In one embodiment, an active stylus includes a receiver and a transmitter configured to receive and transmit signals from and to a device via a touch sensor of the device, wherein the transmitter is integrated with or comprises an adaptive voltage generation circuit including: a boost voltage controller; a comparator; a switch control; and a bleeder circuit. The active stylus further includes a stylus controller configured to: (a) in a first operation state, control the adaptive voltage generation circuit and the transmitter to transmit signals at a second transmit voltage, and (b) in a second operation state different from the first operation state, control the adaptive voltage generation circuit and the transmitter to transmit signals at a first transmit voltage lower than the second transmit voltage.