Device with switched capacitor charge pump sensing circuitry
An example device includes a memory configured to store representations of sensed signals. The example device includes processing circuitry coupled to the memory, the processing circuitry being configured to read or write the representations of the sensed signals in the memory. The example device includes sensing circuitry coupled to the processing circuitry, the sensing circuitry being configured to sense signals indicative of a physiological condition of a patient via a plurality of electrodes and to output to the processor circuitry the representations of the sensed signals. The sensing circuitry includes a switched capacitor charge pump configured to amplify the sensed signals to generate amplified signals.
1 . A device comprising:
memory configured to store representations of sensed physiological signals;
processing circuitry coupled to the memory, the processing circuitry being configured to read or write the representations of the sensed physiological signals in the memory; and
sensing circuitry coupled to the processing circuitry, the sensing circuitry being configured to sense physiological signals, the physiological signals indicative of a physiological condition of a patient via a plurality of electrodes, and to output to the processing circuitry the representations of the sensed physiological signals, wherein the sensing circuitry comprises a switched capacitor charge pump configured to amplify the sensed physiological signals to generate amplified physiological signals, wherein the switched capacitor charge pump:
is configured to operate without a fixed bias current; and
comprises a Fibonacci series charge pump.
2 . The device of claim 1 , wherein the switched capacitor charge pump comprises a plurality of passive devices and a plurality of passive switches.
3 . The device of claim 1 , wherein the Fibonacci series charge pump comprises two or more stages.
4 . The device of claim 1 , wherein the sensing circuitry further comprises a filter coupled to the switched capacitor charge pump, the filter configured to filter the amplified physiological signals.
5 . The device of claim 1 , further comprising:
an analog to digital converter coupled to the switched capacitor charge pump, the analog to digital converter being configured to convert the amplified physiological signals into digital physiological signals.
6 . The device of claim 1 , wherein the device comprises a pacing device and the sensed physiological signals comprise cardiac signals.
7 . The device of claim 1 , wherein the device comprises an implantable medical device.
8 . A method comprising:
sensing, via electrodes, physiological signals indicative of a physiological condition of a patient;
amplifying, by a switched capacitor charge pump, the physiological signals indicative of the physiological condition of the patient to generate amplified physiological signals, wherein the switched capacitor charge pump:
refrains from operating with a fixed bias current; and
comprises a Fibonacci series charge pump; and
storing, by processing circuitry, representations of the sensed physiological signals in a memory.
9 . The method of claim 8 , wherein the switched capacitor charge pump comprises a plurality of passive devices and a plurality of passive switches.
10 . The method of claim 8 , wherein the Fibonacci series charge pump comprises two or more stages.
11 . The method of claim 8 , further comprising filtering, by a filter, at least one of the sensed physiological signals or the amplified physiological signals.
12 . The method of claim 8 , further comprising converting, by an analog to digital converter, the amplified physiological signals into digital physiological signals.
13 . The method of claim 8 , wherein the method is performed by an implantable medical device.
14 . The method of claim 8 , wherein the method is performed by a pacing device and wherein the sensed physiological signals comprise cardiac signals.
15 . A device comprising:
memory configured to store representations of sensed low frequency physiological signals;
processing circuitry coupled to the memory, the processing circuitry being configured to read or write the representations of the sensed physiological signals in the memory; and
sensing circuitry coupled to the processing circuitry, the sensing circuitry being configured to sense low frequency physiological signals via a plurality of electrodes and to output to the processing circuitry the representations of the sensed low frequency physiological signals, wherein the sensing circuitry comprises a switched capacitor charge pump configured to amplify the sensed low frequency physiological signals to generate amplified low frequency physiological signals, wherein the switched capacitor charge pump:
is configured to operate without a fixed bias current; and
comprises a Fibonacci series charge pump.
16 . The device of claim 15 , wherein the low frequency physiological signals comprise cardiac signals.