The LTC4249 dual ECB furnishes overcurrent protection for two loads. Each channel features a precision enable input, current-monitor output, and ready status output, with a single resistor determining the ECB threshold. If an overcurrent condition arises in either channel, the associated breaker disconnects the input from the load.
It’s worth noting that the relationship between a traditional circuit breaker and an electronic circuit breaker parallels that of a traditional fusible-link device (fuse) and an electronic fuse (eFuse). The former focuses on a single function but lacks flexibility, which may be viewed as either an advantage or limitation, while the latter offers increased sophistication and introduces additional features, functions, and design options.
The open-drain RDY status output drops to a low state following any circuit-breaker “event,” and the ECB latches into the off state. After a one-second cool-off period, the user can reactivate the ECB by toggling the enable input. The circuit breakers incorporate a cool-off timer, overtemperature sensor, short-circuit detector, and inrush controller to ensure operation within a safe working range.
The LTC4249 simplifies voltage sequencing and closed-loop-bias current-control applications through its precision enable inputs, ready outputs, and analog current-monitor outputs. It also offers a 5 percent accurate analog current-monitor output, a filtered (50 s) main overcurrent threshold, a fast (2 s) secondary overcurrent threshold, and integrated 75-m switches.
The LTC4249, with an operating temperature range spanning from -40 to +125°C, is priced at $2.39 per 1,000 pieces. It comes in a 16-lead, 3-mm LQFN package. For applications requiring compliance with creepage and clearance specifications up to 65 V, a 12-lead “skipped leading” 3-4 mm LQFN package is also available.