SNVSB23 March   2018 LP87521-Q1 , LP87522-Q1 , LP87523-Q1 , LP87524-Q1 , LP87525-Q1

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
    1.     Simplified Schematic
  3. 3 Description
    1.     Efficiency vs Output Current
  4. 4 Revision History
  5. 5 Device Comparison Table
  6. 6 Pin Configuration and Functions
    1.     Pin Functions
  7. 7 Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 ESD Ratings
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information
    5. 7.5 Electrical Characteristics
    6. 7.6 I2C Serial Bus Timing Requirements
    7. 7.7 Typical Characteristics
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Descriptions
      1. 8.3.1 Multi-Phase DC/DC Converters
        1. 8.3.1.1 Overview
        2. 8.3.1.2 Multiphase Operation, Phase Adding, and Phase-Shedding
        3. 8.3.1.3 Transition Between PWM and PFM Modes
        4. 8.3.1.4 Multiphase Switcher Configurations
        5. 8.3.1.5 Buck Converter Load-Current Measurement
        6. 8.3.1.6 Spread-Spectrum Mode
      2. 8.3.2 Sync Clock Functionality
      3. 8.3.3 Power-Up
      4. 8.3.4 Regulator Control
        1. 8.3.4.1 Enabling and Disabling Regulators
        2. 8.3.4.2 Changing Output Voltage
      5. 8.3.5 Enable and Disable Sequences
      6. 8.3.6 Device Reset Scenarios
      7. 8.3.7 Diagnosis and Protection Features
        1. 8.3.7.1 Power-Good Information (PGOOD Pin)
        2. 8.3.7.2 Warnings for Diagnosis (Interrupt)
          1. 8.3.7.2.1 Output Power Limit
          2. 8.3.7.2.2 Thermal Warning
        3. 8.3.7.3 Protection (Regulator Disable)
          1. 8.3.7.3.1 Short-Circuit and Overload Protection
          2. 8.3.7.3.2 Overvoltage Protection
          3. 8.3.7.3.3 Thermal Shutdown
        4. 8.3.7.4 Fault (Power Down)
          1. 8.3.7.4.1 Undervoltage Lockout
      8. 8.3.8 GPIO Signal Operation
      9. 8.3.9 Digital Signal Filtering
    4. 8.4 Device Functional Modes
      1. 8.4.1 Modes of Operation
    5. 8.5 Programming
      1. 8.5.1 I2C-Compatible Interface
        1. 8.5.1.1 Data Validity
        2. 8.5.1.2 Start and Stop Conditions
        3. 8.5.1.3 Transferring Data
        4. 8.5.1.4 I2C-Compatible Chip Address
        5. 8.5.1.5 Auto-Increment Feature
    6. 8.6 Register Maps
      1. 8.6.1 Register Descriptions
        1. 8.6.1.1  OTP_REV
        2. 8.6.1.2  BUCK0_CTRL1
        3. 8.6.1.3  BUCK1_CTRL1
        4. 8.6.1.4  BUCK2_CTRL1
        5. 8.6.1.5  BUCK3_CTRL1
        6. 8.6.1.6  BUCK0_VOUT
        7. 8.6.1.7  BUCK0_FLOOR_VOUT
        8. 8.6.1.8  BUCK1_VOUT
        9. 8.6.1.9  BUCK1_FLOOR_VOUT
        10. 8.6.1.10 BUCK2_VOUT
        11. 8.6.1.11 BUCK2_FLOOR_VOUT
        12. 8.6.1.12 BUCK3_VOUT
        13. 8.6.1.13 BUCK3_FLOOR_VOUT
        14. 8.6.1.14 BUCK0_DELAY
        15. 8.6.1.15 BUCK1_DELAY
        16. 8.6.1.16 BUCK2_DELAY
        17. 8.6.1.17 BUCK3_DELAY
        18. 8.6.1.18 GPIO2_DELAY
        19. 8.6.1.19 GPIO3_DELAY
        20. 8.6.1.20 RESET
        21. 8.6.1.21 CONFIG
        22. 8.6.1.22 INT_TOP1
        23. 8.6.1.23 INT_TOP2
        24. 8.6.1.24 INT_BUCK_0_1
        25. 8.6.1.25 INT_BUCK_2_3
        26. 8.6.1.26 TOP_STAT
        27. 8.6.1.27 BUCK_0_1_STAT
        28. 8.6.1.28 BUCK_2_3_STAT
        29. 8.6.1.29 TOP_MASK1
        30. 8.6.1.30 TOP_MASK2
        31. 8.6.1.31 BUCK_0_1_MASK
        32. 8.6.1.32 BUCK_2_3_MASK
        33. 8.6.1.33 SEL_I_LOAD
        34. 8.6.1.34 I_LOAD_2
        35. 8.6.1.35 I_LOAD_1
        36. 8.6.1.36 PGOOD_CTRL1
        37. 8.6.1.37 PGOOD_CTRL2
        38. 8.6.1.38 PGOOD_FLT
        39. 8.6.1.39 PLL_CTRL
        40. 8.6.1.40 PIN_FUNCTION
        41. 8.6.1.41 GPIO_CONFIG
        42. 8.6.1.42 GPIO_IN
        43. 8.6.1.43 GPIO_OUT
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Applications
      1. 9.2.1 Design Requirements
        1. 9.2.1.1 Inductor Selection
        2. 9.2.1.2 Input Capacitor Selection
        3. 9.2.1.3 Output Capacitor Selection
        4. 9.2.1.4 Snubber Components
        5. 9.2.1.5 Supply Filtering Components
        6. 9.2.1.6 Current Limit vs. Maximum Output Current
      2. 9.2.2 Detailed Design Procedure
      3. 9.2.3 Application Curves
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Device Support
      1. 12.1.1 Third-Party Products Disclaimer
    2. 12.2 Documentation Support
      1. 12.2.1 Related Documentation
    3. 12.3 Related Links
    4. 12.4 Receiving Notification of Documentation Updates
    5. 12.5 Community Resources
    6. 12.6 Trademarks
    7. 12.7 Electrostatic Discharge Caution
    8. 12.8 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

Refer to the PDF data sheet for device specific package drawings

Mechanical Data (Package|Pins)
  • RNF|26
Thermal pad, mechanical data (Package|Pins)
Orderable Information

7.5 Electrical Characteristics

–40°C ≤ TJ ≤ +140°C, CPOL = 22 µF/phase, specified VVANA, VVIN_Bx , VNRST, VVOUT_Bx, and IOUT range, unless otherwise noted. Typical values are at TJ = 25°C, VVANA = VVIN_Bx = 3.7 V, and VOUT = 1 V, unless otherwise noted(1)(2).
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
EXTERNAL COMPONENTS
CIN Input filtering capacitance Connected from VIN_Bx to PGND_Bx 1.9 10 µF
COUT Output filtering capacitance per phase, local 10 22 µF
CPOL Optional point-of-load (POL) capacitance per phase 22 µF
COUT-TOTAL Total output capacitance (local and POL) 4-phase output Output voltage slew-rate ≤ 3.8 mV/µs 1000 µF
3-phase output Output voltage slew-rate ≤ 3.8 mV/µs 750
2-phase output Output voltage slew-rate ≤ 3.8 mV/µs 500
1-phase output Output voltage slew-rate ≤ 3.8 mV/µs 250
ESRC ESR of the input and output capacitor 1 MHz ≤ f ≤ 10 MHz 2 10 mΩ
L Inductance of the inductor 0.47 µH
–30% 30%
DCRL Inductor DCR 25 mΩ
BUCK REGULATOR
VVIN_Bx Input voltage range 2.8 3.7 5.5 V
VVOUT_Bx Programmable output voltage range 0.6 3.36 V
Output voltage step size 0.6 V ≤ VVOUT < 0.73 V 10 mV
0.73 V ≤ VVOUT < 1.4 V 5
1.4 V ≤ VVOUT ≤ 3.36 V 20
IOUT Output current(3) The maximum output current from device is 10A regardless of device phase configurations. 4-phase output VIN ≥ 3 V 10 A
2.8 V ≤ VIN < 3 V 7.2
3-phase output VIN ≥ 3 V 9.0
2.8 V ≤ VIN < 3 V 6.5
2-phase output VIN ≥ 3 V 8.0
2.8 V ≤ VIN < 3 V 6.0
1-phase output VIN ≥ 3 V 4.0
2.8 V ≤ VIN < 3 V 3.0
Input and output voltage difference
Minimum voltage between VIN_x and VOUT to fulfill the electrical characteristics		 0.5 V
VVOUT_DC DC output voltage accuracy, includes voltage reference, DC load and line regulations, process, and temperature VOUT < 1 V, PWM mode –20 20 mV
VOUT ≥ 1 V, PWM mode –2% 2%
VOUT < 1 V, PFM mode –20 40 mV
VOUT ≥ 1 V, PFM mode –2% 2% + 20 mV
Ripple voltage 4-phase output PWM mode, ESRC < 2 mΩ, L = 0.47 µH 3 mVp-p
PFM mode, L = 0.47 µH 4
3-phase output PWM mode, ESRC < 2 mΩ, L = 0.47 µH 4
PFM mode, L = 0.47 µH 5
2-phase output PWM mode, ESRC < 2 mΩ, L = 0.47 µH 6
PFM mode, L = 0.47 µH 7
1-phase output, PWM mode, ESRC < 2 mΩ, L = 0.47 µH 8
PFM mode, L = 0.47 µH 14
DCLNR DC line regulation IOUT = IOUT(max) 0.1 %/V
DCLDR DC load regulation in PWM mode VOUT = 1 V, 0 A ≤ IOUT ≤ IOUT(max) 0.8%
TLDSR Transient load step response 4-phase output 0 A ≤ IOUT ≤ 8 A, tr = tf = 10 µs, PWM mode, COUT = 22 µF/phase, L = 0.47 µH, CPOL = 22 µF/phase –3% 3% mV
0.1 A ≤ IOUT ≤ 8 A, tr = tf = 1 µs, PWM mode, COUT = 22 µF/phase, L = 0.47 µH, CPOL = 22 µF/phase ±40
3-phase output 0 A ≤ IOUT ≤ 6 A, tr = tf = 10 µs, PWM mode, COUT = 22 µF/phase, L = 0.47 µH, CPOL = 22 µF/phase –3% 3%
0.1 A ≤ IOUT ≤ 6 A, tr = tf = 1 µs, PWM mode, COUT = 22 µF/phase, L = 0.47 µH, CPOL = 22 µF/phase ±40
2-phase output 0 A ≤ IOUT ≤ 4 A, tr = tf = 10 µs, PWM mode, COUT = 22 µF/phase, L = 0.47 µH, CPOL = 22 µF/phase –3% 3%
0.1 A ≤ IOUT ≤ 4 A, tr = tf = 1 µs, PWM mode, COUT = 22 µF/phase, L = 0.47 µH, CPOL = 22 µF/phase ±40
1-phase output 0 A ≤ IOUT ≤ 2 A, tr = tf = 10 µs, PWM mode, COUT = 22 µF, L = 0.47 µH, CPOL = 22 µF –3% 3%
0.1 A ≤ IOUT ≤ 2 A, tr = tf = 1 µs, PWM mode, COUT = 22 µF, L = 0.47 µH, CPOL = 22 µF ±40
TLNSR Transient line response VVIN_Bx stepping 3 V ↔ 3.5 V, tr = tf = 10 µs, IOUT = IOUT(max) ±5 mV
ILIM FWD Forward current limit (peak for each switching cycle)
The max peak current limit of all combined phases cannot exceed 14A.		 Programmable range 1.5 5 A
Step size 0.5
Accuracy, VVIN_Bx ≥ 3 V, ILIM ≥ 3 A –5% 7.5% 20%
Accuracy, 2.8 V ≤ VVIN_Bx < 3 V, ILIM ≥ 3. A –20% 7.5% 20%
ILIM NEG Negative current limit per phase (peak for each switching cycle) 1.6 2 2.4 A
RDS(ON) HS FET On-resistance, high-side FET Each phase, between VIN_Bx and SW_Bx pins, I = 1 A 29 65 mΩ
RDS(ON) LS FET On-resistance, low-side FET Each phase, between SW_Bx and PGND_Bx pins, I = 1 A 17 35 mΩ
fSW Switching frequency, PWM mode 1.8 2 2.2 MHz
Current balancing for multiphase outputs Current mismatch between phases, IOUT > 1 A/phase 10%
Start-up time (soft start) From ENx to VOUT = 0.35 V (slew-rate control begins), COUT_TOTAL = 44 µF/phase 200 µs
Output voltage slew-rate(4) COUT-TOTAL ≤ 80 µF/phase –15% 10 15% mV/µs
COUT-TOTAL ≤ 130 µF/phase –15% 7.5 15%
COUT-TOTAL ≤ 250 µF/phase –15% 3.8 15%
COUT-TOTAL ≤ 500 µF/phase –15% 1.9 15%
COUT-TOTAL ≤ 500 µF/phase –15% 0.94 15%
COUT-TOTAL ≤ 500 µF/phase –15% 0.47 15%
IPFM-PWM PFM-to-PWM current threshold(5) 600 mA
IPWM-PFM PWM-to-PFM current threshold(5) 200 mA
IADD Phase adding level (multiphase rails) From 1-phase to 2-phase 1 A
From 2-phase to 3-phase 2
From 3-phase to 4-phase 3
ISHED Phase shedding level (multiphase rails) From 2-phase to 1-phase 0.7 A
From 3-phase to 2-phase 1.5
From 4-phase to 3-phase 2.4
Output pulldown resistance Regulator disabled 160 230 300 Ω
Output voltage monitoring for PGOOD pin Overvoltage monitoring (compared to DC output-voltage level, VVOUT_DC) 39 50 64 mV
Undervoltage monitoring (compared to DC output-voltage level, VVOUT_DC) –53 –40 –29
Debounce time during regulator enable PGOOD_SET_DELAY = 0h 4 10 µs
Debounce time during regulator enable PGOOD_SET_DELAY = 1h 10 11 13 ms
Deglitch time during operation and after voltage change 4 10 µs
Power-good threshold for interrupt BUCKx_PG_INT, difference from final voltage Rising ramp voltage, enable or voltage change –20 –14 –8 mV
Falling ramp voltage, voltage change 8 14 20
Power-good threshold for status bit BUCKx_PG_STAT During operation, status signal is forced to 0h during voltage change –20 –14 –8 mV
EXTERNAL CLOCK AND PLL
Nominal frequency of the external input clock 1 24 MHz
Nominal frequency step size of the external input clock 1 MHz
Required accuracy from nominal frequency of the external input clock –30% 10%
Delay time for missing external clock detection 1.8 µs
Delay and debounce time for external clock detection 20 µs
Clock change delay (internal to external)
delay from valid clock detection to use of external clock		 600 µs
Cycle-to-cycle PLL output clock jitter 300 ps, p-p
PROTECTION FUNCTIONS
Thermal warning Temperature rising, TDIE_WARN_LEVEL = 0h 115 125 135 °C
Temperature rising, TDIE_WARN_LEVEL = 1h 127 137 147
Thermal warning hysteresis 20 °C
Thermal shutdown Temperature rising 140 150 160 °C
Thermal shutdown hysteresis 20 °C
VANAOVP VANA overvoltage Voltage rising 5.6 5.8 6.1 V
Voltage falling 5.45 5.73 5.96
VANA overvoltage hysteresis 40 mV
VANAUVLO VANA undervoltage lockout Voltage rising 2.51 2.63 2.75 V
Voltage falling 2.5 2.6 2.7
LOAD CURRENT MEASUREMENT
Current measurement range Output current for maximum code  20.47 A
Resolution LSB 20 mA
Measurement accuracy IOUT > 1 A < 10%
Measurement time PFM mode (automatically changing to PWM mode for the measurement) 45 µs
PWM mode 4
CURRENT CONSUMPTION
Shutdown current consumption From VANA and VIN_Bx pins, NRST = 0 V, VANA = VIN_Bx = 3.7 V 1.4 µA
Standby current consumption From VANA and VIN_Bx pins, NRST = 1.8 V, VANA = VIN_Bx = 3.7 V, regulators disabled 6.7 µA
Active current consumption in PFM mode 4-phase enabled: From VANA and VIN_Bx pins, NRST = 1.8 V, VANA = VIN_Bx = 3.7 V, IOUT = 0 mA, not switching, one regulator enabled, internal RC oscillator, PGOOD monitoring enabled 77 µA
3-phase enabled: From VANA and VIN_Bx pins, NRST = 1.8 V, VANA = VIN_Bx = 3.7 V, IOUT = 0 mA, not switching, one regulator enabled, internal RC oscillator, PGOOD monitoring enabled 71
2-phase enabled: From VANA and VIN_Bx pins, NRST = 1.8 V, VANA = VIN_Bx = 3.7 V, IOUT = 0 mA, not switching, one regulator enabled, internal RC oscillator, PGOOD monitoring enabled 65
1-phase enabled: From VANA and VIN_Bx pins, NRST = 1.8 V, VANA = VIN_Bx = 3.7 V, IOUT = 0 mA, not switching, one regulator enabled, internal RC oscillator, PGOOD monitoring enabled 57
Active current consumption during PWM operation Each phase 17 mA
PLL and clock detector current consumption Additional current consumption when internal RC oscillator, clock detector and PLL are enabled 2 mA
DIGITAL INPUT SIGNALS: NRST, EN1, EN2, EN3, EN4, SCL, SDA, GPIO1, GPIO2, GPIO3, CLKIN
VIL Input low level 0.4 V
VIH Input high level 1.2 V
VHYS Hysteresis of Schmitt trigger inputs 10 77 200 mV
ENx pulldown resistance ENx_PD = 1h 500 kΩ
NRST pulldown resistance Always present 650 1150 1700 kΩ
DIGITAL OUTPUT SIGNALS: nINT
VOL Output low level ISOURCE = 2 mA 0.4 V
RP External pullup resistor To VIO supply 10 kΩ
DIGITAL OUTPUT SIGNALS: SDA
VOL Output low level ISOURCE = 10 mA 0.4 V
DIGITAL OUTPUT SIGNALS: PGOOD, GPIO1, GPIO2, GPIO3
VOL Output low level ISOURCE = 2 mA 0.4 V
VOH Output high level, configured to push-pull ISINK = 2 mA VVANA – 0.4 VVANA V
VPU Supply voltage for external pull-up resistor, configured to open-drain VVANA V
RPU External pullup resistor, configured to open-drain 10 kΩ
ALL DIGITAL INPUTS
ILEAK Input current All logic inputs over pin voltage range (except NRST) −1 1 µA
(1) All voltage values are with respect to network ground.
(2) Minimum (Min) and Maximum (Max) limits are specified by design, test, or statistical analysis. Typical (Typ) numbers are not verified, but do represent the most likely norm.
(3) The maximum output current can be limited by the forward current limit ILIM FWD and by the junction temperature. The power dissipation inside the die depends on the length of the current pulse and efficiency and the junction temperature may increase to thermal shutdown level if the board and ambient temperatures are high.
(4) Output capacitance, forward and negative current limits and load current may limit the maximum and minimum slew rates. The actual set fixed slew rate value for specific part number is listed in corresponding TRM document.
(5) The final PFM-to-PWM and PWM-to-PFM switchover current varies slightly and is dependent on the output voltage, input voltage, and the inductor current level.