SLUUBG6 May   2017 BQ25700A , BQ25703A

 

  1.   bq2570x Evaluation Module
    1.     Trademarks
    2. 1 Introduction
      1. 1.1 EVM Features
      2. 1.2 General Description
    3. 2 Test 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. 3 Bill of Materials, Board Layout, and Schematics
      1. 3.1 Bill of Materials
      2. 3.2 Board Assembly Layout
      3. 3.3 Schematic

1.2 General Description

The bq2570x evaluation modules are complete charger modules for evaluating an SMBUS or I2C-controlled buck boost charge using the bq2570x devices.

The bq2570x EVM does not include the EV2400 interface board. To evaluate the bq2570x EVM, order an EV2400 interface board separately.

The bq2570x 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 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 bq2570x 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 bq2570x 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 data sheets – bq25700A (SLUSCQ8) and bq25703A (SLUSCU1).

Table 1 lists the I/O descriptions.

Table 1. I/O Description

Jack Description
J1–VIN Input: positive terminal
J1–GND Input: negative terminal (ground terminal)
J2-ILIM_control External converter disable; logic high to pull the ILIM pin down
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-BAT Connected to battery pack output
J5-GND Ground
J6-SYS Connected to system output
J6-GND Ground

Table 2 displays the controls and key parameters settings.

Table 2. Controls and Key Parameters Setting

Jack Description Factory Setting
JP1
JP7		 Inrush control setting:
spa1. Bypass inrush control circuit
spa1. JP1 on: bypasses input FETs Q9 and Q10 external selector spa1.
spa1. JP7 top two connection (pin 2 is connected to pin 3): VBUS pin on ACP
spa2. Enable inrush control circuit
spa2. JP1 off: CHRG_OK controls Q9 and Q10 external selector
spa2. JP7 bottom two connection: VBUS pin on VIN 		Bypass inrush control circuit:
spaJP1 installed
spaJP7 top two position installed
spa(pin2 is connected pin3)
JP2
JP3
JP4		 CELL setting:
spa1S: JP2, JP3, JP4 all open, measure CELL pin voltage 1.2 V
spa2S: JP2 closed, JP3 and JP4 open, measure CELL pin voltage 2.7 V
spa3S: JP3 closed, JP2 and JP4 open, measure CELL pin voltage 3.5 V
spa4S: JP2, JP3 closed, JP4 open, measure CELL pin voltage 4.2 V Bat
sparemoval, short JP4 		2S setting: JP2 installed JP3, JP4 all open
JP5 Jumper on: Pre-bias ILIM_HIZ
Jumper off: Ground ILIM_HIZ 		Installed
JP6 For input current setting:
spa Jumper on: ILIM_HIZ LOW.
spa Jumper off: Allow pre-bias ILIM_HIZ 		Not installed
JP8 Jumper on: On-board LDO to drive the EVM 3V3
Jumper off: disconnect on-board LDO to drive the EVM 3V3 		Installed

Table 3 lists the recommended operating conditions.

Table 3. Recommended Operating Conditions

Symbol Description MIN TYP MAX Unit
Supply voltage, VIN Input voltage from ac adapter input 3.5 5/12/19 24 V
Battery voltage, VBAT Voltage applied at VBAT terminal 0 19.2 V
Supply current, IAC Maximum input current from ac adapter input 0 3 A
Output current, Iout Output current 0 8 A
Operating junction temperature range, TJ 0 125 °C