Apparatus and methods for negative voltage generation with reduced clock feed-through

A wireless device comprising:

• a voltage regulator configured to generate a regulated voltage from a battery voltage;
• a first charge pump configured to receive power from the regulated voltage and to generate a first negative voltage based on timing of a first clock phase;
• a second charge pump configured to receive power from the regulated voltage and to generate a second negative voltage based on the first negative voltage and on timing of a second clock phase, the second negative voltage having a voltage level less than the first negative voltage;
• a poly-phase oscillator configured to generate the first clock phase and the second clock phase with different phases such that the first charge pump and the second charge pump draw from the regulated voltage at different points in time;
• and
• a dithering circuit configured to dither at least one of the first clock phase or the second clock phase.

A method of negative voltage generation in a wireless device, the method comprising:

• generating a regulated voltage from a battery voltage using a voltage regulator;
• powering a first charge pump and a second charge pump using the regulated voltage;
• generating a first negative voltage based on timing of a first clock phase using the first charge pump;
• generating a second negative voltage based on the first negative voltage and on timing of a second clock phase using the second charge pump, the second negative voltage having a voltage level less than the first negative voltage;
• generating the first clock phase and the second clock phase with different phases using a poly-phase oscillator such that the first charge pump and the second charge pump draw from the regulated voltage at different points in time;
• and
• providing the second negative voltage to a level shifter array.

A method of negative voltage generation in a wireless device, the method comprising:

• generating a regulated voltage from a battery voltage using a voltage regulator;
• powering a first charge pump and a second charge pump using the regulated voltage;
• generating a first negative voltage based on timing of a first clock phase using the first charge pump;
• generating a second negative voltage based on the first negative voltage and on timing of a second clock phase using the second charge pump, the second negative voltage having a voltage level less than the first negative voltage;
• generating the first clock phase and the second clock phase with different phases using a poly-phase oscillator such that the first charge pump and the second charge pump draw from the regulated voltage at different points in time;
• and
• dithering at least one of the first clock phase or the second clock phase using a dithering circuit.

A switch controller comprising:

• a voltage regulator configured to generate a regulated voltage from a battery voltage;
• a plurality of charge pumps electrically connected in series with one another, the plurality of charge pumps including a first charge pump configured to receive power from the regulated voltage and to generate a first negative voltage based on timing of a first clock phase, and a second charge pump configured to receive power from the regulated voltage and to generate a second negative voltage based on timing of a second clock phase, the second negative voltage having a voltage level less than the first negative voltage;
• a poly-phase oscillator configured to generate the first clock phase and the second clock phase with different phases such that the first charge pump and the second charge pump operate out-of-phase with one another;
• and
• a level shifter array configured to receive the second negative voltage.

A switch controller comprising:

• a voltage regulator configured to generate a regulated voltage from a battery voltage;
• a plurality of charge pumps electrically connected in series with one another, the plurality of charge pumps including a first charge pump configured to receive power from the regulated voltage and to generate a first negative voltage based on timing of a first clock phase, and a second charge pump configured to receive power from the regulated voltage and to generate a second negative voltage based on timing of a second clock phase, the second negative voltage having a voltage level less than the first negative voltage;
• a poly-phase oscillator configured to generate the first clock phase and the second clock phase with different phases such that the first charge pump and the second charge pump operate out-of-phase with one another;
• and
• a dithering circuit configured to dither at least one of the first clock phase or the second clock phase.