BQ7694003DBTR: Technical Parameters, Applications, Layout Guidelines and More
02 February 2024
The BQ7694003DBTR is a multi-function battery management integrated circuit produced by Texas Instruments, typically used to monitor and manage lithium-ion or lithium-polymer batteries. It is designed to provide battery protection functions, including monitoring and protection of over-voltage, under-voltage, over-charge current and over-discharge current, to ensure that the battery operates within a safe range. This article will introduce it in detail from the aspects of technical parameters, applications, layout guidelines, etc.
The BQ7694003DBTR lithium-ion and lithium phosphate battery monitor is a powerful analog front-end (AFE) device suitable for battery pack monitoring and protection solutions in next-generation high-power systems such as light-duty electric vehicles, power tools, and uninterruptible power supplies. Its design focuses on low power consumption, and the current consumption of the overall chip can be controlled by turning on or off sub-blocks within the IC. In addition, SHIP mode provides an easy way to put the battery pack into an ultra-low power state. The device is surface mount mounted and has an operating temperature range of 40°C to 85°C.
Alternatives and equivalents:
• The operating supply current of BQ7694003DBTR is 40 uA.
• Its output voltage is 0V to 16V.
• Its working power supply voltage is 6V to 25V.
• Its operating temperature is -40°C to 85°C.
• Its installation method is SMD or SMT.
• The manufacturer of BQ7694003DBTR is Texas Instruments.
• BQ7694003DBTR belongs to the category of integrated circuit.
• BQ7694003DBTR has 44 pins and comes in TSSOP-44 package and tape and reel packaging.
The BQ7694003DBTR device supports up to 10 series units, while the BQ76940 device supports up to 15 series units. Through I2C, the host controller can use the BQ769x0 to implement battery pack management functions such as monitoring (battery voltage, battery pack current, battery pack temperature), protection (controlling charge/discharge FETs) and balancing. The integrated A/D converter enables purely digital readout of key system parameters, including battery voltage and internal or external temperature, and is calibrated during TI's manufacturing process. In order to improve the reliability of the battery pack, BQ7694003DBTR includes hardware protection for voltage (OV, UV) and current (OCD, SCD).
• Drones: Li-ion batteries are the main source of energy for drones, and the BQ7694003DBTR can be used to monitor and protect drone batteries against safety risks caused by overcharging, over-discharging, and other issues.
• Solar storage system: Li-ion batteries are often used to store solar energy in solar storage systems. The BQ7694003DBTR can be used to monitor and protect these batteries to ensure their safe operation in different charge or discharge cycles.
• Industrial power systems: By integrating with the control systems of industrial equipment, the BQ7694003DBTR can provide real-time information about the status of the batteries, enabling the operator or the system to make timely adjustments or take necessary protective measures. For example, when the battery voltage is too high or too low, it can automatically shut down the battery to prevent damage; when the battery temperature is abnormal, it can trigger an alarm or cooling system to ensure safety.
• Emergency power systems: In emergency power systems that require long and reliable operation, the BQ7694003DBTR can be used to monitor and protect the battery. It monitors parameters such as battery voltage, current and temperature in real time to ensure that the battery is always in a safe and efficient operating condition. Through preventive protection measures, the BQ7694003DBTR can extend the service life of the battery and ensure that the battery can quickly provide the required power in case of emergency.
• Portable electronic devices: Li-ion batteries have become the primary power solution in portable electronic devices such as laptops and smartphones. The BQ7694003DBTR provides powerful battery monitoring and protection for these devices, which require high battery safety and performance due to their portability and long duration of use.
• Electric vehicles: The BQ7694003DBTR allows real-time monitoring of each individual battery. In the lithium battery pack of an electric vehicle, if a battery cell fails or its performance decreases, it will not only affect the performance of the whole battery pack, but also may cause safety problems. It can accurately monitor the parameters such as voltage, current and temperature of each battery cell to detect abnormalities and deal with them in time, thus preventing the whole battery pack from being damaged due to the problems of a single cell.
It is strongly recommended for best measurement performance to keep high current signals from interfering with the measurement system inputs and ground. A second key recommendation is to ensure that the BQ769x0 input filtering capacitors and power capacitors are connected to a common ground with as little parasitic resistance between the connections as possible.
The following figure shows a guideline of how to place key components compared to respective ground zones, based on the BQ76920, BQ76930, and BQ76940 EVMs.
The BQ7694003DBTR chip has the following features to balance and protect the battery pack:
• Battery protection: With built-in protection functions such as overcharge detection, overdischarge detection, and overcurrent detection, it can effectively prevent battery damage and safety accidents.
• Communication interface: The BQ7694003DBTR usually also provides a communication interface, such as I2C or SPI, to communicate with an external microprocessor or controller. This allows the system to monitor the battery status in real time and take appropriate action when needed.
• Temperature monitoring: The BMS can also monitor the temperature of the battery pack. Excessively high or low temperatures can cause damage to the battery, so the BQ7694003DBTR can monitor the temperature via a temperature sensor and take protective measures when needed.
• Battery equalization: The BQ7694003DBTR can activate the battery equalization function when the voltage of a single cell in the battery pack exceeds or falls below a set threshold. By adjusting the current flow between the batteries, the equalization function can ensure that the voltage of each single cell remains within a safe range, extending the life of the battery pack.
The BQ7694003DBTR features several status registers revealing the present condition of the battery, along with alarms and faults. By examining the register values, we can identify triggered alarms or faults, such as overcharging, overdischarging, overcurrent, or temperature irregularities. Once the nature of the problem has been determined, we should take appropriate measures to fix it. For example, if it is an overcharging problem, we can stop the charging operation; if it is an overdischarging problem, we can stop the discharging. We need to ensure that our systems have appropriate protection and recovery mechanisms to cope with these failure situations.
In some cases, we may need to adjust the configuration and settings of the BQ7694003DBTR to suit a particular application. This may include modifying the thresholds for overcharge and overdischarge, adjusting the trigger point for temperature protection, and so on. Should the issue endure, it is imperative to engage in system-level troubleshooting to inspect potential issues related to battery connections, sensor connections, and system power. It is essential to verify the functionality of hardware connections and ensure the proper operation of both sensors and batteries. Additionally, we need to check if there are firmware or software updates available to resolve known issues or improve system stability and performance.
Frequently Asked Questions
1. What does a battery management system do?
The task of battery management systems is to ensure the optimal use of the residual energy present in a battery.
2. What is the operating temperature range of BQ7694003DBTR?
The operating temperature of BQ7694003DBTR ranges from -40°C to 85°C.
3. What is the primary function of the BQ7694003DBTR?
The BQ7694003DBTR is a battery monitor and protector IC designed for use in lithium-ion and lithium-polymer battery packs.
4. What communication interfaces are supported by the BQ7694003DBTR?
The BQ7694003DBTR supports communication interfaces such as I2C and HDQ for easy integration with microcontrollers or other control systems.