Transmitter with power supply rejection

An apparatus comprising:

• a driver which is operable on two separate and different power supplies;
• a ring oscillator including at least three drivers, wherein an individual driver of the ring oscillator is a substantial replica of the driver, wherein the ring oscillator is to operate on a filtered version of one of the two separate and different power supplies;
• and
• circuitry to adjust a performance parameter of the driver according to an output of the ring oscillator.

A system comprising:

• a memory;
• a processor coupled to the memory, the processor having a Universal Serial Bus (USB) compliant driver, which comprises a driver comprising a push-pull transmitter, wherein the processor includes:
• a first circuitry to sense variation in a power supply;
• and
• a second circuitry coupled to the first circuitry and to the driver, wherein the second circuitry is to generate a code according to an output of the first circuitry, wherein the code is provided to the driver to adjust a performance parameter of the driver;
• and
• a wireless interface to allow the processor to communicate with another device.