An N-tap feedforward equalizer (FFE) comprises a set of N FFE taps coupled together in parallel, a filter coupled between the (N−1)th FFE tap and the Nth FFE tap, and a summer coupled to an output of the set of N FFE taps. Each FFE tap includes a unique sample-an-hold (S/H) circuit that generates a unique time-delayed signal and a unique transconductance stage that generates a unique transconductance output based on the unique time-delayed signal. The filter causes the N-tap FFE to have the behavior of greater than N taps. In some examples, the filter is a first order high pass filter that causes coefficients greater than N to have an opposite polarity of the Nth coefficient. In some examples, the filter is a first order low pass filter that causes coefficients greater than N to have the same polarity as the Nth coefficient.

A semiconductor device according to the present embodiment includes a plurality of switching elements and a plurality of variable capacitance elements. The switching elements are switching elements connected in series between a first control terminal and a second control terminal and plural types of capacitance control signals can be supplied to the first control terminal and the second control terminal. The variable capacitance elements have capacitance control terminals connected to corresponding one ends of the switching elements, respectively.

An undervoltage detection circuit includes a voltage divider, a voltage-to-current (V-to-I) converter and a current comparator. The voltage divider divides a supply voltage to generate a divided voltage. The V-to-I converter converts the divided voltage into a first current based on a first V-to-I transfer function, and converts the divided voltage into a second current based on a second V-to-I transfer function different from the first V-to-I transfer function. The current comparator compares the first and second currents to generate a comparison signal that indicates whether the supply voltage is sufficiently large.

An amplifier circuit with in-band gain degradation compensation is shown. The amplifier circuit has an input-stage amplifier, at least one intermediate-stage amplifier, and an output-stage amplifier cascaded between an input port and an output port of the amplifier circuit. A compensation capacitor is coupled between the output port of the amplifier circuit and an output port of the input-stage amplifier. A high-order damping circuit is coupled to an output port of the intermediate-stage amplifier.

An electronic system comprising a voltage-to-current converter and a proportional-to-absolute-temperature (PTAT) circuit is disclosed. The voltage-to-current converter is configured to receive one of a control voltage, a supply voltage, a scaled-down version of the control voltage, and a scaled-down version of the supply voltage, and generate a set of currents. The PTAT circuit is coupled with the voltage-to-current converter such that each current of the set of currents is one of sourced to the PTAT circuit and sank from the PTAT circuit. Further, the PTAT circuit is configured to receive at least one of the supply voltage and the control voltage, and generate a set of reference voltages. The control voltage is generated based on the set of reference voltages and the supply voltage.

DC-DC power converter control comprises current starved delay lines for phase shifting control signals that set and reset a RS flip-flop to provide controllable PWM pulse widths from narrow to wide at a clock frequency. Precise pulse width control and a guaranteed minimum pulse width for pulse frequency modulation (PFM) control the DC-DC power converter during low power demand is also provided. PFM control maintains the same pulse width while decreasing the number of pulses per second when the output voltage exceeds an upper value and increases the number of pulses per second when the output voltage is less than a lower value. Voltage-to-current converters provide control currents to the current starved delay lines that provide the control signals to the SET and RESET inputs of the RS flip-flop. A D-flip-flop may further be used to improved circuit operation when generating high duty cycle (>50 percent) pulse widths.

A current-mode Schmitt Trigger includes a plurality of current output stages connected to a common supply voltage that powers the current-mode Schmitt Trigger, a main input on one of the current output stages that receives an input current, and a non-inverting output on a different one of the current output stages that is shorted to the main input to establish a positive closed-loop feedback and supplies a non-inverting output current as the input current. The current-mode Schmitt Trigger includes only active components.

A power supply includes a primary winding, a secondary winding, a switch, and a controller. The secondary winding is magnetically coupled to the primary winding. The switch is coupled to the secondary winding and controls a state of current through the secondary winding. The controller controls the state of the switch based on an integrator voltage derived from monitoring a voltage from the secondary winding. For example, the controller activates the switch to an ON state in response to detecting a condition in which the magnitude of the monitored voltage of the secondary winding crosses a threshold value such as a magnitude of an output voltage produced from the secondary winding.

Disclosed is an integrated circuit including a first bias current generating circuit. The first bias current generating circuit includes a first amplifier receiving a reference voltage and a first voltage and amplifying a difference between them to output a first output voltage, a first bias current generator receiving the first output voltage and outputting a first bias current in response to the first output voltage, a variable resistor receiving the first bias current and outputting the first voltage in response to the first bias current and a calibration code, a second bias current generator receiving the first output voltage and outputting a second bias current to a peripheral circuit in response to the first output voltage, and a third bias current generator receiving the first output voltage and outputting a third bias current to an external device through a first pad in response to the first output voltage.

Voltage-to-current converters that include two current mirrors are disclosed. In an example voltage-to-current converter each current mirror is a complementary current mirror in that one of its input and output transistors is a P-type transistor and the other one is an N-type transistor. Such voltage-to-current converters may be implemented using bipolar technology, CMOS technology, or a combination of bipolar and CMOS technologies, and may be made sufficiently compact and accurate while operating at sufficiently low voltages and consuming limited power.