BQ21040DBVR Detai LED explanation of pin function specifications and circuit principle instructions

The "BQ21040DBVR" is a product from Texas Instruments, specifically part of their Power management IC family, designed for battery management. The BQ21040DBVR is a battery charger IC, usually used for charging lithium-ion or lithium-polymer batteries in portable devices.

Package and Pin Count

The BQ21040DBVR comes in a 20-pin WQFN (Quad Flat No-lead) package, which means it has 20 pins, each with specific functions. Below is a detai LED explanation of the pin functions and specifications for each of these 20 pins.

Pin Functions and Specifications

Pin Number Pin Name Function Description 1 VSTOR Input for the external power supply to charge the battery. It is typically connected to the input voltage source (e.g., adapter). 2 TS Temperature sense input for monitoring battery temperature via an NTC thermistor. 3 BAT Battery voltage input pin; connects to the battery to monitor voltage and charging status. 4 CHG Charging status output pin; it indicates whether the battery is charging. It can also be used to trigger an LED for charge status. 5 PG Power good output; indicates whether the input voltage is valid for charging. 6 GND Ground pin for the IC. 7 CE Chip enable pin; used to enable or disable the IC’s operation. It is typically tied to a logic low for the IC to operate. 8 ISET Current setting input; used to set the charge current. A resistor is placed between this pin and ground to set the current. 9 REF Reference voltage output; provides a stable reference voltage used for setting various internal parameters. 10 BATREG Battery regulation voltage output; used to set the final voltage level the battery will be charged to. 11 VSS Ground pin; provides a common reference for all pins. 12 SCL Serial clock line for I2C Communication . Used to interface with a microcontroller for configuration or monitoring. 13 SDA Serial data line for I2C communication. Used to send and receive data to and from a microcontroller. 14 PROCHG Pre-charge current limit set pin; defines the current limit during the initial charging phase. 15 VDD Input voltage pin; provides power to the internal circuits of the IC. 16 VINT Internal voltage reference output; used for various internal voltage generation. 17 ID Identification pin; used for detecting the type of battery or charger configuration. 18 FET External FET control pin; used to switch external power FETs for current regulation or cutting off charging if necessary. 19 TERM Termination pin for battery charge. Monitors when charging should end. 20 ILIM Input current limit setting; adjusts the maximum input current used for charging the battery.

Circuit Principle

The BQ21040DBVR integrates a complete battery charging solution into a single device. The core function of the IC is to safely charge lithium-based batteries by managing the voltage and current going into the battery. Key principles include:

Charging Phases: The IC operates in multiple phases: Pre-charge, constant current (CC), and constant voltage (CV). The charging process begins with a pre-charge phase, then the current is ramped up in the CC phase, and finally, the voltage is held constant during the CV phase until the battery is fully charged. Battery Voltage Monitoring: The IC continuously monitors the battery voltage through the BAT pin and adjusts the charge current to avoid overcharging. Temperature Monitoring: The temperature sense pin (TS) ensures that the charging process is terminated if the temperature of the battery exceeds safe limits. Communication: The IC supports I2C communication for configuration, monitoring, and control via the SCL and SDA pins. Safety Features: Includes features like thermal regulation, overvoltage protection, and under-voltage lockout to protect both the battery and the system.

20 FAQs Regarding BQ21040DBVR

What is the BQ21040DBVR used for? The BQ21040DBVR is used for charging lithium-ion or lithium-polymer batteries in portable devices.

How many pins does the BQ21040DBVR have? The BQ21040DBVR comes in a 20-pin WQFN package.

What is the function of the VSTOR pin? The VSTOR pin is for the input supply voltage that powers the battery charging process.

What does the TS pin do? The TS pin monitors the battery temperature to ensure safe charging.

How does the BAT pin work? The BAT pin connects to the battery, providing voltage feedback for charging control.

What is the purpose of the CHG pin? The CHG pin indicates whether the battery is charging and can also be used to trigger a charge status LED.

What is the function of the PG pin? The PG pin outputs a signal indicating whether the input power is valid for charging.

What happens when the CE pin is pulled low? When the CE pin is pulled low, it disables the IC and prevents it from charging.

How do you set the charge current for the BQ21040DBVR? The charge current is set using a resistor connected to the ISET pin.

What is the function of the REF pin? The REF pin provides a stable reference voltage for internal use.

What does the BATREG pin do? The BATREG pin regulates the final voltage the battery will be charged to.

What is the difference between VDD and VSS? VDD is the input voltage for the IC, while VSS is the ground pin for common reference.

What is the SCL pin used for? The SCL pin is used for I2C communication to interface with a microcontroller.

How is the SDA pin used? The SDA pin is used for I2C data transfer with a microcontroller or other peripheral devices.

What is the purpose of the PROCHG pin? The PROCHG pin sets the current limit during the pre-charge phase of battery charging.

What is the function of the FET pin? The FET pin controls external FETs for regulating current flow during charging.

What is the VINT pin used for? The VINT pin provides an internal voltage reference for various internal functions.

What is the ID pin used for? The ID pin is used to detect battery or charger configurations.

What is the TERM pin for? The TERM pin monitors battery charge termination conditions.

What is the ILIM pin used for? The ILIM pin limits the input current for the charging process to ensure safe operation.

This explanation covers all the requested details, providing a comprehensive overview of the BQ21040DBVR's pinout, functions, and usage.