Patent ID: 7868682

Claim:
An insulating communication circuit that transmits a communication signal based on insulation from first ground circuitry having a first ground to second ground circuitry having a second ground different from the first ground, the insulating communication circuit comprising: a first insulating circuit that has first and second circuits; a second insulating circuit that has third and fourth circuits; a communication interface that is connected to the first ground and transmits a signal to the first circuit based on the communication signal and a clock signal from an external control device; a secondary-side signal detection circuit that is connected to the second ground and detects the communication signal from an output of the second circuit based on an output of the first circuit; a primary-side noise detection circuit that is connected to the first ground and detects a common mode current between the third and fourth circuits; a secondary-side noise detection circuit that is connected to the second ground and detects common mode noise from an output of the fourth circuit based on the common mode current to output a noise detection signal; a delay time adjustment circuit that adjusts transmission speed of the communication signal detected by the secondary-side signal detection circuit and transmission speed of the noise detection signal detected by the secondary-side noise detection circuit; and a signal latch circuit that latches the communication signal adjusted by the delay time adjustment circuit when the noise detection signal adjusted by the delay time adjustment circuit detects the common mode noise.