1. A liquid drop emitter comprising:
(a) a chamber formed in a substrate and including a nozzle for emitting drops of a liquid;
(b) a thermo-mechanical actuator, extending into the chamber from at least one wall of the chamber, the thermo-mechanical actuator including a movable element comprising a plurality of layers, the movable element residing in a first position proximate to the nozzle;
(c) the movable element including a bending portion which bends when heated, the bending portion including at least one opening through the plurality of layers of the movable element to permit passage of the liquid through the at least one opening; and
(d) apparatus adapted to apply heat pulses to the movable element resulting rapid deflection of the movable element to a second position, ejection of a liquid drop, and passage of liquid through the at least one opening.
2. The liquid drop emitter of claim 1 wherein the liquid drop emitter is a drop-on-demand ink jet printhead and the liquid is an ink for printing image data.
3. The liquid drop emitter claim 1 wherein one of the plurality of layers includes a deflector layer constructed of a deflector material having a high coefficient of thermal expansion and another of the plurality of layers includes a low expansion layer, attached to the deflector layer, constructed of a low expansion material having a low coefficient of thermal expansion.
4. The liquid drop emitter claim 3 wherein the deflector material is electrically resistive and the apparatus adapted to apply a heat pulse includes a resistive heater formed in the deflector layer.
5. The liquid drop emitter claim 4 wherein the deflector material is titanium aluminide.
6. The liquid drop emitter of claim 1 wherein the movable element is an elongated structure having a lengthwise axis and the at least one opening is substantially symmetric about the lengthwise axis.
7. The liquid drop emitter of claim 1 wherein the nozzle has a cross sectional area An for passage of the liquid, the at least one opening having a total cross sectional area Am for passage of the liquid, wherein An<Am<10An.
8. A liquid drop emitter comprising:
(a) a chamber formed in a substrate and including a nozzle for emitting drops of a liquid;
(b) a thermo-mechanical actuator including a cantilevered element extending from an anchor wall of the chamber and a free end residing in a first position proximate to the nozzle, the cantilevered element comprising a plurality of layers;
(c) the cantilevered element including a bending portion which bends when heated, the bending portion including at least one opening through the plurality of layers, located in a center of the bending portion, to permit passage of the liquid through the at least one opening; and
(d) apparatus adapted to apply heat pulses to the thermo-mechanical actuator resulting rapid deflection of the free end to a second position, ejection of a liquid drop, and passage of liquid through the at least one opening.
9. The liquid drop emitter of claim 8 wherein the liquid drop emitter is a drop-on-demand ink jet printhead and the liquid is an ink for printing image data.
10. The liquid drop emitter claim 8 wherein one of the plurality of layers includes a deflector layer constructed of a deflector material having a high coefficient of thermal expansion and another of the plurality of layers includes a low expansion layer, attached to the deflector layer, constructed of a low expansion material having a low coefficient of thermal expansion.
11. The liquid drop emitter claim 10 wherein the deflector material is electrically resistive and the apparatus adapted to apply a heat pulse includes a resistive heater formed in the deflector layer.
12. The liquid drop emitter claim 11 wherein the deflector material is titanium aluminide.
13. The liquid drop emitter of claim 11 wherein the resistive heater is configured to have a first resistor segment and a second resistor segment each extending from the anchor wall and the at least one opening is located between the first and second resistor segments.
14. The liquid drop emitter of claim 13 wherein the at least one opening includes slot portions that define a central stationary portion of the cantilevered element that does not bend when the bending portion is heated.
15. The liquid drop emitter of claim 14 wherein the anchor wall of the chamber has an upper anchor wall portion and the upper anchor wall portion is extended along the central stationary portion of the cantilevered element.
16. The liquid drop emitter of claim 14 wherein the thermal conductivity of the deflector material is substantially greater than the thermal conductivity of the low expansion material and the low expansion material is removed in the central stationary portion of the cantilevered element.
17. The liquid drop emitter of claim 14 wherein the thermal conductivity of the low expansion material is substantially greater than the thermal conductivity of the deflector material and the deflector material is removed in the central stationary portion of the cantilevered element.
18. The liquid drop emitter of claim 14 wherein the substrate further includes a heat sink portion and a third material having high thermal conductivity is laminated to the central stationary portion and brought into good thermal contact with the heat sink portion.
19. The liquid drop emitter of claim 8 wherein the nozzle has a cross sectional area An for passage of the liquid, the at least one opening having a total cross sectional area Am for passage of the liquid, wherein An<Am <10An.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. An apparatus, comprising:
a processor chip having multiple power domains that are each to be supplied by a low dropout (LDO) voltage regulator circuit,
wherein each LDO voltage regulator circuit includes:
(i) at least one power gate transistor to provide different supply modes including a switched-on mode, a switched-off mode, and a variable voltage output mode, and
(ii) voltage regulation control circuitry to be enabled during the variable voltage mode and disabled during the switched-on and switched-off modes.
2. The apparatus of claim 1, wherein the voltage regulation control circuitry comprises at least one analog control loop to regulate output voltage from the at least one power gate transistor during the variable voltage mode, the analog control loop to be disabled during the switched-on and switched-off modes.
3. The apparatus of claim 1, further comprising:
selection logic for each LDO voltage regulation circuit to disable the voltage regulator control circuitry for the switched-on and switched-off modes.
4. The apparatus of claim 1, wherein the voltage regulation circuitry for each LDO voltage regulation circuit further comprises: (i) an operational amplifier (op-amp) having a first input terminal configured to receive a reference voltage, a second input terminal coupled with an output terminal of the op-amp to form a feedback loop; (ii) a predriver unit coupled to the output terminal of the op-amp; and (iii) a driver unit, wherein the predriver unit is coupled to the driver unit, which is coupled to the at least one power gate transistor to cause it to produce an output voltage based on the reference voltage during the variable voltage mode.
5. The apparatus of claim 4, wherein the op-amp comprises an operational transconductance amplifier.
6. The apparatus of claim 4, wherein the op-amp is configured to receive the reference voltage from a bandgap reference voltage generator configured to generate the reference voltage based on a voltage identification (VID) signal.
7. The apparatus of claim 4, wherein the predriver unit includes an N-type transistor and wherein the driver unit includes a P-type transistor.
8. The apparatus of claim 4, wherein the predriver unit and the driver unit further comprise one or more biasing resistors.
9. The apparatus of claim 4, further comprising:
a filter coupled in between the predriver and the driver unit.
10. A computing system, comprising:
a processor chip;
an external voltage supply to provide power to the processor chip; and
IO devices coupled to the processor chip to provide a user with access to the computing system, the processor chip having two or more logic blocks with separate power domains, wherein each power domain is powered from an associated at least one power gate unit having a supply input coupled to the external voltage supply, a control input, and a supply output to provide an internal voltage supply to a respective power domain;
wherein each power domain has a low dropout (LDO) control circuit coupled to the control input of its associated at least one power gate unit and selection logic, the LDO control circuit to control the at least one power gate unit to provide a variable voltage output in a variable voltage output mode, the selection logic to disable the LDO control circuit to save power for a switch mode where the at least one power gate transistor is to be either (i) switched on to couple the external voltage supply to the internal voltage supply for an on mode, or (ii) switched off to de-couple the external voltage supply from the internal voltage supply for an off mode.
11. The computing system of claim 10, wherein the LDO control circuit includes a low speed loop circuit and a high speed loop circuit.
12. The computing system of claim 10, wherein the at least one power gate unit comprises a P-type transistor device.
13. The computing system of claim 10, wherein each power domain includes multiple power gate units controlled from a common LDO control circuit.
14. The computing system of claim 10, wherein the selection logic turns onoff power gate units within a power domain sequentially in a daisy-chain manner.