SLUUCS1 October   2023 BQ25185

 

  1.   1
  2.   Description
  3.   Features
  4. 1Evaluation Model Overview
    1. 1.1 Introduction
    2. 1.2 Kit Contents
    3. 1.3 Specifications
    4. 1.4 Device Information
  5. 2Hardware
    1. 2.1 EVM Setup
    2. 2.2 EVM Connectors and Test Points
  6. 3Testing Procedures
    1. 3.1 Equipment
    2. 3.2 Charge Mode
    3. 3.3 Factory Mode Entry and Exit
  7. 4Hardware Design Files
    1. 4.1 Schematics
    2. 4.2 Layout
    3. 4.3 Bill of Materials
  8. 5Additional Information
    1. 5.1 Trademarks
  9. 6Revision History

3.2 Charge Mode

Connect the equipment as follows:

  • Power Supply PS #1: VIN of the BQ25185EVM at 5 V

  • Power Supply PS #2: VBAT of the BQ25185EVM at 3.7 V

  • Scope Channel SC#1: VIN at TP4

  • Scope Channel SC#2: VBAT at TP7

  • Scope Channel SC#3: VSYS at TP5

Procedure:

  1. Connect 13 kOhm resistor using S1 switch box. Verify that the resistance from VSET/ILIM pin to GND is 13kOhm

    1. This sets the battery regulation voltage to 4.2 V and the input current limit to 1100 mA

  2. Measure the resistance from ISET to GND.

    1. The resulting fast charge current will follow the equation:

  3. Power on PS #1

    1. Verify that the voltage at VSYS is about 4.5 V

  4. Power on PS #2

    1. Verify that current going into PS#2 is the configured charge current

    2. Another method is to use the voltage at the ISET pin. The voltage at the ISET pin

To change the charge current:

  1. Use the equation Ichg = 300/RIset (AΩ/Ω)

  2. Measure the Resistance on the Iset pin

  3. Adjust the R14 potentiometer to get the right RIset for your desired ICHG

  4. Move the jumper on JP1 to the ADJ position

Note:

The ISET resistance should only be measured when the device is powered off but the ISET potentiometer can be adjusted during operation.

To adjust the charge voltage (VSET) and input current limit (ILim):

  1. Refer to the VSET and IILIM table in the datasheet to see how the resistance on the IILIM pin affects the VBATREG and ILim

  2. Adjust R15-R18 on S1 to set the correct resistance for your desired VSET and ILim

  3. Turn off and on PS#1

Note:

The device will change the VSET/ILIM setting each time a new charge cycle is started (when VIN is plugged in and when /CE is pulled low).