Abstract: A method for charging a battery, and electronic device using the method, includes charging the battery with a first charge current Im at constant current in a mth charge-discharge cycle of the battery, wherein the battery has a first cut-off voltage V1 when the constant current charging stage of the battery is cut off in the mth charge-discharge cycle. The first charge current Im is calculated according to a formula Im=In+k×In, where, 0<k?1, In is the charging current of the constant current charging stage of the battery or another battery identical to the battery in the nth charge-discharge cycle, or In can be a preset value, n is an integer and is greater than or equal to 0, and m is an integer greater than n, the value of k is not the same in at least two charge-discharge cycles of the battery.

Abstract: A display driver includes a line latch circuit; a first D/A conversion circuit; a second D/A conversion circuit; a first amplifier circuit configured to initialize charges of a capacitor of a first switched capacitor circuit in a first initialization period and output a data voltage in a first output period; a second amplifier circuit configured to initialize charges of a capacitor of a second switched capacitor circuit in a second initialization period and output a data voltage in a second output period; and a control circuit. The control circuit is configured to end the second initialization period of the second amplifier circuit before display data is latched by the line latch circuit at a latch timing and an output of the first amplifier circuit changes.

Abstract: An output driver for an audio system includes a pre-charge circuit. The pre-charge circuit includes a charging amplifier and a feedback bias circuit. A charging amplifier includes an output node for coupling to a capacitive load, a first input node for receiving a reference voltage, a second input node for coupling to the output node of the charging amplifier, and a bias node for receiving a bias current. An output current of the charging amplifier varies with the bias current. The feedback bias circuit is coupled to the output node to sense an output voltage of the charging amplifier, and configured to provide the bias current that varies with the output voltage of the charging amplifier.

Abstract: Systems, methods and apparatuses described herein generally provide a millimetre size package-free complementary metal-oxide-semiconductor (“CMOS”) chip (referred to as a “die”) for the in situ (on-site) measurement or imaging of electrochemically detectable analytes.

Abstract: Trimming components within an oscillator comprising: a trim-capable current source, wherein the trim-capable current source comprises a trimmable resistor and a trimmable current component, a comparator comprising a first input terminal that couples to the trim-capable current source and the second input terminal that couples to a reference voltage source, a switch coupled to the first input terminal and the trim-capable current source, and a trim-capable capacitor coupled to the switch, wherein the switch is coupled between the trim-capable capacitor and the trim-capable current source.

Abstract: A passive illumination ramping circuit for a light-emitting diode (LED) is disclosed. In one or more embodiments, the illumination ramping circuit includes a first control path configured to control an on time of the LED and a second control path configured to control an off time of the LED. In embodiments, the first control path includes a first resistor in series with a first diode, and the second control path includes a second resistor in series with a second diode. The first and second control paths are in parallel with one another, in between a first node and a second node. The illumination ramping circuit further includes a capacitor coupled between the second node and an electrical ground. The illumination ramping circuit further includes a transistor for switching the LED on and off, the transistor including a gate terminal coupled to the second node.

Abstract: An oscillator using a supply regulation loop and a method of operating the oscillator are provided.

Abstract: An example method of trimming a voltage reference in an integrated circuit (IC) includes at a first temperature, sequencing through a first plurality of trim codes for a reference circuit of the voltage reference configured to generate a proportional-to-temperature current and a corresponding first control voltage, and a complementary-to-temperature current and a corresponding second control voltage. The method further includes measuring a voltage output of the voltage reference for each of the first plurality of trim codes to obtain first voltage output values. The method further includes at a second temperature, sequencing through a second plurality of trim codes for the reference circuit. The method further includes measuring the voltage output of the voltage reference for each of the second plurality of trim codes to obtain second voltage output values. The method further includes selecting a trim code for the reference circuit based on the first voltage output values and the second voltage output values.

Abstract: The back EMF (BEMF) of a motor is sensed and compared to a target back EMF (BEMF) to generate an error control signal. The circuit supply voltage is also sensed. A PWM motor control signal is generated in response to a comparison of the error control signal to a ramp signal having a variable slope. The variable slope is selected in response to the sensed circuit supply voltage. The motor is then driven in response to the PWM control signal. The sign of the error control signal is used to selectively short one of motor terminals to a reference voltage supply node while the other motor terminal is driven in response to the PWM control signal.

Abstract: A potentiostat includes a voltage regulator, a current mirror, a capacitor, a comparator, a current source, and a counter. The voltage regulator maintains a voltage on a working electrode of an electrochemical sensor. The current mirror develops a mirror current that mirrors an input current from the working electrode. The capacitor is alternately charged by the mirror current, causing the capacitor voltage to increase at a rate related to the current's magnitude, and discharged by a control current, causing the capacitor voltage to decrease. The comparator outputs a waveform that includes upward and downward transitions based on the variations of the capacitor voltage. The current source produces the control current based on the waveform. The counter counts the number of upward or downward transitions in the waveform during a predetermined sampling period to produce a digital output. The digital output is representative of the magnitude of the input current.

Abstract: An oscillation circuit including a reference voltage generation circuit that adds a proportional-to-absolute-temperature (PTAT) output, which increases in proportion to an absolute temperature, to a complementary-to-absolute-temperature (CTAT) output, which decreases in proportion to an absolute temperature, to generate and output a reference voltage. The oscillation circuit generates an oscillation signal having a desired and fixed frequency.

Abstract: A fully integrated ramp generator circuit includes a first current generator that sources current to first capacitor through a first transistor that is gate controlled by the complement of a periodic signal. The ramping voltage stored on the first capacitor is buffered to an output node as a ramp output signal. A second transistor couples the output node to the first current generator and is gate controlled by the periodic signal. The periodic signal is generated at the output of a flip-flop that receives an input clock signal and reset signal. The reset signal is generated by a comparator circuit operable to compare the voltage on a second capacitor to a reference. The second capacitor is charged by a second current source and discharged by a third transistor that is gate controlled by the periodic signal.

Abstract: An adaptive slope generator can include a current mirror configured to receive a multiplied current that varies as a function of an output voltage and a switching frequency of a switching current. The output voltage can characterize the switching current provided to a load coupled to an inductor. The current mirror can also be configured to receive an oscillation current. The oscillation current can have an amplitude that corresponds to the switching frequency of the switching current. The current mirror can be further configured to generate an output current substantially equivalent to the product of the oscillation current and the output voltage. The adaptive slope generator can also include a ramp generator configured to generate a compensation signal based on the output current. The compensation signal can have a sawtooth shape and a slope that varies as a function of the output voltage.

Abstract: An adaptive slope generator can include a current mirror configured to receive a multiplied current that varies as a function of an output voltage and a switching frequency of a switching current. The output voltage can characterize the switching current provided to a load coupled to an inductor. The current mirror can also be configured to receive an oscillation current. The oscillation current can have an amplitude that corresponds to the switching frequency of the switching current. The current mirror can be further configured to generate an output current substantially equivalent to the product of the oscillation current and the output voltage. The adaptive slope generator can also include a ramp generator configured to generate a compensation signal based on the output current. The compensation signal can have a sawtooth shape and a slope that varies as a function of the output voltage.

Abstract: A signal averaging circuit includes a plurality of switched weighted current sources to generate a total amount of charge. The total amount of charge is representative of a weighted sum of a plurality of input signal samples during an active period of a read enable signal. A timing control signal generator is coupled to receive an input signal and the read enable signal and sequentially switch the plurality of switched weighted current sources to adjust the total amount of charge in response to the input signal during the active period of the read enable signal. A storage circuit is coupled to the plurality of switched weighted current sources to convert the total amount of charge into a voltage representative of an output signal.

Abstract: A triangular waveform generator includes a square waveform clock circuit and an integrating circuit. The integration circuit receives input from the square waveform clock circuit and generates a triangular waveform output. A feedback circuit is operatively connected to the integrating circuit to reduce the audio band noise content in the triangular waveform output. The feedback circuit acts as a DC balance without significant sacrifice in the linearity of the triangular waveform output.

Abstract: The sawtooth wave generation circuit includes: a switch circuit configured to switch a connection state thereof between a first connection state, in which a current from a current source is flowed from a first terminal of the output capacitor to a second terminal of the output capacitor, and a second connection state, in which a current from the current source is flowed from the second terminal of the output capacitor to the first terminal of the output capacitor; a switch control circuit configured such that, in each connection state of the switch circuit, if an output voltage has reached a predetermined threshold which is set in relation to an intermediate voltage, the switch control circuit controls the switch circuit to switch the connection state to the other connection state at least during a part of a predetermined period thereafter.

Abstract: A class-D power amplifier capable of reducing electromagnetic interference includes an integrator, a triangular wave generator, a comparator, a gate driver, a feedback circuit, and an output stage circuit. The integrator is used for receiving an input signal and potential of ground, and outputting a first voltage. The comparator is used for comparing the first voltage with a triangular wave generated by the triangular wave generator to output a pulse-width modulation signal. The gate driver is used for driving the output stage circuit to output an output voltage according to the pulse-width modulation signal. Therefore, the class-D power amplifier reduces the electromagnetic interference by the triangular wave.

Abstract: The sawtooth wave generation circuit includes: a switch circuit configured to switch a connection state thereof between a first connection state, in which a current from a current source is flowed from a first terminal of the output capacitor to a second terminal of the output capacitor, and a second connection state, in which a current from the current source is flowed from the second terminal of the output capacitor to the first terminal of the output capacitor; a switch control circuit configured such that, in each connection state of the switch circuit, if an output voltage has reached a predetermined threshold which is set in relation to an intermediate voltage, the switch control circuit controls the switch circuit to switch the connection state to the other connection state at least during a part of a predetermined period thereafter.

Abstract: An oscillation circuit including a reference voltage generation circuit that adds a proportional-to-absolute-temperature (PTAT) output, which increases in proportion to an absolute temperature, to a complementary-to-absolute-temperature (CTAT) output, which decreases in proportion to an absolute temperature, to generate and output a reference voltage. The oscillation circuit generates an oscillation signal having a desired and fixed frequency.

Abstract: An integrated circuit includes a saw-tooth generator including a saw tooth node configured to have a saw-tooth voltage generated thereon; and a first switch having a first end connected to the saw tooth node. The integrated circuit further includes a second switch coupled between an output node and an electrical ground, wherein the first switch and the second switch are configured to operate synchronously. A first current source is connected to the saw tooth node. A second current source is connected to the output node.

Abstract: A circuit for generating a signal comprising a first transistor having a drain, a gate and a source. A second transistor having a drain, a source and a gate coupled to the gate of the first transistor to form a current mirror. A current source coupled to the source of the first transistor. A diode-connected transistor having a drain coupled to the source of the second transistor, a source and a gate that forms an output. A variable resistor having a first terminal coupled to the source of diode-connected transistor and a second terminal. A capacitor coupled to the second terminal of the variable resistor.

Abstract: An optical receiver suitable for connecting to a photodiode generating a photocurrent with a sensing resistor and a diode circuit in parallel with the sensing resistor to limit the voltage across the sensing resistor. The diode circuit allows for a larger resistor providing greater sensitivity without risking violating the necessary headroom available to the photodiode.

Abstract: A circuit configured to output a ramp signal having a potential varying depending on time includes a voltage supply unit configured to supply a plurality of voltages having different amplitudes, a current supply unit, an integration circuit configured to output the ramp signal, and a capacitive element. The voltage supply unit is connected to one terminal of the capacitive element. The integration circuit and the current supply unit are connected to another terminal of the capacitive element.

Abstract: A triangular waveform generator includes a square waveform clock circuit and an integrating circuit. The integration circuit receives input from the square waveform clock circuit and generates a triangular waveform output. A feedback circuit is operatively connected to the integrating circuit to reduce the audio band noise content in the triangular waveform output. The feedback circuit acts as a DC balance without significant sacrifice in the linearity of the triangular waveform output.

Abstract: System and method for generating one or more ramp signals. The method includes an oscillator configured to generate at least a clock signal, and a ramp signal generator configured to receive at least the clock signal and generate a first ramp signal. Additionally, the ramp signal generator is coupled to a first resistor including a first terminal and a second terminal. The first resistor is configured to receive an input voltage at the first terminal and is coupled to the ramp signal generator at the second terminal. Moreover, the first resistor is associated with a first resistance value. Also, the clock signal is associated with at least a predetermined frequency. The predetermined frequency does not change if the input voltage changes from a first magnitude to a second magnitude. The first magnitude is different from the second magnitude.

Abstract: In a switch mode power supply, a circuit and method for switching between an internal clock and an external synchronization clock when a stable external clock has been detected, and for switching back to operating the power supply using said internal clock when a predetermined number of sequential external clock pulses exceed a predetermined switching period dropout threshold or are otherwise missing. In one embodiment, a power system comprises a plurality of power supplies connected in parallel to a common load and where each power supply is synchronized to the external clock when a stable external clock has been detected by each.

Abstract: A circuit includes a level-crossing detector to generate a level-crossing detection signal when an input signal crosses a predetermined voltage level. A first stage set of capacitors is operatively coupled to the level-crossing detector. A ramp circuit is operatively coupled to the set of series-connected capacitors. A second stage set of capacitors is operatively coupled to the first stage set of capacitors and the ramp circuit. The ramp circuit includes a feedback capacitor and a preset switch to provide a linear ramp output.

Abstract: An integrated circuit includes a saw-tooth generator including a saw tooth node configured to have a saw-tooth voltage generated thereon; and a first switch having a first end connected to the saw tooth node. The integrated circuit further includes a second switch coupled between an output node and an electrical ground, wherein the first switch and the second switch are configured to operate synchronously. A first current source is connected to the saw tooth node. A second current source is connected to the output node.

Abstract: Waveform generation circuits are provided. A waveform generation circuit includes a waveform generation block configured to generate a waveform signal corresponding to a driving control signal, and a control signal generation block configured to generate the driving control signal to compensate the waveform signal for an environmental factor affecting the waveform generation circuit.

Abstract: A triangular waveform generator includes a square waveform clock circuit and an active integrator. The active integrator receives input from the square waveform clock circuit and generates a triangular waveform output. An active feedback network is operatively added to the active integrator to reduce the audio band noise content in the triangular waveform output. The feedback network acts as a DC balance without significant sacrifice in the linearity of the triangular waveform output.

Abstract: A driving apparatus having driving circuits formed to correspond to driven circuits arranged on a circuit board. Each driving circuit includes a driving control unit for driving the corresponding driven circuit, a reference voltage generation unit for generating a reference voltage according to a temperature of the corresponding driven circuit, a control voltage generation unit for generating, based on the reference voltage supplied from the reference voltage generation unit, a control voltage for driving the corresponding driven circuit, the control voltage generation unit supplying the generated control voltage to the driving control unit, a switch device formed between the control voltage generation unit and the reference voltage generation unit, and a switch control unit for driving the switch device based on an inputted control signal. The control voltage generation unit is connected to the reference voltage generation unit of another of the driving circuits via the switch device.

Abstract: A current generator circuit included in a triangle-wave generator circuit in a control circuit includes plural stages of current mirrors connected in parallel with each other. The plural stages of current mirrors are placed so that the sum of output currents output therefrom becomes an output current of the current generator circuit. A switching element that controls the on/off state of a current in accordance with the amount of load current of a DCDC converter is connected to each of the current mirrors.

Abstract: For efficiency improvement of a LED display system including a charge pump and a LED connected to either the voltage input terminal or the voltage output terminal of the charge pump, either one or both of two current regulators are enabled according to a voltage detected from the LED, for establishing a driving current for the LED. When the detected voltage is higher than a threshold, the first one of the current sources is enabled sole. When the detected voltage is lower than the threshold, the second one of the current sources is enabled sole, or both the current sources are enabled, or the current sources are alternatively enabled.

Abstract: A drive circuit applying two or more drive voltages to a charge transfer unit includes at least one current mirror circuit that receives a reference current and outputs a predetermined current; at least one switch circuit that switches the current output from the at least one current mirror circuit to apply the multiple drive voltages to the charge transfer unit; and at least one time constant circuit that gives a predetermined time constant to the reference current in the switching by the switch circuit.

Abstract: A sawtooth generator circuit comprises a first triangular waveform generator with equal ramp up and ramp down rates and a second triangular waveform generator with equal ramp up and ramp down rates and which are equal to the ramp up and ramp down rates of the first triangular waveform generator. The first and second triangular waveform generators are controlled to be 180 degrees out of phase. A switching arrangement alternately switches the increasing or decreasing ramps of the first and second triangular waveform generators to an output of the sawtooth generator circuit. The invention provides a sawtooth generator circuit which is suitable for high frequency applications, with low current consumption and low ground bounce. A very fast falling edge can be obtained.

Abstract: A slope compensation circuit includes an oscillator for generating a first clock signal having a reference frequency, a ramp signal generator for generating a ramp signal having a duty ratio of about 50% or higher based on the first clock signal, and a slope compensation signal generator for outputting a slope compensation current based on the ramp signal.

Abstract: This patent discloses an efficient PWM controller for generating a pulse signal in response to a feedback signal, capable of operating in a normal mode or a green mode, comprising: a capacitor for building a saw-tooth signal by current integration, the saw-tooth signal having a ramp-up period and a ramp-down period; a first composite current source for the ramp-up period, detachable into a first constant current source and a first variable current source; and a second composite current source for the ramp-down period, detachable into a second constant current source and a second variable current source; wherein, the first variable current source is attached to the first constant current source and the second variable current source is attached to the second constant current source respectively in the green mode.

Abstract: A spread-spectrum circuit including an inverter, a current source, a control unit and a shaping circuit is provided. An input terminal of the inverter receives an original clock signal. The current source is coupled to a current transmission terminal of the inverter. The control unit includes a control circuit, and changes the current magnitude of the current source according to the original clock signal to control the charging/discharging speed of an output terminal of the inverter, so that the output terminal outputs a voltage signal. The shaping circuit shapes the voltage signal into a spread-spectrum clock signal.

Abstract: A triangle wave generating circuit comprising: a pulse generating circuit configured to generate a plurality of pulse signals with the same period and with phases different from one another; and a plurality of charge/discharge circuits configured to be supplied with the plurality of pulse signals, respectively, the plurality of charge/discharge circuits each including: a current supply circuit configured to supply to a capacitor a first current for charging at a predetermined current value or a second current for discharging at a predetermined current value; and a charge/discharge control circuit configured to switch between the first current and the second current when the pulse signals are supplied thereto and when a voltage across the capacitor reaches a predetermined reference voltage, the first current and the second current supplied from the current supply circuit to the capacitor.

Abstract: A triangular waveform generator includes a square waveform clock circuit and an active integrator. The active integrator receives input from the square waveform clock circuit and generates a triangular waveform output. An active feedback network is operatively added to the active integrator to reduce the audio band noise content in the triangular waveform output. The feedback network acts as a DC balance without significant sacrifice in the linearity of the triangular waveform output.

Abstract: A sawtooth generator adapted to produce a sawtooth voltage, a method of operating the same, and a power converter employing the sawtooth generator and method. In one embodiment, the sawtooth generator includes a current source, coupled to a clock with a clock frequency, configured to produce a reference current proportional to the clock frequency. The sawtooth generator also includes an active network including a switch and a capacitor coupled to the current source and configured to provide a sawtooth voltage with a waveform slope produced across the capacitor substantially proportional to the reference current.

Abstract: A triangle waveform generator is set forth that comprises a capacitive element, a regulator, and a control circuit. The regulator is configured to charge the capacitive element in responsive to a first control signal and to discharge the capacitive element in response to a second control signal. The control circuit is responsive to a reference waveform to generate the first and second control signals. In one example, the control circuit generates the first and second control signals in response to the amplitude, frequency, phase, and symmetry of the reference waveform.

Abstract: A first switched capacitor circuit is connected to the source of one MOS transistor of a current mirror pair configured by a pair of MOS transistors and a second switched capacitor circuit is connected to the source of the other MOS transistor. Each of the first and second switched capacitor circuits includes a capacitor and a switch connected in parallel with the capacitor and the switch is on/off-controlled based on a clock signal of a preset cycle. Each of the first and second switched capacitor circuits equivalently functions as a resistor with large resistance and a variation in the output current of the current mirror circuit based on a variation in the threshold voltages of the pair of MOS transistors can be reduced even if the power source voltage is reduced.

Abstract: A DC-DC converter for converting an input voltage and generating an output voltage. The DC-DC converter includes an adjustment resistor. A control circuit generates a control signal and includes an external terminal to which the adjustment resistor is externally connected. A switching transistor is connected to the control circuit and turned on or off in accordance with the control signal. The control circuit includes an oscillator that generates an oscillation signal. The control circuit generates the control signal based on the oscillation signal and a signal that is in accordance with an output voltage or output current of the DC-DC converter. The oscillator monitors a first amount of current flowing through the external terminal of the control circuit and generates the oscillation signal in a cycle that is accordance with the monitoring result.

Abstract: A slope compensation circuit includes apparatus includes an oscillator for generating a first clock signal having a reference frequency, a ramp signal generator for generating a ramp signal having a duty ratio of about 50% or higher based on the first clock signal, and a slope compensation signal generator for outputting a slope compensation current based on the ramp signal.

Abstract: A low power servo-controlled single clock ramp generator (100) includes a fast switched comparator (102), charge pump (110) and voltage-to-current converter (120) connected to provide a feedback control mechanism under control of a pulse comparison clock signal (pulse_comp) and a reset pulse clock signal (rst_pulse) that are generated from a single input clock signal (clkin) so that there are well defined time intervals between pulses in the pulse comparison clock signal and the reset pulse clock signal, thereby providing a ramp signal (Vramp_out) having a stable, frequency-independent amplitude that is not limited by the reference voltage.

Abstract: In one embodiment, a single input terminal of a parameter control circuit is utilized to form two different parameters of the parameter control circuit. In another embodiment, the parameter control circuit can include charging and discharging current mirrors.

Abstract: A high-voltage sawtooth current driving circuit and a memory device including the same are described. In the high-voltage sawtooth current driving circuit includes a charge pump circuit configured to output a first voltage, a regulating circuit configured to regulate a second voltage using the first voltage output from the charge pump circuit, and a sawtooth current driver configured to generate a sawtooth current in response to the second voltage regulated by the regulating circuit.

Abstract: A semiconductor device includes a current control circuit for outputting and sinking a current in synchronization with a received clock signal; and a current/voltage conversion circuit having a first capacitor charged and discharged by the current control circuit outputting and sinking the current, respectively, and outputting a triangular wave based on the charge stored in the first capacitor.