REDUCED SIZE INKJET PRINTHEAD HEATER CHIP HAVING INTEGRAL VOLTAGE REGULATOR AND REGULATING CAPACITORS

摘要

An inkjet printhead heater chip (25) has an integral voltage regulator (331) that derives two output voltages (336, 338) from a single chip input voltage (331). One of the two output voltages powers control logic circuitry (340) as the other powers FET drivers (350). Preferred output voltages include +3.3 volts for the control logic circuitry and +7.5 volts for the FET drivers. A Vgs of the FET (360) is about +7.5 volts which enables a FET area width of about 400 microns. Outputs of the control logic circuitry provide input to the FET drivers. A resistive heater (RH) for rejecting ink couples between a drain of the FET and the chip input voltage. Voltage regulating capacitors exist on the heater chip in parallel with the input voltage and each of the output voltages. Preferred capacitors have a gate oxide and a polysilicon layer overlying a substrate. Inkjet printers for housing the printheads are also disclosed.