Dual 3 MHz, 600 mA Buck Regulator with 150 mA LDO ADP5022 FEATURES GENERAL DESCRIPTION Input voltage range: 2.4 V to 5.5 V Tiny 16-ball, 2 mm × 2 mm WLCSP package Overcurrent and thermal protection Soft start Factory programmable undervoltage lockout on VDDA system supply of either 2.2 V or 3.9 V Factory programmable default output voltages for all 3 channels Buck1 and Buck2 key specifications Current mode architecture for excellent transient response 3 MHz operating frequency Uses tiny multilayer inductors and capacitors Forced PWM and auto PWM/PSM modes Out-of-phase operation for reduced input filtering 100% duty cycle low dropout mode 24 μA typical quiescent current per channel, no switching LDO key specifications Stable with 1 μF ceramic output capacitors High PSRR 60 dB up to 10 KHz Low output noise 65 μV rms output noise at VOUT3 = 3.3 V Low dropout voltage: 150 mV @ 150 mA load 11 μA typical ground current at no load The ADP5022 is a micro power management unit (micro PMU) that combines two high performance buck regulators and a low dropout regulator (LDO) in a tiny 16-ball 2.08 mm × 2.08 mm WLCSP to meet demanding performance and board space requirements. The high switching frequency of the buck regulators enables tiny multilayer external components and minimizes the board space required. When the MODE pin is set high, the buck regulators operate in forced PWM mode. When the MODE pin is set low, the buck regulators automatically switch operating modes, depending on the load current level. At higher output loads, the buck regulators operate in PWM mode. When the load current falls below a predefined threshold, the regulators operate in power save mode (PSM), improving the light-load efficiency. The two bucks operate out-of-phase to reduce the input capacitor requirement and noise. The low quiescent current, low dropout voltage, and wide input voltage range of the ADP5022 LDO extends the battery life of portable devices. The LDO maintains power supply rejection greater than 60 dB for frequencies as high as 10 kHz while operating with a low headroom voltage. Each regulator in the ADP5022 has a dedicated, independent enable pin. A high voltage level applied to the enable pin activates the respective regulator. The default output voltages are factory programmable and can be set to a wide range of options. USB devices Handheld products Multivoltage power for processors, ASICS, FPGAs, and RF chipsets VIN = 2.4V TO 5.5V SW1 VIN1 C2 4.7µF ON OFF BUCK1 EN1 VOUT1 MODE VIN2 MODE BUCK2 ON EN2 OFF SW2 VOUT2 PGND2 EN_BK2 COUT_3 VOUT1 @ 600mA C4 10µF PGND1 EN_BK1 MODE C3 4.7µF L1 1µH PWM L2 1µH C3 C1 PWM/PSM 5.0mm LDO1 VOUT3 VOUT3 @ 150mA C6 1µF EN_LDO1 AGND Figure 1. Typical Applications Circuit INDUCTOR OFF EN3 08253-001 VIN3 ON C2 VOUT2 @ 600mA C5 10µF VDDA C1 1µF C4 L1 INDUCTOR ADP5022 COUT_1 COUT_2 4.7mm 08253-061 APPLICATIONS Figure 2. Typical PCB Layout Rev. A Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other rights of third parties that may result from its use. Specifications subject to change without notice. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Trademarks and registered trademarks are the property of their respective owners. One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. Tel: 781.329.4700 www.analog.com Fax: 781.461.3113 ©2009 Analog Devices, Inc. All rights reserved. ADP5022 TABLE OF CONTENTS Features .............................................................................................. 1 Theory of Operation ...................................................................... 16 Applications ....................................................................................... 1 Power Management Unit........................................................... 16 General Description ......................................................................... 1 Buck Section................................................................................ 17 Revision History ............................................................................... 2 LDO Section ............................................................................... 18 Specifications..................................................................................... 3 Applications Information .............................................................. 19 Buck1 and Buck2 Specifications ................................................. 4 Buck External Component Selection....................................... 19 LDO Specifications ...................................................................... 5 LDO Capacitor Selection .......................................................... 20 Absolute Maximum Ratings............................................................ 6 PCB Layout Guidelines .................................................................. 22 Thermal Data ................................................................................ 6 Evaluation Board schematics and Artwork ................................ 23 Thermal Resistance ...................................................................... 6 Suggested Layout ........................................................................ 23 ESD Caution .................................................................................. 6 Outline Dimensions ....................................................................... 25 Pin Configuration and Function Descriptions ............................. 7 Ordering Guide .......................................................................... 25 Typical Performance Characteristics ............................................. 8 REVISION HISTORY 11/09—Revision A: Initial Version Rev. A | Page 2 of 28 ADP5022 SPECIFICATIONS VDDA = VIN1 = VIN2 = 3.6 V, VIN3 = (VOUT3 + 0.5 V) or 2.4 V, whichever is greater, VIN3 ≤ VIN1, TJ = −40°C to +125°C, unless otherwise noted. 1 Table 1. Parameter INPUT VOLTAGE RANGE System and Buck Input Supplies Voltage Range Symbol Test Conditions/Comments Min VDDA, VIN1, and VIN2 Low UVLO level models High UVLO level models LDO Input Supply Voltage Range SHUTDOWN CURRENT VIN3 IGND-SD THERMAL SHUTDOWN Thermal Shutdown Threshold Thermal Shutdown Hysteresis EN1, EN2, EN3, MODE INPUTS EN1, EN2, EN3, MODE Input Logic High EN1, EN2, EN3, MODE Input Logic Low EN1, EN2, EN3, MODE Input Leakage Current STANDBY CURRENT All Channels Enabled, No Load All Channels Enabled, No Load, No Buck Switching VIN3 UNDERVOLTAGE LOCKOUT Input Voltage Rising Input Voltage Falling VDDA UNDERVOLTAGE LOCKOUT Input Voltage Rising Input Voltage Falling 1 Typ Max Unit 2.4 5.5 V 4.5 2.3 5.5 5.5 V V 2 μA μA EN1 = EN2 = EN3 = GND EN1 = EN2 = EN3 = GND TJ = −40°C to +85°C 0.5 TSDTH TSDHYS TJ rising 150 20 VIH VIL VI-LEAKAGE VDDA = VIN1 = VIN2 VDDA = VIN1 = VIN2 Pin at (VDDA = VIN1 = VIN2) or GND 1.2 ISTBY ISTBY-NOSW UVLOVIN3RISE UVLOVIN3FALL UVLOVDDARISE UVLOVDDAFALL °C °C 0.05 0.4 1 V V μA 80 59 85 μA μA 2.20 V V 4.15 2.35 V V V V 1.45 High UVLO level (factory programmed) Low UVLO level (factory programmed) High UVLO level (factory programmed) Low UVLO level (factory programmed) All limits at temperature extremes are guaranteed via correlation using standard statistical quality control. Rev. A | Page 3 of 28 3.40 2.00 ADP5022 BUCK1 AND BUCK2 SPECIFICATIONS VDDA = VIN1 = VIN2 = 3.6 V, VIN3 = (VOUT3 + 0.5 V) or 2.4 V, whichever is greater, VIN3 ≤ VIN1, TJ = −40°C to +125°C, unless otherwise noted. 1 Table 2. Parameter OPERATING SUPPLY CURRENT Buck1 Only Symbol Test Conditions/Comments IGND1 ILOAD1 = 0 mA, device not switching, EN1 = VDDA, EN2 = EN3 = GND ILOAD2 = 0 mA, device not switching, EN2 = VDDA, EN1 = EN3 = GND ILOAD1 = ILOAD1 = 0 mA, device not switching, EN1 = EN2 = VDDA, EN3 = GND Buck2 Only IGND2 Buck1 and Buck2 Only IGND1-2 OUTPUT VOLTAGE ACCURACY NFET On Resistance Current Limit OSCILLATOR FREQUENCY START-UP TIME 2 From Shutdown State 1 2 Typ Max Unit 24 μA 32 μA 48 64 μA +3 % VOUT1, VOUT2 PWM mode, VIN1 = VIN2 = 2.4 V to 5.5 V, ILOAD1 = ILOAD2 = 0 mA − 600 mA POWER SAVE MODE TO PWM CURRENT THRESHOLD PWM TO POWER SAVE MODE CURRENT THRESHOLD SW CHARACTERISTICS, BUCK1 and BUCK2 PFET On Resistance Min −3 IPSM-PWM 105 mA IPWM-PSM 100 mA RPFET RNFET ILIMIT1, ILIMIT2 FSW Typical at VIN1 = VIN2 = 3.6 V Typical at VIN1 = VIN2 = 5.0 V Typical at VIN1 = VIN2 = 3.6 V Typical at VIN1 = VIN2 = 5.0 V PFET switch peak current limit TSTARTUP12-SD 750 2.5 165 125 125 100 950 3.0 250 All limits at temperature extremes are guaranteed via correlation using standard statistical quality control. Start-up time is defined as the time from a rising edge on EN1/EN2 to VOUT1/VOUT2 reaching 90% of their nominal value. Rev. A | Page 4 of 28 275 220 1050 3.5 mΩ mΩ mΩ mΩ mA MHz μs ADP5022 LDO SPECIFICATIONS VDDA = VIN1 = VIN2 = 3.6 V, VIN3 = (VOUT3 + 0.5 V) or 2.3 V, whichever is greater, VIN3 ≤ VIN1, IOUT3 = 10 mA; CIN3 = COUT3 = 1 μF, TJ = −40°C to +125°C, unless otherwise noted. 1 Table 3. Parameter OPERATING SUPPLY CURRENT 2 Symbol IVIN3-GND Test Conditions/Comments Min IOUT3 = 0 μA IOUT3 = 10 mA IOUT3 = 150 mA OUTPUT VOLTAGE ACCURACY REGULATION Line Regulation Load Regulation 3 DROPOUT VOLTAGE 4 START-UP TIME 5 From Shutdown State CURRENT-LIMIT THRESHOLD 6 OUTPUT NOISE POWER SUPPLY REJECTION RATIO Typ Max Unit 11 16 31 21 29 43 μA μA μA +2 % 0.002 +0.03 0.0075 %/ V %/mA 7 110 150 mV mV 200 240 350 μs mA VOUT3 100 μA < IOUT3 < 150 mA, VIN3 = (VOUT3 + 0.5 V) to 5.5 V −2 ∆VOUT3/∆VIN3 ∆VOUT3/∆IOUT3 VIN3 = (VOUT3 + 0.5 V) to 5.5 V, IOUT = 1 mA IOUT3 = 1 mA to 150 mA −0.03 VDROPOUT VOUT3 = 3.0 V, IOUT3 = 10 mA VOUT3 = 3.0 V, IOUT3 = 150 mA TSTARTUP3-SD ILIMIT3 OUTNOISE 160 10 Hz to 100 kHz, VIN3 = 5 V, VOUT3 = 3.3 V 10 Hz to 100 kHz, VIN3= 5 V, VOUT3 = 2.4 V 10 Hz to 100 kHz, VIN3 = 5 V, VOUT3 = 1.2 V 65 52 40 μV rms μV rms μV rms 10 kHz, VIN3 = 5 V, VOUT3 = 3.3 V 10 kHz, VIN3 = 5 V, VOUT3 = 2.3 V 10 kHz, VIN3 = 5 V, VOUT3 = 1.2 V 60 66 70 dB dB dB PSRR 1 All limits at temperature extremes are guaranteed via correlation using standard statistical quality control. LDO operating supply current is the current drawn from VIN3 to AGND when the LDO is enabled. Whenever any regulator channel is enabled, current is drawn from VIN1 to AGND. This current is 8 μA typical and is included in the IGND1, IGND2, and IGND1-2 specifications. 3 Based on an end-point calculation using 1 mA and 150 mA loads. 4 Dropout voltage is defined as the input-to-output voltage differential when the input voltage is set to the nominal output voltage. This applies only for output voltages above 2.3 V. 5 Start-up time is defined as the time between the rising edge of EN3 to VOUT3 being at 90% of its nominal value. 6 Current-limit threshold is defined as the current at which VOUT3 drops to 90% of the specified typical value. For example, the current limit for a 3.0 V output voltage is defined as the current that causes the output voltage to drop to 90% of 3.0 V or 2.7 V. 2 Rev. A | Page 5 of 28 ADP5022 ABSOLUTE MAXIMUM RATINGS Table 4. Parameter VDDA, VIN1, VIN2, VIN3, VOUT1, VOUT2, VOUT3, EN1, EN2, EN3, MODE to GND Storage Temperature Range Operating Junction Temperature Range Soldering Conditions Rating −0.3 V to +6 V −65°C to +150°C −40°C to +125°C JEDEC J-STD-020 Stresses above those listed under Absolute Maximum Ratings may cause permanent damage to the device. This is a stress rating only; functional operation of the device at these or any other conditions above those indicated in the operational section of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. θJA of the package is based on modeling and calculation using a 4-layer board. The junction-to-ambient thermal resistance is highly dependent on the application and board layout. In applications where high maximum power dissipation exists, close attention to thermal board design is required. The value of θJA may vary, depending on PCB material, layout, and environmental conditions. The specified values of θJA are based on a 4-layer, 4” × 3” circuit board. Refer to JEDEC JESD 51-9 for detailed information on the board construction. For additional information, see the AN-617 Application Note, MicroCSPTM Wafer Level Chip Scale Package. THERMAL RESISTANCE θJA is specified for the worst-case conditions, that is, a device soldered on a circuit board. THERMAL DATA Table 5. Thermal Resistance Absolute maximum ratings apply individually only, not in combination. Package Type 16-Ball, 0.5 mm Pitch WLCSP The ADP5022 can be damaged when the junction temperature limits are exceeded. Monitoring ambient temperature (TA) does not guarantee that the junction temperature (TJ) is within the specified temperature limits. In applications with high power dissipation and poor thermal resistance, the maximum ambient temperature may have to be derated. In applications with moderate power dissipation and low PCB thermal resistance, the maximum ambient temperature may exceed the maximum limit as long as the junction temperature is within specification limits. TJ of the device is dependent on TA, the power dissipation (PD) of the device, and the junction-to-ambient thermal resistance (θJA) of the package. Maximum TJ is calculated from TA and PD using the following formula: ESD CAUTION TJ = TA + (PD × θJA) Rev. A | Page 6 of 28 θJA 65 Unit °C/W ADP5022 PIN CONFIGURATION AND FUNCTION DESCRIPTIONS BALL A1 INDICATOR 2 1 VOUT3 AGND 3 4 VIN3 VDDA A VIN1 EN1 EN2 VIN2 SW1 EN3 MODE SW2 B C PGND1 VOUT1 VOUT2 PGND2 TOP VIEW (BALL SIDE DOWN) Not to Scale 08253-002 D Figure 3. Pin Configuration Table 6. Pin Function Descriptions Pin No. A1 A2 A3 A4 B1 B2 B3 B4 C1 C2 C3 C4 D1 D2 D3 D4 Mnemonic VOUT3 AGND VIN3 VDDA VIN1 EN1 EN2 VIN2 SW1 EN3 MODE SW2 PGND1 VOUT1 VOUT2 PGND2 Description LDO Output Voltage and Sensing Input. Analog Ground. LDO Input Supply (VIN3 ≤ VIN1 = VIN2 = VDDA). Supply Input for the Housekeeping Block and UVLO Sensing. Buck1 Input Supply (VIN1 = VIN2 = VDDA). Buck1 Activation. Set EN1 = high: turn on Buck1. Set EN1 = low: turn off Buck1. Buck2 Activation. Set EN2 = high: turn on Buck2. Set EN2 = low: turn off Buck2. Buck2 Input Supply (VIN2 = VIN1 = VDDA). Buck1 Switching Node. LDO Activation. Set EN3 = high: turn on LDO. EN3 = low: turn off LDO. Buck1/Buck2 Operating Mode: MODE = high: forced PWM operation. MODE = low: auto PWM/PSM operation. Buck2 Switching Node. Dedicated Power Ground for Buck1. Buck1 Output Voltage Sensing Input. Buck2 Output Voltage Sensing Input. Dedicated Power Ground for Buck2. Rev. A | Page 7 of 28 ADP5022 TYPICAL PERFORMANCE CHARACTERISTICS VIN1 = VIN2 = VIN3 = VDDA = 5.0 V, TA = 25°C, unless otherwise noted. T T SW 4 VOUT1 1 VOUT 2 VOUT2 EN 2 1 IIN VOUT3 3 BW BW CH2 2.00V BW M 200µs A CH1 1.92V T 45.40% CH1 2.00V CH3 5.00V Figure 4. 3-Channel Start-Up Waveforms, VIN3 Cascaded from VOUT1 BW BW CH2 50.0mA Ω BW M 40.0µs BW CH4 5.00V T 11.20% A CH3 2.2V 08253-020 CH1 2.00V CH3 2.00V 08253-023 3 Figure 7. Buck2 Startup, VOUT2 = 1.8 V, IOUT2 = 5 mA 0.15 0.00010 0.14 0.00008 OUTPUT CURRENT (A) 0.13 IINA (A) 0.00006 0.00004 0.12 0.11 PSM TO PWM 0.10 PWM TO PSM 0.09 0.08 0.00002 0.07 2.4 Figure 5. System Quiescent Current vs. Input Voltage, VOUT1 = 0.8 V, VOUT2 = 2.5 V, VIN3 = VOUT2, VOUT3 = 1.2 V, All Channels Unloaded 2.9 3.4 3.9 4.4 INPUT VOLTAGE (V) 5.4 Figure 8. Buck 2 PSM to PWM Transition, VOUT2 = 1.8 V T TA = +25°C TA = –40°C TA = +85°C 3.354 SW 3.334 4 VOUT VOUTA (V) 2 4.9 08253-067 0.06 08253-064 0 2.4 2.6 2.8 3.0 3.2 3.4 3.6 3.8 4.0 4.2 4.4 4.6 4.8 5.0 5.2 5.4 VIN (V) EN 3.314 3.294 1 3.274 IIN BW BW CH2 50.0mA Ω BW M 40.0µs BW CH4 5.00V T 11.20% A CH3 2.2V Figure 6. Buck1 Startup, VOUT1 = 3.3 V, IOUT1 = 10 mA 3.234 08253-021 CH1 2.00V CH3 5.00V 0 0.1 0.2 0.3 IOUT (A) 0.4 0.5 0.6 08253-058 3.254 3 Figure 9. Buck1 Load Regulation Across Temperature, VOUT1 = 3.3 V, Auto Mode Rev. A | Page 8 of 28 ADP5022 100 1.834 TA = +25°C TA = –40°C TA = +85°C 1.824 90 80 70 EFFICIENCY (%) VOUTB (V) 1.814 1.804 1.794 VIN = 3.6V VIN = 4.5V VIN = 5.5V 60 50 40 30 1.784 20 1.774 0 0.1 0.2 0.3 IOUT (A) 0.4 0.5 0.6 0 0.0001 08253-057 1.764 Figure 10. Buck2 Load Regulation Across Temperature, VOUT2 = 1.8 V, Auto Mode 0.01 IOUT (A) 0.1 1 Figure 13. Buck1 Efficiency vs. Load Current, Across Input Voltage, VOUT1 = 3.3 V, Auto Mode 100 1.834 VIN = 5.5V VIN = 4.5V VIN = 3.6V VIN = 2.4V 1.824 90 80 70 EFFICIENCY (%) 1.814 1.804 1.794 60 50 40 30 1.784 VIN = 3.6V VIN = 4.5V VIN = 5.5V 20 1.774 10 0 0.1 0.2 0.3 IOUT (A) 0.4 0.5 0.6 0 0.001 08253-054 1.764 Figure 11. Buck 2 Load Regulation Across Input Voltage, VOUT1 = 1.8 V, PWM Mode 0.01 0.1 1 IOUT (A) 08253-039 VOUTB (V) 0.001 08253-038 10 Figure 14. Buck1 Efficiency vs. Load Current, Across Input Voltage, VOUT1 = 3.3 V, PWM Mode 100 3.354 90 80 3.334 EFFICIENCY (%) 3.294 3.274 60 50 40 30 VIN = 3.6V VIN = 4.5V VIN = 5.5V 10 3.234 0 0.1 0.2 0.3 IOUT (A) 0.4 0.5 VIN = 5.5V VIN = 4.5V VIN = 3.6V VIN = 2.4V 20 0.6 08253-055 3.254 Figure 12. Buck1 Load Regulation Across Input Voltage, VOUT2 = 3.3 V, PWM Mode Rev. A | Page 9 of 28 0 0.0001 0.001 0.01 IOUT (A) 0.1 1 08253-036 VOUTA (V) 70 3.314 Figure 15. Buck2 Efficiency vs. Load Current, Across Input Voltage, VOUT2 = 1.8 V, Auto Mode 100 100 90 90 80 80 70 70 EFFICIENCY (%) 60 50 40 40 0 0.001 0.01 0.1 10 1 IOUT (A) 0 0.0001 08253-035 10 Figure 16. Buck2 Efficiency vs. Load Current, Across Input Voltage, VOUT2 = 1.8 V, PWM Mode 90 90 80 80 70 70 EFFICIENCY (%) 100 60 50 40 0.01 IOUT (A) 0.1 1 60 50 40 30 VIN = 2.4V VIN = 3.6V VIN = 4.5V VIN = 5.5V 10 0.001 0.01 IOUT (A) 0.1 10 1 0 0.0001 Figure 17. Buck1 Efficiency vs. Load Current, Across Input Voltage, VOUT1 = 0.8 V, Auto Mode 3.4 80 3.3 70 3.2 FREQUENCY (MHz) 3.5 90 60 50 40 30 VIN = 2.4V VIN = 3.6V VIN = 4.5V VIN = 5.5V 0.01 0.1 IOUT (A) 0.01 IOUT (A) 0.1 1 TA = +25°C TA = –40°C TA = +85°C 3.1 3.0 2.9 2.8 2.7 2.6 1 08253-065 10 0.001 Figure 20. Buck2 Efficiency vs. Load Current, Across Temperature, VOUT2 = 1.8 V, Auto Mode 100 20 TA = +25°C TA = –40°C TA = +85°C 20 08253-034 20 08253-063 30 0 0.001 0.001 Figure 19. Buck1 Efficiency vs. Load Current, Across Temperature, VOUT1 = 3.3 V, Auto Mode 100 0 0.0001 TA = –40°C TA = +25°C TA = +85°C 20 08253-062 VIN = 5.5V VIN = 4.5V VIN = 3.6V VIN = 2.4V 20 EFFICIENCY (%) 50 30 30 EFFICIENCY (%) 60 2.5 0 Figure 18. Buck1 Efficiency vs. Load Current, Across Input Voltage, VOUT1 = 0.8 V, PWM Mode 0.1 0.2 0.3 0.4 OUTPUT CURRENT (A) 0.5 0.6 Figure 21. Buck2 Switching Frequency vs. Output Current, Across Temperature, VOUT2 = 1.8 V, PWM Mode Rev. A | Page 10 of 28 08253-040 EFFICIENCY (%) ADP5022 ADP5022 T T VOUT VOUT 1 1 ISW ISW 2 2 SW SW CH2 500mA Ω M 4.00µs A CH2 BW CH4 2.00V T 28.40% BW 240mA CH1 50mV Figure 22. Typical Waveforms, VOUT1 = 3.3 V, IOUT1 = 30 mA, Auto Mode CH2 500mA Ω M 400ns A CH2 BW CH4 2.00V T 28.40% BW 220mA 08253-026 4 CH1 50.0V 08253-025 4 Figure 25. Typical Waveforms, VOUT2 = 1.8 V, IOUT2 = 30 mA, PWM Mode T T VOUT 1 VIN ISW VOUT 1 2 SW SW 3 BW CH2 500mA Ω M 4.00µs A CH2 BW CH4 2.00V T 28.40% 220mA CH1 50.0mV CH3 1.00V BW BW M 1.00ms CH4 2.00V A CH3 4.80V BW T 30.40% Figure 23. Typical Waveforms, VOUT2 = 1.8 V, IOUT2 = 30 mA, Auto Mode 08253-012 CH1 50.0V 08253-024 4 Figure 26. Buck1 Response to Line Transient, Input Voltage from 4.5 V to 5.0 V, VOUT1 = 3.3 V, PWM Mode T T VOUT 1 VIN ISW VOUT 2 1 SW SW 4 3 BW CH2 500mA Ω M 400ns A CH2 BW CH4 2.00V T 28.40% 220mA CH1 50.0mV CH3 1.00V BW BW M 1.00ms CH4 2.00V BW T 30.40% Figure 24. Typical Waveforms, VOUT1 = 3.3 V, IOUT1 = 30 mA, PWM Mode Rev. A | Page 11 of 28 A CH3 4.80V 08253-013 CH1 50mV 08253-027 4 Figure 27. Buck2 Response to Line Transient, VIN = 4.5 V to 5.0 V, VOUT2 = 1.8 V, PWM Mode ADP5022 T T SW SW 4 4 VOUT 1 VOUT 1 IOUT IOUT 2 BW CH2 50.0mA Ω BW M 20.0µs A CH2 BW T 60.000µs CH4 5.00V 356mA CH1 100mV BW CH2 200mA Ω CH4 5.00V BW M 20.0µs A CH2 88.0mA BW T 19.20% Figure 28. Buck1 Response to Load Transient, IOUT1 from 1 mA to 50 mA, VOUT1 = 3.3 V, Auto Mode 08253-018 CH1 50.0mV 08253-016 2 Figure 31. Buck2 Response to Load Transient, IOUT2 from 20 mA to 180 mA, VOUT2 = 1.8 V, Auto Mode T T SW VOUT2 2 4 SW1 VOUT 3 1 VOUT1 1 SW2 IOUT 2 BW CH2 50.0mA Ω BW M 20.0µs A CH2 BW CH4 5.00V T 22.20% 379mA CH1 5.00V CH3 5.00V BW BW CH2 5.00V CH4 5.00V BW M 400ns A CH4 1.90V BW T 50.00% Figure 29. Buck2 Response to Load Transient, IOUT2 from 1 mA to 50 mA, VOUT2 = 1.8 V, Auto Mode 08253-066 CH1 50.0mV 08253-015 4 Figure 32. VOUT and SW Waveforms for Buck1 and Buck2 in PWM Mode Showing Out-of-Phase Operation T T SW 4 IIN 2 VOUT 1 VOUT 1 EN IOUT 2 BW CH2 200mA Ω CH4 5.00V BW M 20.0µs A CH2 BW T 20.40% 408mA CH1 2.00V CH3 5.00V BW BW CH2 50.0mA Ω BW M 40.0µs A CH3 2.2V BW T 11.20% Figure 30. Buck1 Response to Load Transient, IOUT1 from 20 mA to 180 mA, VOUT1 = 3.3 V, Auto Mode Rev. A | Page 12 of 28 Figure 33. LDO Startup, VOUT3 = 3.0 V, IOUT3 = 5 mA 08253-022 CH1 50.0mV 08253-017 3 ADP5022 2.820 50 2.815 45 40 2.800 2.795 VIN = 3.3V VIN = 4.5V VIN = 5.0V VIN = 5.5V 2.790 2.785 0.04 0.06 0.08 IOUT (A) 0.10 0.12 0.14 Figure 34. LDO Load Regulation Across Input Voltage, VOUT3 = 2.8 V 20 3.8 4.3 4.8 INPUT VOLTAGE (V) 5.3 Figure 37. LDO Ground Current vs. Input Voltage, Across Output Load, VOUT3 = 2.8 V 50 TA = –40°C TA = +25°C TA = +85°C 45 40 GROUND CURRENT (µA) 2.83 2.82 2.81 2.80 2.79 2.78 35 30 25 20 15 2.77 10 2.76 5 0 0.02 0.04 0.06 0.08 0.10 IOUT (A) 0.12 0.14 0.16 0 08253-049 2.75 Figure 35. LDO Load Regulation Across Temperature, VIN3 = 3.3 V, VOUT3 = 2.8 V 0 2.5 2.5 2.0 2.0 VOUTA (V) 3.0 1.5 IOUT = 150mA IOUT = 100mA IOUT = 10mA IOUT = 1mA IOUT = 100µA 0 2.4 2.6 2.8 3.0 3.2 3.4 3.6 3.8 4.0 4.2 4.4 4.6 4.8 5.0 5.2 5.4 VIN (V) 0.06 0.08 0.10 LOAD CURRENT (A) 0.12 0.14 1.5 1.0 VIN = 3.6V VIN = 4.5V VIN = 5.5V 0.5 0 08253-045 0.5 0.04 Figure 38. LDO Ground Current vs. Output Load, VIN3 = 3.3 V, VOUT3 = 2.8 V 3.0 1.0 0.02 08253-044 2.84 VOUTC (V) 150mA 100mA 10mA 1mA 100µA 1µA 15 0 3.3 2.85 VOUTC (V) 25 5 08253-046 0.02 30 10 2.780 0 35 Figure 36. LDO Line Regulation Across Output Load, VOUT3 = 2.8 V 0 0.05 0.10 0.15 0.20 0.25 IOUT (A) 0.30 0.35 0.40 08253-030 VOUTC (V) 2.805 08253-043 GROUND CURRENT (µA) 2.810 Figure 39. LDO Current Capability Across Input Voltage, VOUT3 = 2.8 V Rev. A | Page 13 of 28 ADP5022 65 T 5VIN 60 IOUT 3.3VIN RMS NOISE (µV) 55 2 VOUT 1 50 45 40 35 CH2 100mA Ω BW BW M 40.0µs A CH2 52.0mA T 19.20% 25 0.001 08253-019 CH1 100mV Figure 40. LDO Response to Load Transient, IOUT3 from 1 mA to 80 mA, VOUT3 = 2.8 V 0.01 0.1 1 ILOAD (mA) 10 100 08253-048 30 Figure 43. LDO Output Noise vs. Load Current, Across Input Voltage, VOUT3 = 3.0 V 0 T –10 –20 VIN PSRR (dB) –30 VOUT 2 1 100µA 1mA 10mA 50mA 100mA 150mA –40 –50 –60 –70 –80 3 M 100µs BW BW A CH3 T 28.40% 4.80V 08253-014 CH1 20.0mV CH3 1.00V Figure 41. LDO Response to Line Transient, Input Voltage from 4.5 V to 5.5 V, VOUT3 = 2.8 V 100 1k 10k 100k FREQUENCY (Hz) 1M 10M 08253-050 –90 –100 10 Figure 44. LDO PSRR Across Output Load, VIN3 = 3.3 V, VOUT3 = 2.8 V 60 0 5VIN 55 –20 3.3VIN –40 45 PSRR (dB) 40 –80 35 100µA 1mA 10mA 50mA 100mA 150mA –100 0.01 0.1 1 ILOAD (mA) 10 100 08253-047 30 25 0.001 –60 –120 10 Figure 42. LDO Output Noise vs. Load Current, Across Input Voltage, VOUT3 = 2.8 V 100 1k 10k 100k FREQUENCY (Hz) 1M 10M 08253-051 RMS NOISE (µV) 50 Figure 45. LDO PSRR Across Output Load, VIN3 = 3.3 V, VOUT3 = 3.0 V Rev. A | Page 14 of 28 ADP5022 0 PSRR (dB) –40 –10 –20 –30 PSRR (dB) –20 0 100µA 1mA 10mA 50mA 100mA 150mA –60 –80 100µA 1mA 10mA 50mA 100mA 150mA –40 –50 –60 –70 –80 –100 1k 10k 100k FREQUENCY (Hz) 1M 10M 08253-053 100 –100 10 Figure 46. LDO PSRR Across Output Load, VIN3 = 5.0 V, VOUT3 = 2.8 V 100 1k 10k 100k FREQUENCY (Hz) 1M 10M 08253-052 –90 –120 10 Figure 47. LDO PSRR Across Output Load, VIN3 = 5.0 V, VOUT3 = 3.0 V Rev. A | Page 15 of 28 ADP5022 THEORY OF OPERATION VOUT1 VOUT2 GM ERROR AMP GM ERROR AMP PWM COMP PWM COMP VIN1 SOFT START SOFT START PSM COMP PSM COMP VIN2 ILIMIT LOW CURRENT ILIMIT PWM/ PSM CONTROL BUCK1 PWM/ PSM CONTROL BUCK2 LOW CURRENT SW2 SW1 OSCILLATOR DRIVER AND ANTISHOOT THROUGH DRIVER AND ANTISHOOT THROUGH SYSTEM UNDERVOLTAGE LOCK OUT THERMAL SHUTDOWN PGND1 PGND2 LDO UNDERVOLTAGE LOCK OUT EN1 EN2 R1 ENABLE CONTROL LDO CONTROL EN3 ADP5022 VDDA VIN3 AGND VOUT3 MODE 08253-003 R2 Figure 48. Functional Block Diagram POWER MANAGEMENT UNIT The ADP5022 is a micro power management units (micro PMU) combining two step-down (buck) dc-to-dc converters and a single low dropout linear regulator (LDO). The high switching frequency and tiny 16-ball WLCSP package allow for a small power management solution. To combine these high performance converters and regulators into the micro PMU, there is a system controller allowing them to operate together. Each regulator has a dedicated enable pin. EN1 controls the activation for Buck1, EN2 controls the activation for Buck2, and EN3 controls the activation of the LDO. Logic high applied to the ENx pin turns on the regulator, and a logic low applied to the ENx pin turns off the regulator. When a regulator is turned on, the output voltage is controlled through a soft start circuit to avoid a large inrush current due to the discharged output capacitors. The buck regulators can operate in forced PWM mode if the MODE pin is at a logic high level. In forced PWM mode, the switching frequency of the two bucks is always constant and does not change with the load current. If the MODE pin is at a logic low level, the switching regulators operate in an auto PWM/ PSM mode. In this mode, the regulators operate at fixed PWM frequency when the load current is above the power saving current threshold. When the load current falls below the power saving current threshold, the regulator in question enters power saving mode where the switching occurs in bursts. The burst repetition is a function of the current load and the output capacitor value. This operating mode reduces the switching and quiescent current losses. The auto PWM/PSM mode transition is controlled independently for each buck regulator. The two bucks operate synchronized to each other. Rev. A | Page 16 of 28 ADP5022 Thermal Protection PWM Mode In the event that the junction temperature rises above 150°C, the thermal shutdown circuit turns off the converters and the LDO. Extreme junction temperatures can be the result of high current operation, poor circuit board design, or high ambient temperature. A 20°C hysteresis is included so that when thermal shutdown occurs, the bucks and LDO do not return to operation until the on-chip temperature drops below 130°C. When coming out of thermal shutdown, soft start is initiated. In PWM mode, the bucks operate at a fixed frequency of 3 MHz set by an internal oscillator. At the start of each oscillator cycle, the PFET switch is turned on, sending a positive voltage across the inductor. Current in the inductor increases until the current sense signal crosses the peak inductor current threshold that turns off the PFET switch and turns on the NFET synchronous rectifier. This sends a negative voltage across the inductor, causing the inductor current to decrease. The synchronous rectifier stays on for the rest of the cycle. The buck regulates the output voltage by adjusting the peak inductor current threshold. Undervoltage Lockout To protect against battery discharge, undervoltage lockout (UVLO) circuitry is integrated in the system. If the input voltage on VDDA drops below a typical 2.15 V UVLO threshold, all channels shut down. In the buck channels, both the power switch and the synchronous rectifier turn off. When the voltage on VDDA rises above the UVLO threshold, the part is enabled once more. Power Save Mode (PSM) Alternatively, the user can select device models with a UVLO set at a higher level, suitable for USB applications. For these models, the device hits the turn-off threshold when the input supply drops to 3.65 V typical. Enable/Shutdown When all three enable pins are held low, the device is in shutdown mode, and the input current remains below 2 μA. The bucks smoothly transition to PSM operation when the load current decreases below the PSM current threshold. When either of the bucks enter power save mode, an offset is induced in the PWM regulation level, which makes the output voltage rise. When the output voltage reaches a level approximately 1.5% above the PWM regulation level, PWM operation is turned off. At this point, both power switches are off, and the buck enters an idle mode. The output capacitor discharges until the output voltage falls to the PWM regulation voltage, at which point the device drives the inductor to make the output voltage rise again to the upper threshold. This process is repeated while the load current is below the PSM current threshold. PSM Current Threshold BUCK SECTION The two bucks use a fixed frequency and high speed current mode architecture. The bucks operate with an input voltage of 2.4 V to 5.5 V. Control Scheme The bucks operate with a fixed frequency, current mode PWM control architecture at medium to high loads for high efficiency but shift to a power save mode (PSM) control scheme at light loads to lower the regulation power losses. When operating in fixed frequency PWM mode, the duty cycle of the integrated switches is adjusted and regulates the output voltage. When operating in PSM at light loads, the output voltage is controlled in a hysteretic manner, with higher output voltage ripple. During part of this time, the converter is able to stop switching and enters an idle mode, which improves conversion efficiency. The PSM current threshold is set to 100 mA. The bucks employ a scheme that enables this current to remain accurately controlled, independent of input and output voltage levels. This scheme also ensures that there is very little hysteresis between the PSM current threshold for entry to and exit from the PSM. The PSM current threshold is optimized for excellent efficiency over all load currents. Oscillator/Phasing of Inductor Switching The ADP5022 ensures that both bucks operate at the same switching frequency when both bucks are in PWM mode. Additionally, the ADP5022 ensures that when both bucks are in PWM mode, they operate out-of-phase, whereby the Buck2 PFET starts conducting exactly half a clock period after the Buck1 PFET starts conducting. Rev. A | Page 17 of 28 ADP5022 Enable/Shutdown LDO SECTION The bucks start operation with soft start when the EN1 or EN2 pin is toggled from logic low to logic high. Pulling the EN1 or EN2 pin low disables that channel. The LDO is a low quiescent current, low dropout linear regulator and provides up to 150 mA of output current. Drawing a low 30 μA quiescent current (typical) at full load makes the LDO ideal for battery-operated portable equipment. Short-Circuit Protection The bucks include frequency foldback to prevent output current runaway on a hard short. When the voltage at the feedback pin falls below half the target output voltage, indicating the possibility of a hard short at the output, the switching frequency is reduced to half the internal oscillator frequency. The reduction in the switching frequency allows more time for the inductor to discharge, preventing a runaway of output current. Soft Start The bucks have an internal soft start function that ramps the output voltage in a controlled manner upon startup, thereby limiting the inrush current. This prevents possible input voltage drops when a battery or a high impedance power source is connected to the input of the converter. Current Limit Each buck has protection circuitry to limit the amount of positive current flowing through the PFET switch and the amount of negative current flowing through the synchronous rectifier. The positive current limit on the power switch limits the amount of current that can flow from the input to the output. The negative current limit prevents the inductor current from reversing direction and flowing out of the load. 100% Duty Operation The LDO operates with an input voltage of 2.3 V to 5.5 V. It also provides high power supply rejection ratio (PSRR), low output noise, and excellent line and load transient response with just a small 1 μF ceramic input and output capacitor. Internally, the LDO consists of a reference, an error amplifier, a feedback voltage divider, and a PMOS pass transistor. Output current is delivered via the PMOS pass device, which is controlled by the error amplifier. The error amplifier compares the reference voltage with the feedback voltage from the output and amplifies the difference. If the feedback voltage is lower than the reference voltage, the gate of the PMOS device is pulled lower, allowing more current to flow and increasing the output voltage. If the feedback voltage is higher than the reference voltage, the gate of the PMOS device is pulled higher, reducing the current flowing to the output. LDO Undervoltage Lockout The ADP5022 integrates an undervoltage lockout function on the VIN3 input voltage, which ensures that the LDO output drive is disabled whenever VIN3 is below a threshold of approximately 2.0 V. Where the ADP5022 is configured to supply VIN3 from either VOUT1 or VOUT2, this ensures that the LDO powers up safely in this cascaded configuration. With a drop in input voltage or with an increase in load current, the buck may reach a limit where, even with the PFET switch on 100% of the time, the output voltage drops below the desired output voltage. At this limit, the buck transitions to a mode where the PFET switch stays on 100% of the time. When the input conditions change again and the required duty cycle falls, the buck immediately restarts PWM regulation without allowing overshoot on the output voltage. This is particularly useful in battery-powered applications to achieve the longest operation time by taking full advantage of the whole battery voltage range. Maintaining regulation is dependent on the input voltage, load current, and output voltage. This can be calculated from the following equation: VIN(MIN) = VOUT(MAX) + ILOAD(MAX) × (RDS(on)MAX + RL) where: VOUT(MAX) is the nominal output voltage plus the maximum tolerance. ILOAD(MAX) is the maximum load current plus inductor ripple current. RDS(on)MAX is the maximum P-channel switch RDS(on). RL is the DC resistance of the inductor. Rev. A | Page 18 of 28 ADP5022 APPLICATIONS INFORMATION BUCK EXTERNAL COMPONENT SELECTION Output Capacitor Trade-offs between performance parameters such as efficiency and transient response can be made by varying the choice of external components in the applications circuit, as shown in Figure 1. Higher output capacitor values reduce the output voltage ripple and improve load transient response. When choosing this value, it is also important to account for the loss of capacitance due to output voltage dc bias. Inductor Ceramic capacitors are manufactured with a variety of dielectrics, each with a different behavior over temperature and applied voltage. Capacitors must have a dielectric adequate to ensure the minimum capacitance over the necessary temperature range and dc bias conditions. X5R or X7R dielectrics with a voltage rating of 6.3 V or 10 V are recommended for best performance. Y5V and Z5U dielectrics are not recommended for use with any dc-to-dc converter because of their poor temperature and dc bias characteristics. The high switching frequency of the ADP5022 bucks allows for the selection of small chip inductors. For best performance, use inductor values between 0.7 μH and 3 μH. Suggested inductors are shown in Table 7. The peak-to-peak inductor current ripple is calculated using the following equation: VOUT × (VIN − VOUT ) VIN × f SW × L The worst-case capacitance accounting for capacitor variation over temperature, component tolerance, and voltage is calculated using the following equation: where: fSW is the switching frequency. L is the inductor value. CEFF = COUT × (1 − TEMPCO) × (1 − TOL) The minimum dc current rating of the inductor must be greater than the inductor peak current. The inductor peak current is calculated using the following equation: I PEAK = I LOAD( MAX ) + I RIPPLE 2 Inductor conduction losses are caused by the flow of current through the inductor, which has an associated internal dc resistance (DCR). Larger sized inductors have smaller DCR, which may decrease inductor conduction losses. Inductor core losses are related to the magnetic permeability of the core material. Because the bucks are high switching frequency dc-to-dc converters, shielded ferrite core material is recommended for its low core losses and low EMI. where: CEFF is the effective capacitance at the operating voltage. TEMPCO is the worst-case capacitor temperature coefficient. TOL is the worst-case component tolerance. In this example, the worst-case temperature coefficient (TEMPCO) over −40°C to +85°C is assumed to be 15% for an X5R dielectric. The tolerance of the capacitor (TOL) is assumed to be 10%, and COUT is 9.2481 μF at 1.8 V, as shown in Figure 49. Substituting these values in the equation yields CEFF = 9.2481 μF × (1 − 0.15) × (1 − 0.1) = 7.0747 μF To guarantee the performance of the bucks, it is imperative that the effects of dc bias, temperature, and tolerances on the behavior of the capacitors be evaluated for each application. Table 7. Suggested 1.0 μH Inductors Model LQM2MPN1R0NG0B LQM18FN1R0M00B CBMF1608T1R0M EPL2014-102ML GLFR1608T1R0M-LR 0603LS-102 MDT2520-CN 12 ISAT (mA) 1400 150 290 900 230 400 1350 DCR (mΩ) 85 26 90 59 80 81 85 10 CAPACITANCE (µF) Vendor Murata Murata Taiyo Yuden Coilcraft TDK Coilcraft Toko Dimensions (mm) 2.0 × 1.6 × 0.9 1.6 × 0.8 × 0.8 1.6 × 0.8 × 0.8 2.0 × 2.0 × 1.4 1.6 × 0.8 × 0.8 1.8 × 1.69 × 1.1 2.5 × 2.0 × 1.2 8 6 4 2 0 0 1 2 3 4 5 DC BIAS VOLTAGE (V) Figure 49. Typical Capacitor Performance Rev. A | Page 19 of 28 6 08253-004 I RIPPLE = ADP5022 Input Capacitor The peak-to-peak output voltage ripple for the selected output capacitor and inductor values is calculated using the following equation: VRIPPLE = Higher value input capacitors help to reduce the input voltage ripple and improve transient response. Maximum input capacitor current is calculated using the following equation: I RIPPLE V IN = (2π × f SW ) × 2 × L × C OUT 8 × f SW × C OUT I CIN ≥ I LOAD ( MAX ) Capacitors with lower equivalent series resistance (ESR) are preferred to guarantee low output voltage ripple, as shown in the following equation: ESRCOUT ≤ VOUT (VIN − VOUT ) VIN To minimize supply noise, place the input capacitor as close to the VIN pin of the BUCK as possible. As with the output capacitor, a low ESR capacitor is recommended. VRIPPLE I RIPPLE The effective capacitance needed for stability, which includes temperature and dc bias effects, is a minimum of 7 μF and a maximum of 40 μF. The effective capacitance needed for stability, which includes temperature and dc bias effects, is a minimum of 3 μF and a maximum of 10 μF. A list of suggested capacitors is shown in Table 9. Table 8. Suggested 10 μF Capacitors Table 9. Suggested 4.7 μF Capacitors Vendor Murata Taiyo Yuden TDK Panasonic Type X5R X5R X5R X5R Model GRM188R60J106 JMK107BJ475 C1608JB0J106K ECJ1VB0J106M Case Size 0603 0603 0603 0603 Voltage Rating (V) 6.3 6.3 6.3 6.3 The buck regulators require 10 μF output capacitors to guarantee stability and response to rapid load variations and to transition in and out the PWM/PSM modes. In certain applications, where one or both buck regulator powers a processor, the operating state is known because it is controlled by software. In this condition, the processor can drive the MODE pin according to the operating state; consequently, it is possible to reduce the output capacitor from 10 μF to 4.7 μF because the regulator does not expect a large load variation when working in PSM mode, see Figure 50. ACTIVATION INPUTS ALWAYS ON VDDA VCORE C4 4.7µF MODE VIN3 C1 1µF PROCESSOR SW2 GPIO PGND2 VIO C5 4.7µF ANALOG SUB-SYSTEM EN2 C6 1µF LDO CAPACITOR SELECTION Output Capacitor The ADP5022 LDO is designed for operation with small, spacesaving ceramic capacitors but functions with most commonly used capacitors as long as care is taken with the ESR value. The ESR of the output capacitor affects stability of the LDO control loop. A minimum of 0.70 μF capacitance with an ESR of 1 Ω or less is recommended to ensure stability of the ADP5022. Transient response to changes in load current is also affected by output capacitance. Using a larger value of output capacitance improves the transient response of the ADP5022 to large changes in load current. Table 10. Suggested 1.0 μF Capacitors EN1 VOUT3 Model GRM188R60J475ME19D JMK107BJ475 ECJ-0EB0J475M Connecting a 1 μF capacitor from VIN3 to GND reduces the circuit sensitivity to printed circuit board (PCB) layout, especially when long input traces or high source impedance are encountered. If greater than 1 μF of output capacitance is required, increase the input capacitor to match it. L2 1µH VOUT2 Type X5R X5R X5R Voltage Rating (V) 6.3 6.3 6.3 Input Bypass Capacitor VANA 08253-005 VIN 2.5V TO 5.5V ADP5022 L1 1µH C2 MICRO PMU SW1 VIN1 4.7µF VOUT1 VIN2 PGND1 C3 4.7µF Vendor Murata Taiyo Yuden Panasonic Case Size 0402 0402 0402 EN3 Figure 50. Processor System Power Management with PSM/PWM Control Vendor Murata TDK Panasonic Taiyo Yuden Rev. A | Page 20 of 28 Type X5R X5R X5R X5R Model GRM155B30J105K C1005JB0J105KT ECJ0EB0J105K LMK105BJ105MV-F Case Size 0402 0402 0402 0402 Voltage Rating (V) 6.3 6.3 6.3 10.0 ADP5022 Input and Output Capacitor Properties Use any good quality ceramic capacitors with the ADP5022 as long as they meet the minimum capacitance and maximum ESR requirements. Ceramic capacitors are manufactured with a variety of dielectrics, each with a different behavior over temperature and applied voltage. Capacitors must have a dielectric adequate to ensure the minimum capacitance over the necessary temperature range and dc bias conditions. X5R or X7R dielectrics with a voltage rating of 6.3 V or 10 V are recommended for best performance. Y5V and Z5U dielectrics are not recommended for use with any LDO because of their poor temperature and dc bias characteristics. Figure 51 depicts the capacitance vs. voltage bias characteristic of a 0402 1 μF, 10 V, X5R capacitor. The voltage stability of a capacitor is strongly influenced by the capacitor size and voltage rating. In general, a capacitor in a larger package or higher voltage rating exhibits better stability. The temperature variation of the X5R dielectric is about ±15% over the −40°C to +85°C temperature range and is not a function of package or voltage rating. 1.2 CEFF = CBIAS × (1 − TEMPCO) × (1 − TOL) where: CBIAS is the effective capacitance at the operating voltage. TEMPCO is the worst-case capacitor temperature coefficient. TOL is the worst-case component tolerance. In this example, the worst-case temperature coefficient (TEMPCO) over −40°C to +85°C is assumed to be 15% for an X5R dielectric. The tolerance of the capacitor (TOL) is assumed to be 10% and CBIAS is 0.94 μF at 1.8 V as shown in Figure 51. Substituting these values into the following equation. CEFF = 0.94 μF × (1 − 0.15) × (1 − 0.1) = 0.719 μF Therefore, the capacitor chosen in this example meets the minimum capacitance requirement of the LDO over temperature and tolerance at the chosen output voltage. To guarantee the performance of the ADP5022, it is imperative that the effects of dc bias, temperature, and tolerances on the behavior of the capacitors are evaluated for each application. 0.8 0.6 0.4 0.2 0 0 1 2 3 4 DC BIAS VOLTAGE (V) 5 6 08253-006 CAPACITANCE (µF) 1.0 Use the following equation to determine the worst-case capacitance accounting for capacitor variation over temperature, component tolerance, and voltage. Figure 51. Capacitance vs. Voltage Characteristic Rev. A | Page 21 of 28 ADP5022 PCB LAYOUT GUIDELINES Poor layout can affect ADP5022 performance, causing electromagnetic interference (EMI) and electromagnetic compatibility (EMC) problems, ground bounce, and voltage losses. Poor layout can also affect regulation and stability. A good layout is implemented using the following guidelines: • • • • Place the inductor, input capacitor, and output capacitor close to the IC using short tracks. These components carry high switching frequencies, and large tracks act as antennas. Rev. A | Page 22 of 28 Route the output voltage path away from the inductor and SW node to minimize noise and magnetic interference. Maximize the size of ground metal on the component side to help with thermal dissipation. Use a ground plane with several vias connecting to the component side ground to further reduce noise interference on sensitive circuit nodes. ADP5022 EVALUATION BOARD SCHEMATICS AND ARTWORK C2 0603 4.7µF J2 B1 C3 0603 4.7µF J3 C1 0402 1µF J4 R1 0Ω B4 A4 A3 A2 C3 B2 J5 B3 C2 J7 J6 VIN1 VIN2 SW1 BUCK1 VDDA VOUT1 PGND1 C1 L1 1µH J8 COUT_1 0603 10µF D2 D1 J9 VIN3 AGND SW2 MODE EN1 BUCK2 PGND2 EN2 EN3 VOUT2 LDO VOUT3 C4 L2 1µH D3 D4 COUT_3 0402 1µF Figure 52. Evaluation Board Schematic 08253-008 SUGGESTED LAYOUT 08253-009 Figure 53. Top Layer, Recommended Layout Figure 54. Second Layer, Recommended Layout J13 J12 A1 R2 0Ω Rev. A | Page 23 of 28 J10 COUT_2 0603 10µF J11 08253-007 J1 08253-010 ADP5022 08253-011 Figure 55. Third Layer, Recommended Layout Figure 56. Bottom Layer, Recommended Layout Rev. A | Page 24 of 28 ADP5022 OUTLINE DIMENSIONS 0.660 0.602 0.544 2.12 2.08 SQ 2.04 0.022 REF SEATING PLANE 4 3 2 1 A BALL 1 IDENTIFIER 0.330 0.310 0.290 B 1.50 REF C D 0.50 REF 0.04 NOM COPLANARITY BOTTOM VIEW (BALL SIDE UP) 0.280 0.250 0.220 013009-B 0.380 0.352 0.324 TOP VIEW (BALL SIDE DOWN) Figure 57. 16-Ball Wafer Level Chip Scale Package [WLCSP] Back-Coating Included (CB-16-7) Dimensions shown in millimeters ORDERING GUIDE Model ADP5022ACBZ-1-R72 ADP5022ACBZ-2-R72 ADP5022ACBZ-4-R72 1 Output Voltage (V)1 VOUT1 = 3.3 V VOUT2 = 1.5 V VOUT3 = 1.8 V VOUT1 = 1.2 V VOUT2 = 1.8 V VOUT3 = 2.8 V VOUT1 = 3.3 V VOUT2 = 1.8 V VOUT3 = 3.3 V Undervoltage Lockout Level Low Temperature Range −40°C to +125°C Package Description 16-Ball Wafer Level Chip Scale Package [WLCSP] Package Option CB-16-7 Branding Code L9H Low −40°C to +125°C 16-Ball Wafer Level Chip Scale Package [WLCSP] CB-16-7 L9J High −40°C to +125°C 16-Ball Wafer Level Chip Scale Package [WLCSP] CB-16-7 LG7 For additional voltage options, contact a local sales or distribution representative. Additional output voltages and UVLO available are Buck1 and Buck2: 3.3 V, 3.0 V, 2.8 V, 2.5 V, 2.3 V, 2.0 V, 1.82 V, 1.8 V, 1.6 V, 1.5 V, 1.3 V, 1.2 V, 1.1 V, 1.0 V, 0.9 V, 0.8 V LDO: 3.3 V, 3.0 V, 2.9 V, 2.8 V, 2.775 V, 2.5 V, 2.0 V, 1.875 V, 1.8 V, 1.75 V, 1.7 V, 1.65 V, 1.6 V, 1.55 V, 1.5 V, 1.2 V UVLO: 2.25 V or 3.9 V 2 Z = RoHS Compliant Part. Rev. A | Page 25 of 28 ADP5022 NOTES Rev. A | Page 26 of 28 ADP5022 NOTES Rev. A | Page 27 of 28 ADP5022 NOTES ©2009 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. D08253-0-11/09(A) Rev. A | Page 28 of 28