Abstract:
A voltage converter controller and a voltage converter circuit, either of which includes a voltage-drop compensating circuit for compensating a voltage drop between an output voltage and a load. The voltage-drop compensating circuit includes a trans-conductance stage and a squarer. The trans-conductance stage outputs a compensating sink current to a voltage dividing terminal of the output voltage and outputs a compensating source current to a reference voltage terminal of an error amplifier. An input terminal of the squarer is coupled to an output terminal of the error amplifier. An output terminal of the squarer is coupled to an input terminal of the trans-conductance stage.
Abstract:
A switching power converting apparatus includes a voltage conversion module, a detecting unit, and a switching signal generating unit. The voltage conversion module converts an input voltage into an output voltage associated with a secondary side current, which flows through a secondary winding of a transformer and is generated based on a switching signal. The detecting unit generates a detecting signal based on the output voltage and a predetermined reference voltage. The switching signal generating unit generates the switching signal based on the detecting signal and an adjusting signal so that the secondary side current is gradually increased during a start period of the switching power converting apparatus.
Abstract:
An oscillator circuit includes: a switched-capacitor filter filtering a voltage at a common node between a current generating unit and a frequency-controlled resistor so as to generate a filtered voltage; an amplifier generating a control voltage based on the filtered voltage and a voltage at a common node between the current generating unit and a reference resistor; a voltage-controlled oscillator generating an oscillation signal based on the control voltage; and a control signal generating unit generating, based on the oscillation signal, a control input having a frequency proportional to that of the oscillation signal. The frequency-controlled resistor has a resistance variable according to the control input.
Abstract:
A temperature detecting circuit and method thereof, adapted to a voltage converter circuit which includes a current detecting circuit having a detecting output port outputting a current detecting signal proportional to an output current of the voltage converter circuit, includes: a current signal processing unit, having a signal input port coupling to the detecting output port, a first detecting output port generating a first processing signal with a first temperature coefficient, a second detecting output port generating a second processing signal with a second temperature coefficient, wherein the first and the second processing signals are proportional to the current detecting signal; and, a temperature calculating unit, receiving the first and the second processing signals and performing calculation to derive a temperature value.
Abstract:
A switching power converting apparatus is capable of converting an input voltage to an output voltage, and includes a transformer, a primary side control module, and a secondary side control module. The secondary side control module utilizes voltage clamping techniques or current-drawing techniques to stop self-excited conversion from the input voltage to the output voltage when the output voltage is greater than a predetermined target voltage, or utilizes a non-self-excited conversion architecture.
Abstract:
A power off delay circuit includes a switch connected between an external power input terminal and an internal power supply terminal, a capacitor connected to the internal power supply terminal, and a hysteresis comparator to switch the switch according to the voltages of the external power input terminal and the internal power supply terminal. During on-time of the switch, the external power input terminal is connected to the internal power supply terminal and the capacitor can be charged by the external power source. When the switch is off, the capacitor provides electric power for an internal circuit. Application of the power off delay circuit to an audio system may eliminate the turn-off pops of the audio system.
Abstract:
An oscillator generates a clock signal according to a voltage, a current and a capacitance, and a frequency jitter circuit and method use a random number to modulate the voltage, the current or the capacitance, or a count value to modulate the capacitance, to jitter the frequency of the clock signal.
Abstract:
A high voltage H-bridge driver circuit has a high voltage terminal and a floating node to be connected with a high side switch therebetween. When turning on the high side switch, a high voltage offset detection circuit detects a voltage related to the voltage at the floating node for triggering a zero voltage switching signal.
Abstract:
An inductor equivalent circuit is disclosed. The circuit comprises a reference current source, a first current mirror, a second current mirror, two operational amplifiers OP1 and OP2, a capacitor, a first transistor, a second transistor, a mirror resistor set, and a bypass current source in parallel with the capacitor. An input signal is through OP1 and second transistor to control the reference current source. The first mirror current is then feed-back a signal to the first transistor through an OP2. The current signal makes the drain current of the first transistor lags the input voltage signal by 90null due to the capacitor coupled with the first mirror current source. The mirror resistor set can be resistors having one common terminal grounded, and other terminals each, respectively, coupled with the first and the second transistor and the capacitor, or can be composed of transistors and all of them with gate property biased so that the transistors in the mirror resistor set are operated in an ohmic region. The second mirror current provides an output current of the inductor equivalent circuit for next cascade stage.
Abstract:
A resistance adjustable of resistance mirror circuit comprises: a master resistor R0, a reference current source terminal providing a current value I0 through the master resistor R0 to ground; a first transistor; a current mirror source terminal providing a current value nI0, through the first transistor to ground; an operational amplifier having a positive terminal connecting to a drain of the first transistor, a negative terminal connecting to the other terminal of the master resistor R0, and an output terminal connecting to a gate of the first transistor; a mirror resistor set composed of a plurality of transistors in parallel each other and having their source electrode connecting to ground. Each transistor of the mirror resistor set has a ratio of channel width over channel length being m-fold of that of the first transistor, where m, n is any positive numbers. Since gates of the transistors connect to the output terminal of the operational amplifier, each of the transistors therefore has an equivalent resistance Reqnull(1/nm)R0.