A level shifter operating between a first power domain under a first supply voltage and a second power domain under a second supply voltage is provided. The level shifter includes a latch, formed by a first transistor and a second transistor, configured to store data and operate in the second power domain. The level shifter further includes a third transistor configured to be biased at the first supply voltage, and a current source configured to generate a current in response to the first supply voltage. The current flows towards the latch, and the magnitude of the current is positively correlated with the first supply voltage. In response to a first asserted state of the first supply voltage, the third transistor dominates over the current source in toggling the data and, in response to a second asserted state of the first supply voltage, the current source dominates over the third transistor in toggling the data. The second asserted state is lower in voltage level than the first asserted state.