B57211P0121M351

Overview

The B57211P0121M351 is an inrush current limiting thermistor from the TDK P11 series. It features a nominal resistance of 120 Ohms at 25°C with a tolerance of ±20%. The component supports a maximum steady-state current of 3 A and has a physical diameter of 13.00 mm (0.512 inches). It utilizes a leaded package configuration with a lead spacing of 7.50 mm.

Feature Summary

• Provides effective limitation of high inrush currents during power-up phases
• Utilizes negative temperature coefficient characteristics for self-regulating thermal response
• Designed for robust performance within industrial and consumer electronic applications

Applications

• Power supply input stages
• Consumer electronics protection
• Industrial equipment circuit protection

Procurement Notes

Verify the specific ordering code against official TDK documentation to ensure correct resistance and tolerance specifications. Confirm that the leaded package dimensions align with the target PCB layout requirements. Check for any recent product change notices regarding marking or material composition updates prior to finalizing procurement orders.

Selection Notes

Select this component based on the required 120 Ohm initial resistance and 3 A steady-state current capacity. Ensure the 13 mm diameter fits the available board space. Consider the thermal environment and expected inrush duration to verify adequate energy absorption capabilities for the specific application design constraints.

Part Context

This part belongs to the EPCOS (now TDK) P11 series of NTC inrush current limiters. These components are designed to protect sensitive electronic circuits from damage caused by high initial charging currents. The series offers various resistance values and package sizes to suit different power levels and form factor requirements across multiple industries.

Replacement Considerations

Consult official TDK cross-reference lists for verified substitutes. Generic equivalents may not match the precise thermal characteristics or mechanical dimensions required for reliable operation in critical protection circuits.