Abstract:
A resistor in a pair of resistors is selectively coupled to a current source through a selection switch during the reset phase of a voltage-mode sense amplifier so that one evaluation node for the voltage-mode sense amplifier is discharged from a power supply voltage by an ohmic voltage drop across the selectively-coupled resistor to null an offset for the voltage-mode sense amplifier.
Abstract:
A low voltage differential signaling driver is disclosed and may include a current steering output circuit having a first driver output and a second driver output. The low voltage differential signaling driver may also include a programmable on-chip resistor.
Abstract:
An amplifier driver circuit (10A) includes first (11-1) and second (11-2) feedback amplifiers including first (14-1) and second (14-2) upper current mirrors, respectively, and first (16-1) and second (16-2) lower current mirrors, respectively, first (12-1) and second (12-2) amplifier input stages receiving a common mode input signal, and first (18-1) and second (18-2) amplifier output stages coupled to outputs of the first and second amplifier input stages, respectively. Each current mirror has an input and first (OUT1) and second (OUT2) outputs. Upper bias terminals of the first and second amplifier input stages are coupled to the inputs of the first and second upper current mirrors, respectively, and are cross-coupled to the second outputs of the second and first lower current mirrors, respectively. Lower bias terminals of the first and second amplifier input stages are coupled to the inputs of the first and second lower current mirrors, respectively, and are cross-coupled to the second outputs of the second and first upper current mirrors, respectively, to oppose signals at the inputs of the current mirrors in response to the common mode input signal.
Abstract:
Fully differential amplifier circuits are described herein that set the common mode voltage as well as reduce the output offset voltage (offset cancellation). A circuit according to one embodiment includes a first section for generating first and second output signals on first and second outputs from first and second input signals, a first negative feedback loop coupled to the first section, and a second negative feedback loop coupled to the first section. A second section controls the first negative feedback loop for adjusting the first output signal towards a common mode voltage level, and for reducing an offset voltage of the first output signal in different loop bandwidths. A third section controls the second negative feedback loop for adjusting the second output signal towards the common mode voltage level, and for reducing an offset voltage of the second output signal in different loop bandwidths.
Abstract:
In one embodiment, the present disclosure includes a circuit comprising an amplifier having an input and an output, an offset detection circuit to detect an offset of the amplifier at the output of the amplifier, and an offset generation circuit having an input coupled to the offset detection circuit and an output coupled to the input of the amplifier to generate an offset at the input of the amplifier during an operational phase of the amplifier based on the detected offset. The generated offset cancels a least a portion of the offset of the amplifier. In one implementation, the amplifier is a sense amplifier in a memory.
Abstract:
An amplifier driver circuit (10A) includes first (11-1) and second (11-2) feedback amplifiers including first (14-1) and second (14-2) upper current mirrors, respectively, and first (16-1) and second (16-2) lower current mirrors, respectively, first (12-1) and second (12-2) amplifier input stages receiving a common mode input signal, and first (18-1) and second (18-2) amplifier output stages coupled to outputs of the first and second amplifier input stages, respectively. Each current mirror has an input and first (OUT1) and second (OUT2) outputs. Upper bias terminals of the first and second amplifier input stages are coupled to the inputs of the first and second upper current mirrors, respectively, and are cross-coupled to the second outputs of the second and first lower current mirrors, respectively. Lower bias terminals of the first and second amplifier input stages are coupled to the inputs of the first and second lower current mirrors, respectively, and are cross-coupled to the second outputs of the second and first upper current mirrors, respectively, to oppose signals at the inputs of the current mirrors in response to the common mode input signal.
Abstract:
Topologies for Class AB amplifiers which have reduced quiescent power consumption are disclosed. An exemplary amplifier according to the present invention comprises two transconductance amplifying cells, each having an output transistor. Each output transistor is biased such that it conducts a small quiescent current which is preferably sufficient in magnitude to reduce amplifier distortion. The class AB amplifiers are well suited for low power supply voltage applications, such as hearing aids.
Abstract:
Various aspects of this disclosure describe reducing distortion of a power amplifier (202) by coupling a common mode signal (V cm ), such as determined from a voltage supply signal (V boost ) of the power amplifier (202) or output of the power amplifier (202), to an input of the power amplifier (202). A resistive digital-to-analog converter (DAC) can be coupled to the power amplifier (202), and a common mode signal is modulated onto differential reference voltages of the DAC, causing the common mode signal to exist at both the input and output of the power amplifier (202) at approximately the same time. Consequently, current flowing at differential inputs of the power amplifier (202) due to the common mode component drops to zero, causing distortions due to common mode to differential mode conversion to be reduced.