SNVSAL1C December   2017  β€“ June 2021 LP87702-Q1

PRODUCTION DATA  

  1. Features
  2. Applications
  3. Description
  4. Revision History
  5. Description (continued)
  6. Pin Configuration and Functions
  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 Parameters
    7. 7.7 Typical Characteristics
  8. Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Descriptions
      1. 8.3.1  Step-Down DC/DC Converters
        1. 8.3.1.1 Overview
        2. 8.3.1.2 Transition Between PWM and PFM Modes
        3. 8.3.1.3 Buck Converter Load Current Measurement
      2. 8.3.2  Boost Converter
      3. 8.3.3  Spread-Spectrum Mode
      4. 8.3.4  Sync Clock Functionality
      5. 8.3.5  Power-Up
      6. 8.3.6  Buck and Boost Control
        1. 8.3.6.1 Enabling and Disabling Converters
        2. 8.3.6.2 Changing Buck Output Voltage
      7. 8.3.7  Enable and Disable Sequences
      8. 8.3.8  Window Watchdog
      9. 8.3.9  Device Reset Scenarios
      10. 8.3.10 Diagnostics and Protection Features
        1. 8.3.10.1 Voltage Monitorings
        2. 8.3.10.2 Interrupts
        3. 8.3.10.3 Power-Good Information to Interrupt, PG0, and PG1 Pins
          1. 8.3.10.3.1 PGx Pin Gated (Unusual) Mode
          2. 8.3.10.3.2 PGx Pin Operation in Continuous Mode
          3. 8.3.10.3.3 Summary of PG0, PG1 Gated, and Continuous Operating Modes
        4. 8.3.10.4 Warning Interrupts for System Level Diagnostics
          1. 8.3.10.4.1 Output Power Limit
          2. 8.3.10.4.2 Thermal Warning
        5. 8.3.10.5 Protections Causing Converter Disable
          1. 8.3.10.5.1 Short-Circuit and Overload Protection
          2. 8.3.10.5.2 Overvoltage Protection
          3. 8.3.10.5.3 Thermal Shutdown
        6. 8.3.10.6 Protections Causing Device Power Down
          1. 8.3.10.6.1 Undervoltage Lockout
      11. 8.3.11 OTP Error Correction
      12. 8.3.12 Operation of GPO Signals
      13. 8.3.13 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 LP8770_map Registers
  9. Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1 Application Components
          1. 9.2.2.1.1 Inductor Selection
          2. 9.2.2.1.2 Buck Input Capacitor Selection
          3. 9.2.2.1.3 Buck Output Capacitor Selection
          4. 9.2.2.1.4 Boost Input Capacitor Selection
          5. 9.2.2.1.5 Boost Output Capacitor Selection
          6. 9.2.2.1.6 Supply Filtering Components
      3. 9.2.3 Current Limit vs Maximum Output Current
      4. 9.2.4 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 Third-Party Products Disclaimer
    2. 12.2 Receiving Notification of Documentation Updates
    3. 12.3 Support Resources
    4. 12.4 Trademarks
    5. 12.5 Electrostatic Discharge Caution
    6. 12.6 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

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

Pin Configuration and Functions

GUID-13B7A572-FD8F-47F9-9A95-FC1E621448B4-low.gifFigure 6-1 RHB Package32-Pin VQFN With Thermal PadTop View
Table 6-1 Pin Functions
PIN TYPE DESCRIPTION
NAME NUMBER
AGND 4 G Ground
CLKIN 22 D/I/O External clock input. Alternative function is general purpose digital output 2 (GPO2). Second alternative function is watchdog disable (WD_DIS)
EN1 19 D/I Programmable Enable 1 signal.
FB_B0 2 A Output voltage feedback for Buck0.
FB_B1 3 A Output voltage feedback for Buck1.
GPO0 12 D/O General purpose digital output 0.
nINT 1 D/O Open-drain interrupt output. Active LOW.
NRST 11 D/I Reset signal for the device.
PG0 29 D/O Programmable power-good indication signal.
PG1 32 D/O Programmable power-good indication signal. Alternative function is general purpose digital output 1 (GPO1).
PGND_B0 23, 24 P/G Power ground for Buck0.
PGND_B1 17, 18 P/G Power Ground for Buck1.
PGND_BST 10 P/G Power ground for boost.
SCL 20 D/I Serial interface clock input for I2C access. Connect a pullup resistor. Alternative function is programmable to the enable 2 signal.
SDA 21 D/I/O Serial interface data input and output for I2C access. Connect a pullup resistor. Alternative function is programmable to the enable 3 signal.
SW_B0 25, 26 P/O Buck0 switch node.
SW_B1 15, 16 P/O Buck1 switch node.
SW_BST 9 P/I Boost input. Bypass switch input when this mode is selected.
VANA 5 P Supply voltage for analog and digital blocks. Must be connected to same node with VIN_Bx.
VMON1 30 A/I Voltage monitoring input 1.
VMON2 31 A/I Voltage monitoring input 2.
VIN_B0 27, 28 P/I Input for Buck0. The separate power pins VIN_Bx are not connected together internally – VIN_Bx pins must be connected together in the application and be locally bypassed.
VIN_B1 13, 14 P/I Input for Buck1. The separate power pins VIN_Bx are not connected together internally – VIN_Bx pins must be connected together in the application and be locally bypassed.
VOUT_BST 8 P/O Boost output. Bypass switch output when this mode is selected.
WD_RESET 6 D/O Reset output from window watchdog
WDI 7 D/I Digital input signal for window watchdog
Thermal pad N/A G
A: Analog Pin, D: Digital Pin, G: Ground Pin, P: Power Pin, I: Input Pin, O: Output Pin