Electronic Circuit Breaker Reduces Power Loss

Apr 27, 2005 3:41 PM

Linear Technology’s LTC4213 electronic circuit breaker senses load currents using the R_DS(ON) of an external MOSFET. This new method not only reduces voltage and power loss in the switch path, but also lowers the cost and simplifies design. This is especially beneficial to low-voltage systems since the sense resistor voltage drop constitutes a significant portion of the supply voltage. For ultra low voltage applications, the LTC4213 operates over a bias supply range of 2.3 V to 6 V and monitors voltages from ground up to 6 V.

The electronic circuit breaker offers three pin-selectable V_DS thresholds of 25 mV, 50 mV and 100 mV. The select pin can be stepped dynamically, allowing a higher circuit breaker threshold at startup and a lower threshold after the supply current has settled. The circuit breaker also provides dual-level and dual-response time functions for overcurrent protection by integrating a slow and a fast comparator. This further enhances the circuit breaker performance by differentiating between slight overcurrent faults or catastrophic short-circuit conditions.

The precise performance of the LTC4213 makes it ideal for systems requiring continual protection of low voltage supplies. Offered in a 12-lead DFN package and specified over the commercial and industrial temperature ranges, pricing for the LTC4213 starts at $1.50 each in 1000-piece quantities.

For more information, visit www.linear.com.