After the ideal diode and the Off-Grid Battery Management System developments, we made a design that combines some of the acquired know-how into this new device. This load switch is a combination of a solid state 'high-side' switch and an ideal diode. This allows for switching of biased DC loads from batteries. The switch connects the battery to the load, while the ideal diode prevents current back-flow via the intrinsic body diode of the switching mosfet, yet prevents the energy-wasting forward voltage drop.
- Operating voltage 8-30V (derated below 12V)
- Peak voltage 60V
- Current rating 200A continuous
- Disconnect current 600A
- Inrush current 3kA (minimum circuit impedance 10mΩ)
- Selectable 1A pre-charge for high-capacitive loads
- Heavy duty M6 screw terminals
- Forward voltage (Vfw) 4mV/A or ~50mV, whichever is larger
- Integrated inductive clamping diodes
- Selectable latched fault shutdown or auto-retry
- Remote control enable input
- Current monitor output 10mV/A
- Fault output signal (open drain 60V/1A)
- Operating temperature -20°C to +150°C
- Switch-on temperature +70°C max
- Thermal start and shutdown protection
The load switch is protected with over-current protection and thermal protection. The current protection disables the load switch in case of over-current or short circuit. An optional auto retry mode tries to re-enable the output after a fault. Thermal protection prevents the load to switch on when the temperature of the switching FET is too high to give a suitable margin for inrush current handling. In that case, the enable action is delayed until the temperature has dropped sufficiently. Thermal protection also disables the load when the temperatures get too high because of the normal operating conduction losses.
A 33V 6kW unidirectional TVS diode clamps induction induced pulses from the wiring to the battery. On the output side, an anti-parallel 1200A diode clamps the induction induced pulses from the load and it's wiring.
A 4-pin connector provides access to the enable control input, a open drain fault indicator output and a current monitor output. These signals are referenced to a PTC protected ground signal. This PTC prevents inductive disconnect transients from the load to couple into the control electronics.