The BQ25890RTWR is a part of the Texas Instruments (TI) product lineup, specifically a highly integrated battery charger and Power Management IC for single-cell lithium-ion (Li-ion) and lithium-polymer (LiPo) batteries. The part number indicates the device’s packaging and specifications.
Regarding the pin function specifications and the circuit principle instructions, the detai LED explanation of the device involves describing the full pinout, along with the specific functionality of each pin. Since this device is complex, it's necessary to break down each of its pins' functionalities and how they relate to the broader circuit design.
BQ25890RTWR Packaging and Pinout
Packaging: The BQ25890RTWR comes in a VQFN-20 (Very Thin Quad Flat No-lead) package. This package has 20 pins in total, and each of these pins plays a crucial role in controlling various aspects of charging, monitoring, and communication for battery systems.
Pinout and Functions: Here is the detailed description of the pin functions:
Pin # Pin Name Function Description 1 BAT Battery Input Pin. Used for connecting to the positive terminal of the battery. 2 SYS System Power Output. Powers the system from the battery or external input power. 3 ISET Current Set Pin. Determines the current limit by connecting to a resistor. 4 TS Temperature Sense Pin. Monitors the battery's temperature for thermal regulation. 5 ILIM Input Current Limit. Sets the limit for the input current. 6 STAT1 Status Output 1. Used for indicating charging status through a LED or another indicator. 7 STAT2 Status Output 2. Similar to STAT1, provides another status indication. 8 CHGIN Charge Input Pin. This is where the charging voltage is supplied. 9 CHG Charge Enable. This pin enables or disables charging functionality. 10 SDA Data Line for I2C communication. Used for sending and receiving data to/from a microcontroller or other devices. 11 SCL Clock Line for I2C communication. Works alongside the SDA pin for communication protocols. 12 VSTOR Storage Pin. Used to store the external system voltage to be supplied to the system. 13 PGND Power Ground. Provides a common ground for the device. 14 AGND Analog Ground. Used for sensitive analog circuitry ground reference. 15 VDD Voltage Supply Pin. This pin is connected to the supply voltage, typically from a DC input. 16 PCHG Pre-Charge Indicator Pin. Indicates when the pre-charge phase is active during the charging cycle. 17 VSTBY Standby Pin. Used to place the device in a low power standby mode. 18 EN Enable Pin. Used to turn the charger on or off based on the control signal. 19 SRP System Reserve Pin. Used for reserving some capacity in the system. 20 SRN System Reserve Negative Pin. Complements SRP for system reserve functionality.Circuit Principle Instructions
The BQ25890RTWR is designed to efficiently manage the charging and monitoring of a single-cell lithium-ion or lithium-polymer battery. It integrates many functions to make the charging process easier, including thermal regulation, current regulation, and power-path management. The device supports multiple charging profiles and can provide information about the battery status via I2C communication.
Input Power Management : It regulates the input current, ensuring that the battery charges safely without exceeding its limits. This is controlled via the ILIM pin. Charge Management: The device controls charging phases like pre-charging, constant current, and constant voltage using the CHG pin, while monitoring the battery temperature and voltage to prevent overcharging. System Power: The SYS pin powers the connected system directly from the battery, enabling the device to handle power switching between input and battery sources seamlessly. Monitoring: Through the SDA and SCL I2C pins, the BQ25890RTWR can communicate battery data, like voltage, current, temperature, and charging status, to a microcontroller for further decision-making. Temperature Sensing: The TS pin allows the monitoring of the battery temperature to protect against overheating.20 Common FAQ for BQ25890RTWR
Q1: What is the BQ25890RTWR used for? A1: The BQ25890RTWR is used as a single-cell battery charger and power management IC for lithium-ion and lithium-polymer batteries.
Q2: How many pins does the BQ25890RTWR have? A2: The BQ25890RTWR has 20 pins in its VQFN-20 package.
Q3: What does the BAT pin do? A3: The BAT pin connects to the positive terminal of the battery and allows the charger IC to manage the battery's charge and discharge cycles.
Q4: What is the function of the TS pin? A4: The TS pin monitors the battery temperature to prevent overheating during charging.
Q5: What is the purpose of the ISET pin? A5: The ISET pin is used to set the current limit by connecting a resistor, controlling the maximum charging current.
Q6: Can the charging be disabled? A6: Yes, the charging can be disabled using the CHG pin, which acts as a charge enable control.
Q7: What is the significance of the STAT1 and STAT2 pins? A7: The STAT1 and STAT2 pins are used for indicating the charging status (e.g., charging, fully charged) with external LEDs.
Q8: How is the BQ25890RTWR controlled? A8: The BQ25890RTWR is controlled via the I2C interface using the SDA and SCL pins.
Q9: What is the role of the CHGIN pin? A9: The CHGIN pin is used to connect the charging input power, supplying voltage to charge the battery.
Q10: How does the device handle input power? A10: The input power is managed via the CHGIN pin, with the ILIM pin setting the current limit.
Q11: What does the SYS pin do? A11: The SYS pin provides the system power from the battery or external input power.
Q12: What is the VSTOR pin for? A12: The VSTOR pin is used to store and manage the external system voltage supplied to the system.
Q13: How is thermal regulation handled? A13: Thermal regulation is done using the TS pin, which monitors battery temperature to ensure safe charging conditions.
Q14: What does the PGND pin represent? A14: The PGND pin is the power ground, serving as the reference ground for the power components.
Q15: How can the system be put into low power mode? A15: The system can be put into low power standby mode using the VSTBY pin.
Q16: What does the EN pin do? A16: The EN pin is used to enable or disable the charger.
Q17: Can the device be used with different battery chemistries? A17: No, the BQ25890RTWR is specifically designed for lithium-ion and lithium-polymer batteries.
Q18: How is the input current limited? A18: The input current is limited using the ILIM pin by connecting a resistor to set the current limit.
Q19: How do the STAT1 and STAT2 pins indicate charging status? A19: These pins can be connected to LEDs to visually show the charging status such as "charging" or "charged."
Q20: What happens if the TS pin detects an over-temperature condition? A20: If the TS pin detects an over-temperature condition, the charger will stop charging to protect the battery from damage.
This detailed explanation provides a comprehensive view of the pin functions, the device's role in power management, and answers to common questions.