The TPS54561DPRR is a DC-DC buck converter produced by Texas Instruments (TI). The part number indicates a specific model of the TPS54x family, which are step-down voltage regulators known for efficient Power conversion.
Packaging and Pin Function Overview
The TPS54561DPRR is available in a VQFN-20 package, which means it has 20 pins in total. Below is a detailed explanation of the functions of each pin, followed by a table and FAQ.
Pin Functions and Descriptions (VQFN-20 Package)
Pin 1 (PVIN): Power Input - This pin is connected to the input power supply. The input voltage typically ranges from 4.5V to 60V.
Pin 2 (PH): Power Switch Node - This pin connects to the switching node of the power converter. It is used to connect to the external inductor and is where the high-voltage switching occurs.
Pin 3 (VOUT): Output Voltage - This pin provides the regulated output voltage from the converter, used to power external devices.
Pin 4 (PGND): Power Ground - This pin serves as the ground connection for the power section of the converter. It must be connected to the system ground.
Pin 5 (VCC): Control Supply Voltage - This is the control voltage supply pin, typically 5V or 3.3V, that powers the internal control circuitry of the converter.
Pin 6 (COMP): Compensation Pin - This pin is used for external compensation of the control loop. External components are required to stabilize the feedback loop.
Pin 7 (EN): Enable Pin - This pin is used to enable or disable the device. A logic high on this pin enables operation, while a logic low disables the converter.
Pin 8 (SS/ENA): Soft-Start / Enable Pin - This pin controls the soft-start feature, which limits the inrush current during startup. It also functions as an enable pin.
Pin 9 (FB): Feedback Pin - This pin connects to the external voltage divider to set the output voltage. It is the input for the feedback control loop.
Pin 10 (PG): Power Good Output - This pin provides a logic signal indicating when the output voltage is within tolerance. It can be used to monitor the output voltage.
Pin 11 (SW): Switch Node - This is the switching node connected to the inductor. It is used to transfer energy from the input to the output by switching the transistor .
Pin 12 (NC): No Connection - This pin is not internally connected and is typically not used in circuit designs.
Pin 13 (GND): Ground - This pin serves as the common ground for both the power section and the control section of the converter.
Pin 14 (OUT): Output Pin - This pin is the output of the converter, where the regulated voltage is available.
Pin 15 (VREF): Reference Voltage Output - This pin provides a stable reference voltage used for voltage regulation and system operations.
Pin 16 (BST): Bootstrap Pin - This pin is used for driving the internal high-side MOSFET gate, providing the necessary voltage for efficient switching.
Pin 17 (CS+): Current Sense Positive Pin - This pin connects to the positive side of the current sensing network. It helps in current limiting and monitoring.
Pin 18 (CS-): Current Sense Negative Pin - This pin connects to the negative side of the current sensing network.
Pin 19 (RT/CLK): Timing Resistor / Clock Pin - This pin is used to set the switching frequency through an external resistor or, in some cases, for clock synchronization.
Pin 20 (SYNC): Synchronization Pin - This pin allows the synchronization of multiple devices to work in phase, reducing electromagnetic interference ( EMI ).
Pin Function Table
Pin Number Pin Name Function 1 PVIN Power input pin for the device (4.5V to 60V input range) 2 PH Power switch node, connected to the external inductor 3 VOUT Output voltage, the regulated output from the converter 4 PGND Power ground pin for the converter’s power section 5 VCC Control supply voltage, powers the internal control circuitry 6 COMP Compensation pin for external control loop compensation 7 EN Enable pin for enabling/disabling the converter 8 SS/ENA Soft-start pin for controlling inrush current; also functions as an enable pin 9 FB Feedback pin for output voltage regulation through an external voltage divider 10 PG Power good output, indicating when output voltage is within tolerance 11 SW Switching node, connects to the inductor and facilitates power transfer during switching cycle 12 NC No connection; not used in circuit designs 13 GND Common ground for both the power section and control section 14 OUT Output pin, where the regulated voltage is available 15 VREF Reference voltage output used for voltage regulation 16 BST Bootstrap pin used for driving the internal high-side MOSFET gate 17 CS+ Positive current sense pin, part of the current monitoring system 18 CS- Negative current sense pin, part of the current monitoring system 19 RT/CLK Timing resistor or clock synchronization pin for setting switching frequency or clocking devices 20 SYNC Synchronization pin for phase alignment of multiple devices20 Frequently Asked Questions (FAQ)
Q: What is the input voltage range of TPS54561DPRR? A: The input voltage range for the TPS54561DPRR is from 4.5V to 60V.
Q: How do I enable the TPS54561DPRR? A: The device can be enabled by applying a logic high to the EN pin.
Q: What is the purpose of the SS/ENA pin? A: The SS/ENA pin controls the soft-start feature to limit inrush current at startup, and it can also be used to enable the device.
Q: Can I connect multiple TPS54561DPRR devices in parallel? A: Yes, multiple devices can be synchronized using the SYNC pin to reduce electromagnetic interference (EMI).
Q: What is the feedback voltage for the TPS54561DPRR? A: The feedback voltage (VFB) for the TPS54561DPRR is typically 0.8V, used for output voltage regulation.
Q: How can I adjust the output voltage of the TPS54561DPRR? A: The output voltage is set by selecting an appropriate external resistor divider connected to the FB pin.
Q: What is the maximum output current of the TPS54561DPRR? A: The TPS54561DPRR can provide up to 6A of output current.
Q: What is the function of the PG pin? A: The PG pin provides a logic signal indicating when the output voltage is within tolerance.
Q: How do I protect the TPS54561DPRR from overcurrent? A: The TPS54561DPRR features internal current sense pins (CS+ and CS-) for overcurrent protection.
Q: What should I connect to the PH pin? A: The PH pin is connected to the switching node of the converter and to the external inductor.
Q: What is the role of the VREF pin? A: The VREF pin provides a stable reference voltage used by the device for voltage regulation.
Q: Can I adjust the switching frequency of the TPS54561DPRR? A: Yes, the switching frequency can be set using an external resistor connected to the RT/CLK pin.
Q: What happens if I connect the EN pin low? A: If the EN pin is connected low, the TPS54561DPRR will be disabled, and it will not output any voltage.
Q: How do I minimize EMI when using multiple devices? A: Multiple devices can be synchronized using the SYNC pin to ensure they switch in phase, reducing EMI.
Q: Can the TPS54561DPRR handle a wide range of input voltages? A: Yes, the device can handle a wide input voltage range from 4.5V to 60V.
Q: What is the purpose of the BST pin? A: The BST pin is used to provide the necessary voltage for driving the high-side MOSFET gate.
Q: How do I ensure stable operation of the control loop? A: Stability can be achieved by selecting appropriate external components for the COMP pin to compensate the control loop.
Q: Can I use the TPS54561DPRR in automotive applications? A: Yes, the TPS54561DPRR is suitable for automotive and industrial applications requiring high efficiency and wide input voltage range.
Q: Is the TPS54561DPRR suitable for high-power applications? A: Yes, the TPS54561DPRR is capable of delivering up to 6A of output current, making it suitable for high-power applications.
Q: What is the typical efficiency of the TPS54561DPRR? A: The typical efficiency of the TPS54561DPRR is up to 95%, depending on the input voltage and load conditions.
This detailed breakdown covers all aspects of the TPS54561DPRR including its packaging, pin functions, and frequently asked questions.