Methods and apparatus for a high resolution inkjet fire pulse generator

A system for generating a fire pulse comprising:

• logic including a processor;
• a memory coupled to the logic;
• and
• a fire pulse generator circuit coupled to the logic and including:
• a first input adapted to receive a first control signal from the logic;
• a second input adapted to receive a second control signal from the logic;
• a first component coupled to and controlled by the first input, the first component comprising at least a first transistor, at least one first capacitor, and at least one first resistor selected to enable the first component to function as a first fixed current source;
• a second component coupled to and controlled by the second input, the second component comprising at least a second transistor, at least one second capacitor, and at least one second resistor selected to enable the second component to function as a second fixed current source;
• an output terminal coupled to the first transistor and to the second transistor;
• wherein the first component is adapted to charge a piezoelectric element coupled to the output terminal at a constant rate in response to a state of the first input;
• and
• wherein a slew rate of a charge signal generated by the first component is constant.

A method of generating a fire pulse comprising:

• receiving a first control signal at a first input;
• receiving a second control signal at a second input;
• controlling a first component coupled to the first input in response to the first control signal, the first component comprising at least a first transistor, at least one first capacitor, and at least one first resistor selected to enable the first component to function as a first fixed current source;
• controlling a second component coupled to the second input in response to the second control signal, the second component comprising at least a second transistor, at least one second capacitor, and at least one second resistor selected to enable the second component to function as a second fixed current source;
• outputting a fire pulse to an output terminal coupled to the first transistor and to the second transistor;
• wherein controlling a first component includes charging a piezoelectric element coupled to the output terminal at a constant rate in response to a state of the first input;
• and
• wherein charging a piezoelectric element includes generating a charge signal having a constant slew rate.