To ensure low current operation, the undervoltage and overvoltage resistive dividers are connected to a strobed ground, lowering their average current draw by 50 times. By controlling back-to-back N-channel MOSFETs, the LTC4231 survives and also protects downstream circuitry from reversed batteries up to -40V. Deep discharge is prevented by undervoltage protection which cuts off low voltage batteries, while oscillations from battery recovery after load removal are avoided by adjustable hysteresis. As well as this, a timed circuit breaker and fast current limit provides dual level overcurrent protection.
The LTC4231 is available in two options: the LTC4231-1 and the LTC4231-2. After an overcurrent fault, the former remains off, while the latter automatically attempts to turn on after a 500ms cooldown period. The controller, which is offered in 12-pin MSOP and 3x3mm QFN packages, operates within 0 to 70°C commercial and -40 to 85°C industrial temperature ranges. Accommodating a wide range of battery chemistries including lead-acid, Li-Ion and stacked NiCd, the LTC4231 is suitable for use with applications that utilise solar power or energy harvesting.1,000-piece pricing starts at $2.25 each.