1. A drain regulator for a NOR flash memory, comprising:
a pump source, configured to pump a supply voltage to a high voltage at an HV node;
a pass transistor, coupled between the HV node and a bit line, wherein the pass transistor is controlled by a control signal to generate a bit-line voltage at the bit line;
a voltage divider, dividing the bit-line voltage by a factor to generate a feedback voltage at a feedback node;
a Y-path gate, coupled between the bit line and a selected cell of the NOR flash memory and biasing the selected cell with a drain voltage;
an amplifier, supplied with the HV voltage and comparing the feedback voltage with a reference voltage to generate the control signal; and
a current detector, sensing a current flowing through the Y-path gate to generate a sense signal to the feedback node for keeping the drain voltage constant.
2. The drain regulator of claim 1, wherein the voltage divider comprises:
a first resistance unit, comprising a first resistance and coupled between the bit line and the feedback node; and
a second resistance unit, comprising a second resistance and coupled between the feedback node and a ground, wherein the factor is the second resistance divided by a sum of the first resistance and the second resistance.
3. The drain regulator of claim 1 wherein the Y-path gate is a column decoder configured to select the bit line.
4. The drain regulator of claim 1 wherein the amplifier is an operational amplifier.
5. The drain regulator of claim 1, wherein the pass transistor is a first N-type transistor, wherein the current detector comprises:
a second N-type transistor, comprising a gate terminal coupled to the control signal, a drain terminal coupled to the bit line, and a source terminal; and
a current mirror, comprising a current sink node sinking a sink current and a current reference node sinking a reference current, wherein the current sink node is coupled to the feedback node and the current reference node is coupled to the source terminal of the second N-type transistor, wherein the sink current is the reference current multiplied by a predetermined number.
6. The drain regulator of claim 5, wherein the current mirror comprises:
a first P-type transistor, comprising a gate terminal with a bias voltage applied, a drain terminal, and a source terminal coupled to the source terminal of the second N-type transistor;
a third N-type transistor, comprising a gate terminal coupled to a drain terminal and a source terminal coupled to a ground; and
a fourth N-type transistor, comprising a gate terminal coupled to the gate terminal of the third N-type transistor, a drain terminal coupled to the feedback node, and a source terminal coupled to the ground.
7. A drain regulator for a NOR flash memory, comprising:
a pump source, configured to pump a supply voltage to a high voltage at a HV node;
a pass transistor, coupled between the HV node and a bit line, wherein the pass transistor is controlled by a control signal to generate a bit-line voltage at the bit line;
a voltage divider, dividing the bit-line voltage by a factor to generate a feedback voltage at a feedback node;
a Y-path gate, coupled between the bit line and a selected cell of the NOR flash memory and biasing the selected cell with a drain voltage, wherein a current flowing through the Y-path gate is determined by an overdrive of the pass transistor;
an amplifier, supplied with the HV voltage and comparing the feedback voltage with a reference voltage to generate the control signal; and
a current detector, sensing the overdrive of the pass transistor to sink a sink current from the feedback node to a ground.
8. The drain regulator of claim 7, wherein the voltage divider comprises:
a first resistance unit, comprising a first resistance and coupled between the bit line and the feedback node; and
a second resistance unit, comprising a second resistance and coupled between the feedback node and a ground, wherein the factor is the second resistance divided by a sum of the first resistance and the second resistance.
9. The drain regulator of claim 7 wherein the Y-path gate is a column decoder configured to select the bit line.
10. The drain regulator of claim 7 wherein the amplifier is an operational amplifier.
11. The drain regulator of claim 7, wherein the pass transistor is a first N-type transistor, wherein the current detector comprises:
a second N-type transistor, comprising a gate terminal coupled to the control signal, a drain terminal coupled to the bit line, and a source terminal; and
a current mirror, comprising a current sink node sinking a sink current and a current reference node sinking a reference current, wherein the current sink node is coupled to the feedback node and the current reference node is coupled to the source terminal of the second N-type transistor, wherein the sink current is the reference current multiplied by a predetermined number.
12. The drain regulator of claim 11, wherein the current mirror comprises:
a first P-type transistor, comprising a gate terminal with a bias voltage applied, a drain terminal, and a source terminal coupled to the source terminal of the second N-type transistor;
a third N-type transistor, comprising a gate terminal coupled to a drain terminal and a source terminal coupled to a ground; and
a fourth N-type transistor, comprising a gate terminal coupled to the gate terminal of the third N-type transistor, a drain terminal coupled to the feedback node, and a source terminal coupled to the ground.
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. A fuel vaporizer, comprising:
at least one surface; and
at least one glass coated thick film resistor applied to said at least one surface, said thick film resistor heating said surface;
wherein fuel vaporizes on contact with said heated surface.
2. The fuel vaporizer of claim 1, further including a heater body having a fuel inlet and a fuel vapor exit holes opposite from said fuel inlet, wherein said heater body encloses said at least one surface, wherein liquid fuel enters said heater body through said fuel inlet, and wherein fuel vapor exits said heater body through said fuel vapor exit holes.
3. The fuel vaporizer of claim 2, wherein said heater body further includes an air connection, and wherein pressurized air enters said heater body through said air connection.
4. The fuel vaporizer of claim 1, wherein said at least one surface comprises the inside surface of an external heater body and the inside surface of an internal heater body, wherein said external heater body and said internal heater body form a cavity that receives said fuel, and wherein said glass coated thick film resistor is applied to an outer circumferential surface of said external heater body and to the inside and outside of said internal heater body.
5. The fuel vaporizer of claim 1, wherein said at least one surface comprises a plurality of heater plates each including at least one fuel and fuel vapor exit hole, wherein said each of said heater plates includes one of said at least one glass coated thick film resistors, and wherein said heater plates are positioned such that said fuel and generated fuel vapors cascade through said at least one fuel and fuel vapor exit hole from one of said heater plates to another of said heater plates.
6. The fuel vaporizer of claim 1, wherein said at least one surface comprises a plurality of axially arranged heater plates forming a plurality of passages that receive said fuel, and wherein at least one of said glass coated thick film resistors is applied to an outer surface of said heater plates.
7. The fuel vaporizer of claim 1, further including at least one temperature sensor applied to said at least one surface.
8. The fuel vaporizer of claim 1, wherein a fuel metering device supplies said fuel to said at least one surface.
9. The fuel vaporizer of claim 8, further including thermal insulation inhibiting heat transfer from a heater body enclosing said at least one surface to said fuel metering device.
10. The fuel vaporizer of claim 1, wherein said fuel is diesel fuel, and wherein said vaporized fuel is used in an exhaust after-treatment process.
11. A fuel vaporizer assembly for vaporizing a hydrocarbon-based fuel, comprising:
a housing having an assembly flange;
a fuel metering device assembled into said housing;
a fuel vaporizer assembled into said assembly flange and including an external heater body, an internal heater body, and a cavity formed in between, said cavity receiving liquid fuel from said fuel metering device; and
a plurality of glass coated thick film resistors applied to a plurality of surfaces of said external heater body and said internal heater body, said thick film resistors heating said external heater body and said internal heater body;
wherein fuel vapors are generated on contact of said liquid fuel with said external heater body and said internal heater body.
12. The fuel vaporizer assembly of claim 11, further including thermal insulation, wherein said thermal insulation is positioned between said assembly flange and said external heater body, between said housing and said fuel metering device, and between said assembly flange and a downstream device.
13. The fuel vaporizer assembly of claim 12, wherein said downstream device is a fuel reformer that receives said fuel vapors.
14. The fuel vaporizer assembly of claim 11, wherein said external heater body includes a plurality of fuel vapor exit holes that release said fuel vapors.
15. The fuel vaporizer assembly of claim 11, wherein said housing includes a plurality of cooling fins extending from an outer circumference of said housing above said assembly flange.
16. The fuel vaporizer assembly of claim 11, further including an air connection integrated into said housing and said external heater body, said air connection providing a passage for pressurized air into said cavity formed in between said external heater body and said internal heater body.
17. A fuel vaporizer for vaporizing a hydrocarbon-based fuel, comprising:
generally cylindrical heater body enclosing a cavity;
an air connection integrated into said heater body, said air connection providing a passage for compressed air into said cavity;
a plurality of heater plates horizontally inserted into said heater body and retained within said heater body, each of said heater plates including at least one fuel and fuel vapor exit hole;
a plurality of glass coated thick film resistors applied to said heater plates; and
a plurality of temperature sensors, wherein one of said temperature sensors is applied to each of said heater plates;
wherein said cavity receives said hydrocarbon-based fuel in liquid form;
wherein fuel vapors are generated on contact of said fuel with said heater plates; and
wherein said fuel and said fuel vapors cascade from one of said heater plates to an adjacent heater plate through said exit holes.
18. The fuel vaporizer of claim 17, wherein said heater body includes a flange and an open end opposite from said flange, wherein said flange is assembled into a housing that receives a fuel metering device, and wherein said open end releases said fuel vapors.
19. The fuel vaporizer of claim 17, wherein a first stage heater plate is a fuel inlet heater plate positioned adjacent to a fuel inlet integrated into said heater body, said fuel inlet heater plate including a center fuel and fuel vapor exit hole, one of said glass coated thick film resistors, and one of said temperature sensors, wherein said fuel inlet heater plate is also a third stage heater plate.
20. The fuel vaporizer of claim 19, wherein a second stage heater plate includes a plurality of fuel and fuel vapor exit holes positioned proximate to a circumference of said plate, one of said glass coated thick film resistors, and one of said temperature sensors, said second stage heater plate receiving said fuel and said fuel vapors from said first stage heater plate.
21. The fuel vaporizer of claim 19, wherein a fourth stage heater plate is a vapor exit heater plate positioned proximate to said open end of said housing, said vapor exit heater plate including a plurality of fuel vapor exit holes, one of said glass coated thick film resistors, and one of said temperature sensors, said fourth stage heater plate receiving said fuel and said fuel vapors from said third stage heater plate, wherein the number of fuel vapor exit holes is higher than the number of said fuel and fuel vapor exit hole of said first stage and said second staged heater plates.
22. A fuel vaporizer, comprising:
at least one heater plate being formed from at least one extruded component and including a plurality of passages for a fluid to flow through;
a flanged housing including an inlet for said fluid and an air connection and forming an inlet manifold;
a heater plate holder receiving said at least one heater plate, wherein said heater plate holder is installed in said flanged housing;
a plurality of glass coated thick film resistors applied to an outside of said at least one heater plate, wherein said thick film resistors create a plurality of different heating zones; and
a temperature sensor positioned within each of said heating zones;
wherein said fluid enters said passages through said inlet in liquid form, is vaporized on contact with said at least one heater plate, and exits said passages in vapor form.
23. The fuel vaporizer of claim 22, wherein each of said heating zones is monitored and controlled individually.
24. The fuel vaporizer of claim 22, wherein pressurized air enters said passages through said air connection and purges any remains of said fluid.
25. The fuel vaporizer of claim 22, wherein said at least one heater plate is an extruded tubing having a rectangular cross-section and including two flat parallel surfaces connected on the sides with a radius wall; wherein a series of ribs extends between said two flat surfaces forming said passages.
26. The fuel vaporizer of claim 25, wherein an additional heater plate including two flat parallel surfaces is positioned adjacent to said at least one heater plate such that one of said flat surfaces of said at least one heater plates contacts one of said flat surfaces of said additional heater plate.