The part number TPS2557DRBR is from the Texas Instruments (TI) brand. It is a current-limiting switch that offers adjustable current limits, overcurrent protection, and thermal shutdown features for Power distribution.
Package Type and Pin Count
Package Type: SOT-23-6 (Small Outline Transistor package with 6 pins) Pin Count: 6Below is a detailed pinout description and function of each pin for the TPS2557DRBR in the SOT-23-6 package:
Pinout and Functionality Table
Pin Pin Name Pin Function 1 VCC Power supply input pin. Connect this pin to the positive voltage rail (typically 2.5V to 6V). 2 GND Ground pin. Connect this pin to the system ground. 3 IN Input pin for the power source. This pin connects to the input voltage that requires current limiting (can be VBUS, VCC, or other power sources). 4 OUT Output pin. The current-limited output is provided at this pin. It supplies power to the load. 5 SET Adjustable current limit setting. This pin is used to set the threshold of the current limit by using an external resistor. 6 EN Enable pin. When high, this pin enables the TPS2557. When low, it disables the device and places it in shutdown mode, drawing negligible current.Detailed Pin Functions
VCC Pin (Pin 1): The VCC pin is the power supply input. It is the primary voltage source for the device, typically in the range of 2.5V to 6V. Connect to the system power supply for the device to function properly. GND Pin (Pin 2): The GND pin is used for ground connection. This pin is critical for establishing a reference ground in the circuit. Connect directly to the system's ground. IN Pin (Pin 3): The IN pin is the input voltage pin. It receives the power from the source that needs current limiting. This voltage is supplied to the load through the OUT pin after current limiting. It is typically used to connect the source voltage, such as VBUS or VCC. OUT Pin (Pin 4): The OUT pin is the output of the current-limiting switch. It supplies power to the load. The output is regulated to limit current to a specified value, preventing overcurrent damage. SET Pin (Pin 5): The SET pin is used to adjust the current limit by connecting an external resistor to set the desired current threshold. The current limit is directly proportional to the external resistor value, and this pin plays a crucial role in defining the operating current. EN Pin (Pin 6): The EN pin controls the device’s operation. When this pin is high, the device is enabled, and normal operation occurs. When it is low, the device is placed into a shutdown state, where no current is passed through the OUT pin. This pin can be controlled by a logic signal to enable or disable the device as needed.20 Frequently Asked Questions (FAQ)
Q1: What is the operating voltage range for the TPS2557DRBR?
A1: The operating voltage range for the TPS2557DRBR is from 2.5V to 6V.Q2: What is the current limit setting method for the TPS2557DRBR?
A2: The current limit is set using an external resistor connected to the SET pin (Pin 5). The current limit is proportional to the resistance value.Q3: How do I enable the TPS2557DRBR?
A3: To enable the TPS2557DRBR, set the EN pin (Pin 6) high. A logic high on this pin activates the device.Q4: What happens when the EN pin is set low?
A4: Setting the EN pin low places the device in shutdown mode, cutting off the current to the output.Q5: Can the TPS2557DRBR work without the SET pin being connected?
A5: No, the SET pin must be connected to define the current limit value. An unconnected SET pin can cause undefined behavior.Q6: What is the output voltage range of the TPS2557DRBR?
A6: The output voltage at the OUT pin depends on the input voltage and the current-limiting setting but will generally follow the input voltage as long as current limit is not triggered.Q7: Can the TPS2557DRBR be used to limit voltage?
A7: No, the TPS2557DRBR is a current-limiting device and does not regulate voltage. It protects the circuit by limiting the amount of current supplied to the load.Q8: Is thermal shutdown available in the TPS2557DRBR?
A8: Yes, the TPS2557DRBR includes thermal shutdown protection, which disables the device if the junction temperature exceeds the safe threshold.Q9: How can I increase the current limit of the TPS2557DRBR?
A9: To increase the current limit, reduce the resistance value connected to the SET pin (Pin 5). Lower resistance increases the current limit threshold.Q10: How do I calculate the current limit with the SET resistor?
A10: The current limit is calculated using the formula:
[ I{LIMIT} = \frac{V{SET}}{R{SET}} ] where (V{SET}) is the reference voltage (typically 0.6V) and (R_{SET}) is the external resistor connected to the SET pin.Q11: Can the TPS2557DRBR be used to protect USB devices?
A11: Yes, the TPS2557DRBR is commonly used to protect USB devices from overcurrent by limiting the current flowing to USB peripherals.Q12: What happens if the current exceeds the limit?
A12: If the current exceeds the set limit, the TPS2557DRBR will shut down the output to protect the circuit. It will automatically recover once the overcurrent condition is resolved.Q13: What is the thermal shutdown threshold for the TPS2557DRBR?
A13: The thermal shutdown typically activates at around 150°C, and the device will resume operation once the temperature falls below the threshold.Q14: Is the TPS2557DRBR suitable for high-power applications?
A14: The TPS2557DRBR is ideal for low to moderate power applications, such as USB ports or small power distribution systems. For high-power applications, consider a higher-rated current-limiting device.Q15: How fast is the current limiting response in TPS2557DRBR?
A15: The TPS2557DRBR provides fast current limiting, typically within microseconds, to protect the circuit from overcurrent conditions.Q16: Can the TPS2557DRBR be used for both AC and DC circuits?
A16: The TPS2557DRBR is designed for DC circuits. It is not suitable for AC power applications.Q17: Does the TPS2557DRBR provide reverse current protection?
A17: No, the TPS2557DRBR does not provide reverse current protection. If reverse current protection is required, additional circuitry must be added.Q18: What is the maximum current limit for the TPS2557DRBR?
A18: The maximum current limit is determined by the external resistor and can typically be adjusted up to around 2A.Q19: Can the TPS2557DRBR be used for automotive applications?
A19: Yes, the TPS2557DRBR can be used in automotive applications, provided the operating voltage range and current limits meet the specific needs of the automotive system.Q20: How should I handle the SET resistor for reliable operation?
A20: Ensure that the SET resistor is correctly rated for power dissipation and that it is properly mounted to avoid fluctuations in the current limit.Let me know if you need more details!
