Patent ID: 7521963

Claim:
An apparatus for providing an interface for an I2C slave module, the apparatus comprising: a level shifter circuit comprising: (1) a first input connected to an I2C compatible bus, (2) a second input connected to a busy signal line from the I2C slave module, and (3) an output connected to an input of the I2C slave module; wherein the I2C compatible bus and the I2C slave module operate using different supply voltage values and the level shifter circuit shifts signals between the I2C compatible bus and the I2C slave module; and wherein the level shifter circuit changes a value of bias current in the level shifter circuit in response to a busy signal from the I2C slave module on the busy signal line, wherein the level shifter circuit provides a low power value of bias current when the busy signal from the I2C slave module is not asserted.