Neuromodulation systems in accordance with embodiments of the invention can use a feed-forward common-mode cancellation (CMC) path to attenuate common-mode (CM) artifacts appearing at a voltage input, thus allowing for the simultaneous recording of neural data and stimulation of neurons. In several embodiments of the invention, the feed-forward CMC path is utilized to attenuate the common-mode swings at V.sub.in,CM, which can restore the linear operation of the front-end for differential signals. In several embodiments, the neuromodulation system may utilize an anti-alias filter (AAF) that includes a duty-cycles resistor (DCR) switching at a first frequency f.sub.1, followed by a DCR switching at a second frequency f.sub.2. The AAF allows for a significantly reduced second frequency f.sub.2 that enables the multi-rate DCR to increase the maximum realizable resistance, which is dependent upon the frequency ratio f.sub.1/f.sub.2.

This application relates to circuitry for monitoring for instability of an amplifier. The amplifier (100) has a first signal path between an amplifier input (IN.sub.N) and an amplifier output (V.sub.OUT) and a feedback path from the output to form a feedback loop with at least part of the first signal path. A comparator (212) has a first input configured to receive a first signal (IN.sub.N) derived from a first amplifier node which is part of said feedback loop and a second input configured to receive a second signal (IN.sub.P) derived from a second amplifier node which varies with the signal at the amplifier input but does not form part of said feedback loop. The comparator is configured to compare the first signal to the second signal and generate a comparison signal (COMP), wherein in the event of amplifier instability the comparison signal comprises a characteristic indicative of amplifier instability.

Various embodiments of the present technology may provide methods and apparatus for an amplifier integrated circuit. The amplifier integrated circuit may provide two amplifiers, one amplifier set to a low gain bandwidth product to amplify at a higher speed and the other amplifier set to a high gain bandwidth product to amplify at a lower speed. The amplifier integrated circuit may further provide a switching circuit connected to the amplifiers, wherein the switching circuit is responsive to a control signal and operates to selectively activate the high speed amplifier and the low speed amplifier in sequence.

An isolation circuit and a method for providing isolation between two dies are provided. The isolation circuit includes: an isolation module, configured to generate an isolation signal based on an input signal from a first die and to provide isolation between the first die and a second die, where the isolation signal is smaller than the input signal in amplitude, and the first die is coupled with the second die; a latch module, configured to latch the isolation signal at a certain level and output a latched signal; an amplifier module, configured to amplify the latched signal. In the isolation circuit, a modulation module and a demodulation module can be saved.

Various embodiments of the present technology may provide methods and apparatus for an amplifier integrated circuit. The amplifier integrated circuit may provide two amplifiers, one amplifier set to a low gain bandwidth product to amplify at a higher speed and the other amplifier set to a high gain bandwidth product to amplify at a lower speed. The amplifier integrated circuit may further provide a switching circuit connected to the amplifiers, wherein the switching circuit is responsive to a control signal and operates to selectively activate the high speed amplifier and the low speed amplifier in sequence.

An analog-to-digital converter (10) comprises a first and a second sampling capacitor (24, 25), a first integrator (26), a first and a second input switch (31, 32) coupling a first input terminal (11) and a common mode terminal (39) to a first electrode of the first sampling capacitor (24), a third and a fourth input switch (33, 34) coupling a second input terminal (12) and the common mode terminal (39) to a first electrode of the second sampling capacitor (25), a fifth and a sixth input switch (35, 36) coupling a second electrode of the first sampling capacitor (24) to an amplifier common mode terminal (40) and the first integrator input (27), and a seventh and an eighth input switch (37, 38) coupling a second electrode of the second sampling capacitor (25) to the amplifier common mode terminal (40) and the second integrator input (28).

An isolation circuit and a method for providing isolation between two dies are provided. The isolation circuit includes: an isolation module, configured to generate an isolation signal based on an input signal from a first die and to provide isolation between the first die and a second die, where the isolation signal is smaller than the input signal in amplitude, and the first die is coupled with the second die; a latch module, configured to latch the isolation signal at a certain level and output a latched signal; an amplifier module, configured to amplify the latched signal. In the isolation circuit, a modulation module and a demodulation module can be saved.

The disclosed systems, structures, and methods are directed to a two wire-based clock multiplication unit (CMU), employing a first phase lock loop (PLL) configured to generate a first high-speed clock frequency f.sub.1 encoded in differential mode, a second PLL configured to generate a second high-speed clock frequency f.sub.2 encoded in common mode, and a summer configured to combine the differential mode encoding the first high-speed clock frequency f.sub.1 and the common mode encoding the second high-speed clock frequency f.sub.2 and transmit the combined differential and common mode high-speed clock frequencies on a two wire-based conductor bus. In addition, systems, structures, and methods directed to a two wire-based clock recovery module and a two wire-based clock recovery module have also been disclosed.

An internal power supply for an amplifier is disclosed. The internal power supply floats according to a common mode voltage at the input to the amplifier and according to an input voltage at an input stage of the amplifier. Powering the input stage of the amplifier using the floating supply allows for the use of low voltage devices even when the range of possible common mode voltages includes high voltages. The use of low voltage devices can correspond to performance improvement for the amplifier and can help reduce the size of the amplifier. The internal supply can accommodate both positive and negative common mode voltages and can be used for current sense amplifiers of any gain.

A read-out circuitry for acquiring a multi-channel biopotential signal, comprises: a plurality of read-out signal channels, each receiving an input signal from a unique signal electrode; a reference channel receiving a reference signal from a reference electrode; wherein each read-out signal channel and the reference channel comprises a channel amplifier connected to receive the input signal in a first input node and with an output node connected to a second input node via a channel feedback loop; wherein each signal channel amplifier comprises a capacitor between the second input nodes of the signal channel amplifier and the reference channel amplifier, and wherein each signal channel feedback loop and the reference channel feedback loop comprise a filter.