Texas Instruments Evaluation Module for BQ76925 Analog Front End for 3 to 6 Series Lithium-Ion Cells BQ76925EVM BQ76925EVM 데이터 시트
제품 코드
BQ76925EVM
Circuit Details and Configuration
WARNING
Use caution when mating batteries with a charger power supply.
Some power supplies cannot tolerate current being fed into their
output terminals. A battery connected to a power supply can easily
cause this to happen. A properly sized blocking diode connected
to the positive output voltage of the power supply can provide
adequate protection against backfeed from the battery and into the
power supply electronics.
Some power supplies cannot tolerate current being fed into their
output terminals. A battery connected to a power supply can easily
cause this to happen. A properly sized blocking diode connected
to the positive output voltage of the power supply can provide
adequate protection against backfeed from the battery and into the
power supply electronics.
1.3.8
Electronic Load
An electronic load is often needed to sink current or power from the battery and through the EVM. A
constant-current load provides a good means of evaluating the performance of the bq76925 when a
battery is used. Equipment rating depends on the application. Typical criteria for electronic load selection
are a voltage rating of up to 4.5 V/cell and up to 20-A discharge capability with 10-mA resolution.
constant-current load provides a good means of evaluating the performance of the bq76925 when a
battery is used. Equipment rating depends on the application. Typical criteria for electronic load selection
are a voltage rating of up to 4.5 V/cell and up to 20-A discharge capability with 10-mA resolution.
1.3.9
Digital Multimeter
One or two digital multimeters (DMM) capable of voltage, current, and temperature measurement equal to
or greater than the accuracy ratings of the bq76925 are needed for adequate evaluation. Numerous test
clips on the PCB can accept a DMM.
or greater than the accuracy ratings of the bq76925 are needed for adequate evaluation. Numerous test
clips on the PCB can accept a DMM.
1.3.10
Oscilloscope
An oscilloscope may be needed if evaluation of waveforms or timing measurements is required. Typical
waveforms that a user may be interested in are the I2C signals (100 kHz), cell-balancing waveforms or
capture of the activation time of the ALERT signal after an overcurrent event may be of interest. These
signals can happen down to the 10s of microseconds time base.
waveforms that a user may be interested in are the I2C signals (100 kHz), cell-balancing waveforms or
capture of the activation time of the ALERT signal after an overcurrent event may be of interest. These
signals can happen down to the 10s of microseconds time base.
2
Circuit Details and Configuration
This section highlights the important features of the EVM circuit, gives some operating instructions, and
also provides a description of the connector pin assignments. Read through this section before using the
EVM for the first time.
also provides a description of the connector pin assignments. Read through this section before using the
EVM for the first time.
CAUTION
Do not connect the battery, power supplies, or interface at this time. Wait until
the next section.
the next section.
2.1
Connections
Pin 1 on all multisignal-pin headers is indicated by a square solder pad.
2.1.1
BATT+, BATT
–
(CN1, CN2)
These connections connect the battery terminals to the circuit.
The positive, current-carrying connection of the battery connects to the BATT+ terminal (CN1).
The negative, current-carrying connection of the battery connects to the BATT
–
terminal (CN2).
The BATT
±
connections are single, heavy-duty screw terminals that feature a 6-32
×
1/4-in.-long screw.
This connector is rated to 30 A, maximum. Actual current is limited to a lower value (20 A) by other circuit
board components.
board components.
6
bq76925EVM Evaluation Module
SLUU514
–
July 2011
Copyright
©
2011, Texas Instruments Incorporated