Neural　stimulators　with　high-voltage　output　stage　have　the　risk　of　transistor　breakdown.　This　work　presents　two　circuit　designs　for　detecting　malfunction　of　the　high-voltage　transistors　at　the　output　stage,　so　that　warning　signals　can　be　generated　when　transistor　breakdown　happens.　The　first　detection　scheme　uses　a　circuit　containing　a　high-voltage　comparator　with　high-voltage　switches.　The　second　scheme　uses　a　low-voltage　comparator　and　a　step-down　module　to　reduce　the　voltage　of　the　signal　to　be　detected.　Both　circuits　are　designed　in　Cadence　using　180-nm　BCD　CMOS　technology.　The　functions　of　the　proposed　circuits　have　been　verified　by　simulation　results　with　a　high-voltage　neural　stimulator.　Performances　comparison　is　made　and　shows　that　scheme　two　could　be　chosen　as　a　preferred　solution.　In　both　scenarios,　the　total　system　power　consumption　is　below　30　μ　W,　and　the　detection　response　time　is　under　300　ns.　The　detection　circuits　proposed　in　this　work　could　improve　the　safety　of　neural　stimulator　with　high-voltage　output　stages.　©　2024　IEEE.