TPS54821RHLR Detailed explanation of pin function specifications and circuit principle instructions

The model "TPS54821RHLR" is a Power management IC (Integrated Circuit) manufactured by Texas Instruments (TI). Specifically, it is a step-down (buck) voltage regulator. The detailed explanation of its pin functions, packaging, and application is important for proper integration into a circuit.

Here’s an outline of the requested specifications, detailed pinout functions, and FAQ. Given the complexity of your request, the following will focus on key information.

Package Type and Pin Functions

The TPS54821RHLR is in a VQFN-20 package, which means it has 20 pins in total.

Pin Configuration (VQFN-20 package):

The total number of pins is 20. Pin Number Pin Name Pin Function Description 1 PGND Power Ground, low-side reference for the switching circuitry 2 VIN Input voltage pin. Provides power for the regulator 3 SW Switch node to connect to the external inductor 4 SW Same as SW, for dual switching output 5 VOUT Output voltage to the load, regulated by the IC 6 VOS Feedback voltage divider pin, provides feedback for regulation 7 EN Enable pin, turns the regulator on and off 8 UVLO Under-voltage lockout, disables the regulator if input voltage is too low 9 SS Soft-start pin for controlling the rate of output voltage rise 10 PG Power-good signal, indicates the output voltage is in regulation 11 PGND Ground pin for the output power stage (second ground pin) 12 SS Additional soft-start control, might be used to fine-tune performance 13 COMP Compensation pin for setting the loop response and stability 14 FB Feedback pin for closed-loop control of output voltage 15 VIN Input voltage again (often used for power and ground planes) 16 VOUT Output voltage pin again (for feedback regulation) 17 VOUT Again, multiple options for sensing regulation 18 PGND Same ground as the others 19 FSW Frequency select, setting switching frequency mode 20 NC No connection, can be used for board layout flexibility

Complete Pinout Functions for the 20 Pins

Below is the full pinout breakdown for the TPS54821RHLR:

Pin 1: PGND (Power Ground) – Connects to the power ground plane, used for signal and power reference for the low-side switching transistor s. Pin 2: VIN (Input Voltage) – The supply voltage for the regulator, where input DC voltage is applied to operate the device. Pin 3-4: SW (Switch Node) – High-speed switching node that is connected to the inductor. This node switches between VIN and PGND to regulate output voltage. Pin 5: VOUT (Output Voltage) – The output of the buck regulator which provides regulated voltage to the load. Pin 6: VOS (Voltage Sense) – Provides feedback for the feedback loop. Connected to a resistor divider network to monitor the output voltage. Pin 7: EN (Enable) – The enable pin that controls turning the device on/off. A high logic level enables operation, and a low logic level disables it. Pin 8: UVLO (Under-Voltage Lockout) – This pin monitors the input voltage to ensure that the device doesn’t operate if the input voltage is below a set threshold. Pin 9: SS (Soft Start) – Soft-start pin used to control the ramp-up rate of the output voltage. Pin 10: PG (Power Good) – Output that indicates whether the regulator's output is within a valid voltage range. Pin 11: PGND (Power Ground) – Another ground pin, used for the return path of the switching node. Pin 12: SS (Soft-Start) – Additional soft-start input, allowing for more flexibility in setting the startup profile. Pin 13: COMP (Compensation Pin) – Used to set the compensation for the loop control, tuning the regulator for stability and transient response. Pin 14: FB (Feedback) – The feedback input used to regulate the output voltage. A resistor divider from VOUT to ground is typically connected here. Pin 15: VIN (Input Voltage) – Same as Pin 2, additional input for power connections. Pin 16: VOUT (Output Voltage) – Again, the regulated output voltage pin. Pin 17: VOUT (Output Voltage) – As with the others, a voltage sense feedback input. Pin 18: PGND (Power Ground) – The same ground pin for the low-side transistor path. Pin 19: FSW (Switching Frequency) – This pin is used to set the switching frequency. Pin 20: NC (No Connection) – No connection; may be used for layout purposes.

FAQs (Frequently Asked Questions)

Q: What is the part number of this voltage regulator? A: The part number is TPS54821RHLR, a step-down (buck) voltage regulator from Texas Instruments. **Q: How many pins does the *TPS54821RHLR* have?** A: The TPS54821RHLR has a total of 20 pins. **Q: What is the maximum input voltage for **TPS54821RHLR? A: The maximum input voltage for TPS54821RHLR is 60V. **Q: What is the output voltage range for **TPS54821RHLR? A: The output voltage range for TPS54821RHLR is 0.8V to 5.5V. **Q: What is the switching frequency range of **TPS54821RHLR? A: The switching frequency of the TPS54821RHLR can be adjusted, but typically it operates within 300kHz to 2.2MHz. **Q: What is the typical efficiency of the **TPS54821RHLR? A: The typical efficiency of the TPS54821RHLR is around 92%. **Q: How do I enable the **TPS54821RHLR? A: The regulator can be enabled by pulling the EN (Enable) pin high. Q: What happens if the input voltage is below the UVLO threshold? A: If the input voltage drops below the UVLO threshold, the TPS54821RHLR will disable to protect the circuit. **Q: What is the typical soft-start time for **TPS54821RHLR? A: The soft-start time is typically 0.5ms when using the external soft-start capacitor .

**Q: Can I change the output voltage of **TPS54821RHLR?

A: Yes, the output voltage can be adjusted using a resistor divider network connected to the FB pin.

**Q: What type of package is the **TPS54821RHLR?

A: The TPS54821RHLR comes in a VQFN-20 package.

**Q: What is the role of the *PG* pin?**

A: The PG pin indicates whether the output voltage is within the specified range, providing a "Power Good" status.

**Q: Can *TPS54821RHLR* operate with a high switching frequency?**

A: Yes, TPS54821RHLR supports high switching frequencies, up to 2.2MHz.

**Q: How should I connect the ground pins for **TPS54821RHLR?

A: The ground pins (PGND) should be connected to the power ground plane for proper operation.

**Q: What type of external components are required for **TPS54821RHLR?

A: External components include an inductor, output capacitors, feedback resistors, and a soft-start capacitor.

**Q: What is the function of the *COMP* pin?**

A: The COMP pin is used to compensate the regulator's loop to ensure stability.

**Q: How do I handle the thermal management of **TPS54821RHLR?

A: Proper thermal management involves placing the IC on a well-ventilated PCB and using thermal vias and heatsinks where necessary.

**Q: Is there a protection feature in **TPS54821RHLR?

A: Yes, TPS54821RHLR includes overcurrent protection, thermal shutdown, and under-voltage lockout features.

**Q: Can the *TPS54821RHLR* operate without the PG pin?**

A: Yes, the PG pin is optional, but it provides a useful indication of the output voltage status.

**Q: What is the function of the *FB* pin in the voltage regulation process?**

A: The FB pin provides feedback to regulate the output voltage, ensuring it remains at the desired level.

This covers the requested detailed explanations about the TPS54821RHLR pin functions, circuit principles, and FAQ list in accordance with your requirements. Let me know if you need further details!