Semiconductor device having variable parameter selection based on temperature and test method
View Patent ↗A semiconductor device that may include temperature sensing circuits is disclosed. The temperature sensing circuits may be used to control various parameters, such as internal regulated supply voltages, internal refresh frequency, or a word line low voltage. In this way, operating specifications of a semiconductor device at worst case temperatures may be met without compromising performance at normal operating temperatures. Each temperature sensing circuit may include a selectable temperature threshold value as well as a selectable temperature hysteresis value. In this way, temperature performance characteristics may be finely tuned. Furthermore, a method of testing the temperature sensing circuits is disclosed in which a current value may be monitored and temperature threshold values and temperature hysteresis values may be thereby determined.
1. An apparatus comprising:
a first temperature-sensing circuit configured to provide a first temperature indication based on a first temperature threshold resistance, wherein the first temperature-sensing circuit includes:
a first amplifier comprising a first positive input and a first negative input, wherein the first negative input is configured to be driven by a temperature-independent signal;
a first transistor electrically connected to the first positive input, wherein the first transistor is configured to be controlled by a temperature signal; and
a first temperature hysteresis resistance, wherein the first temperature hysteresis resistance and the first temperature threshold resistance are both electrically connected in series to the first positive input, and wherein the first hysteresis resistance is configured to be controlled, at least in part, by an output of the first amplifier;
a driver circuit including first and second driver outputs, wherein the driver circuit is configured to:
receive the first temperature indication;
provide a first output voltage to the first driver output if the first temperature indication is in a first state; and
provide a second output voltage to the first driver output if the first temperature indication is in a second state; and
a second amplifier configured to amplify a third output voltage from the second driver output and provide the amplified third output voltage back to the driver circuit.
2. The apparatus of claim 1 , further comprising a periphery device, wherein the first driver output is configured to power the periphery device.
3. The apparatus of claim 1 , further comprising a memory device, wherein the first driver output is configured to bias a bit line of the memory device.
4. The apparatus of claim 3 , wherein the memory device is a dynamic random-access memory (DRAM) device.
5. The apparatus of claim 1 , wherein the second amplifier comprises a differential amplifier, and wherein the differential amplifier is configured such that:
a first input of the differential amplifier receives the third output voltage; and
a second input of the differential amplifier receives the temperature-independent signal.
6. The apparatus of claim 5 , wherein the third output voltage at the second driver output is configured to change proportionally to the first or second output voltage provided at the first driver output.
7. The apparatus of claim 5 , wherein the differential amplifier is configured to be activated.
8. The apparatus of claim 1 , wherein the first temperature threshold resistance is programmable.
9. The apparatus of claim 1 , wherein the first temperature hysteresis resistance is programmable.
10. The apparatus of claim 1 , further comprising a second temperature-sensing circuit configured to provide a second temperature indication based on a second temperature threshold resistance, wherein the driver circuit is further configured to:
receive the second temperature indication;
provide a fourth output voltage to the first driver output if the second temperature indication is in a third state; and
provide a fifth output voltage to the first driver output if the second temperature indication is in a fourth state.
11. The apparatus of claim 1 , wherein the driver circuit further comprises a variable resistor configured to receive the first temperature indication.
12. A method comprising:
sensing a first temperature with a first temperature-sensing circuit configured to provide a first temperature indication based on a first temperature threshold resistance, wherein the first temperature-sensing circuit includes:
a first amplifier comprising a first positive input and a first negative input, wherein the first negative input is configured to be driven by a temperature-independent signal;
a first transistor electrically connected to the first positive input, wherein the first transistor is configured to be controlled by a temperature signal; and
a first temperature hysteresis resistance, wherein the first temperature hysteresis resistance and the first temperature threshold resistance are both electrically connected in series to the first positive input, and wherein the first temperature hysteresis resistance is configured to be controlled, at least in part, by an output of the first amplifier;
driving a first driver output of a driver circuit, wherein the first driver output is driven with:
a first voltage if the first temperature indication is in a first state; and
a second voltage if the first temperature indication is in a second state;
amplifying a third voltage from a second driver output of the driver circuit; and
providing the amplified third voltage back to the driver circuit.
13. The method of claim 12 , further comprising powering a periphery device with the first or second voltage provided at the first driver output.
14. The method of claim 12 , further comprising biasing a bit line of a memory device with the first or second voltage provided at the first driver output.
15. The method of claim 14 , wherein the memory device is a dynamic random-access memory (DRAM) device.
16. The method of claim 12 , wherein said amplifying a third voltage comprises amplifying a difference between the third voltage and the temperature-independent signal.
17. The method of claim 16 , wherein the third voltage at the second driver output changes proportionally to the first or second voltage provided at the first driver output.
18. The method of claim 12 , further comprising programming the first temperature threshold resistance.
19. The method of claim 12 , further comprising programming the first temperature hysteresis resistance.
20. The method of claim 12 , further comprising:
sensing a second temperature with a second temperature-sensing circuit configured to provide a second temperature indication based on a second temperature threshold resistance; and
driving the first driver output of the driver circuit, wherein the first driver output is driven with:
a fourth voltage if the second temperature indication is in a third state; and
a fifth voltage if the second temperature indication is in a fourth state.
21. The method of claim 12 , wherein the driver circuit comprises a variable resistor configured to receive the first temperature indication.