BQ24780SRUYR Detailed explanation of pin function specifications and circuit principle instructions

The "BQ24780SRUYR" is a part from Texas Instruments. It is a Battery Charger IC designed for high-efficiency charging applications, especially for lithium-ion or lithium-polymer batteries. Let me break down the key aspects of the part, including its pin functions, package details, and common FAQs related to the device.

1. Package and Pin Details:

The BQ24780SRUYR comes in a QFN (Quad Flat No-lead) package, with a total of 28 pins.

Pin Function List (28-pin QFN Package):

Here is a detailed breakdown of the function of each pin:

Pin Number Pin Name Pin Function 1 GND Ground pin. Connects to system ground. 2 ACN Input AC Negative. Connects to AC negative voltage or the return path for AC. 3 ACP Input AC Positive. Connects to AC positive voltage or input Power from the adapter. 4 BAT Battery Input. Connects to the positive terminal of the battery. 5 VSTOR Storage Voltage. Connects to the battery and is used for storing and monitoring the battery charge. 6 SYS System Output. Connects to the system load or device receiving power from the charger. 7 TS Thermal Sense pin. Used to monitor temperature for battery protection and regulation. 8 PGOOD Power Good. Indicates if the input power or charger is functioning properly. 9 I2C SDA I2C Data. This is the data line for communication over I2C. 10 I2C SCL I2C Clock . This is the clock line for I2C communication. 11 ACOK AC OK. Indicates if the AC adapter is working and delivering the correct voltage. 12 FET Gate Controls MOSFET switching for various functions. 13 ILIM Current Limit Pin. Determines the current limits for charging and power supply. 14 CE Chip Enable Pin. Enables or disables the chip's internal functions. 15 EN Enable Pin for other peripherals like switching regulators. 16 BATFET Battery FET Control. Used to control the FET for charging and discharge control. 17 PGND Power Ground. Used to connect to the return path of power circuits. 18 VDD Power supply input for the IC. Must be connected to a 5V or 12V power rail, depending on the configuration. 19 NTC Negative Temperature Coefficient for monitoring temperature changes. 20 OVP Over-voltage Protection. Protects against excessive voltage that could damage the battery. 21 FET OUT Output FET control. Determines the status of the MOSFET controlling the battery charging. 22 FET IN Input FET control. Determines the status of the MOSFET controlling the battery input. 23 BOOST Boost input for voltage regulation. 24 NTC1 NTC thermistor input for battery or system temperature monitoring. 25 VREF Voltage reference pin. Used to set the internal reference voltages for the charger. 26 PWM Pulse Width Modulation for controlling the charging cycles. 27 BATREG Battery Regulation Pin. Helps regulate the voltage applied to the battery. 28 INTVCC Internal Voltage Supply for logic and internal circuits.

2. FAQ - Common Questions and Answers:

Here are 20 commonly asked questions about the BQ24780SRUYR with detailed answers:

Q1: What is the purpose of the ACN and ACP pins on the BQ24780SRUYR? A1: The ACN and ACP pins are used to receive the AC input voltage. ACN is connected to the negative side, and ACP to the positive side of the AC power source.

Q2: How does the battery voltage regulation work on the BQ24780SRUYR? A2: The battery voltage is regulated by the BATREG pin, which ensures that the battery is charged to the correct voltage as determined by the system's charging profile.

Q3: What is the function of the TS pin? A3: The TS pin monitors the temperature of the battery or system to ensure that it stays within safe limits during charging or operation.

Q4: How can I use the I2C communication pins on this device? A4: The I2C SDA and SCL pins are used for serial communication with a microcontroller or processor, allowing configuration and monitoring of the charger settings.

Q5: Can the BQ24780SRUYR be used for charging other battery types? A5: Yes, the BQ24780SRUYR is suitable for charging lithium-ion or lithium-polymer batteries, but custom configurations may be required for other chemistries.

Q6: How does the device protect against overvoltage? A6: The OVP pin and internal circuitry provide overvoltage protection to prevent the battery from being exposed to dangerous voltage levels.

Q7: What is the role of the PGOOD pin? A7: The PGOOD pin indicates whether the system's charging circuitry is functioning correctly and delivering proper voltage and current.

Q8: How do the NTC pins function? A8: The NTC pins are connected to thermistors that measure temperature changes, allowing for thermal protection during charging.

Q9: What is the current limit set by the ILIM pin? A9: The ILIM pin allows you to configure the current limit for the charger to prevent excessive current draw during the charging process.

Q10: How is the battery FET controlled? A10: The BATFET pin is used to control the MOSFETs that manage the charging and discharging of the battery, ensuring safe operation.

Q11: Can I control the system load using the SYS pin? A11: Yes, the SYS pin provides the regulated power to the system load, supplying power from the battery or external adapter.

Q12: What does the FET OUT pin control? A12: The FET OUT pin controls the MOSFET for battery charge or discharge, ensuring the correct flow of power to the battery or system.

Q13: Can I use this charger for high-power devices? A13: The BQ24780SRUYR is designed for applications that need efficient power management, but ensure you do not exceed the current and voltage ratings for your system.

Q14: What happens if the ACOK pin goes low? A14: If the ACOK pin goes low, it means the input power source is either disconnected or malfunctioning, and the device will stop charging.

Q15: How does the BQ24780SRUYR monitor input power? A15: The device monitors input voltage and current through the ACP and ACN pins, along with the ACOK pin, to ensure proper power delivery.

Q16: What are the advantages of using the BQ24780SRUYR in a system? A16: The device offers features like efficient charging, protection against overvoltage and overcurrent, temperature monitoring, and flexible communication through I2C.

Q17: What is the maximum current supported by this charger? A17: The current is configurable via the ILIM pin, but the device typically supports currents suitable for small to medium-sized batteries and devices.

Q18: How can I monitor the charging status? A18: You can monitor the status via the PGOOD pin and I2C communication for detailed status and fault reporting.

Q19: What does the VREF pin do? A19: The VREF pin provides a reference voltage to the internal circuits of the charger to ensure accurate operation.

Q20: Can I use the BQ24780SRUYR for charging multiple batteries in parallel? A20: Yes, the device supports charging multiple cells in parallel, as long as the system's design is appropriately configured.

This summary should provide a clear and complete understanding of the BQ24780SRUYR and its functions. Let me know if you'd like additional details!