An isolation device provides high common mode transient immunity without increasing the supply voltage rails in the transmitter side. In one aspect, the disclosed isolation device implements a self-boosting scheme to increase a voltage swing of a transmission signal under a lesser supply voltage rail. The disclosed isolation device includes a first stage circuit, a boost circuit, and a second stage circuit. The first stage circuit is configured to generate first and second signals each having a first voltage within a supply voltage range. The boost circuit is configured to provide a boosted voltage range greater than the supply voltage range responsive to at least one of the first or second signal. The second stage circuit is configured to generate an output signal based on either one of the first or second signal, such that the output signal has a second voltage within the boosted voltage range.