US 2025/0038670 A1Published application

Data communication for galvanic isolated dc-dc converter on fully integrated architecture with coreless transformer

AssigneeSTMicroelectronics International N.V.

InventorsStefano PERROTTA, Salvatore Giuseppe PRIVITERA, Francesco PULVIRENTI

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Abstract

A DC-DC converter includes a primary-side control-circuit having an oscillator driving a transformer in response to assertion of a PWM-signal to transmit power from the primary to the secondary and ceasing in response to deassertion of the PWM-signal, and a receiver demodulator circuit receiving/demodulating a feedback signal sent from the secondary to the primary by comparing an instantaneous value of an envelope indicative of voltages at the primary-coil to an average-value of the envelope to produce a reset-signal. A PWM circuit asserts the PWM-signal in response to a set-signal and deasserts the PWM-signal in response to assertion of the reset-signal. A secondary-side control-circuit rectifies the received power, asserts an intermediate feedback-signal if feedback indicative of the output voltage is greater than a reference-voltage, and connects a capacitance between the secondary and ground in response to assertion of the intermediate feedback-signal to modulate and send the feedback to the primary.

Claims16

Dependent claims

A device comprising a DC-DC converter, wherein the DC-DC converter comprises:

a transformer having a primary coil and a secondary coil;
a primary-side control circuit comprising:
an oscillator configured to drive the transformer in response to assertion of a pulse width modulation (PWM) signal to thereby transmit power from the primary to the secondary, and to cease driving the transformer in response to deassertion of the PWM signal;
a receiver demodulator circuit configured to receive and demodulate a feedback signal sent from the secondary to the primary by comparing an instantaneous value of an envelope indicative of voltages at the primary coil to an average value of the envelope to thereby produce a reset signal;
and
a PWM circuit configured to assert the PWM signal in response to a set signal and deassert the PWM signal in response to assertion of the reset signal;
and
a secondary-side control circuit configured to:
rectify the power received at the secondary to generate an output voltage;
assert an intermediate feedback signal if a feedback voltage indicative of the output voltage is greater than or equal to a reference voltage;
and
connect a capacitance between the secondary and the ground in response to assertion of the intermediate feedback signal to thereby modulate and send the feedback signal from the secondary-side to the primary-side.

9 more elements

A DC-DC converter, comprising:

a transformer having a primary coil and a secondary coil;
an oscillator coupled to the transformer and configured to drive the transformer in response to a pulse width modulation (PWM) signal;
a receiver demodulator comprising:
a first RC filter coupled between a first terminal of the primary coil and a first input of an envelope circuit;
a second RC filter coupled between a second terminal of the primary coil and a second input of the envelope circuit;
a third RC filter coupled between the output of the envelope circuit and a first input terminal of a comparator;
a switch coupled between the first input terminal of the comparator and an intermediate node, the switch being controlled by the PWM signal;
a fourth RC filter coupled between the intermediate node and a second input terminal of the comparator;
and
a combinatorial circuit configured to generate a reset signal based upon output from the comparator;
and
a flip flop having a data input coupled to receive an input voltage, a clock input coupled to receive a set signal, a reset input coupled to receive the reset signal, and an output at which the PWM signal is generated.

9 more elements

Dependencies are inferred from the claim text.

Facts

Application: 18/225,955Filed 25 Jul 2023
Published: 30 Jan 2025
Term ends: Not estimatedThe source records don’t support an estimate.

Classification8 codes

H02M 3/33523
With automatic control of the output voltage or current, e.g. flyback converters: with galvanic isolation between input and output of both the…
H03K 17/18
Electronic switching or gating, i.e. not by contact-making and –breaking: modifications for indicating state of switch
H02M 1/0012
Details of control, feedback or regulation circuits: control circuits using digital or numerical techniques
H03K 17/61
With galvanic isolation between the control circuit and the output circuit: using transformer coupling