DC-DC boost converter
A DC-DC boost converter and apparatus including the same are disclosed. In one embodiment, the DC-DC converter comprises an input for receiving a first voltage at a first level, where the first voltage is negative; a transformer coupled to the input to convert the first voltage to a second voltage at a second level, where the second level is higher than the first level and the second voltage is positive; and an output connected to the transformer to output the second voltage.
1. A DC/DC converter comprising:
an input for receiving a first voltage at a first level, the first voltage being negative;
a first capacitor connected to the input;
a transformer coupled to the input and the first capacitor, via a switch, to convert the first voltage to a second voltage at a second level, the second level being higher than the first level, and wherein the second voltage is positive, wherein the switch is closed to connect the input to the transformer after voltage across the first capacitor builds up to a predetermined level, the predetermined level set to hold off the transformer until sufficient energy is stored in the first capacitor;
an output connected to the transformer to output the second voltage; and
a second capacitor connected to the output, wherein capacitance ratio of the first capacitor to the second capacitor is 1000:1 or 6000:1.
2. The converter defined in claim 1 wherein the input is to receive a rectified input.
3. The converter defined in claim 1 further comprising a transistor connected to the transformer to switch current through the transformer in order to convert the first voltage to the second voltage.
4. The converter defined in claim 1 wherein the transistor comprises a p-channel transistor.
5. The converter defined in claim 1 ,
wherein capacitance ratio of the first capacitor to the second capacitor is 1000:1, the converter further comprising:
a p-channel transistor connected to the transformer to switch current through the transformer in order to convert the first voltage to the second voltage.
6. A device comprising:
an antenna;
a load; and
an energy harvester coupled to the antenna and the load, wherein the energy harvester comprises
an RF rectifier to output a first voltage determined by rectified RF energy in response to received RF energy;
a DC/DC converter coupled to the RF rectifier to convert the first voltage to a second voltage, wherein the DC/DC converter comprises
an input for receiving a first voltage at a first level, the first voltage being negative;
a first capacitor connected to the input;
a transformer coupled to the input and the first capacitor, via a switch, to convert the first voltage to the second voltage at a second level, the second level being higher than the first level, and wherein the second voltage is positive, wherein the switch is closed to connect the input to the transformer after voltage across the first capacitor builds up to a predetermined level, the predetermined level set to hold off the transformer until sufficient energy is stored in the first capacitor,
an output connected to the transformer to output the second voltage; and
a second capacitor connected to the output, wherein capacitance ratio of the first capacitor to the second capacitor is 1000:1 or 6000:1;
an energy storage reservoir coupled to the output of the DC/DC converter to store energy at the second voltage.
7. The device defined in claim 6 wherein the DC/DC converter further comprises a transistor connected to the transformer to switch current through the transformer in order to convert the first voltage to the second voltage.
8. The device defined in claim 7 wherein the transistor comprises a p-channel transistor.
9. The device defined in claim 6 wherein the capacitance ratio of the first capacitor to the second capacitor is 1000:1, and wherein the converter further comprises a p-channel transistor connected to the transformer to switch current through the transformer in order to convert the first voltage to the second voltage.
10. The device defined in claim 6 further comprising a third reservoir coupled to a second reservoir to receive energy transferred from the second reservoir periodically.
11. A sensor device comprising:
an antenna;
an RF communication unit;
a sensor;
a controller; and
an ambient RF energy harvester coupled to the antenna, the RF communication unit, the sensor and the controller to harvest ambient RF power to run the RF communication unit, the sensor and the controller, wherein the RF energy harvester includes a DC/DC converter having
an input for receiving a first voltage at a first level, the first voltage being negative,
a first capacitor connected to the input,
a transformer coupled to the input and the first capacitor, via a switch, to convert the first voltage to the second voltage at a second level, the second level being higher than the first level, and wherein the second voltage is positive, wherein the switch is closed to connect the input to the transformer after voltage across the first capacitor builds up to a predetermined level, the predetermined level set to hold off the transformer until sufficient energy is stored in the first capacitor,
an output connected to the transformer to output the second voltage, and
a second capacitor connected to the output, wherein capacitance ratio of the first capacitor to the second capacitor is 1000:1 or 6000:1.
12. The sensor device defined in claim 11 wherein the capacitance ratio of the first capacitor to the second capacitor is 1000:1, and wherein the converter further comprises a p-channel transistor connected to the transformer to switch current through the transformer in order to convert the first voltage to the second voltage.