An analog signal is transported across an isolation channel using edge modulation/demodulation of a pulse width modulated (PWM) signal. An edge modulator is responsive to rising edges of the PWM signal to generate first pulses having a first predetermined pulse width and is responsive to receipt of falling edges of the PWM signal to generate second pulses having a second predetermined pulse width with the same polarity as the first pulses. On the opposite side of the isolation channel an edge demodulating circuit recreates the PWM signal using the first and second pulses. The rise and falling edges of the PWM signals can be distinguished based on the pulse width of the first and second pulses. A second order pulse width modulator may be used to generate the PWM signal.