SLUSAX1F December 2012  – January 2018

UNLESS OTHERWISE NOTED, this document contains PRODUCTION DATA. 

  1. Features
  2. Applications
  3. Description
  4. Revision History
  5. Device Comparison Table
  6. Pin Configuration and Functions
  7. Specifications
    1. 7.1Absolute Maximum Ratings
    2. 7.2ESD Ratings
    3. 7.3Recommended Operating Conditions
    4. 7.4Thermal Information
    5. 7.5DC Characteristics
    6. 7.6Timing Requirements
    7. 7.7Typical Characteristics
  8. Detailed Description
    1. 8.1Overview
    2. 8.2Functional Block Diagram
    3. 8.3Feature Description
      1. 8.3.1Sense Positive Input for Vx
      2. 8.3.2Output Drive, OUT
      3. 8.3.3Supply Input, VDD
    4. 8.4Device Functional Modes
      1. 8.4.1NORMAL Mode
      2. 8.4.2OVERVOLTAGE Mode
      3. 8.4.3Customer Test Mode
  9. Application and Implementation
    1. 9.1Application Information
      1. 9.1.1Design Requirements
      2. 9.1.2Detailed Design Procedure
        1. 9.1.2.1Application Curves
    2. 9.2Systems Examples
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1Layout Guidelines
    2. 11.2Layout Example
  12. 12Device and Documentation Support
    1. 12.1Related Links
    2. 12.2Receiving Notification of Documentation Updates
    3. 12.3Community Resources
    4. 12.4Trademarks
    5. 12.5Electrostatic Discharge Caution
    6. 12.6Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Features

  • 2-, 3-, 4-, and 5-Series Cell Overvoltage Protection
  • Internal Delay Timer
  • Fixed OVP Threshold
  • High-Accuracy Overvoltage Protection:
    ± 10 mV
  • Low Power Consumption ICC ≈ 1 µA
    (VCELL(ALL) < VPROTECT)
  • Low Leakage Current Per Cell Input < 100 nA
  • Small Package Footprint
    • 8-pin QFN (3.00 mm × 4.00 mm)

Applications

  • Protection for Li-Ion Battery Packs Used in:
    • Handheld Garden Tools
    • Handheld Power Tools
    • Cordless Vacuum Cleaners
    • UPS Battery Backup
    • Light Electric Vehicles (eBike, eScooter, Pedal Assist Bicycles)

Description

The bq7718xy family of products provide an overvoltage monitor and protector for Li-Ion battery pack systems. Each cell is monitored independently for an overvoltage condition. For quicker production-line testing, the bq7718xy device provides a Customer Test Mode (CTM) with greatly reduced delay time.

In the bq7718xy device, an internal delay timer is initiated upon detection of an overvoltage condition on any cell. Upon expiration of the delay timer, the output is triggered into its active state (either high or low depending on the configuration).

Device Information Table(1)

PART NUMBERPACKAGEBODY SIZE (NOM)
bq771800WSON (8)3.00 mm × 4.00 mm
  1. For all available packages, see the orderable addendum at the end of the data sheet and the Device Comparison Table.

Simplified Schematic

bq7718 Block_Diagram.gif