What is claimed is:
1. A polished glass disk medium substrate formed of a mixture of glass forming raw materials comprising
about 35% to about 50% by weight SiO2;
about 13% to about 15.5% by weight Al2O3;
about 10% to about 30% by weight MgO; and
about 5% to about 20% by weight TiO2.
2. The polished glass disk medium substrate according to claim 1, wherein the raw materials further comprise about 0.1% to about 8% by weight Li2O.
3. The polished glass disk medium substrate according to claim 1, wherein the raw materials further comprise about 0.1% to about 22% by weight ZnO.
4. The polished glass disk medium substrate according to claim 1, wherein the raw materials further comprise about 0.1% to about 5% by weight P2O5.
5. The polished glass disk medium substrate according to claim 1, wherein the raw materials further comprise about 0.1% to about 12% by weight ZrO2.
6. The polished glass disk medium substrate according to claim 1, wherein the raw materials further comprise about 0.1% to about 9% by weight CaO.
7. The polished glass disk medium substrate according to claim 1, wherein the raw materials further comprise about 0.1% to about 9% by weight Nb2O5.
8. The polished glass disk medium substrate according to claim 1, wherein the raw materials further comprise about 0.1% to about 9% by weight Ta2O5.
9. The polished glass disk medium substrate according to claim 1, wherein the raw materials further comprise about 0.1% to about 9% by weight K2O.
10. The polished glass disk medium substrate according to claim 1, wherein the raw materials further comprise about 0.1% to about 9% by weight B2O3.
11. The polished glass disk medium substrate according to claim 1, wherein the raw materials further comprise about 0.1% to about 9% by weight Y2O3.
12. The polished glass disk medium substrate according to claim 1, wherein the raw materials further comprise about 0.1% to about 9% by weight Sb2O3.
13. The polished glass disk medium substrate according to claim 1, wherein the raw materials further comprise about 0.1% to about 9% by weight As2O3.
14. The polished glass disk medium substrate according to claim 1, said raw materials consisting essentially of
about 35% to about 50% by weight SiO2;
about 13% to about 15.5% by weight Al2O3;
about 10% to about 30% by weight MgO;
about 5% to about 20% by weight TiO2.
15. The polished glass disk medium substrate according to claim 14, further containing one or more of the following:
about 0.1% to about 8% by weight Li2O;
about 0.1% to about 22% by weight ZnO;
about 0.1% to about 5% by weight P2O5;
about 0.1% to about 12% by weight ZrO2;
about 0.1% to about 9% by weight CaO;
about 0.1% to about 9% by weight Nb2O5;
about 0.1% to about 9% by weight Ta2O5;
about 0.1% to about 9% by weight K2O;
about 0.1% to about 9% by weight B2O3;
about 0.1% to about 9% by weight Y2O3;
about 0.1% to about 9% by weight Sb2O3; and
about 0.1% to about 9% by weight As2O3.
16. The polished glass disk medium substrate according to claim 14, wherein said substrate is essentially free of BaO, ZrO2, B2O3 and NiO.
17. The polished glass disk medium substrate according to claim 1, comprising crystalline phases and amorphous phases.
18. The polished glass disk medium substrate according to claim 17, wherein the crystalline phases represent about 50 to about 60 percent by weight of the total glass composition.
19. The polished glass disk medium substrate according to claim 17, comprising a crystalline phase of clinoenstatite.
20. The polished glass disk medium substrate according to claim 19, wherein the crystalline phase of clinoenstatite represents at least about 80 percent by weight of the crystalline phases.
21. The polished glass disk medium substrate according to claim 17, comprising a crystalline phase of enstatite.
22. The polished glass disk medium substrate according to claim 22, wherein the crystalline phase of enstatite represents less than or equal to about 20 percent by weight of the crystalline phases.
23. The polished glass disk medium substrate according to claim 17, comprising a crystalline phase of magnesium aluminum silicate.
24. The polished glass disk medium substrate according to claim 23, wherein the crystaline phase of magnesium aluminum silicate represents less than or equal to about 20 percent by weight of the crystalline phases.
25. The polished glass disk medium substrate according to claim 17, comprising a crystalline phase of Zn2Ti3O8.
26. The polished glass disk medium substrate according to claim 25, wherein the crystalline phase of Zn2Ti3O8 represents less than or equal to about 20 percent by weight of the crystalline phases.
27. The polished glass disk medium substrate according to claim 17, comprising a crystalline phase of Zn2TiO4.
28. The polished glass disk medium substrate according to claim 27, wherein the crystalline phase of Zn2TiO4 represents less than or equal to about 20 percent by weight of the crystalline phase.
29. The polished glass disk medium substrate according to claim 1, comprising a main crystalline phase of clinoenstatite and a secondary crystalline phase of enstatite.
30. The polished glass disk medium substrate according to claim 29, further comprising one or more of a crystalline phase of magnesium aluminum silicate, a crystalline phase of zinc titanium oxide, and a crystalline phase of zinc titanium oxide.
31. The polished glass disk medium substrate according to claim 1, wherein said glass substrate has a Young’s modulus of 110 or higher.
32. The polished glass disk medium substrate according to claim 1, wherein said substrate is prepared by heating glass forming raw materials to a temperature, T1, between about 500 and 680 C. to generate crystal nuclei; heating at a temperature, T2, between about 680 and abot 800 C. to grow crystal nuclei; and cooling to obtain crystallized glass.
33. A recording disk comprising the polished glass disk medium substrate defined in claim 1.
34. The recording disk according to claim 33, wherein said recording disk is a hard disk.
35. The recording disk according to claim 33, wherein said recording disk is a magnetic disk.
36. The recording disk according to claim 33, wherein said recording disk is an optical disk.
37. The recording disk according to claim 33, wherein said recording disk is a magnetic-optical disk.
38. A method of making a glass disk medium substrate comprising:
heating glass forming raw materials to a temperature sufficiently high to melt the raw materials;
forming a disk medium substrate; and
crystallizing the disk medium substrate, wherein said crystallizing comprises heating the disk medium substrate to a temperature, T1, between about 500 and 680 C. to generate crystal nuclei; heating at a temperature, T2, between about 680 and about 800 C. to grow crystal nuclei; and cooling to obtain crystalized glass.
39. The method according to claim 38, further comprising polishing said glass disk medium substrate.
40. The method according to claim 38, wherein said glass disk medium substrate formed has a Young’s modulus of 110 or higher.
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 sense amplifier, comprising
a bias circuit configured to provide a bias voltage having a magnitude responsive to maintaining a substantially constant loop gain; and
an amplifier stage coupled to the bias circuit to receive the bias voltage and configured to amplify a input current at an input-output node, the current amplifier stage having a loop gain controlled at least in part to the bias voltage.
2. The sense amplifier of claim 1 wherein the bias circuit comprises a beta multiplier reference circuit.
3. The sense amplifier of claim 1 wherein the bias circuit comprises:
a first pair of transistors having gates coupled together, one of the transistors having a gate coupled to its source;
a second pair of transistors having gates coupled together, one of the transistors having a gate coupled to its drain and a bias voltage output node from which the bias voltage is provided; and
a resistance coupled to the transistor of the second pair not having a gate coupled to its drain.
4. The sense amplifier of claim 1, wherein the current amplifier stage comprises:
a pair of transistors having gates cross-coupled to a drain of the other transistor;
a pair of bias transistors, each coupled to a source of a respective one of the pair of transistors and further coupled to receive the bias voltage from the bias circuit;
a pair of resistances, each coupled to the drain of a respective one of the pair of transistors, the loop gain of the current amplifier stage matching a loop gain of the bias voltage circuit.
5. The sense amplifier of claim 4 where having a magnitude and each of the resistance of the amplifier stage comprises a resistance having a magnitude equal to the magnitude of the resistance of the bias circuit.
6. The sense amplifier of claim 4 wherein the bias circuit comprises at least one transistor having transistor dimensions and wherein each of the bias transistors of the amplifier stage have transistor dimensions the same as the transistor dimensions of the at least one transistor of the bias circuit.
7. The sense amplifier of claim 1 wherein the current amplifier comprises a differential current amplifier stage configured to sense and amplify a differential input current at differential input-output nodes.
8. The sense amplifier of claim 1 wherein the current amplifier and bias circuit are configured to have substantially the same loop gain.
9. A memory, comprising:
an array of memory cells;
readwrite circuitry coupled to the memory cells and configured to amplify read data read from the array, the readwrite circuitry including a sense amplifier, comprising:
a bias circuit configured to provide a bias voltage having a magnitude responsive to maintaining a substantially constant loop gain; and
a current amplifier stage coupled to the bias circuit to receive the bias voltage and configured to amplify input signals representing read data from the array that are coupled to an input-output node, the current amplifier stage having a loop gain controlled at least in part to the bias voltage.
10. A method for amplifying a current input, comprising
providing a bias voltage;
adjusting a magnitude of the bias voltage to maintain a substantially constant loop gain of a differential current mode amplifier; and
sensing a differential input and amplifying the same.
11. The method of claim 10, further latching a sensed state following the sensing of the differential input.
12. The method of claim 10 wherein providing a bias voltage comprises providing a bias voltage from a beta multiplier reference circuit.
13. A sense amplifier, comprising:
a sense amplifier stage configured to receive differential input signals and amplify the same, the current amplifier having a loop gain;
a latch mode circuit coupled to the sense amplifier stage configured to control the sense amplifier stage to latch a sensed state; and
a loop gain control circuit coupled to the sense amplifier stage and configured to control the loop gain of the sense amplifier stage.
14. The sense amplifier of claim 13 wherein the sense amplifier stage comprises a sense amplifier stage having a loop gain set according to a bias voltage and wherein the loop gain control circuit comprises a bias circuit configured to generate the bias voltage to control the loop gain of the sense amplifier stage.
15. The sense amplifier of claim 14 wherein the bias circuit comprises a beta multiplier reference circuit.
16. The sense amplifier of claim 14 wherein the bias circuit comprises a bias circuit configured to maintain a substantially constant loop gain and generate a bias voltage in response thereto.
17. The sense amplifier of claim 13 wherein the latch mode circuit is configured to increase the loop gain of the amplifier stage.