A fluid ejection device includes a plurality of analog devices, and a storage element storing an authentication value based on electrical characteristics of a subset of the plurality of analog devices.

A printhead comprises: a printing element; a driving circuit configured to drive the printing element; an analog signal processing circuit configured to process one or more analog signals; a bias circuit configured to supply a bias voltage to the analog signal processing circuit; and a control terminal to which a control signal is inputted, wherein, in a state where the analog signal processing circuit and the bias circuit are receiving a supply of power, it is possible to switch starting and stopping of at least one of the analog signal processing circuit and the bias circuit based on the control signal.

A fluid ejection device includes a plurality of analog devices, and a storage element storing an authentication value based on electrical characteristics of a subset of the plurality of analog devices.

A fluid ejection device includes a plurality of analog devices, and a storage element storing an authentication value including a plurality of bits, a first bit of the plurality of bits based on measured electrical characteristics of a first subset of the analog devices, and a second bit of the plurality of bits based on measured electrical characteristics of a second subset of the analog devices, the second subset different from the first subset.

A fluid printhead including a plurality of heater elements that are driven to nucleate bubbles in fluid so that the fluid is ejected from the printhead in the form of drops, a plurality of drive elements, each drive element selectively driving a corresponding one of the plurality of heater elements in accordance with a printer controller, and a drop detection system that includes a plurality of drop detection cells, each drop detection cell detecting a change in electrical resistance of a corresponding one of the plurality of heater elements that occurs upon drop formation.

A printhead with a separate address generator for ink level sensors is described. In an example, a printhead includes drop ejectors fluidically coupled to nozzles, at least one nozzle address generator, nozzle decoders coupled to nozzle address generator(s) and the drop ejectors, ink level sensors each having a sensor circuit in a sensor chamber and a purging resistor circuit, a sensor address generator, and sensor decoders coupled to the sensor address generator and the purging resistor circuit in each of the ink level sensors.

A fluid printhead including a plurality of heater elements that are driven to nucleate bubbles in fluid so that the fluid is ejected from the printhead in the form of drops, a plurality of drive elements, each drive element selectively driving a corresponding one of the plurality of heater elements in accordance with a printer controller, and a drop detection system that includes a plurality of drop detection cells, each drop detection cell detecting a change in electrical resistance of a corresponding one of the plurality of heater elements that occurs upon drop formation.

A fluid ejection device includes a plurality of analog devices, and a storage element storing an authentication value including a plurality of bits, a first bit of the plurality of bits based on measured electrical characteristics of a first subset of the analog devices, and a second bit of the plurality of bits based on measured electrical characteristics of a second subset of the analog devices, the second subset different from the first subset.

A fluid printhead including a plurality of heater elements that are driven to nucleate bubbles in fluid so that the fluid is ejected from the printhead in the form of drops, a plurality of drive elements, each drive element selectively driving a corresponding one of the plurality of heater elements in accordance with a printer controller, and a drop detection system that includes a plurality of drop detection cells, each drop detection cell detecting a change in electrical resistance of a corresponding one of the plurality of heater elements that occurs upon drop formation.

A fluid printhead including a plurality of heater elements that are driven to nucleate bubbles in fluid so that the fluid is ejected from the printhead in the form of drops, a plurality of drive elements, each drive element selectively driving a corresponding one of the plurality of heater elements in accordance with a printer controller, and a drop detection system that includes a plurality of drop detection cells, each drop detection cell detecting a change in electrical resistance of a corresponding one of the plurality of heater elements that occurs upon drop formation.