Linear Technology LTC2977 Demo Board: Octal Power Supply Manager [Requires DC1613] DC2028A User Manuals

Table of Contents

• Features

  1
• Applications

  1
• Typical Application

  1
• Description

  1
• Absolute Maximum Ratings

  4
• Order Information

  4
• Pin Configuration

  4
• Electrical Characteristics

  5
• PMBus Timing Diagram

  9
• Typical Performance Characteristics

  10
• Pin Functions

  13
• Block Diagram

  15
• Operation

  16
  • Operation Overview

    16
    • EEPROM

      17
  • Reset

    17
  • Write-Protect Pin

    17
  • Other Operations

    17
    • Clock Sharing

      17
  • PMBus Serial Digital Interface

    18
    • PMBus

      18
    • Device Address

      21
    • Processing Commands

      22
• PMBus Command Summary

  23
  • Summary Table

    23
    • Data Formats

      27
• PMBus Command Description

  28
  • Addressing and Write Protect

    28
    • PAGE

      28
    • WRITE_PROTECT

      28
    • MFR_PAGE_FF_MASK

      29
    • MFR_I2C_BASE_ADDRESS

      29
    • MFR_COMMAND_PLUS, MFR_DATA_PLUS0, MFR_DATA_PLUS1, MFR_STATUS_PLUS0, and MFR_STATUS_PLUS1

      30
    • Reading Fault Log Using Command Plus and Mfr_data_plus0

      31
    • Peek Operation using Mfr_data_plus0

      32
    • Enabling and Disabling Poke Operations

      32
    • Poke Operation Using Mfr_data_plus0

      32
    • Command Plus Operations Using Mfr_data_plus1

      32
  • Operation, Mode and EEPROM Commands

    33
    • OPERATION

      33
    • ON_OFF_CONFIG

      34
    • CLEAR_FAULTS

      34
    • STORE_USER_ALL and RESTORE_USER_ALL

      35
    • CAPABILITY

      35
    • VOUT_MODE

      35
  • Output Voltage Related Commands

    36
    • VOUT_COMMAND, VOUT_MAX, VOUT_MARGIN_HIGH, VOUT_MARGIN_LOW, VOUT_OV_FAULT_LIMIT, VOUT_OV_WARN_LIMIT, VOUT_UV_WARN_LIMIT, VOUT_UV_FAULT_LIMIT, POWER_GOOD_ON and POWER_GOOD_OFF

      36
  • Input Voltage Related Commands

    36
    • VIN_ON, VIN_OFF, VIN_OV_FAULT_LIMIT, VIN_OV_WARN_LIMIT, VIN_UV_WARN_LIMIT and VIN_UV_FAULT_LIMIT

      36
  • Temperature Related Commands

    37
    • OT_FAULT_LIMIT, OT_WARN_LIMIT, UT_WARN_LIMIT and UT_FAULT_LIMIT

      37
  • Timer Limits

    37
    • TON_DELAY, TON_RISE, TON_MAX_FAULT_LIMIT and TOFF_DELAY

      37
  • Fault Response for Voltages Measured by the High Speed Supervisor

    38
    • VOUT_OV_FAULT_RESPONSE and VOUT_UV_FAULT_RESPONSE

      38
  • Fault Response for Values Measured by the ADC

    39
    • OT_FAULT_RESPONSE, UT_FAULT_RESPONSE, VIN_OV_FAULT_RESPONSE and VIN_UV_FAULT_RESPONSE

      39
  • Timed Fault Response

    40
    • TON_MAX_FAULT_RESPONSE

      40
  • Status Commands

    41
    • STATUS_BYTE

      41
    • STATUS_WORD

      41
    • STATUS_VOUT

      42
    • STATUS_INPUT

      42
    • STATUS_TEMPERATURE

      42
    • STATUS_CML

      43
    • STATUS_MFR_SPECIFIC

      43
  • ADC Monitoring Commands

    44
    • READ_VIN

      44
    • READ_VOUT

      44
    • READ_TEMPERATURE_1

      44
    • PMBUS_REVISION

      44
  • Manufacturer Specific Commands

    45
    • MFR_CONFIG_LTC2977

      45
    • Tracking Supplies On and Off

      46
    • Tracking Implementation

      48
    • MFR_CONFIG_ALL_LTC2977

      49
    • MFR_FAULTBz0_PROPAGATE, MFR_FAULTBz1_PROPAGATE

      50
    • MFR_PWRGD_EN

      51
    • MFR_FAULTB00_RESPONSE, MFR_FAULTB01_RESPONSE, MFR_FAULTB10_RESPONSE and MFR_FAULTB11_RESPONSE

      52
    • MFR_VINEN_OV_FAULT_RESPONSE

      53
    • MFR_VINEN_UV_FAULT_RESPONSE

      54
    • MFR_RETRY_COUNT

      55
    • MFR_RETRY_DELAY

      55
    • MFR_RESTART_DELAY

      55
    • MFR_VOUT_PEAK

      56
    • MFR_VIN_PEAK

      56
    • MFR_TEMPERATURE_PEAK

      56
    • MFR_DAC

      57
    • MFR_POWERGOOD_ASSERTION_DELAY

      57
    • MFR_PADS

      58
    • MFR_SPECIAL_ID

      59
    • MFR_SPECIAL_LOT

      59
    • MFR_VOUT_DISCHARGE_THRESHOLD

      59
    • MFR_COMMON

      60
    • USER_DATA_00, USER_DATA_01, USER_DATA_02, USER_DATA_03, USER_DATA_04, MFR_LTC_RESERVED_1 and MFR_LTC_RESERVED_2

      60
    • MFR_VOUT_MIN

      61
    • MFR_VIN_MIN

      61
    • MFR_TEMPERATURE_MIN

      61
    • MFR_STATUS_2

      62
    • MFR_TELEMETRY

      63
  • Watchdog Operation

    64
    • MFR_WATCHDOG_T_FIRST and MFR_WATCHDOG_T

      64
  • Bulk Programming the User EEPROM Space

    65
    • MFR_EE_UNLOCK

      65
    • MFR_EE_ERASE

      66
    • MFR_EE_DATA

      66
    • Response When Part Is Busy

      67
    • MFR_EE Erase and Write Programming Time

      67
  • Fault Log Operation

    67
    • MFR_FAULT_LOG_STORE

      67
    • MFR_FAULT_LOG_RESTORE

      67
    • MFR_FAULT_LOG_CLEAR

      68
    • MFR_FAULT_LOG_STATUS

      68
    • MFR_FAULT_LOG

      69
• Applications Information

  76
  • Overview

    76
  • Powering the LTC2977

    76
  • Setting Command Register Values

    76
  • Sequence, Servo, Margin and Restart Operations

    76
    • Command Units On or Off

      76
    • On Sequencing

      77
    • On State Operation

      77
    • Servo Modes

      77
    • DAC Modes

      77
    • Margining

      78
    • Off Sequencing

      78
    • VOUT Off Threshold Voltage

      78
    • Automatic Restart Via MFR_RESTART_DELAY Command and CONTROLn pin

      78
  • Fault Management

    78
    • Output Overvoltage and Undervoltage Faults

      78
    • Output Overvoltage and Undervoltage Warnings

      79
    • Configuring the VIN_EN Output

      79
    • Multichannel Fault Management

      81
  • Interconnect Between Multiple LTC2977’s

    81
  • Application Circuits

    82
    • Trimming and Margining DC/DC Converters with External Feedback Resistors

      82
    • Four-Step Resistor Selection Procedure for DC/DC Converters with External Feedback Resistors

      83
    • Trimming and Margining DC/DC Converters with a TRIM Pin

      84
    • Two-Step Resistor and DAC Full-Scale Voltage Selection Procedure for DC/DC Converters with a TRIM Pin

      84
    • Measuring Current

      84
    • Measuring Current with a Sense Resistor

      85
    • Measuring Current with Inductor DCR

      85
    • Single Phase Design Example

      85
    • Measuring Multiphase Currents

      85
    • Multiphase Design Example

      86
    • Anti-aliasing Filter Considerations

      86
    • Sensing Negative Voltages

      87
  • Connecting the DC1613 USB to I2C/SMBus/PMBus Controller to the LTC2977 in System

    87
  • Design Checklist

    89
  • LTpowerPlay: An Interactive GUI for Power System Managers

    89
  • PCB Assembly and Layout Suggestions

    90
    • Bypass Capacitor Placement

      90
    • Exposed Pad Stencil Design

      90
    • PC Board Layout

      91
    • Unused ADC Sense Inputs

      91
• Package Description

  92
• Revision History

  93
• Typical Application

  94
• Related Parts

  94