RU109621U1 - Integrated digital microcircuit with transformer isolation - Google Patents

Abstract

 Integrated digital microcircuit with transformer isolation includes an input buffer controlling drivers 1, 2 and a generator; shapers 1 and 2 are connected to the primary windings of the first and second transformers TX1 and TX2, respectively; the second conclusions of the primary windings are connected to the bus "common 1"; the secondary windings of the first and second transformers TX1 and TX2 are connected to the common 2 bus galvanically isolated from the common 1 bus; the second conclusions of the secondary windings of the first and second transformers TX1 and TX2 are connected respectively to the filters 1 and 2; Filters 1 and 2 are connected to the comparator and with it to the output driver.

Description

Integrated digital microcircuit with transformer isolation refers to the field of microelectronics and electronic equipment, can be used in devices with galvanic isolation for transmitting digital, logical information.

Known transformer-isolated circuits using a single-channel method of transmitting data on the edges of the input signal (Ioffe D., Romanov O. Isolating microcircuits based on iCoupler technology from Analog Devices // Components and Technologies. 2006. No. 7), which have low noise immunity due to transmitting code signals about the signal rise and fall along one transformer isolation channel.

As a prototype, a transformer isolation microcircuit was selected (US 7075329 B2 Н03К 17/16 published March 17, 2005), which includes a transmitter connected to the transformer primary winding, forming a code sequence of two pulses on the front of the input signal and one pulse on the decay of the input signal ; and a receiver connected to the secondary winding of the transformer, restoring the signal front in the presence of dual pulses at the output of the code sequence, the signal decay in the presence of one pulse.

The main disadvantage of the prototype is poor noise immunity.

The utility model is aimed at obtaining a technical result - providing noise immunity of the transmitted signal.

This goal is achieved by the fact that in the integrated digital microcircuit with transformer isolation, the transmitter connected to the two primary windings of the two transformers forms a periodic code sequence of double pulses on the first primary winding in the presence of a high logical level of the input signal or a periodic code sequence of the second primary winding single pulses in the presence of a low logical level of the input signal; a receiver connected to the two secondary windings of the transformers restores a high logic level in the presence of periodic double pulses at the output of the code sequences or a low logical level in the presence of periodic single pulses from the transformer windings; the presence of common-mode interference signals in the first and second transformers does not lead to a change in the logic states at the output of the microcircuit, and the interference signal in one of the transformers is eliminated by restoring the original signal with a periodic code.

Figure 1 presents the structural diagram of an integrated digital circuit with transformer isolation. Integrated digital microcircuit with transformer isolation includes an input buffer controlling drivers 1, 2 and a generator; shapers 1 and 2 are connected to the primary windings of the first and second transformers TX1 and TX2, respectively; the second conclusions of the primary windings are connected to the bus "common 1"; the secondary windings of the first and second transformers TX1 and TX2 are connected to the common 2 bus galvanically isolated from the common 1 bus; the second terminals of the secondary windings of the first and second transformers TX1 and TX2 are connected respectively to the filters 1 and 2; Filters 1 and 2 are connected to the comparator and with it to the output driver.

Integrated digital microcircuit with transformer isolation works in accordance with the time diagram of the signals presented in figure 2. When the logical state of the input signal changes, the reference frequency generator starts, which is converted on the shaper 1 into a periodic sequence of double pulses at a high logical level of the input signal or on shaper 2 into a periodic sequence of single pulses at a low logical level of the input signal. These signals from the shapers are fed to the primary windings of the first and second transformers TX1 and TX2, respectively. From the secondary windings of the first and second transformers TX1 and TX2, useful signals are allocated by filters 1 and 2, respectively. From the selected code sequences, a useful output signal is restored.

Interference-free transmission is carried out in accordance with the time diagram of the signals presented in figure 3. In the presence of a common-mode interference signal 1, which is most likely due to the small dimensions of the transformers, in both transformers TX1 and TX2, selected by filters 1 and 2, the comparator prevents the output driver from changing the logical state. If there is an interference signal 2 in the TX2 transformer during the transfer of a high logical level from the input of the microcircuit, as in the prototype, the logical state of the output signal will change, but when a double sequence is received in the TX1 transformer, the logical signal will be restored to a high level. In the presence of an interference signal 3 in the TX1 transformer, when transmitting a low logical level from the input of the microcircuit, the logical state of the output signal will not change, since a code sequence of double pulses is required.

The technical result is achieved due to the following technical solutions:

- the transmission of signals about the logical state at the input of the microcircuit through two channels of transformer isolation;

- transmission of periodic code sequences that restore the original signal;

- a comparator circuit eliminating common mode interference in transformers.

Claims (1)

Integrated digital microcircuit with transformer isolation includes an input buffer controlling drivers 1, 2 and a generator; shapers 1 and 2 are connected to the primary windings of the first and second transformers TX1 and TX2, respectively; the second conclusions of the primary windings are connected to the bus "common 1"; the secondary windings of the first and second transformers TX1 and TX2 are connected to the common 2 bus galvanically isolated from the common 1 bus; the second terminals of the secondary windings of the first and second transformers TX1 and TX2 are connected respectively to the filters 1 and 2; Filters 1 and 2 are connected to the comparator and with it to the output driver.