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

7.3.2 Sync Clock Functionality

The LP875761-Q1 device contains a CLKIN input to synchronize switching clock of the buck regulator with the external clock. The block diagram of the clocking and PLL module is shown in Figure 7-4. Depending on the PLL_MODE[1:0] bits (in PLL_CTRL register) and the external clock availability, the external clock is selected and interrupt is generated as shown in Table 7-2. The interrupt can be masked with SYNC_CLK_MASK bit in TOP_MASK1 register. The nominal frequency of the external input clock is set by EXT_CLK_FREQ[4:0] bits (in PLL_CTRL register) and it can be from 1 MHz to 24 MHz with 1-MHz steps. The external clock must be inside accuracy limits (–30%/+10%) for valid clock detection.

The NO_SYNC_CLK interrupt (in INT_TOP1 register) is also generated in cases the external clock is expected but it is not available. These cases are start-up (read OTP-to-STANDBY transition) when PLL_MODE[1:0] = 01 and regulator enable (STANDBY-to-ACTIVE transition) when PLL_MODE[1:0] = 10.

GUID-D1C783B3-46ED-41B0-A9A4-AC43D815D872-low.gif Figure 7-4 Clock and PLL Module
Table 7-2 PLL Operation
DEVICE OPERATION MODE PLL_MODE[1:0] PLL AND CLOCK DETECTOR STATE INTERRUPT FOR EXTERNAL CLOCK CLOCK
STANDBY 0h Disabled No Internal RC
ACTIVE 0h Disabled No Internal RC
STANDBY 1h Enabled When external clock appears or disappears Automatic change to external clock when available
ACTIVE 1h Enabled When external clock appears or disappears Automatic change to external clock when available
STANDBY 2h Disabled No Internal RC
ACTIVE 2h Enabled When external clock appears or disappears Automatic change to external clock when available
STANDBY 3h Reserved
ACTIVE 3h Reserved