SNVSAQ6A November 2016  – June 2017 LM5170-Q1


  1. Features
  2. Applications
  3. Description
  4. Revision History
  5. Pin Configuration and Functions
  6. Specifications
    1. 6.1Absolute Maximum Ratings
    2. 6.2ESD Ratings
    3. 6.3Recommended Operating Conditions
    4. 6.4Thermal Information
    5. 6.5Electrical Characteristics
    6. 6.6Typical Characteristics
  7. Detailed Description
    1. 7.1Overview
    2. 7.2Functional Block Diagram
    3. 7.3Feature Description
      1. 7.3.1 Bias Supply (VCC, VCCA)
      2. 7.3.2 Undervoltage Lockout (UVLO) and Master Enable or Disable
      3. 7.3.3 High Voltage Input (VIN, VINX)
      4. 7.3.4 Current Sense Amplifier
      5. 7.3.5 Control Commands
        1. Enable Commands (EN1, EN2)
        2. Command (DIR)
        3. Current Setting Commands (ISETA or ISETD)
      6. 7.3.6 Channel Current Monitor (IOUT1, IOUT2)
      7. 7.3.7 Cycle-by-Cycle Peak Current Limit (IPK)
      8. 7.3.8 Error Amplifier
      9. 7.3.9 Ramp Generator
      10. 7.3.10Soft Start
        1. Control by the SS Pin
        2. Start by MCU Through the ISET Pin
        3. SS Pin as the Restart Timer
      11. 7.3.11Gate Drive Outputs, Dead Time Programming and Adaptive Dead Time (HO1, HO2, LO1, LO2, DT)
      12. 7.3.12PWM Comparator
      13. 7.3.13Oscillator (OSC)
      14. 7.3.14Synchronization to an External Clock (SYNCIN, SYNCOUT)
      15. 7.3.15Diode Emulation
      16. 7.3.16Power MOSFET Failure Detection and Failure Protection (nFAULT, BRKG, BRKS)
        1. Detection Selection at the SYNCOUT Pin
        2. Circuit Breaker Function
      17. 7.3.17Overvoltage Protection (OVPA, OVPB)
        1. Port OVP (OVPA)
        2. OVP (OVPB)
    4. 7.4Device Functional Modes
      1. 7.4.1Multiphase Configurations (SYNCOUT, OPT)
        1. in Star Configuration
        2. of 2, 3, or 4 Phases in Master-Slave Daisy-Chain Configurations
        3. of 6 or 8 Phases in Master-Slave Daisy-Chain Configurations
      2. 7.4.2Multiphase Total Current Monitoring
    5. 7.5Programming
      1. 7.5.1Dynamic Dead Time Adjustment
      2. 7.5.2Optional UVLO Programming
  8. Application and Implementation
    1. 8.1Application Information
      1. 8.1.1Typical Key Waveforms
        1. Power-Up Sequence
        2. to Eight Phase Programming
      2. 8.1.2Inner Current Loop Small Signal Models
        1. Signal Model
        2. Current Loop Compensation
      3. 8.1.3Compensating for the Non-Ideal Current Sense Resistor
      4. 8.1.4Outer Voltage Loop Control
    2. 8.2Typical Application
      1. 8.2.160-A, Dual-Phase, 48-V to 12-V Bidirectional Converter
        1. Requirements
        2. Design Procedure
          1. Determining the Duty Cycle
          2. Oscillator Programming
          3. Power Inductor, RMS and Peak Currents
          4. Current Sense (RCS)
          5. Current Setting Limits (ISETA or ISETD)
          6. Peak Current Limit
          7. Power MOSFETS
          8. Bias Supply
          9. Boot Strap
          10. Generators
          12. Time
          13. Monitors
          14. Pin Usage
          15. Pin Configuration
          16. Compensation
          17. Start
          18. Pins
        3. Curves
  9. Power Supply Recommendations
  10. 10Layout
    1. 10.1Layout Guidelines
    2. 10.2Layout Examples
  11. 11Device and Documentation Support
    1. 11.1Device Support
      1. 11.1.1Development Support
    2. 11.2Receiving Notification of Documentation Updates
    3. 11.3Community Resources
    4. 11.4Trademarks
    5. 11.5Electrostatic Discharge Caution
    6. 11.6Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Orderable Information


  • AEC-Q100 Qualified for Automotive Applications:
    • Device Temperature Grade 1: –40°C to +125°C Ambient Operating Range
    • Device HBM ESD Classification Level 2
    • Device CDM ESD Classification Level C4B
  • 100-V HV-Port and 65-V LV-Port Max Ratings
  • 1% Accurate Bidirectional Current Regulation
  • 1% Accurate Channel Current Monitoring
  • 5-A Peak Half-Bridge Gate Drivers
  • Programmable or Adaptive Dead-Time Control
  • Programmable Oscillator Frequency With Optional Synchronization to External Clock
  • Independent Channel Enable Control Inputs
  • Analog and Digital Channel Current Control Inputs
  • Programmable Cycle-by-Cycle Peak Current Limit
  • HV and LV Port Overvoltage Protection
  • Diode Emulation Prevents Negative Current
  • Programmable Soft-Start Timer
  • MOSFET Failure Detect at Start-Up and Circuit Breaker Control
  • Multiphase Operation Phase Adding or Dropping


  • Automotive Dual-Battery Systems
  • Super-Cap or Battery Backup Power Converters
  • Stackable Buck or Boost Converters

Simplified Application Circuit

LM5170-Q1 simplified_application_schematic_snvsaq6.gif


The LM5170-Q1 controller provides the essential high voltage and precision elements of a dual-channel bidirectional converter for automotive 48-V and 12-V dual battery systems. It regulates the average current flowing between the high voltage and low voltage ports in the direction designated by the DIR input signal. The current regulation level is programmed through analog or digital PWM inputs.

Dual-channel differential current sense amplifiers and dedicated channel current monitors achieve typical current accuracy of 1%. Robust 5-A half-bridge gate drivers are capable of driving parallel MOSFET switches delivering 500 W or more per channel. The diode emulation mode of the synchronous rectifiers prevents negative currents but also enables discontinuous mode operation for improved efficiency with light loads. Versatile protection features include cycle-by-cycle current limiting, overvoltage protection at both HV and LV ports, MOSFET failure detection and overtemperature protection.

An innovative average current mode control scheme maintains constant loop gain allowing a single R-C network to compensate both buck and boost conversion. The oscillator is adjustable up to 500 kHz and can synchronize to an external clock. Multiphase parallel operation is achieved by connecting two LM5170-Q1 controllers for 3- or 4-phase operation, or by synchronizing multiple controllers to phase-shifted clocks for a higher number of phases. A low state on the UVLO pin disables the LM5170-Q1 in a low current shutdown mode.

Device Information(1)

LM5170-Q1TQFP (48)7.00 mm × 7.00 mm
  1. For all available packages, see the orderable addendum at the end of the data sheet.

Channel Current Tracking ISETA Command

LM5170-Q1 waveform_01_channel_current_regulation_tracks_iseta_command_snvsaq6.png

Revision History

Changes from * Revision (November 2016) to A Revision