch is only activated in the fixed output voltage versions. It is not enabled for the adjustable output voltage version TPS62000. Soft Start As the enable pin (EN) goes high, the soft-start function generates an internal voltage ramp. This causes the start-up current to slowly rise preventing output voltage overshoot and high inrush currents. The soft-start duration is typical 1 ms (see Figure 13). When the soft-start function is completed, the error amplifier is connected directly to the internal voltage reference. Enable Logic low on EN forces the TPS62000 into shutdown. In shutdown, the power switch, drivers, voltage reference, oscillator, and all other functions are turned off. The supply current is reduced to less than 1 µA in the shutdown mode. Undervoltage Lockout An undervoltage lockout circuit provides the save operation of the device. It prevents the converter from turning on when the voltage on VIN is less than typically 1.6 V. No Load Operation In case the converter operates in the forced PWM mode and there is no load connected to the output, the converter will regulate the output voltage by allowing the inductor current to reverse for a short period of time. Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): TPS62000-HT 7 TPS62000-HT SLVS917A – MARCH 2009 – REVISED JUNE 2009 .......................................................................................................................................................... www.ti.com ABSOLUTE MAXIMUM RATINGS over operating free-air temperature range (unless otherwise noted) (1) VALUE UNIT Supply voltages on pin VIN and FC (2) –0.3 to 6 V Voltages on pins EN, SYNC, FB, L (2) –0.3 to VIN + 0.3 V 1.6 A Peak switch current (1) (2) 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. All voltage values are with respect to network ground terminal. RECOMMENDED OPERATING CONDITIONS over operating free-air temperature range (unless otherwise noted) TA = –55°C to 125°C MIN VI Supply voltage VO Output voltage range for adjustable output voltage version IO Output current for 3-cell operation (VI ≥ 2.5 V; L = 10 µH, f = 750 kHz) IO Output current for 2-cell operation (VI ≥ 2 V; L = 10 µH, f = 750 kHz) L Inductor (2) (see Note 2) TYP 2 0.8 TA = 210°C (1) MAX MIN 5.5 2 VI 0.8 TYP 5.5 VI 300 200 10 MAX UNIT V V 300 mA 200 mA µH 10 CI Input capacitor (2) 10 10 µF Co Output capacitor (2) (VO ≥ 1.8 V) 10 10 µF Co Output capacitor (2) VO < 1.8 V) 47 47 µF TA Operating ambient temperature –55 (1) (2) 8 210 –55 210 °C Minimum and maximum parameters are characterized for operation at TA = 210°C but may not be production tested at that temperature. Production test limits with statistical guardbands are used to ensure high temperature performance. Refer to application section for further information. Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): TPS62000-HT TPS62000-HT www.ti.com .......................................................................................................................................................... SLVS917A – MARCH 2009 – REVISED JUNE 2009 ELECTRICAL CHARACTERISTICS over recommended operating free-air temperature range (unless oherwise noted), VI = 3.6 V, VO = 2.5 V, IO = 300 mA (TA = –55°C to 125°C), IO = 50 mA (TA = 210°C), EN = VIN TEST CONDITIONS PARAMETER TA = 210°C (1) TA = –55°C to 125°C MIN TYP MAX MIN TYP MAX UNIT SUPPLY CURRENT IO = 0 mA to 300 mA 2.5 5.5 2.5 5.5 IO = 0 mA to 200 mA 2 5.5 2 5.5 VI Input voltage range V I(Q) Operating quiescent current IO = 0 mA, SYNC = GND (PFM-mode enabled) 50 75 1400 4000 µA I(SD) Shutdown current EN = GND 0.1 1 90 200 µA ENABLE VIH EN high-level input voltage VIL EN low level input voltage Ilkg EN input leakage current V(UVLO) Undervoltage lockout threshold 1.5 1.5 V 0.4 EN = GND or VIN 1.2 0.1 1.1 1.6 2 1.2 0.4 V 0.1 1.1 µA 1.6 2 V POWER SWITCH AND CURRENT LIMIT P-channel MOSFET on-resistance VI = VGS = 3.6 V, I = 200 mA 580 670 (2) VI = VGS = 2 V, I = 200 mA 790 850 (2) N-channel MOSFET on-resistance VI = VGS = 3.6 V, IO = 200 mA 580 670 (2) VI = VGS = 2 V, IO = 200 mA 790 800 (2) rDS(on) mΩ mΩ OSCILLATOR fs Oscillator frequency f(SYNC) Synchronization range VIH SYNC high level input voltage VIL SYNC low level input voltage Ilkg SYNC input leakage current 500 CMOS-logic clock signal on SYNC pin (2) 500 1000 200 1000 500 1.3 320 SYNC = GND or VIN 600 kHz 1000 kHz 1.3 V 0.4 Duty cycle of external clock signal (1) 750 0.1 20% 1.1 60% 0.1 20% 0.4 V 1.1 µA 60% Minimum and maximum parameters are characterized for operation at TA = 210°C but may not be production tested at that temperature. Production test limits with statistical guardbands are used to ensure high temperature performance. Measured at 50 mA. Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): TPS62000-HT 9 TPS62000-HT SLVS917A – MARCH 2009 – REVISED JUNE 2009 .......................................................................................................................................................... www.ti.com ELECTRICAL CHARACTERISTICS over recommended operating free-air temperature range (unless otherwise noted), VI = 3.6 V, VO = 2.5 V, IO = 300 mA (TA = –55°C to 125°C), IO = 50 mA (TA = 210°C), EN = VIN, ILIM = VIN PARAMETER VO Adjustable output voltage range TPS62000 Vref Reference voltage TPS62000 VO Fixed output voltage (2) TPS62000 adjustable η (2) (3) (4) 10 MIN TYP MAX MIN 5.5 0.8 0.45 –5.5 5 10 mA < IO ≤ 300 mA –5.5 5 Load regulation VI = 5.5 V; IO = 10 mA to 300 mA VI = 5 V; VO = 3.3 V; IO = 300 mA VI = 3.6 V; VO = 2.5 V; IO = 200 mA IO = 0 mA, time from active EN to VO 0.4 TYP 15 (3) 0.05 13 (4) 0.6% 23% (4) 85% 73% 2 MAX 5.5 0.38 VI = 2.5 V to 5.5 V; 0 mA ≤ IO ≤ 100 mA VI = VO + 0.5 V (min. 2 V) to 5.5 V, IO = 10 mA Efficiency TA = 210°C (1) TA = –55°C to 125°C 0.8 Line regulation Start-up time (1) TEST CONDITIONS 0.75 UNIT V V %V %/V ms Minimum and maximum parameters are characterized for operation at TA = 210°C but may not be production tested at that temperature. Production test limits with statistical guardbands are used to ensure high temperature performance. The output voltage accuracy includes line and load regulation over the full temperature range, TA = –55°C to 125°C. VIN = 5.5 V VIN = 3.3 V to 5.5 V, IO = 100 mA to 300 mA Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): TPS62000-HT TPS62000-HT www.ti.com .......................................................................................................................................................... SLVS917A – MARCH 2009 – REVISED JUNE 2009 TYPICAL CHARACTERISTICS TABLE OF GRAPHS FIGURE η Efficiency vs Load current 3, 4, 5 V(drop) Dropout voltage vs Load current 6 IQ Operating quiescent current vs Input voltage (power save mode) 7 vs Input voltage (forced PWM) 8 fOSC Oscillator frequency vs Free-air temperature 9 Load transient response 10 Line transient response 11 Power save mode operation VO 12 Start-up vs Time 13 Output voltage vs Load current 14 EFFICIENCY vs LOAD CURRENT EFFICIENCY vs LOAD CURRENT 100 VO = 2.5 V Efficiency − % 90 80 VI = 3.6 V 70 VI = 5 V 60 50 40 0.1 Figure 3. 1 10 100 IO − Load Current − mA 1000 Figure 4. Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): TPS62000-HT 11 TPS62000-HT SLVS917A – MARCH 2009 – REVISED JUNE 2009 .......................................................................................................................................................... www.ti.com DROPOUT VOLTAGE vs LOAD CURRENT Figure 5. Figure 6. OPERATING QUIESCENT CURRENT vs INPUT VOLTAGE (POWER SAVE MODE) OPERATING QUIESCENT CURRENT vs INPUT VOLTAGE (FORCED PWM) I(Q) - Operating Quescent Current - mA I(Q) - Operating Quescent Current - mA EFFICIENCY vs LOAD CURRENT Figure 7. 12 Figure 8. Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): TPS62000-HT TPS62000-HT www.ti.com .......................................................................................................................................................... SLVS917A – MARCH 2009 – REVISED JUNE 2009 OSCILLATOR FREQUENCY vs FREE-AIR TEMPERATURE LOAD TRANSIENT RESPONSE 800 750 VI = 3.6 V F - Frequency - kHz 700 650 600 550 500 450 400 350 300 -60 -30 0 30 60 90 120 150 180 210 TA - Free Air Temperature - °C 200 ms/div Figure 9. Figure 10. LINE TRANSIENT RESPONSE POWER SAVE MODE OPERATION 400 ms/div 10 ms/div Figure 11. Figure 12. Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): TPS62000-HT 13 TPS62000-HT SLVS917A – MARCH 2009 – REVISED JUNE 2009 .......................................................................................................................................................... www.ti.com START-UP vs TIME EN 2 V/div VO 1 V/div Power Good 1 V/div II 200 mA/div 250 ms/div Figure 13. OUTPUT VOLTAGE vs LOAD CURRENT 2.55 2.54 VO − Output Voltage − V 2.53 2.52 2.51 2.50 2.49 2.48 2.47 2.46 2.45 0 100 200 300 400 500 600 IO − Load Current − mA Figure 14. 14 Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): TPS62000-HT TPS62000-HT www.ti.com .......................................................................................................................................................... SLVS917A – MARCH 2009 – REVISED JUNE 2009 APPLICATION INFORMATION (1) ADJUSTABLE OUTPUT VOLTAGE VERSION When the adjustable output voltage version (TPS62000DGS) is used, the output voltage is set by the external resistor divider (see Figure 15). The output voltage is calculated as: R1 ö æ VO = 0.45 V ´ ç 1 + R2 ÷ø è (1) With R1 + R2 ≤ 1 MΩ R1 + R2 should not be greater than 1 MW because of stability reasons. For stability reasons, a small bypass capacitor (C(ff)) is required in parallel to the upper feedback resistor, refer to Figure 15. The bypass capacitor value can be calculated as: 1 C(ff) = for Co < 47 mF 2p ´ 30000 ´ R1 (2) 1 C(ff) = for Co ³ 47 mF 2p ´ 5000 ´ R1 (3) R1 is the upper resistor of the voltage divider. For C(ff), choose a value which comes closest to the computed result. L1 = 10 mH VI = 2.7 V to 5.5 V VIN VO = 2.5 V/300 mA L + Ci = 10 mF FB EN R1 = 820 kΩ TPS62000 C(ff) = 6.8 pF + Co = 10 mF SYNC GND PGND FC R2 = 180 kΩ C3 = 0.1 mF Figure 15. Typical Application Circuit for Adjustable Output Voltage Option INDUCTOR SELECTION A 10-µH minimum output inductor is used with the TPS62000. Values larger than 22 µH or smaller than 10 µH may cause stability problems because of the internal compensation of the regulator. For output voltages greater than 1.8 V, a 22-µH inductance might be used in order to improve the efficiency of the converter. After choosing the inductor value of typically 10 µH, two additional inductor parameters should be considered: first the current rating of the inductor and second the dc resistance. The dc resistance of the inductance influences directly the efficiency of the converter. Therefore, an inductor with lowest dc resistance should be selected for highest efficiency. In order to avoid saturation of the inductor, the inductor should be rated at least for the maximum output current plus the inductor ripple current which is calculated as: (1) Application information is provided for commercial temperature as a reference and not for high temperature. Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): TPS62000-HT 15 TPS62000-HT SLVS917A – MARCH 2009 – REVISED JUNE 2009 .......................................................................................................................................................... www.ti.com VO VI L ´ f 1 DIL = VO ´ IL(max) = IO(max) + DIL 2 (4) Where: ƒ = Switching frequency (750 kHz typical) L = Inductor value ΔIL = Peak-to-peak inductor ripple current IL(max) = Maximum inductor current The highest inductor current occurs at maximum VI. A more conservative approach is to select the inductor current rating just for the maximum switch current of the TPS62000 which is 1.6 A with ILIM = VIN and 900 mA with ILIM = GND. See Table 1 for recommended inductors. Table 1. Tested Inductors (1) OUTPUT CURRENT INDUCTOR VALUE COMPONENT SUPPLIER COMMENTS High efficiency 10 µH Coilcraft DO3316P-103 Coilcraft DT3316P-103 Sumida CDR63B-100 Sumida CDRH5D28-100 Coilcraft DO1608C-103 Sumida CDRH4D28-100 Smallest solution Coilcraft DO1608C-103 High efficiency Murata LQH4C100K04 Smallest solution 0 mA to 600 mA 10 µH 0 mA to 300 mA (1) Parts are valid for –40°C to 85°C. OUTPUT CAPACITOR SELECTION For best performance, a low ESR output capacitor is needed. At output voltages greater than 1.8 V, ceramic output capacitors can be used to show the best performance. Output voltages below 1.8 V require a larger output capacitor and ESR value to improve the performance and stability of the converter. Table 2. Capacitor Selection OUTPUT VOLTAGE RANGE OUTPUT CAPACITOR OUTPUT CAPACITOR ESR 1.8 V ≤ VI ≤ 5.5 V Co ≥ 10 µF ESR ≤ 120 mΩ 0.8 V ≤ VI < 1.8 V Co ≥ 47 µF ESR > 50 mΩ See Table 3 for recommended capacitors. If an output capacitor is selected with an ESR value ≤ 120 mΩ, its RMS ripple current rating always meets the application requirements. Just for completeness, the RMS ripple current is calculated as: V 1 - O VI 1 IRMS(CO ) = VO ´ ´ L ´ f 2´ 3 (5) The overall output ripple voltage is the sum of the voltage spike caused by the output capacitor ESR plus the voltage ripple caused by charge and discharging the output capacitor: VO VI L ´ f 1 DVO = VO ´ æ ö 1 ´ ç + ESR ÷ è 8 ´ CO ´ f ø (6) Where the highest output voltage ripple occurs at the highest input voltage VI. 16 Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): TPS62000-HT TPS62000-HT www.ti.com .......................................................................................................................................................... SLVS917A – MARCH 2009 – REVISED JUNE 2009 Table 3. Tested Capacitors (1) CAPACITOR VALUE ESR/mΩ COMPONENT SUPPLIER 10 µF 50 Taiyo Yuden JMK316BJ106KL Ceramic 47 µF 100 Sanyo 6TPA47M POSCAP 68 µF 100 Spraque 594D686X0010C2T Tantalum (1) COMMENTS Parts are valid for –40°C to 85°C. 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 10 µF and can be increased without any limit for better input voltage filtering. The input capacitor should be rated for the maximum input ripple current calculated as: VO æ VO ö ´ ç 1÷ VI è VI ø IRMS = IO(max) ´ (7) The worst case RMS ripple current occurs at D = 0.5 and is calculated as: IRMS = IO 2 Ceramic capacitor show a good performance because of their low ESR value, and they are less sensitive against voltage transients compared to tantalum capacitors. Place the input capacitor as close as possible to the input pin of the IC for best performance. LAYOUT CONSIDERATIONS As 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 indicted in bold in Figure 16. The input capacitor should be placed as close as possible to the IC pins as well as the inductor and output capacitor. Place the bypass capacitor, C3, as close as possible to the FC pin. The analog ground, GND, and the power ground, PGND, need to be separated. Use a common ground node as shown in Figure 16 to minimize the effects of ground noise. L1 VI VIN VO L + Ci EN FB R1 TPS62000 C(ff) + Co R2 SYNC GND PGND FC C3 Figure 16. Layout Diagram Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): TPS62000-HT 17 TPS62000-HT SLVS917A – MARCH 2009 – REVISED JUNE 2009 .......................................................................................................................................................... www.ti.com TYPICAL APPLICATION 10 mH 3 (2) 470 kW 10 mF 47 mF 326 kW 524 kW 0.1 mF Sumida CDRH5D28-100 10 mF Ceramic Taiyo Yuden JMK316BJ106KL Sanyo 6TPA47M 0.1 mF Ceramic (1) Use a small R-C filter to filter wrong reset signals during output voltage transitions. (2) A large value is used for C(ff) to compensate for the parasitic capacitance introduced into the regulation loop by Q1. Figure 17. Dynamic Output Voltage Programming As Used in Low Power DSP Applications 18 Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): TPS62000-HT TPS62000-HT www.ti.com .......................................................................................................................................................... SLVS917A – MARCH 2009 – REVISED JUNE 2009 1000 Years of Estimated Life 100 Electromigration Fail Mode 10 1 110 130 150 170 190 210 230 Continous TJ - °C Figure 18. TPS62000SKGD1 Operating Life Derating Chart Notes: 1. See data sheet for absolute maximum and minimum recommended operating conditions. 2. Silicon operating life design goal is 10 years at 105°C junction temperature (does not include package interconnect life). Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): TPS62000-HT 19 PACKAGE OPTION ADDENDUM www.ti.com 19-Jun-2010 PACKAGING INFORMATION Orderable Device Status (1) Package Type Package Drawing Pins Package Qty Eco Plan (2) Lead/ Ball Finish MSL Peak Temp (3) Samples (Requires Login) TPS62000SHKK ACTIVE CFP HKK 10 1 TBD AU N / A for Pkg Type Contact TI Distributor or Sales Office TPS62000SKGD1 ACTIVE XCEPT KGD 0 100 TBD Call TI N / A for Pkg Type Contact TI Distributor or Sales Office (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 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. Customers should obtain the latest relevant information before placing orders and should verify that such information is current and complete. All products are sold subject to TI’s terms and conditions of sale supplied at the time of order acknowledgment. TI warrants performance of its hardware products to the specifications applicable at the time of sale in accordance with TI’s standard warranty. Testing and other quality control techniques are used to the extent TI deems necessary to support this warranty. Except where mandated by government requirements, testing of all parameters of each product is not necessarily performed. TI assumes no liability for applications assistance or customer product design. Customers are responsible for their products and applications using TI components. To minimize the risks associated with customer products and applications, customers should provide adequate design and operating safeguards. TI does not warrant or represent that any license, either express or implied, is granted under any TI patent right, copyright, mask work right, or other TI intellectual property right relating to any combination, machine, or process in which TI products or services are used. Information published by TI regarding third-party products or services does not constitute a license from TI 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 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. Reproduction of this information with alteration is an unfair and deceptive business practice. TI is not responsible or liable for such altered documentation. Information of third parties may be subject to additional restrictions. Resale of TI products or services with statements different from or beyond the parameters stated by TI for that product or service voids all express and any implied warranties for the associated TI product or service and is an unfair and deceptive business practice. TI is not responsible or liable for any such statements. TI products are not authorized for use in safety-critical applications (such as life support) where a failure of the TI product would reasonably be expected to cause severe personal injury or death, unless officers of the parties have executed an agreement specifically governing such use. Buyers represent that they have all necessary expertise in the safety and regulatory ramifications of their applications, and acknowledge and agree that they are solely responsible for all legal, regulatory and safety-related requirements concerning their products and any use of TI products in such safety-critical applications, notwithstanding any applications-related information or support that may be provided by TI. Further, Buyers must fully indemnify TI and its representatives against any damages arising out of the use of TI products in such safety-critical applications. TI products are neither designed nor intended for use in military/aerospace applications or environments unless the TI products are specifically designated by TI as military-grade or "enhanced plastic." Only products designated by TI as military-grade meet military specifications. Buyers acknowledge and agree that any such use of TI products which TI has not designated as military-grade is solely at the Buyer's risk, and that they are solely responsible for compliance with all legal and regulatory requirements in connection with such use. TI products are neither designed nor intended for use in automotive applications or environments unless the specific TI products are designated by TI as compliant with ISO/TS 16949 requirements. Buyers acknowledge and agree that, if they use any non-designated products in automotive applications, TI will not be responsible for any failure to meet such requirements. Following are URLs where you can obtain information on other Texas Instruments products and application solutions: Products Applications Amplifiers amplifier.ti.com Audio www.ti.com/audio Data Converters dataconverter.ti.com Automotive www.ti.com/automotive DLP® Products www.dlp.com Communications and Telecom www.ti.com/communications DSP dsp.ti.com Computers and Peripherals www.ti.com/computers Clocks and Timers www.ti.com/clocks Consumer Electronics www.ti.com/consumer-apps Interface interface.ti.com Energy www.ti.com/energy Logic logic.ti.com Industrial www.ti.com/industrial Power Mgmt power.ti.com Medical www.ti.com/medical Microcontrollers microcontroller.ti.com Security www.ti.com/security RFID www.ti-rfid.com Space, Avionics & Defense www.ti.com/space-avionics-defense RF/IF and ZigBee® Solutions www.ti.com/lprf Video and Imaging www.ti.com/video Wireless www.ti.com/wireless-apps Mailing Address: Texas Instruments, Post Office Box 655303, Dallas, Texas 75265 Copyright © 2010, Texas Instruments Incorporated