TPS80010 www.ti.com SLVSAD1 A – JUNE 2010 – REVISED JUNE 2010 PMU for Alkaline Battery-Powered Applications Check for Samples: TPS80010 FEATURES 1 • • • • • • • • DESCRIPTION 1.8-V Buck DC/DC Converter 3.1-V Boost DC/DC Converter with 3-V Post-Regulation LDO Over 91% Conversion Efficiency Current-Limited Start-Up for Both DC/DC Converters Load Switch With Current-Limited Turnon Battery-Level Monitor Switch 32-Pin, 4-mm × 4-mm × 1-mm VQFN Package ESD Performance Tested per JESD 22 – 2000-V Human-Body Model (A114-B, Class II) – 500-V Charged-Device Model (C101) The TPS80010 provides an integrated power-management solution for 2-cell alkaline battery applications such as wireless mice, keyboards, and video game controllers. The VBUCK 1.8-V output is powered by a buck converter with a load capacity of 100 mA. A power-good (PG) signal is generated when VBUCK is above 90% of its target output voltage. Integrated in the TPS80010 is an 80-mΩ load switch that can be connected to the VBUCK output, allowing more system design flexibility when connecting to multiple loads. The 3.1-V VBOOST output is powered by a boost converter. The VBOOST output voltage is post-regulated by the integrated 3-V LDO. This post-regulation provides a low-noise supply level through the specified battery range. APPLICATIONS • • • Wireless Mice Wireless Keyboards Game Controllers TYPICAL APPLICATION 1.8 V–3.6 V AA AA 10 mF 10 mF VIN_BOOST BAT_FALSELOAD VIN_BUCK PP_BAT 10 W 10 mH SW_BOOST EN_BOOST VO_BOOST EN_LDO FB_BOOST 3.1 V 22 mF EN_BUCK TPS80010 IN_VM EN_SW1 EN_BAT_CHECK 3V OUT_VM 4.7 mF CONTROLLER LED EN_BAT_FLASELOAD 2.2 mH PG SW_BUCK OPTICAL SENSOR 1.8 V 10 mF BAT_CHECK MEMORY/ IO FB_BUCK 1.8 kW MODE_BUCK IN_VIO ADC OUT_VIO TEST1 NC 1.8 kW 1.8 V 1.8-V PERIPHERALS TEST2 GND 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 © 2010, Texas Instruments Incorporated TPS80010 SLVSAD1 A – JUNE 2010 – REVISED JUNE 2010 www.ti.com This device contains circuits to protect its inputs and outputs against damage due to high static voltages or electrostatic fields. These circuits have been qualified to protect this device against electrostatic discharges (ESD) of up to 2 kV according to MIL-STD-883C, Method 3015; however, it is advised that precautions be taken to avoid application of any voltage higher than maximum-rated voltages to these high-impedance circuits. During storage or handling the device leads should be shorted together or the device should be placed in conductive foam. In a circuit, unused inputs should always be connected to an appropriate logic voltage level, preferably either VCC or ground. Specific guidelines for handling devices of this type are contained in the publication Guidelines for Handling Electrostatic-Discharge-Sensitive (ESDS) Devices and Assemblies available from Texas Instruments. ORDERING INFORMATION (1) (1) DEVICE TEMPERATURE PACKAGE ORDERING CODE MARKING TPS80010 –40°C to 85°C VQFN TPS80010ARSMR RSM 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. ABSOLUTE MAXIMUM RATINGS (1) over operating free-air temperature range (unless otherwise noted) MIN MAX VI Input voltage range on all pins –0.3 3.6 V VO Output voltage range on all pins –0.3 3.6 V TJ Junction temperature range –40 125 °C Tstg Storage temperature range –65 150 °C –500 500 V –2 2 kV VESD (1) ESD rating Charged-device model (CDM) on all pins Human-body model (HBM) on all pins UNIT 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. THERMAL INFORMATION TPS80010 THERMAL METRIC (1) VQFN UNIT 32 PINS qJA Junction-to-ambient thermal resistance (2) qJC(top) Junction-to-case (top) thermal resistance (3) (4) qJB Junction-to-board thermal resistance yJT Junction-to-top characterization parameter yJB Junction-to-board characterization parameter Junction-to-case (bottom) thermal resistance qJC(bottom) (1) (2) (3) (4) (5) (6) (7) 2 33.9 °C/W 25.2 °C/W 8 °C/W 0.12 °C/W (6) 7.5 °C/W (7) 1.8 °C/W (5) For more information about traditional and new thermal metrics, see the IC Package Thermal Metrics application report, SPRA953. The junction-to-ambient thermal resistance under natural convection is obtained in a simulation on a JEDEC-standard, high-K board, as specified in JESD51-7, in an environment described in JESD51-2a. The junction-to-case (top) thermal resistance is obtained by simulating a cold plate test on the package top. No specific JEDEC-standard test exists, but a close description can be found in the ANSI SEMI standard G30-88. The junction-to-board thermal resistance is obtained by simulating in an environment with a ring cold plate fixture to control the PCB temperature, as described in JESD51-8. The junction-to-top characterization parameter, yJT, estimates the junction temperature of a device in a real system and is extracted from the simulation data for obtaining qJA, using a procedure described in JESD51-2a (sections 6 and 7). The junction-to-board characterization parameter, yJB, estimates the junction temperature of a device in a real system and is extracted from the simulation data for obtaining qJA , using a procedure described in JESD51-2a (sections 6 and 7). The junction-to-case (bottom) thermal resistance is obtained by simulating a cold plate test on the exposed (power) pad. No specific JEDEC standard test exists, but a close description can be found in the ANSI SEMI standard G30-88. Submit Documentation Feedback Copyright © 2010, Texas Instruments Incorporated Product Folder Link(s): TPS80010 TPS80010 www.ti.com SLVSAD1 A – JUNE 2010 – REVISED JUNE 2010 RECOMMENDED OPERATING CONDITIONS TA = 0°C to 85°C; typical values are at TA = 25°C MIN VBAT Input voltage, VIN BOOST, VIN_BUCK, PP_BAT pins VIO (IN_VIO) Digital I/O operating voltage range TA Ambient temperature TYP 1.95 0 MAX UNIT 3.6 V 1.8 VBAT V 25 85 °C ELECTRICAL CHARACTERISTICS TA = 0°C to 85°C; typical values are at TA = 25°C (unless otherwise noted) PARAMETER TEST CONDITIONS MIN TYP MAX UNIT SUPPLY CURRENT IQ Quiescent current VBAT = 3 V, all modules enabled IOFF Off current VBAT = 3 V RPULLDOWN Internal pulldown resistor EN_BOOST, EN_LDO, EN_SW1, EN_BAT_CHECK, EN_BAT_FALSELOAD 157 VIH Input logic-high voltage EN_BOOST, EN_LDO, EN_SW1, EN_BAT_CHECK, EN_BAT_FALSELOAD 0.7×VIO 51 mA 1 mA DIGITAL I/O EN_BUCK, BUCK_MODE VIL Input logic-low voltage 275 V 0.3×VIO EN_BUCK, BUCK_MODE Output logic-high voltage PG VOL Output logic-low voltage PG IL_DIG Logic-output load current kΩ 0.7×VBAT EN_BOOST, EN_LDO, EN_SW1, EN_BAT_CHECK, EN_BAT_FALSELOAD VOH 383 V 0.7×VBAT VIO – 0.2 V 0.2 1 V mA BUCK CONVERTER VIN Input voltage at VIN_BUCK IO Output current VFB Feedback voltage (output accuracy) VBUCK Buck output voltage ISW Switch current limit IRUSH Inrush current Line regulation Load regulation Efficiency Quiescent current 1.95 PWM, IO = 0 mA to 100 mA, VIN ≥ 1.85 V to 3.6 V, VBUCK = 1.8 V PFM V mA 1.5% 1 1.8 0.56 VIN = 2 V PWM, IO = 100 mA PFM, IO = 100 mA 0.7 A mA 0.9% PFM, VIN = 2.4 V, IO = 0 mA to 100 mA 0.5% PFM , IO = 100 mA, VIN = 2.4 V, VBUCK = 1.8 V 92% PWM, IO = 100 mA, VIN = 2.4 V, VBUCK = 1.8 V 90% PFM, IO = 0 mA, no switching 21 PFM, IO = 0 mA, switching 25 Leakage current into SW_BUCK 0.84 0.9% –0.5% Shutdown current V 150 PWM, VIN = 2.4 V, IO = 0 mA to 100 mA PWM, IO = 0 mA IQ –1.5% 3.6 100 mA 5 mA 0.005 0.15 mA 0.01 1 mA RREC Rectifier on-resistance VGS = 3.6 V 185 380 mΩ RMAIN Main SW on-resistance VGS = 3.6 V 240 480 mΩ ΔVLN Line transient output variation PFM, IO = 50 mA, VIN = 2 V → 3.6 V, Δt = 25 µs 10 20 mV ΔVLD Load transient output variation PFM, VIN = 2.4 V, VBUCK = 1.8 V, IO = 1 mA → 100 mA, Δt = 1 µs 30 40 mV Submit Documentation Feedback Copyright © 2010, Texas Instruments Incorporated Product Folder Link(s): TPS80010 3 TPS80010 SLVSAD1 A – JUNE 2010 – REVISED JUNE 2010 www.ti.com ELECTRICAL CHARACTERISTICS (continued) TA = 0°C to 85°C; typical values are at TA = 25°C (unless otherwise noted) PARAMETER TEST CONDITIONS MIN TYP MAX UNIT BUCK CONVERTER (Continued) PWM, IO = 100 mA, VIN = 2.4 V 1 10 10 20 2.25 2.5 VRIP Output ripple fSW Switching frequency UVLO Undervoltage lockout threshold tSTART Start-up time CL Load capacitance 10 mF L Inductor 2.2 mH PFM, IO = 10 mA, VIN = 3.6 V 2 1.7 mVpp MHz V 10 ms LOAD SWITCH RON Switch on-resistance 120 mΩ Maximum load current VGS = 1.8 V 80 360 mA Turnon inrush current 100 mA 4 ms Output rise time 10%–90% of final VO, CL = 100 µF IOFF Off-state current Switch turned off, IO = 0 mA 2 1 mA tON Turnon time CL = 100 µF 6 ms tOFF Turnoff time CL = 100 µF 10 ms POWER-GOOD RESET VTHRESH Power-good threshold voltage 1.68 1.7 1.72 V ΔtPG Power-good time-out delay 100 150 200 ms VHYS Power-good hysteresis 10 15 mV BOOST CONVERTER Boost mode 1.8 3.1 VIN > VBOOST mode, VBOOST = VIN 3.1 3.6 VIN Input voltage at VIN_BOOST VBOOST Output voltage TA = 0°C–50°C, VIN = 1.8 V to 3.1 V, IO = 0 mA to 50 mA IO Output current VIN = 1.8 V to 3.6 V ISW Switch current limit IRUSH Inrush current VIN = 2 V RREC Rectifier on-resistance VBOOST = 3.1 V RMAIN Main SW on-resistance fSW 3 3.1 3.2 V 50 mA 200 350 475 mA 150 Ω 1 Ω VIN = 2 V to 3 V, IO = 50 mA 0.5% Load regulation VIN = 2 V, IO = 0–50 mA 0.5% Boost efficiency VIN = 2.4 V, IO = 5 mA 91% Oscillator frequency mA 1 Line regulation VIN = 2.4 V, IO = 50 mA V 91 kHz 625 From VIN supply, IO = 0 mA, VIN = 1.8 V, VBOOST = 3.1 V 1 2.5 From VBOOST, IO = 0 mA, VIN = 1.8 V, VBOOST = 3.1 V 4 6.5 Shutdown current 0.1 1 Leakage current into SW_BOOST 0.1 1 VUVLO VIN decreasing 0.5 0.7 ΔVLN Line transient output variation ΔVLD V = 2.4 V, VBOOST = 3.1 V, IO = 1 mA → 50 mA, Load transient output variation IN Δt = 1 µs 5 10 VRIP Output ripple 4 10 mVpp Quiescent current IQ 4 IO = 10 mA, VIN = 1.8 V → VBOOST, ΔT = 25 µs VIN = 1.8 V, IO = 50 mA Submit Documentation Feedback 10 mA V mV mV Copyright © 2010, Texas Instruments Incorporated Product Folder Link(s): TPS80010 TPS80010 www.ti.com SLVSAD1 A – JUNE 2010 – REVISED JUNE 2010 ELECTRICAL CHARACTERISTICS (continued) TA = 0°C to 85°C; typical values are at TA = 25°C (unless otherwise noted) PARAMETER TEST CONDITIONS MIN TYP MAX UNIT BOOST CONVERTER (Continued) IOFF Off-mode current tSTART Start-up time CL Load capacitance L Inductance From enable, VBOOST = 10% → 90% 6 0.1 1 mA 0.25 10 ms 10 22 10 mF mH POST REGULATION LDO VIN Input voltage at IN_VM VLDO Output voltage 10 µA ≤ IO ≤ IOMAX IO Output current Normal mode ILIMIT Current limit VLDO > 1 V ISHORT Short-circuit current Output shorted to ground VREG Line regulation dVLDO/dVIN at IO = Max 0.2 % LREG Load regulation VLDO (IOMIN) – VLDO(IOMAX) 40 mV ΔVLN Load transient response IO = 20 mA/µs, VIN = 3.1 V 50 100 mV IQ Quiescent current IO = 0 mA 16 17.6 µA PSRR Power-supply ripple rejection f = 120 Hz to 1 kHz at IO = IOMAX/2, VIN = 3.1 V VRIP_NORM Output ripple VBAT < 3.1 V, IO = 50 mA, VIN = VBOOST 0.1 1 mVpp VRIP_HIBAT Output ripple VBAT > 3.1 V, IO = 50 mA, VIN = VBOOST 4 10 mVpp Boost plus LDO efficiency 3.1 2.91 3.6 3 3.09 V V 50 mA 300 400 500 mA 30 60 150 mA 40 dB VBAT = 2.4 V, IO = 5 mA, VIN = VBOOST 87% VBAT = 2.4 V, IO = 50 mA, VIN = VBOOST 88% tON Turn-on time IO = 0 mA, VLDO = 90%, CL = 2.9 µF 130 500 µs tOFF Turn-off time IO = 0 mA, VLDO < 0.5 V, CL = 2.9 µF 3.9 5 ms CL Load capacitance Ceramic capacitor, ESR = 10 mΩ to 150 mΩ 10 22 µF 1.8 3.6 V 3.6 V VIN V 4.7 BATTERY LOAD MONITOR VOP Operating voltage VIN Input voltage at PP_BAT VOUT Output voltage at BAT_CHECK ILOAD Load current RON Switch on-resistance 1.8 VIN = 1.8 V to 3.6 V 10 mA 12 15 Ω 1.8 3.6 V 3.6 V BATTERY LOAD SWITCH VOP Operating voltage VIN Input voltage at BAT_FALSELOAD IIN Input current RON Switch on-resistance 240 360 mA 500 mΩ Submit Documentation Feedback Copyright © 2010, Texas Instruments Incorporated Product Folder Link(s): TPS80010 5 TPS80010 SLVSAD1 A – JUNE 2010 – REVISED JUNE 2010 www.ti.com DEVICE INFORMATION SW_BOOST VO_BOOST MODE_BUCK GND2 EN_BUCK VIN_BUCK SW_BUCK GND_BUCK RSM PACKAGE (BOTTOM VIEW) 1 32 EN_BOOST GND_BOOST EN_LDO GND VIN_BOOST EN_BAT_CHECK FB_BOOST FB_BUCK THERMAL PAD IN_VM BAT_FLASELOAD_EN OUT_VM EN_SW1 GND_FALSELOAD BAT_FALSELOAD PP_BAT GND3 PG TEST2 TEST1 IN_VIO OUT_VIO BAT_CHECK OUT_VIO IN_VIO PIN FUNCTIONS PIN NAME NO. I/O DESCRIPTION BAT_CHECK 15 O Battery monitor switch output. Connect to ADC for battery-level check. BAT_FALSELOAD 18 I Battery monitor input for false-load check BAT_FALSELOAD_ EN 28 I Battery false load switch enable EN_BAT_CHECK 30 I Battery-check path enable EN_BOOST 32 I Boost converter enable EN_BUCK 4 I Buck converter enable EN_LDO 31 I Boost post-regulation LDO enable EN_SW1 27 I Buck-load switch (SW1) enable FB_BOOST 12 I Boost-converter feedback input FB_BUCK 29 I Buck converter feedback input GND 10 – GND GND2 5 – Device ground GND3 20 – Device ground GND_BOOST 9 – Boost converter ground GND_BUCK 1 – Buck converter ground 6 Submit Documentation Feedback Copyright © 2010, Texas Instruments Incorporated Product Folder Link(s): TPS80010 TPS80010 www.ti.com SLVSAD1 A – JUNE 2010 – REVISED JUNE 2010 PIN FUNCTIONS (continued) PIN NAME GND_FALSELOAD NO. I/O DESCRIPTION 17 O False load ground IN_VIO 25, 26 – Internal I/O power supply. Load switch 1 input. Connect externally to buck output IN_VM 13 I Boost post-regulation LDO input. Connect externally to VO_BOOST. MODE_BUCK 6 I Buck converter mode control. High for PWM, low for PFM OUT_VIO 23, 24 O Load switch 1 output OUT_VM 14 O Boost post-regulation LDO output PG 21 O Buck power-good indication output. High when VBUCK > 1.7 V PP_BAT 19 I Battery input for level check SW_BOOST 8 IO Boost converter switching node. Inductor connection SW_BUCK 2 O Buck converter switching output. Inductor connection TEST1 22 IO Test pin1 (tie to GND) TEST2 16 O Test pin 2 (do not connect) VIN_BOOST 11 – Boost-converter power supply VIN_BUCK 3 – Buck converter power supply VO_BOOST 7 O Boost converter regulated output Submit Documentation Feedback Copyright © 2010, Texas Instruments Incorporated Product Folder Link(s): TPS80010 7 TPS80010 SLVSAD1 A – JUNE 2010 – REVISED JUNE 2010 www.ti.com FUNCTIONAL BLOCK DIAGRAM BUCK VIN_BUCK EN_BUCK MODE_BUCK Switching Control SW_BUCK GND_BUCK + PFM Soft Start - GND FB_BUCK + + ErrAmp - PWM - VREF PG - PG Comp 1.7V + BUCK LOAD SW EN_SW1 IN_VIO Soft Turn ON OUT_VIO OUT_VM ErrAmp VREF + IN_VM EN_LDO BOOST REG. LDO FB_BOOST ErrAmp + VREF VO_BOOST EN_BOOST TEST1 Regulation & Switching Mode Control with Soft Start SW_BOOST + TEST2 I SENSE - GND_BOOST VIN_BOOST + VIN COMP - BOOST VTH PP_BAT EN_BAT_CHECK BATT MONITOR SWITCH BAT_CHECK VIO L/S BAT_FALSELOAD VIO EN_BAT_FALSELOAD 8 BATTERY LOAD SWITCH Submit Documentation Feedback GND_FALSELOAD Copyright © 2010, Texas Instruments Incorporated Product Folder Link(s): TPS80010 TPS80010 www.ti.com SLVSAD1 A – JUNE 2010 – REVISED JUNE 2010 TYPICAL CHARACTERISTICS 1.830 95 1.825 VBUCK - Buck Output Voltage - V 100 Efficiency - % 90 85 VIN = 2.1 V VIN = 2.4 V 80 VIN = 2.8 V 75 VIN = 3.2 V 70 65 VIN = 3.2 V 1.820 1.815 VIN = 2.8 V 1.810 1.805 VIN = 2.4 V 1.800 VIN = 2.1 V 1.795 60 0.1 1 10 Load - mA 100 Figure 1. Buck Efficiency – MODE_BUCK = 0 1.790 0 10 20 30 40 50 60 Load - mA 70 80 90 100 Figure 2. Buck Output Voltage vs Load – MODE_BUCK = 0 1.805 VBUCK - Buck Output Voltage - V VIN = 2.4 V Iload = 100 mA VIN = 3.2 V 1.803 VIN = 2.8 V VIN = 2.4 V 1.801 1.799 VBUCK VIN = 2.1 V 1.797 10 mV/div 1 ms/div 1.795 0 20 40 60 Load - mA 80 100 Figure 3. Buck Output Voltage vs Load – MODE_BUCK = 1 Figure 4. Buck Output-Voltage Ripple – PWM Submit Documentation Feedback Copyright © 2010, Texas Instruments Incorporated Product Folder Link(s): TPS80010 9 TPS80010 SLVSAD1 A – JUNE 2010 – REVISED JUNE 2010 www.ti.com TYPICAL CHARACTERISTICS (continued) VIN = 2.4 V Iload = 20 mA VBUCK 10 mV/div 10 ms/div Figure 5. Buck Output-Voltage Ripple – PFM Figure 6. Buck Output Load Transient Response 100 VIN = 2 V to 3.6 V in 25 ms Iload = 50 mA VIN = 3.2 V 95 VIN VIN = 2.8 V 90 Efficiency - % 1 V/div VBUCK 20 mV/div 400 ms/div 85 VIN = 2.4 V 80 75 VIN = 2.1 V 70 65 60 0.1 Figure 7. Buck Output Line Transient Response 10 Submit Documentation Feedback 1 Load - mA 10 100 Figure 8. Boost With LDO Efficiency Copyright © 2010, Texas Instruments Incorporated Product Folder Link(s): TPS80010 TPS80010 www.ti.com SLVSAD1 A – JUNE 2010 – REVISED JUNE 2010 TYPICAL CHARACTERISTICS (continued) VIN = 2.4 V Iload = 50 mA VIN = 2.4 V Iload = 0 mA VBOOST VBOOST VLDO VLDO 10 mV/div 1 ms/div 10 mV/div 1 ms/div Figure 9. Boost Output Voltage Ripple Figure 10. Boost Output Voltage Ripple VIN = 1.8 V to 3.1 V Iload = 10 mA VBOOST VIN 10 mV/div 1 V/div 2 ms/div Figure 11. Boost Line Transient Response Figure 12. Boost Load Transient Response Submit Documentation Feedback Copyright © 2010, Texas Instruments Incorporated Product Folder Link(s): TPS80010 11 TPS80010 SLVSAD1 A – JUNE 2010 – REVISED JUNE 2010 www.ti.com TYPICAL CHARACTERISTICS (continued) Inductor Voltage VIN = 1.8 V to 3.1 V Iload = 10 mA 1 V/div 10 mV/div 400 ns/div VBOOST Figure 13. Boost Switching Waveform – Continuous-Current Mode 12 Submit Documentation Feedback Figure 14. Boost Switching Waveform – Discontinuous-Current Mode Copyright © 2010, Texas Instruments Incorporated Product Folder Link(s): TPS80010 TPS80010 www.ti.com SLVSAD1 A – JUNE 2010 – REVISED JUNE 2010 THEORY OF OPERATION Enable The TPS80010 includes two dc-dc converters, a load switch, post-regulation LDO, and battery monitoring switch. Each of these circuits has a dedicated enable pin with an internal pulldown resistor, RPULLDOWN, that can be driven by standard logic or by an open-drain driver. The EN_BUCK pin not only enables the buck converter, but also serves as the master enable for the device. No other circuitry in the TPS80010 can operate without EN_BUCK set high. Buck DC-DC Converter and Load Switch The synchronous step-down (buck) converter in the TPS80010 provides a fixed 1.8-V output with a load capacity of 150 mA. This converter operates with a fixed switching frequency of 2.25 MHz during pulse-width-modulation (PWM) operation at moderate to heavy loads. As the load current decreases, the converter automatically switches to a power-save mode and operates in pulse-frequency-modulation (PFM) mode in order to maximize power efficiency. During PFM operation, the converter positions the output at a voltage about 1% above the nominal output voltage. This feature minimizes the output voltage drops during sudden load transients. The power-save mode can be disabled by setting the MODE_BUCK pin high. The buck converter has internal soft-start circuitry that limits the inrush current during startup to 150 mA, allowing a slow and controlled output-voltage ramp. Once the output voltage reaches 1.7 V, the output monitoring circuitry generates a power-good (PG) output signal. The TPS80010 also includes a load switch that is to be connected externally to the buck output voltage. This switch provides flexibility in the design and power distribution of the end application by allowing several loads (such as memory, I/O, Bluetooth, etc.) to be connected to the same supply while being able to power down or disconnect some of these loads selectively when the end application goes to a low-power mode of operation. This switch has a controlled turnon in order to limit the inrush current caused by the load, and hence the load transient to the buck converter. Boost DC-DC Converter and Post-Regulation LDO The TPS80010 includes a synchronous step-up (boost) converter that provides a 3.1-V fixed output at 50-mA load current. The boost converter is controlled by a hysteretic current-mode controller. This controller regulates the output voltage by keeping the inductor ripple current constant and adjusting the offset of this inductor current depending on the output load. If the required average input current is lower than the average inductor current defined by this constant ripple, the converter goes into discontinuous-current mode (DCM) to keep the efficiency high at low-load conditions. The boost also has a soft-start circuit that limits the inrush current to 150 mA. In order to provide a clean, low-noise supply when VBAT > 3.1 V, the output of the boost is post-regulated by a 3-V LDO. This post-regulation allows the TPS80010 to provide a solid 3-V supply rail to the end application across the full input or battery-voltage range while minimizing the number of external components. In order to minimize power loss through the power path, the LDO allows for 100-mV input-voltage headroom at 50-mA load. Battery Monitoring Switch and False Load The TPS80010 implements a battery-voltage monitor switch to briefly check battery lifetime. The integrated false-load switch connects a specified load to the battery. When this false load is applied, the battery monitor switch is turned on, gating the sensed battery voltage to the ADC in the system. Based on this measurement, the system can determine the battery impedance, and hence, battery health. Submit Documentation Feedback Copyright © 2010, Texas Instruments Incorporated Product Folder Link(s): TPS80010 13 TPS80010 SLVSAD1 A – JUNE 2010 – REVISED JUNE 2010 www.ti.com APPLICATION INFORMATION Typical Application 1.8 V–3.6 V AA AA 10 mF 10 mF VIN_BOOST BAT_FALSELOAD VIN_BUCK PP_BAT 10 W 10 mH SW_BOOST EN_BOOST VO_BOOST EN_LDO FB_BOOST 3.1 V 22 mF EN_BUCK TPS80010 IN_VM EN_SW1 EN_BAT_CHECK 3V OUT_VM 4.7 mF CONTROLLER LED EN_BAT_FLASELOAD 2.2 mH PG SW_BUCK OPTICAL SENSOR 1.8 V 10 mF BAT_CHECK MEMORY/ IO FB_BUCK 1.8 kW MODE_BUCK IN_VIO ADC OUT_VIO TEST1 NC 1.8 V 1.8-V PERIPHERALS TEST2 1.8 kW GND Buck Output Filter Design The TPS80010 buck regulator is designed to operate with inductors in the range of 1.5 µH to 4.7 µH and with output capacitors in the range of 4.7 µF to 22 µF. The part is optimized for operation with a 2.2-µH inductor and 10-µF output capacitor. Larger or smaller inductor values can be used to optimize the performance of the device for specific operation conditions. For stable operation, the L and C values of the output filter must not fall below 1-µH effective inductance and 3.5-µF effective capacitance. Buck Inductor Selection The inductor value has a direct effect on the ripple current. The selected inductor must be rated for its dc resistance and saturation current. The inductor ripple current (ΔIL) decreases with higher inductance and increases with higher VIN or VBUCK. The inductor selection also has an impact on the output-voltage ripple in PFM mode. Higher inductor values lead to lower output-voltage ripple and higher PFM frequency; lower inductor values lead to a higher output-voltage ripple but lower PFM frequency. Equation 1 calculates the maximum inductor current in PWM mode under static load conditions. The saturation current of the inductor should be rated higher than the maximum inductor current, as calculated with Equation 2. This is recommended because during heavy load transients, the inductor current rises above the calculated value. V 1- BUCK VIN ΔIL = VBUCK ´ L ´ f (1) ΔIL ILmax = IOmax + 2 (2) with: f = Switching frequency (2.25 MHz typical) 14 Submit Documentation Feedback Copyright © 2010, Texas Instruments Incorporated Product Folder Link(s): TPS80010 TPS80010 www.ti.com SLVSAD1 A – JUNE 2010 – REVISED JUNE 2010 L = Inductor value ΔIL = Peak-to-peak inductor ripple current ILmax = Maximum inductor current A more conservative approach is to select the inductor current rating just for the switch current limit, ILIMF, of the converter. Accepting larger values of ripple current allows the use of lower inductance values, but results in higher output voltage ripple, greater core losses, and lower output current capability. The total losses of the coil have a strong impact on the efficiency of the dc-dc conversion and consist of both the losses in the dc resistance (R(DC)) and the following frequency-dependent components: • The losses in the core material (magnetic hysteresis loss, especially at high switching frequencies) • Additional losses in the conductor from the skin effect (current displacement at high frequencies) • Magnetic field losses of the neighboring windings (proximity effect) • Radiation losses Buck Output Capacitor Selection The advanced fast-response voltage mode control scheme of the TPS80010 buck regulator allows the use of tiny ceramic capacitors. Ceramic capacitors with low ESR values have the lowest output voltage ripple and are recommended. The output capacitor requires either an X7R or X5R dielectric. Y5V- and Z5U-dielectric capacitors, aside from their wide variation in capacitance over temperature, become resistive at high frequencies. At nominal load current, the device operates in PWM mode and the rms ripple current is calculated as: V 1 - BUCK VIN 1 IRMSCout = VBUCK × ´ L ´ f 2 ´ 3 (3) 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: V 1- BUCK æ ö VIN 1 ΔVBUCK = VBUCK × + ESR ÷ ´ ç L ´ f 8 × C f ´ OUT è ø (4) At light load currents, the converter operates in power-save mode, and the output-voltage ripple depends on the output-capacitor and inductor values. Larger output-capacitor and inductor values minimize the voltage ripple in PFM mode and tighten dc output accuracy in PFM mode. Buck Input Capacitor Selection An input capacitor is required for best input voltage filtering and for minimizing the interference with other circuits caused by high input-voltage spikes. For most applications, a 4.7-µF to 10-µF ceramic capacitor is recommended. Because a ceramic capacitor loses up to 80% of its initial capacitance at 5 V, it is recommended that 10-µF input capacitors be used for input voltages > 4.5 V. The input capacitor can be increased without any limit for better input-voltage filtering. Take care when using only small ceramic input capacitors. When a ceramic capacitor is used at the input and the power is being supplied through long wires, such as from a wall adapter, a load step at the output or VIN step on the input can induce ringing at the VIN_BUCK pin. This ringing can couple to the output and be mistaken as loop instability or could even damage the part by exceeding the maximum ratings. Table 1. Recommended Component List for Buck Converter Component Value Part# Supplier Size LQM2HPN2R2MJ0L Murata 2.5 × 2 × 1.2 (1008) LPS3015-222ML Coilcraft 3 × 3 × 1.5 Inductor 2.2 mH Cacitor (IN) 10 mF GRM188R60J106ME47D Murata 0603 Capacitor (OUT) 10 mF GRM188R60J106ME47D Murata 0603 Submit Documentation Feedback Copyright © 2010, Texas Instruments Incorporated Product Folder Link(s): TPS80010 15 TPS80010 SLVSAD1 A – JUNE 2010 – REVISED JUNE 2010 www.ti.com Boost Inductor Selection To ensure proper operation of the TPS80010 boost dc-dc converter, a suitable inductor must be connected between pins VIN_BOOST and SW_BOOST. Inductor values of 4.7 mH show good performance over the whole input and output voltage range. Choosing other inductance values affects the switching frequency f proportional to 1/L as shown in Equation 5. V ´ (VBOOST - VIN ) 1 L= ´ IN f ´ 200 mA VBOOST (5) Choosing inductor values higher than 4.7 mH can improve efficiency due to reduced switching frequency and correspondingly reduced switching losses. Using inductor values below 2.2 mH is not recommended. Having selected an inductance value, the peak current for the inductor in steady-state operation can be calculated. Equation 6 gives the peak current estimate. ìV ü × IBOOST IL,MAX = í BOOST + 100 mA ý 0.8 × VIN î þ IL,MAX = 200 mA continuous current operation discontinuous current operation (6) IL,MAX is the required minimum inductor-current rating. Note that load-transient or overcurrent conditions may require an even higher current rating. The condition in Equation 7 provides an easy way to determine whether the device is in continuous or discontinuous operation. As long as the condition is true, the device operates in continuous-current mode. If the condition becomes false, discontinuous-current operation is established. VBOOST × IO > 0.8 ´ 100 mA VIN (7) Due to the use of current hysteretic control in the TPS80010 boost, the series resistance of the inductor can impact the operation of the main switch. There is a simple calculation that can ensure proper operation of the TPS80010 boost converter. The relationship between the series resistance (RIN), the input voltage (VIN), and the switch-current limit (ISW) is shown in Equation 8. V RIN < IN ISW (8) Examples: ISW = 400 mA, VIN = 2.5 V (9) In Equation 9, RIN < 2.5 V / 400 mA; therefore, RIN must be less than 6.25 Ω. ISW = 400 mA, VIN = 1.8 V (10) In Equation 10, RIN < 1.8 V / 400 mA; therefore, RIN must be less than 4.5 Ω. Boost Input Capacitor The input capacitor should be at least 10 mF to improve transient behavior of the regulator and EMI behavior of the total power-supply circuit. The input capacitor should be a ceramic capacitor and be placed as close as possible to the VIN_BOOST and GND pins of the IC. These capacitors should be X7R or X5R ceramic capacitors. Boost Output Capacitor For the output capacitor COUT, it is recommended to use small X7R or X5R ceramic capacitors placed as close as possible to the VO_BOOST and GND pins of the IC. If, for any reason, the application requires the use of large capacitors which cannot be placed close to the IC, the use of a small ceramic capacitor with a capacitance value of around 4.7 mF in parallel with the larger one is recommended. This small capacitor should be placed as close as possible to the VO_BOOST and GND pins of the IC. 16 Submit Documentation Feedback Copyright © 2010, Texas Instruments Incorporated Product Folder Link(s): TPS80010 TPS80010 www.ti.com SLVSAD1 A – JUNE 2010 – REVISED JUNE 2010 A minimum effective capacitance value of 6 mF should be used; 10 mF is recommended. If the inductor value exceeds 4.7 mH, the value of the effective output capacitance value must be half the inductance value or higher for stability reasons; see Equation 11. L mF COUT ³ ´ 2 mH (11) When choosing the output capacitor, note the effects of bias voltage, temperature, and tolerance on the effective capacitance of the component. A capacitor in a 0603 package size suffers more capacitance degradation than a 0805 package at a similar bias voltage. For example, either a 22-µF 0603-sized capacitor or a 10-µF 0805-sized capacitor would be required to work with a nominal 10-µH inductor. The TPS80010 boost is not sensitive to ESR in terms of stability. Using low-ESR capacitors, such as ceramic capacitors, is recommended to minimize output-voltage ripple. If heavy load changes are expected, the output capacitor value should be increased to avoid output voltage drops during fast load transients. Table 2. Recommended Component List for Boost Converter Component Value Part# Supplier Size Inductor 10 mH CBC3225T100MR Taiyo Yuden 3.2 × 2.5 × 2.5 (1210) DO3314-103ML Coilcraft Capacitor (IN) 3.3 × 3.3 × 1.4 10 mF GRM188R60J106ME47D Murata Capacitor (OUT) 0603 22 mF AMK107BJ226MA-T Taiyo Yuden 0603 Submit Documentation Feedback Copyright © 2010, Texas Instruments Incorporated Product Folder Link(s): TPS80010 17 PACKAGE OPTION ADDENDUM www.ti.com 28-Jun-2010 PACKAGING INFORMATION Orderable Device TPS80010ARSMR Status (1) ACTIVE Package Type Package Drawing VQFN RSM Pins Package Qty 32 3000 Eco Plan (2) Green (RoHS & no Sb/Br) Lead/ Ball Finish MSL Peak Temp (3) CU NIPDAU Level-2-260C-1 YEAR Samples (Requires Login) Purchase Samples (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. 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