Flash storage device with power monitoring
View Patent ↗A flash storage device includes a power hold circuit including a double layer capacitor. A power source supplies power to the flash storage device and charges the double layer capacitor. The double layer capacitor supplies power for maintaining integrity of data during a data transfer occurring in the flash storage device when the power supplied by the power source is disrupted. Additionally, the flash storage device can inhibit subsequent data transfers until the power supplied by the power source is restored.
1. A flash storage device, comprising:
a power hold circuit configured to receive a first voltage and supply a second voltage based on the first voltage;
an electrical storage element configured to supply a first threshold voltage based on one of the first voltage or a third voltage;
a power monitoring circuit coupled to the electrical storage element, the power monitoring circuit configured to generate a comparator output using the first voltage and the third voltage, the comparator output being based on a combination of a first comparison of the first voltage with respect to the first threshold voltage and a second comparison of the third voltage with respect to the first threshold voltage;
a flash storage coupled to the power hold circuit; and
a flash storage controller coupled to the flash storage and a respective output of the power monitoring circuit and the power hold circuit, the flash storage controller configured to initiate a data transfer to the flash storage when the comparator output of the power monitoring circuit indicates that the first voltage and the third voltage each is greater than the first threshold voltage, and the flash storage controller configured to determine that the second voltage is greater than a second threshold voltage for completing the data transfer to the flash storage.
2. The flash storage device of claim 1 , further comprising a device power source configured to supply the first voltage, the power monitoring circuit, the electrical storage element and the power hold circuit being coupled to an output of the device power source.
3. The flash storage device of claim 1 , wherein the power monitoring circuit is configured to receive the third voltage from a host power source, the power monitoring circuit being coupled to an output of a host which includes the host power source.
4. The flash storage device of claim 1 , further comprising a data buffer electrically coupled to the flash storage controller and the power hold circuit.
5. The flash storage device of claim 1 , wherein the power monitoring circuit provides the comparator output to the flash storage controller, the flash storage controller being configured to determine whether the comparator output indicates a disruption in power supplied by the first voltage or the third voltage.
6. The flash storage device of claim 1 , wherein the flash storage controller inhibits a subsequent data transfer from occurring in the flash storage device when the comparator output indicates that the first voltage or the third voltage drops below the first threshold voltage.
7. The flash storage device of claim 1 , further comprising a diode element configured to inhibit current flow from the flash storage controller to the power hold circuit when the comparator output indicates disruption in power supplied by the first voltage or the third voltage.
8. The flash storage device of claim 1 , further comprising a device power source coupled to the electrical storage element, the power monitoring circuit and the power hold circuit, the device power source configured to supply the first voltage.
9. The flash storage device of claim 1 , further comprising a host power source coupled to the power monitoring circuit, the host power source configured to supply the third voltage.