Texas Instruments BQ25638 Series User manual

EVM User's Guide: BQ25638EVM
BQ25638x Evaluation Module
Description
The BQ25638EVM evaluation module (EVM) is a
complete evaluation system for the BQ25638 IC, a
buck single-cell battery charger with an input range of
3.9 V - 18 V and NVDC power path management.
The BQ25638EVM has a max input of 18 V and a
max charge current of 5 A.
Get Started
1. Order the EVM on ti.com.
2. Order the EV2400 to communicate with the EVM.
3. Download the BQ25638 BQZ file.
4. Download the BQ25638 EVM design files on
ti.com.
Features
• Narrow VDC (NVDC) power path management for
powering the systems and charging the battery.
• Supports I2C communication for systems
configuration and status reporting.
• Test points for key signals available for testing
purposes.
• Jumpers for easy configuration.
• One push-button for wake-up and reset input with
adjustable timers.
• Charge status (STAT) and Power Good (PG)
LEDS for charging monitoring.
• Connections for EV2400.
Applications
•Gaming and computer accessories
•Smart phone, tablet
•IP camera, EPOS
•Portable medical equipment
BQ25638EVM Hardware Board
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1 Evaluation Module Overview
1.1 Introduction
The BMS068 evaluation module (EVM) is a complete charger module for evaluating the BQ25638x devices. The
BQ25638x are I2C-controlled single-cell chargers with NVDC Power Path Management, Integrated ADC, and
OTG Output.
This user's guide provides detailed testing instructions for the BQ25638 evaluation modules (EVM). Also
included are descriptions of the necessary equipment, equipment setup, and procedures. The reference
documentation contains the printed-circuit board layouts, schematics, and the bill of materials (BOM).
Throughout this user's guide, the abbreviations EVM, BQ25638xEVM, BMS068, and the term evaluation module
are synonymous with the BMS068 evaluation module, unless otherwise noted.
Caution
Caution: Hot surface.
Contact can cause burns.
Do not touch!
1.2 Kit Contents
The kit includes the following:
• 1 BQ25638 EVM
1.3 Specifications
Table 1-1 lists the recommended operating conditions for this EVM.
Table 1-1. Recommended Operating Conditions
Symbol Description Min Typ Max Unit
VVBUS, VVAC Input voltage applied to VBUS pin 3.9 18.0 V
VBAT Battery voltage applied to BAT pin 4.8 V
IVBUS Input current into VBUS 3.2 A
ISW Output current from SW flowing to SYS pin load
and battery at BAT pin
5.0 A
IBAT Fast charging current into battery at BAT pin 5.0 A
Continuous RMS discharge current through internal
BATFET
7 A
1.4 Device Information
This EVM does not include the EV2400 or USB2ANY interface boards. To evaluate the EVM, an EV2400 must
be ordered separately to evaluate the EVM with the BQ25638 bqz GUI.
For detailed features and operation, see Table 1-2 for a list of devices and the corresponding data sheets.
Table 1-2. Device Data Sheets
Device Data Sheet EVM Label
BQ25638 SLUSF18 BQ25638EVM
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2 Hardware
2.1 I/O Information
Table 2-1 lists the input and output connections available on this EVM and their respective descriptions.
Table 2-1. EVM I/O Connections
Jack Description
J1(2) - VIN Positive rail of the charger input voltage
J1(1) - GND Ground
J2(1) - SYS Positive rail of the charger system output voltage,
typically connected to the system load
J2(2) - GND Ground
J3(1) - VPMID Positive rail of the charger output voltage for power
bank applications in reverse boost mode (OTG).
This output also shares the rail with the VIN input
rail in forward buck mode
J3(2)-GND Ground
J4(1) - BAT+ Positive rail of the charger battery input, connected
to the positive terminal of the external battery
J4(2) -
TS
Connection available for external thermistor if
required
J4(3) - GND Ground
J5 Input source Micro B USB port
J6 I2C connector for the USB2ANY interface board
J7 I2C connector for the EV2400 interface board
2.2 Jumper Information
Table 2-2 lists the jumper and shunt installations available on this EVM and their respective descriptions.
Table 2-2. EVM Jumper Shunt and Switch Installation
Jack Description BQ25638 Setting
JP1 /INT pull-up. Installed
JP2 SCL pull-up rail. not required if using EV2400. Installed
JP3 SDA pull-up rail. not required if using EV2400. Installed
JP4 I/O Pullup rail selection. Selection has either BAT or SYS as the pullup rail. Installed
Pullup to SYS
JP5 D-_ILIM to 2.2 kohm resistor. Not Installed
JP6 Micro B USB input D- connection to charger D- pin. Not Installed
JP7 PG pin LED indicator connection. On PG enabled chargers, this indicates the Power Good status. Installed
JP8 STAT pin LED indicator connection. This indicates the current charger status. Installed
JP9 Micro B USB input D+ connection to charger D+ pin. Not Installed
JP10 USB2ANY pull-up rail. Not required if using EV2400. Installed
JP11 TS resistor divider pull-up rail. Short pins 1-2
JP12 Charger D+ pin and charger D- pin short connection. Connect this on D+/D- detection enabled
chargers to simulate the connection of a DCP-type USB port as defined by USB BC1.2 and set
IINDPM register to highest setting.
Not Installed
JP13 Connect 10 kohm in parallel with TS resistor network to simulate a battery at 25 C. Disconnect if
using external thermistor.
Installed
JP14 CE pin connection to ground to enable charging. When removed, CE pin pulls up to disable charge. Installed
JP15 D-_ILIM to 3.32 kohm resistor. Not Installed
JP16 D-_ILIM to ground. Installed
S1 QON control switch. Press either for exiting Shipping Mode or System Reset. Default Off
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2.3 Equipment
This section includes a list of supplies required to perform tests on this EVM.
1. Power Supplies: Power Supply #1 (PS #1): A power supply capable of supplying 5 V at 3.5 A is required.
While this part can handle larger voltage and current, the part is not necessary for this procedure.
2. Load #1 for simulating a battery: 4-Quadrant Supply, Constant Voltage < 4.5 V) "Kepco" Load, BOP,
20-5M, DC 0 to ±20 V, 0 to ±5 A (or higher)
Alternative Option: A 0–20V/0–3.5 A, > 30-W DC electronic load set in a constant voltage loading mode
3. Load #2 for simulating a load at SYS or load at VBUS in reverse/OTG mode: Electronic or Resistive
Load capable sinking up to 5-A from up to 9 V (or higher)
4. Meters: 4x "Fluke 75" multi-meters, (equivalent or better).
Alternative Option: (2x) equivalent voltage meters and (2x) equivalent 5-A or higher rated current meters.
5. Computer: A Windows 10 based computer with at least one USB port and a USB cable. Must have the
latest version of Battery Management Studio installed.
6. USB-TO-GPIO Communication Kit: EV2400 USB-based PC interface board.
7. Software: BQStudio software with latest .bqz file for BQ25638x provided by Texas Instruments. Download
and install bqStudio from https://www.ti.com/tool/BQSTUDIO.
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2.4 Hardware Setup
Use the following list to set up the EVM testing equipment:
1. Review EVM jumper connections in Table 2-2.
2. Set PS #1 for 5-V DC, 2-A current limit and then turn off the supply.
3. Connect the output of PS#1 in series with a current meter to J1 (VBUS and PGND).
4. Connect a voltage meter across TP10 (VBUS) and TP29 (PGND), or across J1.
5. Turn on Load #1, set to constant voltage mode, and output to 2.5-V. Disable Load. Connect Load in series
with a current meter (multimeter), ground side, to J4 (BAT and PGND) as shown in Figure 2-1 in not using a
source meter with current measuring capabilities.
6. Connect a voltage meter across TP13 (BAT) and TP27 (PGND), or across J4-3 and J4-1 as in Figure 2-1.
7. Connect a voltage meter across TP14 (SYS) and TP27 (PGND), or across J2-1 and J2-2 as in Figure 2-1.
8. Connect a voltage meter across TP12 (PMID) and TP29 (PGND), or across J3-1 and J3-2 as in Figure 2-1.
9. Connect the EV2400 USB interface board to the computer with a USB cable and from I2C port to J5 with the
4-pin cable as in Figure 2-1.
10. Install shunts as shown in Table 2-2. Note that the shunts in Figure 2-1 are not necessarily installed per the
table.
Power Supply #1
EV2400
4-pin Connector
USB
+
±Load #1
+
±
+
±
VSYS
VBAT
>+
±
Figure 2-1. Test Setup for BQ25638x EVM
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3 Software
3.1 Software Setup
Use the following to set up the EVM testing software:
1. On the computer connected to the EV2400 interface board, launch Battery Management Studio (BQStudio).
Select Charger as seen in Figure 3-1.
Figure 3-1. BQStudio Device Type Selection Window
2. Select the appropriate configuration file based on the device BQ25638x from the window shown in Figure
3-2.
Figure 3-2. BQStudio Charger Selection Window (choose Chargerxxbq25638x.bqz)
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3. Choose , on the window that appears, and the main window of the BQ25638x EVM
software appears, as shown in Figure 3-3.
Figure 3-3. Main Window of BQ25638x EVM Software
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3.2 Test Procedure
3.2.1 Initial Power Up
Use the following steps for enabling the EVM test setup:
1. Make sure that Section 2.4 steps have been followed.
2. Make sure that Section 3.1 steps have been followed.
3. Turn on PS #1:
•Measure → VSYS (SYS-TP19 and PGND-TP21) = 3.70V ±0.2V
Note
Completely disconnect Load #1 from BATTERY connections if different value is seen.
3.2.2 I2C Register Communication Verification
Use the following steps for communication verification :
1. In the EVM software, click the button
• Verify that the GUI reads in the top right corner.
Note
If the device reads verify Section 2.4 and Section 3.2.1 steps have been
followed.
2. In the Field View (see Figure 3-3), make the following changes as necessary:
• Set
• Set
• Set
• Set
• Set
• Set
• Set
• Check
• Uncheck
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3.2.3 Charger Mode Verification
Use the following steps for charger mode verification:
1. PS #1 is on from Section 3.2.1. In the EVM software, click twice.
• Verify that all Fault statuses read Normal.
2. To confirm SYS voltage regulation, enable Load #1 (see Section 2.4) and take DMM measurements as
follows:
•Measure → VSYS (SYS-TP14 and PGND-TP27 or TP29) = 3.65V ±0.3V.
•Measure → VBAT (BAT-TP13 and PGND-TP27 or TP29) = 2.5V ±0.2V.
•Measure → IBAT = 200 mA ±50mA.
3. To confirm battery charge current regulation, change Load #1 to 3.7V and take DMM measurements as
follows:
•Measure → VSYS (SYS-TP14 and PGND-TP27 or TP29) = 3.8V ±0.3V.
•Measure → VBAT (BAT-TP13 and PGND-TP27 or TP29) = 3.7V ±0.2V.
•Measure → IBAT = 480 mA ±100mA.
4. To confirm input current limit operation, in the EVM software on the 16-bit tab, set fast charge current to 1040
mA and then take DMM measurement ( or PS #1 measurement if accurate) as follows:
•Measure → IIN = 500 mA ±200mA.
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3.2.4 Boost Mode Verification
Use the following steps for boost mode verification:
1. Turn off and disconnect PS #1.
2. Set Load #1, the battery simulator, to 3.7V and 2 A current limit.
Note
If Load #1 connected from BATTERY-J4(3) to GND-J4(1) is not a four quadrant supply, then
remove Load #1 and use PS #1, set to 3.7V, 2 A current limit and connect to BATTERY-J4(3) and
GND-J4(1).
3. In the EVM software on the 16-bit tab, confirm that VOTG, the OTG regulation voltage, is set to 5040 mV
and IOTG, the OTG current limit, is set to 1000 mA.
4. In the EVM software on the 8-bit tab, check
5. Connect Load #2 across VPMID-J3(1) and PGND-J3(2).
6. Set Load #2 to 500 mA constant current load and the turn on the load.
7. To confirm the VOTG regulation,
•Measure→ VBUS = 5040 mV + 155 mV
8. Turn off and disconnect the power supply.
9. Remove Load #2 from the connection.
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