Micro PMU with 0.8 A Buck, Two 300 mA LDOs Supervisory, Watchdog and Manual Reset ADP5042 HIGH LEVEL BLOCK DIAGRAM AVIN AVIN VIN1 = 2.3V TO 5.5V VIN1 BUCK C1 1µF EN2 MR ON EN3 FPWM PSM/PWM LDO1 (DIGITAL) WSTAT AVIN EN_LDO2 VIN3 VOUT1 AT 800mA C6 10µF VOUT2 EN_LDO1 ON OFF MODE EN1 VIN2 C3 1µF VOUT1 EN_BK ON OFF VIN3 = 1.7V TO 5.5V L1 1µH PGND C5 4.7µF OFF VIN2 = 1.7V TO 5.5V SW LDO2 (ANALOG) nRSTO WDI1 WDI2 VOUT2 AT 300mA C2 1µF VOUT3 VOUT3 AT 300mA C4 1µF AGND 08811-001 RFILT = 30Ω SUPERVISOR Input voltage range: 2.3 V to 5.5 V One 0.8 A buck regulator Two 300 mA LDOs 20-lead, 4 mm × 4 mm LFCSP package Initial regulator accuracy: ±1% Overcurrent and thermal protection Soft start Undervoltage lockout Open drain processor reset with threshold monitoring ±1.5% threshold accuracy over the full temperate range Guaranteed reset output valid to VCC = 1 V Dual watchdog for secure systems Watchdog 1 controls reset Watchdog 2 controls reset and regulators power cycle Buck key specifications Current mode topology for excellent transient response 3 MHz operating frequency Uses tiny multilayer inductors and capacitors Mode pin selects forced PWM or auto PFM/PSM modes 100% duty cycle low dropout mode LDOs key specifications Low VIN from 1.7 V to 5.5 V Stable with1 μF ceramic output capacitors High PSRR, 60 dB PSRR up to 1 kHz/10 kHz Low output noise 110 μV rms typical output noise at VOUT = 2.8 V Low dropout voltage: 150 mV at 300 mA load −40°C to +125°C junction temperature range MICROPROCESSOR FEATURES Figure 1. GENERAL DESCRIPTION The ADP5042 combines one high performance buck regulator and two low dropout regulators (LDO) in a small 20-lead LFCSP to meet demanding performance and board space requirements. The high switching frequency of the buck regulator enables use of tiny multilayer external components and minimizes the board space. The MODE pin selects the buck mode of operation. When set to logic high, the buck regulators operate in forced PWM mode. When the MODE pin is set to logic low, the buck regulators operate in PWM mode when the load is around the nominal value. When the load current falls below a predefined threshold the regulator operates in power save mode (PSM) improving the light-load efficiency. The low quiescent current, low dropout voltage, and wide input voltage range of the ADP5042 LDOs extend the battery life of portable devices. The two LDOs maintain power supply rejection greater than 60 dB for frequencies as high as 10 kHz while operating with a low headroom voltage. Each regulator is activated by a high level on the respective enable pin. The ADP5042 is available with factory programmable default output voltages and can be set to a wide range of options. The ADP5042 contains supervisory circuits that monitor power supply voltage levels and code execution integrity in microprocessor-based systems. They also provide power-on reset signals. An on-chip dual watchdog timer can reset the microprocessor or power cycle the system (Watchdog 2) if it fails to strobe within a preset timeout period. Rev. 0 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 ©2010 Analog Devices, Inc. All rights reserved. ADP5042 TABLE OF CONTENTS Features .............................................................................................. 1 Buck Section................................................................................ 19 High Level Block Diagram .............................................................. 1 LDO Section ............................................................................... 20 General Description ......................................................................... 1 Supervisory Section ................................................................... 20 Revision History ............................................................................... 2 Applications Information .............................................................. 23 Specifications..................................................................................... 3 Buck External Component Selection....................................... 23 General Specification ................................................................... 3 LDO Capacitor Selection .......................................................... 24 Supervisory Specification ............................................................ 3 Supervisory Section ................................................................... 25 Buck Specifications....................................................................... 5 PCB Layout Guidelines.............................................................. 26 LDO1, LDO2 Specifications ....................................................... 5 Evaluation Board Schematics and Artwork ............................ 27 Input and Output Capacitor, Recommended Specifications .. 6 Suggested Layout ........................................................................ 27 Absolute Maximum Ratings............................................................ 7 Bill of Materials ........................................................................... 28 Thermal Resistance ...................................................................... 7 Application Diagram ................................................................. 28 ESD Caution .................................................................................. 7 Factory Programmable Options ................................................... 29 Pin Configuration and Function Descriptions ............................. 8 Outline Dimensions ....................................................................... 30 Theory of Operation ...................................................................... 18 Ordering Guide .......................................................................... 30 Power Management Unit ........................................................... 18 REVISION HISTORY 12/10—Revision 0: Initial Version Rev. 0 | Page 2 of 32 ADP5042 SPECIFICATIONS GENERAL SPECIFICATION AVIN, VIN1 = (VOUT1+ 0.5 V) or 2.3 V, whichever is greater, AVIN, VIN1 ≥ VIN2, VIN3, TA = 25°C, unless otherwise noted. Regulators are enabled. Table 1. Parameter AVIN UNDERVOLTAGE LOCKOUT Input Voltage Rising Input Voltage Falling SHUTDOWN CURRENT Symbol UVLOAVIN UVLOAVINRISE UVLOAVINFALL IGND-SD Description TJ = −40°C to +125°C Min Thermal Shutdown Threshold Thermal Shutdown Hysteresis ENx, WDIx, MODE, WMOD, MR INPUTS Input Logic High Input Logic Low Input Leakage Current (WMOD Excluded) TSSD TSSD-HYS VIH VIL VI-LEAKAGE 2.5 V ≤ AVIN ≤ 5.5 V 2.5 V ≤ AVIN ≤ 5.5 V ENx = AVIN or GND WMOD Input Leakage Current OPEN-DRAIN OUTPUTS nRSTO, WSTAT Output Voltage Open-Drain Reset Output Leakage Current VI-LKG-WMOD ENx = AVIN or GND, TJ = −40°C to +125°C VWMOD = 3.6 V, TJ = −40°C to +125°C VOL AVIN = 2.3 V to 5.5 V, InRSTO/WSTAT = 3 mA Typ Max Unit 2.25 V V μA μA °C °C 1.95 ENx = GND ENx = GND, TJ = −40°C to +125°C TJ rising 0.1 2 150 20 1.2 0.4 V V μA 1 50 μA μA 1 mV μA 0.05 30 SUPERVISORY SPECIFICATION AVIN, VIN1 = full operating range, TJ = −40°C to +125°C, unless otherwise noted. Table 2. Parameter SUPPLY Supply Current (Supervisory Circuit Only) Min Typ Max Unit Test Conditions/Comments RESET THRESHOLD ACCURACY VTH − 0.8% VTH − 1.5% 45 43 VTH VTH 55 52 VTH + 0.8% VTH + 1.5% μA μA V V RESET THRESHOLD TO OUTPUT DELAY GLITCH IMMUNITY (tUOD) RESET TIMEOUT PERIOD WATCHDOG1 (tRP1) Option A Option B RESET TIMEOUT PERIOD WATCHDOG2 (tRP2) 50 125 400 μs AVIN = 5.5 V, EN1 = EN2 = EN3 = VIN AVIN = 3.6 V, EN1 = EN2 = EN3 = VIN TA = 25°C, sensed on VOUTx TJ = −40°C to +125°C, sensed on VOUTx VTH = VUOT − 50 mV 24 160 30 200 36 240 ms ms 3.5 5 150 2 7 ms μs ms 102 1.6 122.4 1.92 VCC TO RESET DELAY (tRD) REGULATORS SEQUENCING DELAY (tD1, tD2) WATCHDOG INPUTS Watchdog 1 Timeout Period (tWD1) Option A Option B 81.6 1.28 Rev. 0 | Page 3 of 32 ms sec VIN1 falling at 1 mV/μs ADP5042 Parameter Watchdog 2 Timeout Period (tWD2) Option A Option B Option C Option D Option E Option F Option G Option H Watchdog 2 Power Off Period (tPOFF) Option A Option B WDI1 Pulse Width WDI2 Pulse Width Watchdog Status Timeout Period (tWDCLEAR) WDI1 Input Current (Source) WDI1 Input Current (Sink) WDI2 Internal Pull-Down MANUAL RESET INPUT MR Input Pulse Width MR Glitch Rejection MR Pull-Up Resistance MR to Reset Delay Min 6 3.2 6.4 11.2 25.6 51.2 102.4 Typ Max 7.5 9 Watchdog 2 disabled 4 4.8 8 9.6 16 19.2 32 38.4 64 76.8 128 153.8 210 400 80 8 8 −30 11.2 15 −25 45 20 −14 1 25 220 52 280 Rev. 0 | Page 4 of 32 80 Unit Test Conditions/Comments sec min min min min min min ms ms ns µs sec µA µA kΩ µs ns kΩ ns VIL = 0.4 V, VIH = 1.2 V VIL = 0.4 V, VIH = 1.2 V VWDI1 = VCC, time average VWDI1 = 0, time average VCC = 5 V ADP5042 BUCK SPECIFICATIONS AVIN, VIN1 = 3.6 V, VOUT1 = 1.8 V, TJ= −40°C to +125°C for minimum/maximum specifications, L = 1 µH, COUT = 10 µF, and TA = 25°C for typical specifications, unless otherwise noted. 1 Table 3. Parameter INPUT CHARACTERISTICS Input Voltage Range (VIN1) OUTPUT CHARACTERISTICS Output Voltage Accuracy Test Conditions/Comments PWM mode, TA= 25 °C , ILOAD = 100 mA PWM mode VIN1 = 2.3 V to 5.5 V, PWM mode, ILOAD = 1 to 800 mA PWM TO POWER SAVE MODE CURRENT THRESHOLD INPUT CURRENT CHARACTERISTICS DC Operating Current Shutdown Current SW CHARACTERISTICS SW On Resistance Current Limit ACTIVE PULL-DOWN OSCILLATOR FREQUENCY START-UP TIME 1 Min Typ Max Unit 2.3 5.5 V −1 −2 −3 +1 +2 +3 % % % 100 mA ILOAD = 0 mA, device not switching ENx = 0 V, TA = TJ = −40°C to +125°C 21 0.2 35 1.0 μA μA PFET PFET, AVIN = VIN1 = 5 V NFET NFET, AVIN = VIN1 = 5 V PFET switch peak current limit EN1 = 0 V 180 140 170 150 1360 75 3.0 250 240 190 235 210 1600 mΩ mΩ mΩ mΩ mA Ω MHz μs 1100 2.5 3.5 All limits at temperature extremes are guaranteed via correlation using standard statistical quality control (SQC). LDO1, LDO2 SPECIFICATIONS AVIN = 3.6 V, VIN2, VIN3 = (VOUT3 + 0.2 V) or 2.3 V, whichever is greater; AVIN, VIN1 ≥ VIN2, VIN3; IOUT = 10 mA; CIN = COUT = 1 µF; TA = 25°C, unless otherwise noted. Table 4. Parameter INPUT VOLTAGE RANGE OPERATING SUPPLY CURRENT (per LDO) FIXED OUTPUT VOLTAGE ACCURACY REGULATION Line Regulation Symbol VIN2, VIN3 IGND Conditions TJ = −40°C to +125°C IOUT = 0 µA, VOUT = 3.3 V VOUT2, VOUT3 IOUT = 0 µA, VOUT = 3.3 V, TJ = −40°C to +125°C IOUT = 10 mA IOUT = 10 mA, TJ = −40°C to +125°C IOUT = 200 mA IOUT = 200 mA, TJ = −40°C to +125°C IOUT = 10 mA 100 µA < IOUT < 300 mA VIN2, VIN3 = (VOUT2, VOUT3 + 0.5 V) to 5.5 V 100 µA < IOUT < 300 mA VIN2, VIN3 = (VOUT2, VOUT3 + 0.5 V) to 5.5 V TJ = −40°C to +125°C ∆VOUT2/∆VIN2 ∆VOUT3/∆VIN3 VIN2, VIN3 = (VOUT2, VOUT3 + 0.5 V) to 5.5 V IOUT3 = 1 mA TJ = −40°C to +125°C Rev. 0 | Page 5 of 32 Min 1.7 Typ Max 5.5 Unit V µA 50 15 −1 −2 245 +1 +2 µA µA µA µA µA % % −3 +3 % −0.03 +0.03 %/ V 67 105 100 ADP5042 Parameter Load Regulation1 DROPOUT VOLTAGE2 ACTIVE PULL-DOWN START-UP TIME CURRENT-LIMIT THRESHOLD3 OUTPUT NOISE Symbol ∆VOUT2/∆IOUT2 ∆VOUT3/∆IOUT3 VDROPOUT RPDLDO TSTART-UP ILIMIT OUTLDO2NOISE OUTLDO1NOISE POWER SUPPLY REJECTION RATIO PSRR Conditions IOUT2, VOUT3 = 1 mA to 200 mA IOUT2, VOUT3 = 1 mA to 200 mA TJ = −40°C to +125°C VOUT2, VOUT3 = 3.3 V IOUT2, IOUT3 = 10 mA IOUT2, IOUT3 = 10 mA, TJ = −40°C to +125°C IOUT2, IOUT3 = 200 mA IOUT2, IOUT3 = 200 mA, TJ = −40°C to +125°C EN2/EN3 = 0 V VOUT2, VOUT3 = 3.3 V TJ = −40°C to +125°C 10 Hz to 100 kHz, VIN3 = 5 V, VOUT3 = 3.3 V 10 Hz to 100 kHz, VIN3 = 5 V, VOUT3 = 2.8 V 10 Hz to 100 kHz, VIN3 = 5 V, VOUT3 = 1.5 V 10 Hz to 100 kHz, VIN2 = 5 V, VOUT2 = 3.3 V 10 Hz to 100 kHz, VIN2 = 5 V, VOUT2 = 2.8 V 10 Hz to 100 kHz, VIN2 = 5 V, VOUT2 = 1.5 V 1 kHz, VIN2, VIN3 = 3.3 V, VOUT2, OUT3 = 2.8 V, IOUT = 100 mA 100 kHz, VIN2, VIN3 = 3.3 V, VOUT2, VOUT3 = 2.8 V, IOUT = 100 mA 1 MHz, VIN2, VIN3 = 3.3 V, VOUT2, VOUT3 = 2.8 V, IOUT = 100 mA Min Typ 0.002 Max Unit %/mA 0.0075 %/mA 4 5 60 100 335 600 85 470 123 110 59 140 129 66 66 mV mV mV mV Ω μs mA μV rms μV rms μV rms μV rms μV rms μV rms dB 57 dB 60 dB 1 Based on an end-point calculation using 1 mA and 100 mA loads. 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. 3 Current-limit threshold is defined as the current at which the output voltage 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 INPUT AND OUTPUT CAPACITOR, RECOMMENDED SPECIFICATIONS Table 5. Parameter MINIMUM OUTPUT CAPACITANCE (BUCK)1 MINIMUM INPUT AND OUTPUT CAPACITANCE2 (LDO1, LDO2) CAPACITOR ESR Symbol CMIN1 CMIN23 RESR Conditions TJ = −40°C to +125°C TJ = −40°C to +125°C TJ = −40°C to +125°C 1 Min 7 0.70 0.001 Typ Max 40 1 Unit μF μF Ω The minimum output capacitance should be greater than 4.7 μF over the full range of operating conditions. The full range of operating conditions in the application must be considered during device selection to ensure that the minimum capacitance specification is met. 2 The minimum input and output capacitance should be greater than 0.70 μF over the full range of operating conditions. The full range of operating conditions in the application must be considered during device selection to ensure that the minimum capacitance specification is met. X7R and X5R type capacitors are recommended, Y5V and Z5U capacitors are not recommended for use with LDOs or the buck. Rev. 0 | Page 6 of 32 ADP5042 ABSOLUTE MAXIMUM RATINGS Table 6. Parameter AVIN, VINx, VOUTx, ENx, MODE, MR, WDIx, WMOD, WSTAT, nRSTO to GND Storage Temperature Range Operating Junction Temperature Range Soldering Conditions ESD Human Body Model ESD Charged Device Model ESD Machine Model Rating −0.3 V to +6 V −65°C to +150°C −40°C to +125°C JEDEC J-STD-020 3000 V 1500 V 100 V Stresses above those listed under absolute maximum ratings may cause permanent damage to the device. This is a stress rating only and 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. THERMAL DATA Absolute maximum ratings apply individually only, not in combination. Junction-to-ambient thermal resistance (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 JAθ may vary, depending on PCB material, layout, and environmental conditions. The specified value of θJA is based on a four-layer, 4” × 3”, 2.5 oz copper board, as per JEDEC standard. For additional information, see the AN-772 Application Note, A Design and Manufacturing Guide for the Lead Frame Chip Scale (LFCSP). THERMAL RESISTANCE θJA is specified for the worst-case conditions, that is, a device soldered in a circuit board for surface-mount packages. Table 7. Thermal Resistance Package Type 20-Lead, 0.5 mm pitch LFCSP ESD CAUTION The ADP5042 can be damaged when the junction temperature limits are exceeded. Monitoring ambient temperature does not guarantee that the junction temperature 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 can exceed the maximum limit as long as the junction temperature is within specification limits. The junction temperature of the device is dependent on the ambient temperature, the power dissipation of the device (PD), and the junction-to-ambient thermal resistance of the package. Maximum junction temperature is calculated from the ambient temperature and power dissipation using the formula TJ = TA + (PD × θJA) Rev. 0 | Page 7 of 32 θJA 38 θJC 4.2 Unit °C/W ADP5042 20 19 18 17 16 MR WDI1 WMOD MODE EN2 PIN CONFIGURATION AND FUNCTION DESCRIPTIONS 1 2 3 4 5 AD5042 TOP VIEW 15 14 13 12 11 WSTAT VOUT2 VIN2 WDI2 VOUT1 NOTES 1. EXPOSED PAD SHOULD BE CONNECTED TO AGND. 2. NC = NO CONNECT. DO NOT CONNECT TO THIS PIN. 08811-002 AVIN 6 VIN1 7 SW 8 PGND 9 EN1 10 NC VOUT3 VIN3 EN3 nRSTO Figure 2. Pin Configuration—View from Top of the Die Table 8. Preliminary Pin Function Descriptions Pin No. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Mnemonic NC VOUT3 VIN3 EN3 nRSTO AVIN VIN1 SW PGND EN1 VOUT1 WDI2 VIN2 VOUT2 WSTAT 16 17 EN2 MODE 18 WMOD 19 20 TP WDI1 MR AGND Description Do not connect to this pin. LDO2 Output Voltage and Sensing Input. LDO2 Input Supply (1.7 V to 5.5 V). Enable LDO2. EN3 = high: turn on LDO2; EN3 = low: turn off LDO2. Open-Drain Reset Output, Active Low. Regulators Housekeeping and Supervisory Input Supply (2.3 V to 5.5 V). Buck Input Supply (2.3 V to 5.5 V). Buck Switching Node. Dedicated Power Ground for Buck Regulator. Enable Buck. EN1 = high: turn on buck; EN1 = low: turn off buck. Buck Sensing Node. Watchdog 2 (Long Timeout) Refresh Input from Processor. Can be disabled only by factory option. LDO1 Input Supply (1.7 V to 5.5 V). LDO1 Output Voltage and Sensing Input. Open-Drain Watchdog Timeout Status. WSTAT = high: Watchdog 1 timeout or power-on reset; WSTAT = low: Watchdog 2 timeout. Auto cleared after one second. Enable LDO1. EN2 = high: turn on LDO1. EN2 = low: turn off LDO1. Buck Mode. MODE = high: buck regulator operates in fixed PWM mode; MODE = low: buck regulator operates in pulse skipping mode (PSM) at light load and in constant PWM at higher load. Watchdog Mode. WMOD = low: Watchdog 1 normal mode; WMOD = high: Watchdog 1 cannot be disabled by a three-state condition applied on WDI1. Watchdog 1 Refresh Input from Processor. If WDI1 is in high-Z and WMOD is low, Watchdog 1 is disabled. Manual Reset Input, Active Low. Analog Ground (TP = Thermal Pad). Exposed pad should be connected to AGND. Rev. 0 | Page 8 of 32 ADP5042 TYPICAL PERFORMANCE CHARACTERISTICS VIN1 = VIN2 = VIN3 = AVIN = 5.0 V, TA = 25°C, unless otherwise noted. SW 4 VOUT1 1 VOUT2 2 VOUT1 2 VOUT3 3 EN 1 08811-003 3 CH1 2.0V/DIV 1MΩ BW 20.0M CH2 2.0V/DIV 1MΩ BW 500M CH3 2.0V/DIV 1MΩ BW 20.0M A CH1 1.76V CH1 CH2 CH3 CH4 200µs/DIV 50.0MS/s 20.0ns/pt Figure 3. 3-Channel Start-Up Waveforms 08811-006 LOAD 4.0V/DIV 3.0V/DIV 200mA/DIV 5.0V/DIV 1MΩ BW 20.0M A CH1 1MΩ BW 500M 1MΩ BW 20.0M 1MΩ BW 500M 2.24V 50µs/DIV 20.0MS/s 50.0ns/pt Figure 6. Buck Startup, VOUT1 = 1.8 V, IOUT2 = 20 mA 1.0 3.34 –40°C +25°C +85°C 3.32 OUTPUT VOLTAGE (V) 0.8 0.7 0.6 0.5 0.4 0.3 VOUT1 = 1.8V, VOUT2 = VOUT = 3.3V 0.1 0 2.3 2.8 3.3 3.8 4.3 3.28 3.26 3.24 08811-004 0.2 3.30 4.8 3.22 5.3 0 0.1 0.2 0.3 INPUT VOLTAGE (V) 0.4 0.5 0.6 0.7 0.8 0.9 08811-007 SYSTEM QUIESCENT CURRENT (mA) 0.9 1.0 OUTPUT CURRENT (A) Figure 4. System Quiescent Current (Sum of All the Input Currents) vs. Input Voltage, VOUT1 = 1.8 V, VOUT2 = VOUT3 = 3.3 V Figure 7. Buck Load Regulation Across Temperature, VOUT1 = 3.3 V, Auto Mode 1.830 SW 4 –40°C +25°C +85°C 1.825 1.820 VOUT1 OUTPUT VOLTAGE (V) 2 EN 1 08811-005 CH1 CH2 CH3 CH4 2.0V/DIV 2.0V/DIV 100mA/DIV 5.0V/DIV 1MΩ BW 20.0M A CH1 1MΩ BW 500M 1MΩ BW 20.0M 1MΩ BW 500M 2.92V 1.805 1.800 1.795 1.790 1.785 1.780 50µs/DIV 50.0MS/s 20.0ns/pt Figure 5. Buck Startup, VOUT1 = 1.8 V, IOUT1 = 20 mA 1.810 08811-008 3 IIN 1.815 1.775 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 OUTPUT CURRENT (A) Figure 8. Buck Load Regulation Across Temperature, VOUT1 = 1.8 V, Auto Mode Rev. 0 | Page 9 of 32 ADP5042 100 1.795 1.794 90 +85°C 80 1.792 70 +25°C 1.791 EFFICIENCY (%) 1.790 1.789 1.788 60 50 40 30 1.787 20 1.786 1.785 08811-009 –40°C 1.784 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 08811-012 OUTPUT VOLTAGE (V) 1.793 3.6V 4.5V 5.5V 10 0 0.001 0.8 0.01 0.1 1 OUTPUT CURRENT (A) OUTPUT CURRENT (A) Figure 9. Buck Load Regulation Across Temperature, VOUT1 = 1.8 V, PWM Mode Figure 12. Buck Efficiency vs. Load Current, Across Input Voltage, VOUT1 = 3.3 V, PWM Mode 1.797 100 90 1.796 VIN = 5.5V 1.794 70 EFFICIENCY (%) VIN = 4.5V 1.793 VIN = 3.6V 60 50 40 30 20 08811-010 1.791 1.790 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 10 0 0.0001 0.8 2.4V 3.6V 4.5V 5.5V 0.001 OUTPUT CURRENT (A) 0.1 1 Figure 13. Buck Efficiency vs. Load Current, Across Input Voltage, VOUT1 = 1.8 V, Auto Mode 100 100 90 90 80 80 70 70 EFFICIENCY (%) EFFICIENCY (%) 0.01 OUTPUT CURRENT (A) Figure 10. Buck Load Regulation Across Input Voltage, VOUT1 = 1.8 V, PWM Mode 60 50 40 30 2.4V 3.6V 4.5V 5.5V 60 50 40 30 20 20 0.001 0.01 0.1 08811-011 3.6V 4.5V 5.5V 10 0 0.0001 08811-013 1.792 08811-014 OUTPUT VOLTAGE (V) 80 1.795 10 0 0.001 1 OUTPUT CURRENT (A) 0.01 0.1 1 IOUT (A) Figure 11. Buck Efficiency vs. Load Current, Across Input Voltage, VOUT1 = 3.3 V, Auto Mode Figure 14. Buck Efficiency vs. Load Current, Across Input Voltage, VOUT2 = 1.8 V, PWM Mode Rev. 0 | Page 10 of 32 ADP5042 100 1.7 90 1.6 80 EFFICIENCY (%) 70 OUTPUT CURRENT (A) –40ºC +25ºC +85ºC 60 50 40 30 1.5 1.4 1.3 1.2 20 0 0.001 0.01 0.1 1.0 2.6 1 3.6 OUTPUT CURRENT (A) 90 Figure 18. Buck DC Current Capability vs. Input Voltage, VOUT1 = 1.8 V 3.10 –40°C +25°C +85°C –40°C 3.05 80 FREQUENCY (MHz) EFFICIENCY (%) 70 60 50 40 +25°C 3.00 2.95 30 +85°C 08811-016 10 0 0.0001 0.001 0.01 0.1 08811-019 2.90 20 2.85 0 1 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 OUTPUT CURRENT (A) OUTPUT CURRENT (A) Figure 16. Buck Efficiency vs. Load Current, Across Temperature, VOUT1 = 3.3 V, Auto Mode Figure 19. Buck Switching Frequency vs. Output Current, Across Temperature, VOUT1 = 1.8 V, PWM Mode VOUT 100 90 5.6 INPUT VOLTAGE (V) Figure 15. Buck Efficiency vs. Load Current, Across Temperature, VOUT1 = 1.8 V, PWM Mode 100 4.6 08811-018 1.1 08811-015 10 –40°C +25°C +85°C 1 80 EFFICIENCY (%) 70 ISW 60 2 50 40 SW 30 10 0 0.0001 0.001 0.01 0.1 1 OUTPUT CURRENT (A) Figure 17. Buck Efficiency vs. Load Current, Across Temperature, VOUT1 = 1.8 V, Auto Mode Rev. 0 | Page 11 of 32 08811-020 08811-017 20 3 B 20.0M CH1 20.0mV/DIV W CH2 200mA/DIV 1MΩ BW 20.0M B CH3 2.0V/DIV 1MΩ W 20.0M A CH1 2.4mV 5.0µs/DIV 20.0MS/s 50.0ns/pt Figure 20. Typical Waveforms, VOUT1 = 3.3 V, IOUT1 = 30 mA, Auto Mode ADP5042 VOUT 2 VIN ISW 3 VOUT 2 SW SW 1 CH1 2.0V/DIV 1MΩ BW 20.0M B 20.0M CH2 50.0mV/DIV W B 20.0M CH3 500mA/DIV W A CH1 1.56mV 08811-024 08811-021 3 1 B 20.0M CH1 3V/DIV W B 20.0M CH2 50mV/DIV W CH3 900mV/DIV 1MΩ BW 20.0M 5.0µs/DIV 200MS/s 5.0ns/pt Figure 21. Typical Waveforms, VOUT1 = 1.8 V, IOUT2 = 30 mA, Auto Mode A CH3 4.79V 100µs/DIV 10.0MS/s 100ns/pt Figure 24. Buck Response to Line Transient, Input Voltage from 4.5 V to 5.0 V, VOUT1 = 3.3 V, PWM Mode VOUT 2 VIN ISW 3 VOUT 2 SW SW 08811-022 3 CH1 2.0V/DIV 1MΩ BW 20.0M B 20.0M CH2 50.0mV/DIV W B 20.0M CH3 500mA/DIV W A CH1 1.56mV 4 500ns/DIV 200MS/s 5.0ns/pt B 20.0M A CH3 CH2 50mV/DIV W CH3 1V/DIV 1MΩ BW 20.0M CH4 2V/DIV 1MΩ BW 20.0M Figure 22. Typical Waveforms, VOUT1 = 1.8 V, IOUT1 = 30 mA, PWM Mode 1 4.96mV 100µs/DIV 20MS/s 100ns/pt 08811-025 1 Figure 25. Buck Response to Line Transient, VIN = 4.5 V to 5.0 V, VOUT1 = 1.8 V, PWM Mode VOUT SW 1 2 ISW VOUT 2 3 B 20.0M A CH1 CH1 20.0mV/DIV W CH2 200mA/DIV 1MΩ BW 20.0M CH3 2.0V/DIV 1MΩ BW 20.0M 2.4mV 3 200ns/DIV 500MS/s 2.0ns/pt IOUT B 20.0M CH1 4V/DIV W CH2 50mV/DIV 1MΩ BW 20.0M CH3 50mA/DIV 1MΩ BW 20.0M Figure 23. Typical Waveforms, VOUT1 = 3.3 V, IOUT2 = 30 mA, PWM Mode Rev. 0 | Page 12 of 32 A CH3 44mA 200µs/DIV 10MS/s 100ns/pt 08811-026 08811-023 SW Figure 26. Buck Response to Load Transient, IOUT1 from 1 mA to 50 mA, VOUT1 = 3.3 V, Auto Mode ADP5042 SW 1 IIN 3 VOUT VOUT VOUT 1 LOAD A CH3 28mA 200µs/DIV 5MS/s 200ns/pt CH1 1V/DIV 1MΩ BW 500M A CH2 CH2 3V/DIV 1MΩ BW 500M CH3 50mA/DIV 1MΩ BW 20.0M 08811-027 B 20.0M CH1 4V/DIV W B 20.0M CH2 50mV/DIV W CH3 50mA/DIV 1MΩ BW 20.0M EN 2 3 Figure 27. Buck Response to Load Transient, IOUT2 from 1 mA to 50 mA, VOUT2 = 1.8 V, Auto Mode 1.14V 50µs/DIV 2MS/s 500ns/pt 08811-030 2 Figure 30. LDO1 Startup, VOUT3=1.5 V, IOUT3 = 5 mA SW 1 IIN 3 VOUT 2 VOUT 1 LOAD 86mA 200µs/DIV 10MS/s 100ns/pt CH1 1V/DIV 1MΩ BW 500M A CH2 CH2 3V/DIV 1MΩ BW 500M CH3 50mA/DIV 1MΩ BW 20.0M 08811-028 B 20.0M A CH3 CH1 4V/DIV W B 20.0M CH2 50mV/DIV W CH3 50mA/DIV 1MΩ BW 20.0M Figure 28. Buck Response to Load Transient, IOUT1 from 20 mA to 140 mA, VOUT1 = 3.3 V, Auto Mode 1.14V 100µs/DIV 1MS/s 1.0µs/pt 08811-031 EN 2 3 Figure 31. LDO2 Startup, VOUT3=3.3 V, IOUT3 = 5 mA 1.510 SW 2 OUTPUT VOLTAGE (V) 1.508 VOUT1 3 1.506 1.504 1.502 145mA 200µs/DIV 50MS/s 20ns/pt 1.500 0.0001 08811-029 CH2 4V/DIV 1MΩ BW 20.0M A CH3 CH3 50mV/DIV 1MΩ BW 20.0M CH4 50mA/DIV 1MΩ BW 20.0M 3.3V 4.5V 5.0V 5.5V 0.001 0.01 OUTPUT CURRENT (A) Figure 29. Buck Response to Load Transient, IOUT2 from 20 mA to 180 mA, VOUT1 = 1.8 V, PWM Mode Rev. 0 | Page 13 of 32 0.1 08811-032 LOAD 4 Figure 32. LDO1 Load Regulation Across Input Voltage, VOUT2 = 1.5 V ADP5042 1.53 3.35 +85°C +25°C –40°C 3.34 3.33 OUTPUT VOLTAGE (V) OUTPUT VOLTAGE (V) 1.52 +85°C +25°C –40°C 1.51 1.5 1.49 3.32 3.31 3.30 3.29 3.28 3.27 1.48 0.001 0.01 0.1 OUTPUT CURRENT (A) Figure 33. LDO1 Load Regulation Across Temperature, VIN2 = 3.3 V, VOUT2 = 1.5 V 1.515 3.325 100µA 1mA 10mA 100mA 150mA 3.320 3.315 OUTPUT VOLTAGE (V) OUTPUT VOLTAGE (V) 1.500 1.495 1.490 3.310 3.305 3.300 3.295 3.285 4.5 5.0 5.5 3.280 08811-034 3.6 INPUT VOLTAGE (V) Figure 34. LDO1 Line Regulation Across Output Load, VOUT2 = 1.5 V 3.6 4.5 5.0 5.5 INPUT VOLTAGE (V) Figure 37. LDO2 Line Regulation Across Output Load, VOUT3 = 3.3 V 250 3.6V 4.5V 5.0V 5.5V 3.33 200 3.32 CURRENT (µA) OUTPUT VOLTAGE (V) 100µA 1mA 10mA 100mA 150mA 3.290 1.485 3.34 0.1 Figure 36. LDO2 Load Regulation Across Temperature, VIN3 = 3.6 V, VOUT3 = 3.3 V 1.505 3.35 0.01 OUTPUT CURRENT (A) 1.510 1.480 0.001 08811-037 1.520 3.25 0.0001 08811-033 1.47 0.0001 08811-036 3.26 3.31 3.30 3.29 150 100 3.28 3.27 50 0.001 0.01 OUTPUT CURRENT (A) 0.1 Figure 35. LDO2 Load Regulation Across Input Voltage, VOUT3 = 3.3 V Rev. 0 | Page 14 of 32 0 0 0.05 0.10 0.15 LOAD (A) Figure 38. LDO2 Ground Current vs. Output Load, VOUT3 = 2.8 V 08811-038 3.25 0.0001 08811-035 3.26 ADP5042 0.50 1µA 100µA 1mA 10mA 100mA 150mA 0.45 GROUND CURRENT (mA) 0.40 0.35 VIN 0.30 0.25 VOUT 1 2 0.20 0.15 0.10 0.05 2.8 3.3 3.8 4.3 4.8 5.3 5.8 INPUT VOLTAGE (V) 08811-039 0 2.3 08811-042 2 Figure 39. LDO2 Ground Current vs. Input Voltage, Across Output Load, VOUT3 = 2.8 V B 20.0M CH1 10.0mV/DIV W CH2 800mV/DIV 1MΩ BW 20.0M A CH2 5.33V Figure 42. LDO2 Response to Line Transient, Input Voltage from 4.5 V to 5.5 V, VOUT3 = 3.3 V VIN 3 IOUT 1 2 1 VOUT VOUT A CH3 28mA 200µs/DIV 500kS/s 2.0µs/pt B 20.0M CH1 10.0mV/Div W CH2 800mV/Div 1MΩ BW 20.0M 08811-040 CH1 50mV/DIV 1MΩ BW 500M CH3 50mA/DIV 1MΩ BW 20.0M 08811-043 2 Figure 40. LDO2 Response to Load Transient, IOUT3 from 1 mA to 80 mA, VOUT3 = 3.3 V A CH2 5.33V Figure 43. LDO1 Line Transient VIN = 4.5 V to 5.5 V, VOUT2 = 1.5 V 3.0 3 1 OUTPUT VOLTAGE (V) 2.5 IOUT 2.0 1.5 1.0 VOUT 0.5 0 CH1 50mV/DIV 1MΩ W 500M A CH3 CH3 50mA/DIV 1MΩ BW 20.0M 50mA 200µs/DIV 500kS/s 2.0µs/pt 0 0.1 0.2 0.3 0.4 0.5 LOAD CURRENT (A) 08811-041 B Figure 41. LDO1 Response to Load Transient, IOUT3 from 1 mA to 80 mA, VOUT2 = 1.5 V 0.6 0.7 0.8 08811-056 5.5V 4.5V 3.6V Figure 44. LDO1, LDO2 Output Current Capability vs. Input Voltage Rev. 0 | Page 15 of 32 ADP5042 100 VOUT3 = 3.3V, VIN3 = 3.6V, VOUT3 = 1.5V, VIN3 = 1.8V, VOUT3 = 2.8V, VIN3 = 3.1V, ILOAD = 300mA ILOAD = 300mA ILOAD = 300mA NOISE (µV/√Hz) 100 0.001 0.01 0.1 1 LOAD (mA) 10 VIN = 5V VIN = 3.6V VIN = 3.1V VIN = 5V VIN = 1.8V 100 1k 1 0.1 Figure 45. LDO1 Output Noise vs. Load Current, Across Input and Output Voltage 0.01 1 10 100 1k 10k FREQUENCY (Hz) 100k 1M 08811-055 10 0.0001 CH2; VOUT = 3.3V; CH2; VOUT = 3.3V; CH2; VOUT = 2.8V; CH2; VOUT = 1.5V; CH2; VOUT = 1.5V; 08811-044 RMS NOISE (µV) 10 Figure 48. LDO2 Noise Spectrum Across Output Voltage, VIN = VOUT + 0.3 V 100 VOUT2 = 3.3V, VIN2 = 3.6V, ILOAD = 300mA VOUT3 = 3.3V, VIN3 = 3.6V, ILOAD = 300mA VOUT2 = 1.5V, VIN2 = 1.8V, ILOAD = 300mA NOISE (µV/√Hz) RMS NOISE (µV) 10 100 1.0 0.1 0.01 0.1 1 LOAD (mA) 10 100 1k 0.01 10 VOUT2 = 3.3V, VIN2 = 3.6V, ILOAD = 300mA VOUT2 = 1.5V, VIN2 = 1.8V, ILOAD = 300mA VOUT2 = 2.8V, VIN2 = 3.1V, ILOAD = 300mA 1k 10k 100k FREQUENCY (Hz) 1M 10M –10 –20 10 –30 1mA 10mA 100mA 200mA 300mA –40 PSRR (dB) NOISE (µV/√Hz) 100 Figure 49. LDO1 vs. LDO2 Noise spectrum Figure 46. LDO2 Output Noise vs. Load Current, Across Input and Output Voltage 100 VOUT3 = 1.5V, VIN3 = 1.8V, ILOAD = 300mA VOUT2 = 2.8V, VIN2 = 3.1V, ILOAD = 300mA VOUT3 = 2.8V, VIN3 = 3.1V, ILOAD = 300mA 08811-048 0.001 = 3.3V; VIN = 5V = 3.3V; VIN = 3.6V = 2.8V; VIN = 3.1V = 1.5V; VIN = 5V = 1.5V; VIN = 1.8V 08811-045 10 0.0001 CH3; VOUT CH3; VOUT CH3; VOUT CH3; VOUT CH3; VOUT 1.0 –50 –60 –70 0.1 –80 1k 10k 100k FREQUENCY (Hz) 1M 10M Figure 47. LDO1 Noise Spectrum Across Output Voltage, VIN = VOUT + 0.3 V Rev. 0 | Page 16 of 32 –100 10 100 1k 10k 100k FREQUENCY (Hz) 1M 10M 08811-049 –90 100 08811-046 0.01 10 Figure 50. LDO2 PSRR Across Output Load, VIN3 = 3.3 V, VOUT3 = 2.8 V ADP5042 –10 –10 –30 –40 PSRR (dB) –50 –60 –80 –80 –90 –90 –10 –20 100 1k 10k 100k FREQUENCY (Hz) 1M 10M –100 10 –20 –40 –40 PSRR (dB) –30 –50 –60 –80 –80 –90 –90 100 1k 10k 100k FREQUENCY (Hz) 1M 10M Figure 52. LDO2 PSRR Across Output Load, VIN3 = 5 V, VOUT3 = 3.3 V –10 1mA 10mA 100mA 200mA 300mA –40 –50 –60 –70 –80 100 1k 10k 100k FREQUENCY (Hz) 1M 10M 08811-052 –90 –100 10 1M 10M Figure 53. LDO2 PSRR Across Output Load, VIN3 = 3.6 V, VOUT3 = 3.3 V Rev. 0 | Page 17 of 32 1mA 10mA 100mA 200mA 300mA –60 –70 –30 10k 100k FREQUENCY (Hz) –50 –70 –20 1k –10 –30 –100 10 100 Figure 54. LDO1 PSRR Across Output Load, VIN2 = 5.0 V, VOUT2 = 1.5 V 1mA 10mA 100mA 200mA 08811-051 PSRR (dB) –60 –70 Figure 51. LDO2 PSRR Across Output Load, VIN3 = 3.1 V, VOUT3 = 2.8 V PSRR (dB) –50 –70 08811-050 PSRR (dB) –40 –100 10 1mA 10mA 100mA 200mA 300mA 08811-053 –30 –20 –100 10 100 1k 10k 100k FREQUENCY (Hz) 1M 10M 08811-054 –20 1mA 10mA 100mA 200mA 300mA Figure 55. LDO1 PSRR Across Output Load, VIN2 = 1.8 V, VOUT2 = 1.5 V ADP5042 THEORY OF OPERATION VOUT1 WDI2 WDI1 WMOD MR 40kΩ 60Ω ENWD1 ENBK VDDA VDDA AVIN GM ERROR AMP ENWD2 WATCHDOG DETECTOR1 52kΩ POFF 200kΩ PWM COMP WATCHDOG STATUS MONITOR SOFT START VIN1 WATCHDOG DETECTOR2 ILIMIT WSTAT DEBOUNCE PSM COMP R0 PWM/ PSM CONTROL BUCK1 LOW CURRENT VDDA SW R1 A nRSTO B C D Y RESET GENERATOR OSCILLATOR DRIVER AND ANTISHOOT THROUGH VREF SYSTEM UNDERVOLTAGE LOCK OUT PGND 500Ω ENLDO2 THERMAL SHUTDOWN POFF MODE MODE EN1 EN2 EN3 ENABLE AND MODE CONTROL SEL ENBK ENLDO1 R3 R1 ENLDO2 LDO1 CONTROL VDDA VDDA LDO2 CONTROL OPMODE_FUSES ADP5042 VIN2 AGND VOUT2 VIN3 500Ω ENLDO1 R4 VOUT3 08811-057 R2 Figure 56. Functional Block Diagram POWER MANAGEMENT UNIT The ADP5042 is a micro power management unit (micro PMU) combing one step-down (buck) dc-to-dc convertor, two low dropout linear regulators (LDOs), and a supervisory circuit, with dual watchdog, for processor control. The regulators are activated by a logic level high applied to the respective EN pin. The EN1 controls the buck regulator, the EN2 controls LDO1, and the EN3 controls LDO2. The ADP5042 has factory programmed output voltages and reset voltage threshold. Other features available in this device are the mode pin to control the buck switching operation, a status pin informing the external processor which watchdog caused a reset and push-button reset input. The buck regulator 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 buck is always constant and does not change with the load current. If the MODE pin is at logic low level, the switching regulator operates in auto PWM/PSM mode. In this mode, the regulator operates 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 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. 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. Rev. 0 | Page 18 of 32 ADP5042 Thermal Protection PWM Mode In the event that the junction temperature rises above 150°C, the thermal shutdown circuit turns off the buck and the LDOs. 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 buck and LDOs 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 buck operates 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 AVIN drops below a typical 2.15 V UVLO threshold, all channels shut down. In the buck channel, both the power switch and the synchronous rectifier turn off. When the voltage on AVIN rises above the UVLO threshold, the part is enabled once more. Alternatively, the user can select device models with a UVLO set at a higher level, suitable for 5 V applications. For these models, the device hits the turn-off threshold when the input supply drops to 3.65 V typical. Enable/Shutdown The ADP5042 has individual control pins for each regulator. A logic level high applied to the ENx pin activates a regulator, a logic level low turns off a regulator. When regulators are turned off after a Watchdog 2 event (see the Watchdog 2 Input section), the reactivation of the regulator occurs with a factory programmed order (see Table 9). The delay between the regulator activation (tD1, tD2) is 2 ms. Table 9. ADP5042 Regulators Sequencing REGSEQ[1:0] 0 0 0 1 1 0 1 1 Regulators Sequence (First to Last) LDO1 LDO2 Buck Buck LDO1 LDO2 LDO1 Buck LDO2 No sequence, all regulators start at same time BUCK SECTION The buck uses a fixed frequency and high speed current mode architecture. The buck operates with an input voltage of 2.3 V to 5.5 V. Control Scheme The buck operates 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. Power Save Mode (PSM) The buck smoothly transitions to PSM operation when the load current decreases below the PSM current threshold. When the buck enters 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 that is 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 The PSM current threshold is set to 100 mA. The buck employs 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. Short-Circuit Protection The buck includes 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 buck has 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 The 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 Rev. 0 | Page 19 of 32 ADP5042 100% Duty Operation With a dropping 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. LDO SECTION The ADP5042 contains two LDOs with low quiescent current, low dropout linear regulator, and provides up to 300 mA of output current. Drawing a low 15 μA quiescent current (typical) at no load makes the LDO ideal for battery-operated portable equipment. The LDO operates with an input voltage range of 1.7 V to 5.5 V. The wide operating range makes these LDOs suitable for cascading configurations where the LDO supply voltage is provided from the buck regulator. The LDOs also provide 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. LDO2 is optimized to supply analog circuits because it offers better noise performance compared to LDO1. LDO1 should be used in applications where noise performance is not critical. Internally, one 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. SUPERVISORY SECTION The ADP5042 provides microprocessor supply voltage supervision by controlling the reset input of the microprocessor. Code execution errors are avoided during power-up, powerdown, and brownout conditions by asserting a reset signal when the supply voltage is below a preset threshold and by allowing supply voltage stabilization with a fixed timeout reset pulse after the supply voltage rises above the threshold. In addition, problems with microprocessor code execution can be monitored and corrected with a dual-watchdog timer. Reset Output The ADP5042 has an active-low, open-drain reset output. This output structure requires an external pull-up resistor to connect the reset output to a voltage rail that is no higher than 6 V. The resistor should comply with the logic low and logic high voltage level requirements of the microprocessor while supplying input current and leakage paths on the nRSTO pin. A 10 k Ω resistor is adequate in most situations. The reset output is asserted when the monitored rail is below the reset threshold (VTH), when WDI1 or WDI2 is not serviced within the watchdog timeout period (tWD1 and tWD12). Reset remains asserted for the duration of the reset active timeout period (tRP) after VCC rises above the reset threshold or after the watchdog timer times out. Figure 57 illustrates the behavior of the reset output, nRSTO, and it assumes that VOUT2 is selected as the rail to be monitored and supplies the external pull-up connected to the nRSTO output. VOUT2 VTH VTH VOUT2 1V 0V VOUT2 tRP1 nRSTO tRD 0V RSTO tRP1 1V 0V tRD 08811-058 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. Figure 57. Reset Timing Diagram The reset threshold voltage and the sensed rail (VOUT1, VOUT2, VOUT3, or AVIN) are factory programmed. Refer to Table 15 for a complete list of the reset thresholds available for the ADP5042. When monitoring the input supply voltage, AVIN, if the selected reset threshold is below the UVLO level (factory programmable to 2.25 V or 3.6 V) the reset output, nRSTO, is asserted low as soon as the input voltage falls below the UVLO threshold. Below the UVLO threshold, the reset output is maintained low down to ~1 V VIN. This it to ensure that the reset output is not released when there is sufficient voltage on the rail supplying a processor to restart the processor operations. Manual Reset Input The ADP5042 features a manual reset input (MR) which, when driven low, asserts the reset output. When MR transitions from low to high, reset remains asserted for the duration of the reset active timeout period before deasserting. The MR input has a 52 kΩ, internal pull-up, connected to AVIN, so that the input is always high when unconnected. An external push-button switch can be connected between MR and ground so that the user can generate a reset. Debounce circuitry for this purpose is integrated on chip. Noise immunity is provided on the MR input, and fast, negative-going transients of up to 100 ns (typical) are ignored. A 0.1 µF capacitor between MR and ground provides additional noise immunity. Rev. 0 | Page 20 of 32 ADP5042 Watchdog 1 Input VSENSED 1V 0V The ADP5042 features a watchdog timer that monitors microprocessor activity. A timer circuit is cleared with every low-tohigh or high-to-low logic transition on the watchdog input pin (WDI1), which detects pulses as short as 80 ns. If the timer counts through the preset watchdog timeout period (tWD1), reset is asserted. The microprocessor is required to toggle the WDI1 pin to avoid being reset. Failure of the microprocessor to toggle WDI1 within the timeout period, therefore, indicates a code execution error, and the reset pulse generated restarts the microprocessor in a known state. VTH tRP1 nRSTO tWD1 tRP1 08811-059 0V WDI1 0V Figure 58. Watchdog 1 Timing Diagram Watchdog 2 Input The ADP5042 features an additional watchdog timer that monitors microprocessor activity in parallel to the first watchdog with a much longer timeout. This provides additional security and safety in case Watchdog 1 is incorrectly strobed. A timer circuit is cleared with every low-to-high or high-to-low logic transition on the watchdog input pin (WDI2), which detects pulses as short as 8 µs. If the timer counts through the preset watchdog timeout period (tWD2), reset is asserted, followed by a power cycle of all regulators . The microprocessor is required to toggle the WDI2 pin to avoid being reset and powered down. Failure of the microprocessor to toggle WDI2 within the timeout period, therefore, indicates a code execution error, and the reset output nRSTO is forced low for tRP2. Then, all the regulators are turned off for the tPOFF time. After the tPOFF period, the regulators are reactivated according to a predefined sequence (see Table 9). Finally, the reset line (nRSTO) is asserted for tRP1. This guarantees a clean power-up of the system and proper reset. As well as logic transitions on WDI1, the watchdog timer is also cleared by a reset assertion due to an undervoltage condition on the monitored rail. When reset is asserted, the watchdog timer is cleared and does not begin counting again until reset deasserts. Watchdog 1 timer can be disabled by leaving WDI1 floating or by three-stating the WDI1 driver. The pin WMOD controls the Watchdog 1 operating mode. If WMOD is set to logic level low, Watchdog 1 is enabled as long as WDI1 is not in three-state. If WMOD is set to logic level high, Watchdog 1 is always active and cannot be disabled by a three-state condition. WMOD input has an internal 200 kΩ pull-down resistor. Watchdog 1 timeout is factory set to two possible values as indicated in Table 17. As well as logic transitions on WDI2, the watchdog timer is also cleared by a reset assertion due to an undervoltage condition on the VTH monitored rail which can be factory programmable between VOUT1, VOUT2, VOUT3, and AVIN (see Table 20). When reset is asserted, the watchdog timer is cleared and does not begin counting again until reset deasserts. Watchdog 2 timeout is factory set to seven possible values as indicated in Table 18. One additional option allows Watchdog 2 to be factory disabled. AVIN/VINx/ENx tPOFF VOUT1 0V tD1 tD1 VOUT3 0V VOUT2 tD2 tD2 VTH 0V tRP1 nRSTO tWD2 tRP2 tRP1 0V WDI2 0V 08811-060 tWDCLEAR WSTAT Figure 59. Watchdog 2 Timing Diagram (Assuming That VOUT2 Is the Monitored Rail) Rev. 0 | Page 21 of 32 ADP5042 Watchdog Status Indicator situation, WSTAT maintains the previous state (see state flow in Figure 60). In addition to the dual watchdog function, the ADP5042 features a watchdog status monitor available on the WSTAT pin. This pin can be queried by the external processor to determine the origin of a reset. WSTAT is an open-drain output. The external processor can further distinguish a reset caused by a Watchdog 1 timeout from a power failure, status monitor WSTAT indicating a high level, by implementing a RAM check or signature verification after reset. A RAM check or signature failure indicates that a power failure has occurred, whereas a RAM check or signature validation indicates that a Watchdog 1 timeout has occurred. WSTAT outputs a logic level depending on the condition that has generated a reset. WSTAT is forced low if the reset was generated because of a Watchdog 2 timeout. WSTAT is pulled high, through external pull-up, for any other reset cause (Watchdog 1 timeout, power failure or monitored voltage below threshold). The status monitor is automatically cleared (set to logic level high) 10 seconds after the nRSTO low to high transition (tWDCLEAR), processor firmware must be designed being able to read the WSTAT flag before tWDCLEAR expiration after a Watchdog 2 reset. Table 10 shows the possible watchdog decoded statuses. Table 10. Watchdog Status Decoding WSTAT High High Low The WSTAT flag is not updated in the event of a reset due to a low voltage threshold detection or Watchdog 1 event occurring within 10 seconds after nRSTO low to high transition. In this RAM CHECKSUM Failed Ok Don't care RESET ORIGIN Power failure Watchdog 1 Watchdog 2 NO POWER APPLIED TO AVIN. ALL REGULATORS AND SUPERVISORY TURNED OFF NO POWER AVIN > VUVLO AVIN < VUVLO TRANSITION STATE AVIN < VUVLO POR INTERNAL CIRCUIT BIASED REGULATORS AND SUPERVISORY NOT ACTIVATED END OF POR STANDBY ALL ENx = HIGH AVIN < VUVLO ALL ENx = LOW AVIN < VUVLO TRANSITION STATE WSTAT = HIGH WSTAT TIMEOUT (tWDCLEAR ) WDOG2 TIMEOUT (tWD2) TRANSITION STATE WSTAT = 0 WSTAT = LOW WSTAT = 1 ACTIVE ALL REGULATORS AND SUPERVISOR ACTIVATED WDOG1 TIMEOUT (tWD1) AND WSTAT TIMEOUT END OF RESET PULSE (tRP1 ) END OF RESET PULSE (tRP2 ) WSTAT = HIGH POWER OFF VMON < VTH WSTAT = 1 RESET NORMAL Figure 60. ADP5042 State Flow Rev. 0 | Page 22 of 32 END OF (tPOFF) PULSE 08811-061 TRANSITION STATE WDOG1 TIMEOUT (tWD1) RESET SHORT ADP5042 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 66. 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 ADP5042 buck 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 11. 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 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 buck is high switching frequency dc-to-dc converters, shielded ferrite core material is recommended for its low core losses and low EMI. Table 11. Suggested 1.0 μH Inductors Vendor Murata Murata Taiyo Yuden Coilcraft TDK Coilcraft Toko Model LQM2MPN1R0NG0B LQM18FN1R0M00B CBMF1608T1R0M EPL2014-102ML GLFR1608T1R0M-LR 0603LS-102 MDT2520-CN 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 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 61. 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 buck, it is imperative that the effects of dc bias, temperature, and tolerances on the behavior of the capacitors be evaluated for each application. 12 ISAT (mA) 1400 150 290 900 230 400 1350 DCR (mΩ) 85 26 90 59 80 81 85 10 8 6 4 2 0 0 1 2 3 4 5 DC BIAS VOLTAGE (V) Figure 61. Typical Capacitor Performance Rev. 0 | Page 23 of 32 6 08811-062 I PEAK = I LOAD( MAX ) + 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. CAPACITANCE (µF) I RIPPLE = ADP5042 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 13. Table 12. Suggested 10 μF Capacitors Table 13. Suggested 4.7 μF Capacitors Vendor Murata Taiyo Yuden TDK Panasonic Type X5R X5R X5R X5R Case Size 0603 0603 0603 0603 Model GRM188R60J106 JMK107BJ475 C1608JB0J106K ECJ1VB0J106M Voltage Rating (V) 6.3 6.3 6.3 6.3 L1 1µH SW PROCESSOR VOUT1 VIN 2.3V TO 5.5V VIN1 C2 4.7µF VIN2 C1 1µF PGND VOUT2 C4 1µF C3 1µF nRSTO VDDIO Connecting a 1 µF capacitor from VIN2 and VIN3 to GND reduces the circuit sensitivity to printed circuit board (PCB) layout, especially when long input traces or high source impedance is encountered. If greater than 1 µF of output capacitance is required, increase the input capacitor to match it. RESET WDI GPIO1 MODE ENx Input Bypass Capacitor R1 100kΩ VIN3 LDO CAPACITOR SELECTION VCORE C6 4.7µF Table 10. Suggested 1.0 μF Capacitors GPIO2 3 GPIO[x:y] VOUT3 C5 1µF VANA ANALOG SUB-SYSTEM Figure 62. Processor System Power Management with PSM/PWM Control 08811-063 MICRO PMU Model GRM188R60J475ME19D JMK107BJ475 ECJ-0EB0J475M The ADP5042 LDOs are designed for operation with small, space-saving ceramic capacitors, but they function 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 ADP5042. 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 ADP5042 to large changes in load current. ADP5042 AVIN Type X5R X5R X5R Voltage Rating (V) 6.3 6.3 6.3 Output Capacitor The buck regulator requires 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 the 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 62). RFLT 30Ω Vendor Murata Taiyo Yuden Panasonic Case Size 0603 0603 0402 Vendor Murata TDK Panasonic Taiyo Yuden Rev. 0 | Page 24 of 32 Type Model X5R GRM155R61A105ME15 X5R X5R X5R C1005JB0J105KT ECJ0EB0J105K LMK105BJ105MV-F Case Size 0402 0402 0402 0402 Voltage Rating (V) 10.0 6.3 6.3 10.0 ADP5042 Input and Output Capacitor Properties Use any good quality ceramic capacitors with the ADP5042 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 63 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 CAPACITANCE (µF) 1.0 0.8 0.6 To guarantee the performance of the ADP5042, it is imperative that the effects of dc bias, temperature, and tolerances on the behavior of the capacitors be evaluated for each application. SUPERVISORY SECTION Watchdog 1 Input Current To minimize watchdog input current (and minimize overall power consumption), leave WDI1 low for the majority of the watchdog timeout period. When driven high, WDI1 can draw as much as 25 µA. Pulsing WDI1 low-to-high-to-low at a low duty cycle reduces the effect of the large input current. When WDI1 is unconnected and WMOD is set to logic level low, a window comparator disconnects the watchdog timer from the reset output circuitry so that reset is not asserted when the watchdog timer times out. Negative-Going VCC Transients To avoid unnecessary resets caused by fast power supply transients, the ADP5042 is equipped with glitch rejection circuitry. The typical performance characteristic in Figure 64 plots the monitored rail voltage, VTH , transient duration vs. the transient magnitude. The curve shows combinations of transient magnitude and duration for which a reset is not generated for a 2.93 V reset threshold part. For example, with the 2.93 V threshold, a transient that goes 100 mV below the threshold and lasts 8 µs typically does not cause a reset, but if the transient is any larger in magnitude or duration, a reset is generated. 1000 0.4 900 1 2 3 4 DC BIAS VOLTAGE (V) 5 6 Figure 63. Capacitance vs. Voltage Characteristic Use the following equation to determine the worst-case capacitance accounting for capacitor variation over temperature, component tolerance, and voltage. 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 63. Therefore, the capacitor chosen in this example meets the minimum capacitance requirement of the LDO over temperature and tolerance at the chosen output voltage. 500 400 300 200 0 0.1 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. CEFF = 0.94 μF × (1 − 0.15) × (1 − 0.1) = 0.719 μF 600 100 CEFF = CBIAS × (1 − TEMPCO) × (1 − TOL) Substituting these values into the following equation yields: 700 1 10 COMPARATOR OVERDRIVE (% OF VTH) 100 08811-065 0 08811-064 0 TRANSIENT DURATION (µs) 800 0.2 Figure 64. Maximum VTH Transient Duration vs. Reset Threshold Overdrive Watchdog Software Considerations In implementing the watchdog strobe code of the microprocessor, quickly switching WDI1 low to high and then high to low (minimizing WDI1 high time) is desirable for current consumption reasons. However, a more effective way of using the watchdog function can be considered. A low-to-high-to-low WDI1 pulse within a given subroutine prevents the watchdog from timing out. However, if the subroutine becomes stuck in an infinite loop, the watchdog cannot detect this because the subroutine continues to toggle WDI1. A more effective coding scheme for detecting this error involves Rev. 0 | Page 25 of 32 ADP5042 using a slightly longer watchdog timeout. In the program that calls the subroutine, WDI1 is set high. The subroutine sets WDI1 low when it is called. If the program executes without error, WDI1 is toggled high and low with every loop of the program. If the subroutine enters an infinite loop, WDI1 is kept low, the watchdog times out, and the microprocessor is reset (see Figure 65). VCC VOUT2 nRSTO WDI1 WDI2 ADP5042 VCORE VDDIO RESET I/O I/O MICROPROCESSOR START 08811-067 VIN1 VOUT1 Figure 66. Typical Applications Circuit SET WDI HIGH PCB LAYOUT GUIDELINES RESET Poor layout can affect ADP5042 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: PROGRAM CODE SUBROUTINE INFINITE LOOP: WATCHDOG TIMES OUT SET WDI LOW 08811-066 RETURN • • Figure 65. Watchdog Flow Diagram The second watchdog, refreshed through the WDI2 pin, is useful in applications where safety is a very critical factor and the system must recover from unwanted operations, for example, a processor stuck in a continuous loop where Watchdog 1 is kept refreshed or environmental conditions that may unset or damage the processor port controlling the WDI1 pin. In the event of a Watchdog 2 timeout, the ADP5042 power cycles all the supplied rails to guarantee a clean processor start. • • Rev. 0 | Page 26 of 32 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. 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. ADP5042 EVALUATION BOARD SCHEMATICS AND ARTWORK RFILT 30Ω AVIN AVIN TP4 L1 1µH SW VOUT1 TP5 VIN1 = 2.3V TO 5.5V BUCK VIN1 EN_LDO1 C1 1µF VOUT2 AT 300mA SUPERVISOR AVIN EN3 TP8 TP9 nRSTO TP10 WDI1 TP7 WDI2 EN_LDO2 VIN3 C2 1µF TP11 WSTAT EN2 VIN3 = 1.7V TO 5.5V TP2 VOUT2 LDO1 VIN2 VOUT1 AT 800mA TP12 MODE EN1 TP6 C6 10µF PGND EN_BK C5 4.7µF VIN2 = 1.7V TO 5.5V TP1 TP3 VOUT3 LDO2 VOUT3 AT 300mA C3 1µF 08811-068 C4 1µF AGND Figure 67. Evaluation Board Schematic SUGGESTED LAYOUT 0.5 1.0 2.5 2.0 1.5 3.0 3.5 4.0 4.5 5.5 5.0 6.0 6.5 3.3V PPL 7.0 mm GPL 0.5 C3 – 1µF 6.3V/XR5 0402 GPL C4 – 1µF 6.3V/XR5 0402 PPL MODE 2.5 VIN1 NC VOUT3 MR GPL C5 – 4.7µF 10V/XR5 0603 WDI1 GPL AGND SW GPL L1 – 1µH 0603 3.5 PIN 1 PPL PPL 2.0 3.0 VIN3 1.5 EN3 RFILT 30Ω 0402 nRSTO 1.0 GPL PGND WMOD GPL NC ADP5042 4.0 EN1 GPL EN2 GPL WSTAT VIN2 VOUT2 VIAs LEGEND PPL = POWER PLANE (+4V) GPL = GROUND PLANE C6 - 10µF 6.3V/XR5 0603 5.5 6.0 C1 – 1µF 10V/XR5 0402 C2 – 1µF 10V/XR5 0402 1.8V 1.5V mm Figure 68. Layout Rev. 0 | Page 27 of 32 TOP LAYER SECOND LAYER 811-069 5.0 GPL WDI2 GPL VOUT1 4.5 ADP5042 BILL OF MATERIAL4 Table 14. Reference C1, C2, C3, C4 C5 C6 RFILT L1 IC1 Value 1 µF, X5R, 6.3 V 4.7 µF, X5R, 10 V 10 µF, X5R, 6.3 V 30 Ω 1 µH, 0.09 Ω, 290 mA 1 µH, 0.08 Ω, 230 mA 3-regulator micro PMU Part Number LMK105BJ105MV-F LMK107BJ475MA-T JMK107BJ106MA-T Vendor Taiyo Yuden Taiyo Yuden Taiyo Yuden BRC1608T1R0M GLFR1608T1R0M-LR ADP5042 Taiyo Yuden TDK Analog Devices Package 0402 0603 0603 0201/0402 0603 0603 20-Lead LFCSP APPLICATION DIAGRAM AVIN RFILT 30Ω AVIN VIN1 = 2.3V TO 5.5V VIN1 6 8 BUCK 7 9 EN_BK C5 4.7µF 11 SW L1 1µH VOUT1 C6 10µF PGND VOUT1 AT 800mA FPWM ON OFF VIN2 MODE PWM/PSM 10 13 C1 1µF LDO1 (DIGITAL) 14 VOUT2 VOUT2 AT 300mA C2 1µF EN_LDO1 VDD EN2 AVIN 16 SUPERVISOR R1 MR 20 POFF PUSH-BUTTON RESET RESET 5 WDOG2 12 WDOG1 19 R2 WSTAT 15 nRSTO WDI2 WDI1 VDD ON OFF EN3 4 WMOD 17 EN2 16 EN_LDO2 VIN3 = 1.7V TO 5.5V VIN3 C3 1µF 3 LDO2 (ANALOG) OFF NC 1 2 ON VOUT3 AGND Figure 69. Application Diagram Rev. 0 | Page 28 of 32 C4 1µF VOUT3 AT 300mA 08811-070 ON OFF MAIN MICROCONTROLLER VIN2 = 1.7V TO 5.5V EN1 17 ADP5042 FACTORY PROGRAMMABLE OPTIONS Table 15. Reset Voltage Threshold Options1 Selection 111 (For VIN = 5 V − 6%) 110 (For VOUT = 3.3 V) 101 (For VOUT = 3.3 V) 100 (For VOUT = 2.8 V) 011 (For VOUT = 2.8 V) 010 (For VOUT = 2.5 V − 6%) 001 (For VOUT = 2.2 V − 6%) 000 (For VOUT = 1.8 V − 6%) TA = +25°C Typ 4.630 3.080 2.930 2.630 2.500 2.350 2.068 1.692 Min 3.034 2.886 2.591 2.463 Max Min 3.126 2.974 2.669 2.538 3.003 2.857 2.564 2.438 TA = −40°C to +85°C Max 4.700 3.157 3.000 2.696 2.563 2.385 2.099 1.717 Unit V V V V V V V V Table 16. Reset Timeout Options Selection 0 1 Min 24 160 Typ 30 200 Max 36 240 Unit ms ms Typ 102 1.6 Max 122.4 1.92 Unit ms sec Max 9 Unit sec 4.8 9.6 19.2 38.4 76.8 153.6 min min min min min min Max 280 560 Unit ms ms Table 17. Watchdog 1 Timer Options Selection 0 1 Min 81.6 1.12 Table 18. Watchdog 2 Timer Options Selection 000 001 010 011 100 101 110 111 Min 6 3.2 6.4 12.8 25.6 51.2 102.4 Typ 7.5 Watchdog 2 disabled 4 8 16 32 64 128 Table 19. Power-Off Timing Options Selection 0 1 Min 140 280 Typ 200 400 Table 20. Reset Sensing Options Selection 00 01 10 11 1 Monitored Rail VOUT1 pin VOUT2 pin VOUT3 pin AVIN1 pin When monitoring AVIN, the reset threshold selected, by fuse option or by the external resistor divided, must be higher than the UVLO threshold (2.25 V or 3.6 V). Rev. 0 | Page 29 of 32 ADP5042 OUTLINE DIMENSIONS 0.30 0.25 0.18 0.50 BSC PIN 1 INDICATOR 20 16 15 1 EXPOSED PAD 2.75 2.60 SQ 2.35 11 TOP VIEW 0.80 0.75 0.70 0.50 0.40 0.30 5 10 0.25 MIN BOTTOM VIEW 0.05 MAX 0.02 NOM COPLANARITY 0.08 0.20 REF SEATING PLANE 6 FOR PROPER CONNECTION OF THE EXPOSED PAD, REFER TO THE PIN CONFIGURATION AND FUNCTION DESCRIPTIONS SECTION OF THIS DATA SHEET. 020509-B PIN 1 INDICATOR 4.10 4.00 SQ 3.90 COMPLIANT TO JEDEC STANDARDS MO-220-WGGD. Figure 70. 20-Lead Lead Frame Chip Scale Package [LFCSP_WQ] 4 mm × 4 mm Body, Very Very Thin Quad (CP-20-8) Dimensions shown in millimeters ORDERING GUIDE Model1, 2 ADP5042ACPZ-1-R7 Regulator Settings VOUT1 = 1.8 V Supervisory Settings WD1 tOUT = 1.6 sec Temperature Range TJ = −40°C to +125°C Package Description 20-Lead Lead Frame Scale Package [LFCSP_WQ] ADP5042ACPZ-2-R7 VOUT2 = 1.5 V VOUT3 = 3.3 V UVLO = 2.2 V Sequencing: LDO1, LDO2, buck VOUT1 = 1.5 V WD2 tOUT = 128 min Reset tOUT = 200 ms POFF = 200 ms VTH Sensing = VOUT3, 2.93 V WD1 tOUT = 1.6 sec TJ = −40°C to +125°C 20-Lead Lead Frame Scale Package [LFCSP_WQ] VOUT2 = 1.8 V VOUT3 = 3.3 V UVLO = 2.2 V Sequencing: LDO1, LDO2, buck WD2 tOUT = 128 min Reset tOUT = 200 ms POFF = 200 ms VTH Sensing = VOUT3, 2.93 V ADP5042CP-1-EVALZ ADP5042CP-2-EVALZ 1 2 Evaluation Board Evaluation Board Z = RoHS Compliant Part. Monitoring ambient temperature does not guarantee that the junction temperature (TJ) is within the specified temperature limits. Rev. 0 | Page 30 of 32 Package Option CP-20-8 CP-20-8 ADP5042 NOTES Rev. 0 | Page 31 of 32 ADP5042 NOTES ©2010 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. D08811-0-12/10(0) Rev. 0 | Page 32 of 32