SNVSBA3 December   2020 LP875761-Q1

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
  6. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information
    5. 6.5 Electrical Characteristics
    6. 6.6 I2C Serial Bus Timing Requirements
    7. 6.7 Typical Characteristics
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Descriptions
      1. 7.3.1 Multi-Phase DC/DC Converters
        1. 7.3.1.1 Overview
        2. 7.3.1.2 Multiphase Switcher Configurations
        3. 7.3.1.3 Buck Converter Load-Current Measurement
        4. 7.3.1.4 Spread-Spectrum Mode
      2. 7.3.2 Sync Clock Functionality
      3. 7.3.3 Power-Up
      4. 7.3.4 Regulator Control
        1. 7.3.4.1 Enabling and Disabling Regulators
      5. 7.3.5 Enable and Disable Sequences
      6. 7.3.6 Device Reset Scenarios
      7. 7.3.7 Diagnosis and Protection Features
        1. 7.3.7.1 Power-Good Information (PGOOD pin)
        2. 7.3.7.2 Warnings for Diagnosis (Interrupt)
          1. 7.3.7.2.1 Output Power Limit
          2. 7.3.7.2.2 Thermal Warning
        3. 7.3.7.3 Protection (Regulator Disable)
          1. 7.3.7.3.1 Short-Circuit and Overload Protection
          2. 7.3.7.3.2 Overvoltage Protection
          3. 7.3.7.3.3 Thermal Shutdown
        4. 7.3.7.4 Fault (Power Down)
          1. 7.3.7.4.1 Undervoltage Lockout
      8. 7.3.8 GPIO Signal Operation
      9. 7.3.9 Digital Signal Filtering
    4. 7.4 Device Functional Modes
      1. 7.4.1 Modes of Operation
    5. 7.5 Programming
      1. 7.5.1 I2C-Compatible Interface
        1. 7.5.1.1 Data Validity
        2. 7.5.1.2 Start and Stop Conditions
        3. 7.5.1.3 Transferring Data
        4. 7.5.1.4 I2C-Compatible Chip Address
        5. 7.5.1.5 Auto-Increment Feature
    6. 7.6 Register Maps
      1. 7.6.1 Register Descriptions
        1.       53
        2. 7.6.1.1  DEV_REV
        3. 7.6.1.2  OTP_REV
        4. 7.6.1.3  BUCK0_CTRL1
        5. 7.6.1.4  BUCK0_CTRL2
        6. 7.6.1.5  BUCK1_CTRL2
        7. 7.6.1.6  BUCK2_CTRL2
        8. 7.6.1.7  BUCK3_CTRL2
        9. 7.6.1.8  BUCK0_DELAY
        10. 7.6.1.9  GPIO2_DELAY
        11. 7.6.1.10 GPIO3_DELAY
        12. 7.6.1.11 RESET
        13. 7.6.1.12 CONFIG
        14. 7.6.1.13 INT_TOP1
        15. 7.6.1.14 INT_TOP2
        16. 7.6.1.15 INT_BUCK_0_1
        17. 7.6.1.16 INT_BUCK_2_3
        18. 7.6.1.17 TOP_STAT
        19. 7.6.1.18 BUCK_0_1_STAT
        20. 7.6.1.19 BUCK_2_3_STAT
        21. 7.6.1.20 TOP_MASK1
        22. 7.6.1.21 TOP_MASK2
        23. 7.6.1.22 BUCK_0_1_MASK
        24. 7.6.1.23 BUCK_2_3_MASK
        25. 7.6.1.24 SEL_I_LOAD
        26. 7.6.1.25 I_LOAD_2
        27. 7.6.1.26 I_LOAD_1
        28. 7.6.1.27 PGOOD_CTRL1
        29. 7.6.1.28 PGOOD_CTRL2
        30. 7.6.1.29 PGOOD_FLT
        31. 7.6.1.30 PLL_CTRL
        32. 7.6.1.31 PIN_FUNCTION
        33. 7.6.1.32 GPIO_CONFIG
        34. 7.6.1.33 GPIO_IN
        35. 7.6.1.34 GPIO_OUT
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
        1. 8.2.1.1 Inductor Selection
        2. 8.2.1.2 Input Capacitor Selection
        3. 8.2.1.3 Output Capacitor Selection
        4. 8.2.1.4 Snubber Components
        5. 8.2.1.5 Supply Filtering Components
      2. 8.2.2 Detailed Design Procedure
      3. 8.2.3 Application Curves
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Receiving Notification of Documentation Updates
    2. 11.2 Support Resources
    3. 11.3 Trademarks
    4. 11.4 Electrostatic Discharge Caution
    5. 11.5 Glossary
  12. 12Mechanical, 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

8.2.1.3 Output Capacitor Selection

The output capacitors COUT0, COUT1, COUT2, and COUT3 are shown in Section 8.2. A ceramic local output capacitor of 22 μF is required per phase. Use ceramic capacitors, X7R or X7T types; do not use Y5V or F. DC bias voltage characteristics of ceramic capacitors must be considered. The output filter capacitor smooths out current flow from the inductor to the load, helps keep a steady output voltage during transient load changes and decreases output voltage ripple. These capacitors must be selected with sufficient capacitance and sufficiently low ESR and ESL to do these functions. The minimum effective output capacitance to make sure performance is good is 10 μF for each phase including the DC voltage roll-off, tolerances, aging and temperature effects.

The output voltage ripple is caused by the charging and discharging of the output capacitor and also due to its RESR. The RESR is frequency dependent (as well as temperature dependent); make sure the value used for selection process is at the switching frequency of the part. See Table 8-3.

POL capacitor (CPOL0) needs to be used to maintain output voltage stability and improve load transient performance and to decrease the ripple voltage. Note that the output capacitor may be the limiting factor in the output voltage ramp and the maximum total output capacitance listed in electrical characteristics must not be exceeded. At shutdown the output voltage is discharged to 0.6 V level using forced-PWM operation. This can increase the input voltage if the load current is small and the output capacitor is large. Below 0.6 V level the output capacitor is discharged by the internal discharge resistor and with large capacitor more time is required to settle VOUT down as a consequence of the increased time constant.

Table 8-3 Recommended Output Capacitors (X7R or X7T Dielectric)
MANUFACTURERPART NUMBERVALUECASE SIZEDIMENSIONS L × W × H (mm)VOLTAGE RATING (V)
MurataGCM31CR71A226KE0222 µF (10%)12063.2 × 1.6 × 1.610