It is presented a power converter for transferring electric power provided on an input terminal to an energy storage element. The power converter comprises: an inductor; a switch connected to selectively control a connection between the inductor and the input terminal; and a comparator, wherein an output of the comparator controls the switch, a first input of the comparator is supplied with a voltage being proportional to a voltage of the input terminal, and a second input of the comparator is supplied with a voltage being proportional to a current from the input terminal; wherein the energy storage element is connected to a point between the inductor and the switch.

A duty cycle estimation circuit includes a latch circuit that receives a clock signal for a voltage regulator. The latch circuit outputs a duty cycle estimate. The duty cycle estimation circuit also includes a low pass filter coupled to an output of the latch circuit to receive the duty cycle estimate. The duty cycle estimation circuit further includes a comparator that receives, as input, an output of the low pass filter and a voltage regulator output. The comparator feeds back a feedback signal to the latch circuit.

According to an embodiment, a current detection circuit includes a transistor, an operational amplifier, and a transistor. In the transistor, the source and the gate are coupled to the source and the gate of a transistor which is provided on a high side of a drive circuit. The operational amplifier amplifies a potential difference between a drain voltage of the transistor and a drain voltage of the transistor. The transistor is provided over a current path through which a current flowing to the transistor flows, and which has the gate to which an output voltage of the operational amplifier is supplied. A value of the current flowing Through The transistor is detected based on a value of the current flowing through the transistor.

An ultra-low-power mode control circuit for a power converter includes four modules: a level shift circuit, a start circuit, a static clamp circuit, and a control circuit. When a chip is powered on and a core voltage has not been established, the control circuit firstly starts a power source built-in clock to support operation of the power converter. When the core voltage is established, the control circuit determines whether to switch to an external clock according to a level of a mode selection signal. After the core voltage is powered down, the control circuit automatically wakes up the built-in clock to work.

A DC-DC regulator system includes a power circuit which has a first input coupled to receive an input voltage, a second input coupled to receive a control signal and an output to provide a regulated output voltage. The system includes a control circuit which has a first input coupled to receive the regulated output voltage, a second input coupled to receive a reference voltage, a first output to provide the control signal, and a second output to provide a converter clock signal. The system includes an out-of-audio circuit which has a first input coupled to receive a minimum threshold frequency signal, a second input coupled to receive the converter clock signal, a third input coupled to the power circuit output, and a fourth input coupled to receive a bandwidth control clock signal.

To provide a sensor apparatus and sensor system using a low-power input source such as a microbial fuel cell, provided is a sensor apparatus including a microbial fuel cell; a boosting DC-DC circuit that operates based on an input voltage from the microbial fuel cell and boosts the input voltage; a power storage element that stores power output from the boosting DC-DC circuit; and a sensor element that operates based on power output from the power storage element, as well as a sensor system that includes this sensor apparatus and a wireless communication apparatus.

In some examples, an apparatus comprises: an amplifier having an amplifier output and first and second amplifier inputs, the first amplifier input coupled to a reference voltage terminal, and the second amplifier input coupled to a power input terminal; a ramp generation circuit having a reset input and a ramp output; a comparator having a comparator output and first and second comparator inputs, the first comparator input coupled to the amplifier output, and the second comparator input coupled to the ramp output; and a switching signal generation circuit having a circuit input and a circuit output, the circuit input coupled to the comparator output, and the circuit output coupled to a power control terminal.

Novel voltage converter circuits are provided which step-up very low DC input voltages to higher voltages capable of supporting low-power loads. According to embodiments, a voltage step-up power converter circuit may be formed of an oscillator sub-circuit which receives a DC voltage and outputs an AC voltage; a voltage doubler sub-circuit which receives the AC voltage and outputs an augmented AC voltage; and a voltage step-up converter sub-circuit which receives the augmented AC voltage, as a control voltage, and the initial DC voltage and outputs a voltage which is more than the initial DC voltage. These circuits allow electrical energy to be harvested from very low voltage sources and to convert it as efficiently as possible to run a load.

A packaged power module includes a case, and a metal structure that has first and second surfaces. A transistor is also included that has first and second terminals between which current is transmitted when the transistor is activated, and a control terminal controlling the transistor, wherein the first terminal is sintered to the first surface. A first opening through the case exposes the second surface.

An ultra-low-power mode control circuit for a power converter includes four modules: a level shift circuit, a start circuit, a static clamp circuit, and a control circuit. When a chip is powered on and a core voltage has not been established, the control circuit firstly starts a power source built-in clock to support operation of the power converter. When the core voltage is established, the control circuit determines whether to switch to an external clock according to a level of a mode selection signal. After the core voltage is powered down, the control circuit automatically wakes up the built-in clock to work.