Abstract: Delivering electrical stimulation to a body tissue by a circuit. The circuit includes a first and second terminal electrically coupled to body tissue. A sole capacitor has a first electrode and a second electrode. The first electrode is coupled to the first terminal. The second electrode is coupled to a power source through a switch.

Abstract: A supply circuit for an implantable medical device (IMD) is presented. The supply circuit includes a battery, a high current circuit, a current-modifying component, a low current circuit, and a capacitor. The low current circuit is connected to a first terminal of the battery. A current-modifying component is connected to the battery, a capacitor, and to a high current circuit.

Abstract: Delivering electrical stimulation to a body tissue by a circuit. The circuit includes a first and second terminal electrically coupled to body tissue. A sole capacitor has a first electrode and a second electrode. The first electrode is coupled to the first terminal. The second electrode is coupled to a power source through a switch.

Abstract: Delivering electrical stimulation to a body tissue by a circuit. The circuit includes a first and second terminal electrically coupled to body tissue. A sole capacitor has a first electrode and a second electrode. The first electrode is coupled to the first terminal. The second electrode is coupled to a power source through a switch.

Abstract: An integrated current-to-voltage conversion circuit converts a first current to an output voltage representative of the first current. The circuit includes a first contact pad and second and third contact pads capable of being coupled across a first resistor. A first operational amplifier has a first input coupled to the first contact pad for producing a first voltage thereat, a second input for receiving a reference voltage, and a first output coupled to the third contact pad. A second voltage appears at the third contact pad. A second operational amplifier has a second output at which a third voltage appears, a first input coupled to the second output, and a second input coupled to the second contact pad. The output voltage is substantially equal to the difference between the second and third voltages.

Abstract: An integrated current-to-voltage conversion circuit converts a first current to an output voltage representative of the first current. The circuit includes a first contact pad and second and third contact pads capable of being coupled across a first resistor. A first operational amplifier has a first input coupled to the first contact pad for producing a first voltage thereat, a second input for receiving a reference voltage, and a first output coupled to the third contact pad. A second voltage appears at the third contact pad. A second operational amplifier has a second output at which a third voltage appears, a first input coupled to the second output, and a second input coupled to the second contact pad. The output voltage is substantially equal to the difference between the second and third voltages.

Abstract: A low-power operational amplifier comprises a differential input-stage and an output stage. The differential input-stage includes first and second differentially coupled input transistors each having base, emitter, and collector electrodes. A first current mirror circuit is coupled to the first and second input transistors and produces a first current which perturbs the current flowing through the first input transistor. The output stage is coupled to the differential input-stage and to the current mirror circuit and produces a second larger current which perturbs the current flowing through the second input transistor. The ratio of the emitter areas of the first and second input transistors are selected to substantially eliminate offset voltage caused by the difference between the first and second perturbing currents. This device is especially suited for low-power Class A bipolar operational amplifiers such as the type employed in low-power medical devices.

Abstract: A flux-gate magnetometer having a drive signal for reducing the effects of electromagnetic interference (EMI) is provided. The drive signal has a characteristic that varies over time. For example, the drive signal may include a duty cycle that varies over time, the frequency of the drive signal may be varied over time, or the phase shift of the drive signal may vary over time.

Abstract: A digital-to-analog converter switch provides substantially equal propagation delays for both high-to-low and low-to-high transitions of the binary input signal. A ground path transistor and an output transistor are connected to a common node and operated in different states of conduction as determined by the gate voltage on the ground path transistor. A substantially constant current is fed to the node and is either switched through the output transistor or the ground path transistor. In order to compensate for unequal propagation delays in switching the current on and off through the output transistor, additional mimic transistors are provided between the binary input signal and the gate of the ground path transistor. Therefore, transitions in both directions involve one fast and one short propagation delay.

Abstract: A technique for reducing the undesirable effects of amplifier offset voltages in quantizers such as analog-to-digital converters and related devices. The quantizer of the invention has an array of input amplifiers for comparing an input signal with multiple reference voltages, an array of latches for registering output signals from the amplifiers, and signal summing circuitry connected between the amplifiers and the latches, to produce a set of modified amplifier outputs for input to the latches, each of the modified amplifier outputs being derived from a weighted sum of at least three amplifier outputs. In the event of a defect in one or more amplifiers causing unwanted amplifier offsets, the summing circuitry improves linearity without the need for paralleling of transistor components. In one embodiment of the invention, the summing circuitry includes a resistor ladder to which the amplifier outputs are connected and from which the modified outputs are derived.