Abstract: An optical receiver (1) comprises a differential TIA (4) linked with a photodiode (2, 3) providing a current sense signal (Isig_tia). The receiver is configured to provide to the TIA a sense signal as a sense TIA input (Isig_tia) and a second input (Idark_tia) which is a proportion of the maximum sense signal. The proportion input is half of said maximum sense signal. The inputs to the TIA are via cascode circuits (5, 6), thereby providing the advantages of a low input impedance for large area photodiodes at the TIA input, while creating a fully differential signal at the output, and the reduction of TIA bandwidth in burst mode applications, which filters out high frequency noise.

Abstract: A supply circuit for providing pulses of current has a current source, a reference voltage source for controlling magnitude of the current, and a current switch for controlling whether or not the current passes through a load. Also, there is a switch control signal terminal for controlling the current switch, and glitch compensation elements including at least one capacitance circuit and associated capacitor drive circuit for feeding a variable correcting voltage back to the reference voltage, and a controller to control said variable voltage.

Abstract: A voltage comparator (1) has a high switching speed and simplicity of design. It minimizes pulse-width distortion of input digital signals when functioning as a digital input buffer in high speed communications applications. In addition it provides a simple hysteresis circuit (31) that is easily tuneable with a reference current. The hysteresis circuit (31) is dependent on a reference current. This current may be chosen to have a proportionality to temperature, supply, or another selectable parameter, and may be programmable, in order to create the desired hysteresis performance.

Abstract: A receiver has a differential transimpedance amplifier (4) with two inputs and two outputs. The differential transimpedance amplifier (4) provides a differential output and this is peak-detected (15, 16) to provide amplitude reference signals. The differential transimpedance amplifier output and the amplitude reference signals are fed to a differential summing amplifier (10), which provides a fully differential signal to a comparator, or to an automatic gain control circuit (5) to regulate the differential transimpedance amplifier gain. The differential summing amplifier (10) output is a fully differential signal, thereby having lower distortion for DC and burst mode receiver applications.

Abstract: A transconductance circuit has an input terminal (VIN) and an output terminal (Out), a first current source (4) having a gate connected to said input terminal (VIN); and a second current source (5), in parallel with said first current source, and having a higher transconductance and a wider dynamic range than the first current source. The current sources are configured so that at a low input voltage only the first current source (4) is on. A voltage drop circuit provides a lower bias voltage for the second current source than for the first current source.

Abstract: A supply circuit for providing pulses of current has a current source, a reference voltage source for controlling magnitude of the current, and a current switch for controlling whether or not the current passes through a load. Also, there is a switch control signal terminal for controlling the current switch, and glitch compensation elements including at least one capacitance circuit and associated capacitor drive circuit for feeding a variable correcting voltage back to the reference voltage, and a controller to control said variable voltage.

Abstract: A voltage comparator (1) has a high switching speed and simplicity of design. It minimizes pulse-width distortion of input digital signals when functioning as a digital input buffer in high speed communications applications. In addition it provides a simple hysteresis circuit (31) that is easily tuneable with a reference current. The hysteresis circuit (31) is dependent on a reference current. This current may be chosen to have a proportionality to temperature, supply, or another selectable parameter, and may be programmable, in order to create the desired hysteresis performance.

Abstract: A receiver has a differential transimpedance amplifier (4) with two inputs and two outputs. The differential transimpedance amplifier (4) provides a differential output and this is peak-detected (15, 16) to provide amplitude reference signals. The differential transimpedance amplifier output and the amplitude reference signals are fed to a differential summing amplifier (10), which provides a fully differential signal to a comparator, or to an automatic gain control circuit (5) to regulate the differential transimpedance amplifier gain. The differential summing amplifier (10) output is a fully differential signal, thereby having lower distortion for DC and burst mode receiver applications.

Abstract: A transconductance circuit has an input terminal (VIN) and an output terminal (Out), a first current source (4) having a gate connected to said input terminal (VIN); and a second current source (5), in parallel with said first current source, and having a higher transconductance and a wider dynamic range than the first current source. The current sources are configured so that at a low input voltage only the first current source (4) is on. A voltage drop circuit provides a lower bias voltage for the second current source than for the first current source.

Abstract: An apparatus and method for determining characterizing attributes of an actuator is provided. An actuator may be moved to a maximum capacitance position. At the maximum capacitance position, an initial measurement of the actuator capacitance is made. The actuator is moved a predetermined increment toward a first extreme position, and the actuator capacitance is again measured. If the capacitance changed by a threshold amount, the signal preceding the signal that caused the actuator to move is recorded as an approximate response curve end point, or the first extreme position. The actuator is again moved a predetermined increment toward a second extreme position. After each move, the capacitance is measured. If it is determined the capacitance did change by a threshold amount from the previously measured capacitance, the signal related to the previously measured capacitance is recorded as an approximate response curve end point, or the second extreme position.

Abstract: A reference voltage generator circuit may include at least one MOS transistor and at least one bipolar transistor coupled together to provide an electrical path from an input reference potential to an output of the generator circuit. The electrical path may extend through a gate-to-source path of the MOS transistor and further through a base-to-emitter path of the bipolar transistor. The MOS transistor may be biased by a bias current that is proportional to T2·?(T), where T represents absolute temperature and ?(T) represents mobility of a MOS transistor in the bias current generator. Optionally, the reference voltage generator may include N MOS and M multiple bipolar transistors (N?1, M?1), and the output reference voltage may be N*VGS+M*VBE as compared to the input reference potential.

Abstract: An apparatus and method for determining characterizing attributes of an actuator is provided. An actuator may be moved to a maximum capacitance position. At the maximum capacitance position, an initial measurement of the actuator capacitance is made. The actuator is moved a predetermined increment toward a first extreme position, and the actuator capacitance is again measured. If the capacitance changed by a threshold amount, the signal preceding the signal that caused the actuator to move is recorded as an approximate response curve end point, or the first extreme position. The actuator is again moved a predetermined increment toward a second extreme position. After each move, the capacitance is measured. If it is determined the capacitance did change by a threshold amount from the previously measured capacitance, the signal related to the previously measured capacitance is recorded as an approximate response curve end point, or the second extreme position.

Abstract: An apparatus and method for determining characterizing attributes of an actuator is provided. An actuator may be moved to a maximum capacitance position. At the maximum capacitance position, an initial measurement of the actuator capacitance is made. The actuator is moved a predetermined increment toward a first extreme position, and the actuator capacitance is again measured. If the capacitance changed by a threshold amount, the signal preceding the signal that caused the actuator to move is recorded as an approximate response curve end point, or the first extreme position. The actuator is again moved a predetermined increment toward a second extreme position. After each move, the capacitance is measured. If it is determined the capacitance did change by a threshold amount from the previously measured capacitance, the signal related to the previously measured capacitance is recorded as an approximate response curve end point, or the second extreme position.

Abstract: Metal oxide semiconductor (MOS) protection circuits and methods of forming the same are disclosed. In one embodiment, an integrated circuit includes a pad, a p-type MOS (PMOS) transistor, and first and second n-type MOS (NMOS) transistors. The first NMOS transistor includes a drain, a source and a gate electrically connected to the pad, a first supply voltage, and a drain of the PMOS transistor, respectively. The second NMOS transistor includes a gate, a drain, and a source electrically connected to a bias node, a second supply voltage, and a source of the PMOS transistor, respectively. The source of the second NMOS transistor is further electrically connected to a body of the PMOS transistor so as to prevent a current flowing from the drain of the PMOS transistor to the second supply voltage through the body of PMOS transistor when a transient signal event is received on the pad.

Abstract: A detection circuit is coupled to an output terminal of a driver circuit. The detection circuit includes a comparator to compare a signal at the output terminal to a reference signal corresponding to a signal that would be generated if a capacitive load having a relatively high capacitance value were connected to the output terminal. Output of the comparator is sampled at a predetermined time after the driver circuit provides the drive signal. An error signal is generated when the sampled output indicates that the capacitive load having the relatively high capacitance value is actually connected to the output terminal.

Abstract: Metal oxide semiconductor (MOS) protection circuits and methods of forming the same are disclosed. In one embodiment, an integrated circuit includes a pad, a p-type MOS (PMOS) transistor, and first and second n-type MOS (NMOS) transistors. The first NMOS transistor includes a drain, a source and a gate electrically connected to the pad, a first supply voltage, and a drain of the PMOS transistor, respectively. The second NMOS transistor includes a gate, a drain, and a source electrically connected to a bias node, a second supply voltage, and a source of the PMOS transistor, respectively. The source of the second NMOS transistor is further electrically connected to a body of the PMOS transistor so as to prevent a current flowing from the drain of the PMOS transistor to the second supply voltage through the body of PMOS transistor when a transient signal event is received on the pad.

Abstract: A detection circuit is coupled to an output terminal of a driver circuit. The detection circuit includes a comparator to compare a signal at the output terminal to a reference signal corresponding to a signal that would be generated if a capacitive load having a relatively high capacitance value were connected to the output terminal. Output of the comparator is sampled at a predetermined time after the driver circuit provides the drive signal. An error signal is generated when the sampled output indicates that the capacitive load having the relatively high capacitance value is actually connected to the output terminal.

Abstract: A system for a Class AB Amplifier output stage that includes a first push pull system connected to an output terminal including a first driving transistor coupled to the output terminal and a second push pull system connected to the output terminal including a second driving transistor coupled to the output terminal. The amplifier also includes a current mode amplifier where the current mode amplifier's output is coupled to the first driving transistor's gate. The amplifier further includes a pair of resistors, a first resistor coupled to a first input terminal of the current mode amplifier, a second resistor coupled to a second input terminal of the current mode amplifier and coupled to the second driving transistor.

Abstract: A system for a Class AB Amplifier output stage that includes a first push pull system connected to an output terminal including a first driving transistor coupled to the output terminal and a second push pull system connected to the output terminal including a second driving transistor coupled to the output terminal. The amplifier also includes a current mode amplifier where the current mode amplifier's output is coupled to the first driving transistor's gate. The amplifier further includes a pair of resistors, a first resistor coupled to a first input terminal of the current mode amplifier, a second resistor coupled to a second input terminal of the current mode amplifier and coupled to the second driving transistor.

Abstract: An apparatus and method for determining characterizing attributes of an actuator is provided. An actuator may be moved to a maximum capacitance position. At the maximum capacitance position, an initial measurement of the actuator capacitance is made. The actuator is moved a predetermined increment toward a first extreme position, and the actuator capacitance is again measured. If the capacitance changed by a threshold amount, the signal preceding the signal that caused the actuator to move is recorded as an approximate response curve end point, or the first extreme position. The actuator is again moved a predetermined increment toward a second extreme position. After each move, the capacitance is measured. If it is determined the capacitance did change by a threshold amount from the previously measured capacitance, the signal related to the previously measured capacitance is recorded as an approximate response curve end point, or the second extreme position.