SLUUC74 May   2021 BQ25720 , BQ25723

 

  1.   Trademarks
  2. 1Introduction
    1. 1.1 EVM Features
    2. 1.2 General Description
  3. 2Test Summary
    1. 2.1 Definitions
    2. 2.2 Equipment
    3. 2.3 Equipment Setup
    4. 2.4 Procedure
      1. 2.4.1 Charge Function
      2. 2.4.2 OTG Function
  4. 3Bill of Materials, Board Layout, and Schematics
    1. 3.1 Bill of Materials
    2. 3.2 Board Assembly Layout
    3. 3.3 Schematic

General Description

The BQ2572x evaluation modules are complete charger modules for evaluating an SMBus or I2C-controlled buck boost charger using the BQ2572x devices.

The BQ2572x EVM does not include the EV2400 interface board. To evaluate the BQ2572x EVM, order an EV2400 interface board separately.

The BQ2572x is a synchronous NVDC-1 battery buck boost charge controller, offering a low component count, high efficiency solution for space-constrained, multi-chemistry battery charging applications.

The NVDC-1 configuration allows the system to be regulated at the battery voltage, but does not drop below the system minimum voltage. The system keeps operating even when the battery is completely discharged or removed. When load power exceeds the input source rating, the battery supplement mode prevents the input source from being overloaded.

The BQ2572x charges the battery from a wide range of input sources including a 5-V USB adapter to a high-voltage USB PD source and traditional adapters.

During power up, the charger sets the converter to buck, boost, or buck-boost configuration based on the input source and battery conditions. During the charging cycle, the charger automatically transits among buck, boost, and buck-boost configuration without host control.

The BQ2572x monitors adapter current, battery current, and system power. The flexibly programmed PROCHOT output goes directly to the CPU for throttle back, when needed.

For more details on register functions, see the BQ25720 SMBus 1- to 4-Cell Narrow VDC Buck-Boost Battery Charge Controller With System Power Monitor and Processor Hot Monitor and BQ25723 I2C 1- to 4-Cell Narrow VDC Buck-Boost Battery Charge Controller With System Power Monitor and Processor Hot Monitor data sheets.

Table 1-1 lists the I/O descriptions.

Table 1-1 I/O Description
Jack Description
J1–VIN Input: positive terminal
J1–PGND Input: negative terminal (ground terminal)
J2-ILIM_HIZ External converter disable
J2-CHRG_OK CHRG_OK output
J2-ENZ_OTG External OTG disable pin
J2-CELL_control External battery removal control; logic high to pull the CELL pin down
J3–3V3 Onboard 3.3-V output
J3–SDA SMBUS or I2C SDA
J3-SCL SMBUS or I2C SCL
J3-GND Ground
J4-CMPOUT CMPOUT pin output
J4-GND Ground
J4-CMPIN External CMPIN pin input
J5-VBAT Connected to battery pack output
J5-PGND Ground
J6-VSYS Connected to system output
J6-PGND Ground

J7–SDA

SMBUS or I2C SDA
J7-SCL SMBUS or I2C SCL
J7-GND Ground

Table 1-2 displays the controls and key parameters settings.

Table 1-2 Controls and Key Parameters Setting
Jumper Description Factory Setting
JP1 Bypass inrush control circuit
JP1 on: bypasses input FETs Q6 and Q7 external selector
JP1 off: CHRG_OK controls Q6 and Q7 external selector
Installed
JP2 Jumper on: Forward Mode
Jumper off: OTG Mode
Installed
JP3 CELL setting:
1S: JP3(1-2), measure CELL pin voltage 1.5 V
2S: JP3(3-4), measure CELL pin voltage 2.4 V
3S: JP3(5-6), measure CELL pin voltage 3.3 V
4S: JP3(7-8), measure CELL pin voltage 4.5 V
2S setting: JP3(3-4)
JP4 Jumper on: Bat removal Jumper off: Cell setting by JP3 Not installed
JP6 For input current setting:
Jumper on: ILIM_HIZ LOW.
Jumper off: Allow pre-bias ILIM_HIZ
Not installed
JP7 VBUS source selection
JP7 (1-2): VBUS pin on VIN
JP7 (2-3): VBUS pin on ACP
Installed: JP7(1-2)
JP8 Jumper on: Onboard LDO to drive the EVM 3V3
Jumper off: disconnect onboard LDO to drive the EVM 3V3
Installed

Table 1-3 lists the recommended operating conditions.

Table 1-3 Recommended Operating Conditions
SymbolDescriptionMINTYPMAXUnit
Supply voltage, VINInput voltage from AC adapter input3.55, 9, 15, 2026V
Battery voltage, VBATVoltage applied at VBAT terminal019.2V
Supply current, IACMaximum input current from AC adapter input06.4A
Output current, IoutOutput current08A
Operating junction temperature range, TJ0125°C