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AssigneeAnalog Devices Global Unlimited Company
InventorsRares Andrei Bodnar, Christopher Peter Hurrell
Estimating the term…
Input stages for an analog to digital converter wherein charge for charging parasitic capacitances in the input stage, and particularly in the input switch is sourced from a node which means that it does not have to pass through the input RC filter. This has the effect that the input RC filter can be of lower bandwidth, and/or have a larger resistor value, with the consequent result that there is lower power dissipation in the ADC drive circuitry. In one example this effect is realized by providing a separate input into which charge to charge the parasitic capacitances can be fed from external circuitry. In another example an operational amplifier having high (ideally infinite) input impedance can be used to feed charge to the input switch from the input to the RC filter, or from the node between the resistor and capacitor of the filter, again without unsettling the filter.
An input stage for a signal processing block including an analog-to-digital converter (ADC), the input stage comprising a first input node, an RC filter at its input node, and an input switch receiving an input signal to be converted at the input node, provided via the RC filter, the input stage further comprising a second input node separate from said first input node, and first circuitry arranged to bypass the RC filter to drive one or more internal loads via the second input node.
An input stage for an analog-to-digital converter (ADC), the input stage comprising a first input node at which in use an input signal to be converted is received, an RC filter, and an input switch receiving the input signal to be converted via the RC filter, the input stage further comprising a second input node separate from said first input node and further comprising boost circuitry arranged to feed a boost voltage to the input switch during an acquisition phase of the ADC, the boost circuitry providing the boost voltage between the input switch and the second input node.
An input stage for an analog-to-digital converter (ADC), the input stage comprising an input signal line having in series a first input node, a low-pass RC filter, and an input switch, the arrangement of the input signal line being such that in use the input switch receives an input signal to be converted from the input node via the RC filter, the input stage further comprising an amplifier, the amplifier having an input connected at any point on the input signal line between the input node and the input switch, and an output that in use drives one or more internal loads, the internal loads being parasitic capacitances in the input switch.
An input stage for an analog-to-digital converter (ADC), the input stage comprising an input signal line having in series a first input node, a low-pass RC filter, an input switch, and a sampling capacitor, the arrangement of the input signal line being such that in use the input switch receives an input signal to be converted from the input node via the RC filter and outputs the input signal to the sampling capacitor to be sampled for digital conversion, the input stage further comprising a second input node separate from the first input node, and first circuitry connecting the second input node to the sampling capacitor, the arrangement being such that the second input node receives in use a pre-charge signal which is used to pre-charge the sampling capacitor without further amplification being applied to said pre-charge signal.
Dependencies are inferred from the claim text.