Stmicroelectronics (grenoble 2) Sas

St-ericsson Sa

Optis Circuit Technology, LLC

Philippe Pignolo

Vincent Rabary

Pawel Fiedorow

A differential pair for an input stage includes two identical branches in parallel, each branch including a first MOS transistor and a second MOS transistor arranged in series, wherein the first transistor and the second transistor have a channel of the same type, and wherein each of the first transistor and the second transistor has a gate coupled to the same corresponding input of the differential pair and a circuit configured to apply to each of the first transistors a potential difference between a source and a channel-forming region of the first transistor.

Operational amplifier

The present disclosure relates to an electronic device comprising a pair of first transistors, each first transistor being coupled to a first node by a conduction terminal, a pair of second transistors, each second transistor being coupled to a second node by a conduction terminal, and a third transistor coupling the first and second nodes, the control terminal of the third transistor being coupled to the output of an operational amplifier, the operational amplifier being coupled, at its input, to the first node and to a node of application of a reference voltage.

A method of controlling a start-up sequence of a DC/DC Buck converter includes continuously comparing the Buck converter's output voltage with an internal reference voltage and continuously monitoring for a Buck converter start-up signal. If the output voltage is greater than the reference voltage when a Buck converter start-up signal is detected, the Buck converter is switched off and an output capacitor of the Buck converter is discharged through a pull-down unit until the output voltage substantially equals the internal reference voltage and then restarting the Buck converter.

Method and apparatus for controlling a start-up sequence of a DC/DC buck converter

A pulse width modulation controller (PWM) is disclosed which has a MOSFET () responsive to the error voltage (Verror) signal from the PWM amplifier () to detect a transient condition without delay &#x394;Td. The MOSFET drain generates and applies a detection signal (S) to a delaying circuit (D). The delaying circuit (D) is responsive to the transient detection signal (S) to asynchronously output two latch signals (S) and (S) which on application to respective latch circuits (L, L) cause a change in conduction state of PMOS () and NMOS (). This arrangement reduces voltage undershoot.

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Crolles, France

Philippe Pignolo