SLUUCB5E June   2020  – July 2022 BQ25792 , BQ25798

 

  1.   BQ25792EVM, BQ25798BKUPEVM and BQ25798EVM (BMS034) Evaluation Module
  2. 1Introduction
    1. 1.1 EVM Features
    2. 1.2 I/O Descriptions
    3. 1.3 Recommended Operating Conditions
  3. 2Test Setup and Results
    1. 2.1 Equipment
    2. 2.2 Equipment Setup
    3. 2.3 Software Setup
      1. 2.3.1 BQSTUDIO using EV2400
      2. 2.3.2 TI Charger GUI for USB2ANY
    4. 2.4 Test Procedure
      1. 2.4.1 Initial Settings
      2. 2.4.2 Communication Verification
      3. 2.4.3 Charge Mode Verification
      4. 2.4.4 OTG Mode Verification
  4. 3PCB Layout Guidelines
  5. 4Board Layout, Schematic and Bill of Materials
    1. 4.1 BMS034 Board Layout
    2. 4.2 BQ2579XEVM (BMS034) Schematics
    3. 4.3 Bill of Materials
  6. 5Revision History

2.4.3 Charge Mode Verification

Use the following steps for charge mode verification, including pre-charge, CC and CV phases for boost operation:

  1. PS1 and Load #1 should be on from Section 2.4.1. In the EVM GUI, it is generally recommended to read REG22-REG27 (or READ ALL REGISTERS) one time in order to show all the interrupts (from status changes, automated routine completion, faults) that occurred since the last read. Reading those registers a second clears the interrupts. After reading the registers,
    • Verify ➡ REG1B reports all Normal, meaning no DPM loops active and no WD timer fault (bits 7-4), VAC1 Present (bit2), VBUS Present (bit 0) and Power Good (bit 3)
  2. Reinstall the shunt on jumper J17 to enable charge
    • Verify ➡ STAT LED (D13) is lit
  3. Take measurements as follows, noting that you may have to adjust the output of the load to accommodate for voltage drop across the leads from the load to the EVM:
    • Measure ➡ VVBUS-PGND (TP23 and TP44) = 5.0 V ±0.2 V
    • Measure ➡ VBAT-PGND (TP29 and TP46) = 5.0 V ±0.2 V
    • Measure ➡ IBAT_SENSE (voltage across 0.01 ohm resistor between TP19 and TP20) = 240 mA ±60 mA
    • Click READ ALL REGISTERS and Verify ➡ REG1Cb[7:5] reports pre charge
  4. Increase Load #1 regulation voltage to 8.0 V and take measurements as follows, noting that you may have to adjust the output of the load to accommodate for voltage drop across the leads from the load to the EVM:
    • Measure ➡ VVBUS-PGND (TP23 and TP44) = 5.0 V ±0.2 V
    • Measure ➡ VBAT-PGND (TP29 and TP46) = 8.0 V ±0.1 V
    • Measure ➡ IBAT_SENSE (voltage across 0.01-Ω resistor between TP19 and TP20) = 500 mA ±50 mA
    • Measure ➡ IVAC1_SENSE (voltage across 0.01-Ω resistor between TP1 and TP2) = 900 mA ±60 mA
    • Click READ ALL REGISTERS and Verify ➡ REG1Cb[7:5] reports fast charge
  5. Increase Load #1 regulation voltage to 8.4 V and take measurements as follows:
    • Measure ➡ VBAT-PGND (TP29 and TP46) = 8.4 V ±0.04 V
    • Measure ➡ IBAT_SENSE (voltage across 0.01-Ω resistor between TP19 and TP20) = 0 mA ±10 mA
    • Click READ ALL REGISTERS and Verify ➡ REG1Cb[7:5] reports termination
  6. Helpful hints when changing voltages and register settings from those above during charge mode:
    • If increasing charge current or adding a load at SYS J3 terminal, you will likely need to disable the EN_ILIM bit using 8-bit register tab/Charger Single-bit Registers/REG14b[1] and increase the IINDPM register setting in 16-bit register tab/Charger Multi-bit Registers/REG06b[8:0].
    • If increasing the input voltage above 8 V for the charger to enter buck mode, you will need to increase the VAC_OVP from 7 V default using 8-bit register tab/Charger Multi-bit Registers/REG10b[5:4].
    • The battery configuration is set at startup using the PROG pin (Jumpers JP24 to JP31). The battery configuration can also be changed using 16-bit register tab/Charger Multi-bit Registers/REG0Ab[7:6]. Note that the SYSMIN and charge current charge with cell configuration.
    • The status, fault and interrupt bits report are helpful debug tools.