SIGNAL TRANSMISSION CIRCUIT

• US 20150303811A1
• Filed: 07/01/2015
• Published: 10/22/2015
• Est. Priority Date: 06/25/2013
• Status: Active Grant

• Current Assignee: Fuji Electric Company Limited (Fuji Electric Systems Company Limited)
• Original Assignee: Fuji Electric Company Limited (Fuji Electric Systems Company Limited)
• Inventors: AKAHANE, Masashi
• Granted Patent: US 10,050,525 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H02M 1/08 Circuits specially adapted for the generation of control voltages for semiconductor devices incorporated in static converters
• CPC Class Codes: H02M 1/32 Means for protecting converters other than automatic disconnection
• CPC Class Codes: H02M 3/156 with automatic control of output voltage or current, e.g. switching regulators
• CPC Class Codes: H02M 3/158 including plural semiconductor devices as final control devices for a single load
• CPC Class Codes: H03K 17/18 Modifications for indicating state of switch
• CPC Class Codes: H03K 19/018521 of complementary type, e.g. CMOS
• CPC Class Codes: H03K 2217/0063 High side switches, i.e. the higher potential [DC] or life wire [AC] being directly connected to the switch and not via the load
• CPC Class Codes: H03K 2217/0072 Low side switches, i.e. the lower potential [DC] or neutral wire [AC] being directly connected to the switch and not via the load

Abstract

Included are an output circuit, provided in a high side circuit, that selectively generates and outputs multiple kinds of pulse signal in accordance with the level of priority of a multiple of signals, a switch element, driven so as to be turned on and off by a pulse signal output from the output circuit, that is turned on and off to transmit the power supply voltage of the high side circuit to a low side circuit, a voltage conversion circuit, provided in the low side circuit, that converts the power supply voltage transmitted via the switch element into a pulse signal in the low side circuit, and a signal analysis circuit that analyzes the pulse signal obtained via the power conversion circuit and restores the multiple of signals.

Claims

1. A signal transmission circuit, comprising:

an output circuit, provided in a high side circuit that operates with a first potential as a reference potential, that selectively generates and outputs a plurality of kinds of pulse signal in accordance with the level of priority of a plurality of signals;

a switch element, driven so as to be turned on and off by a pulse signal output from the output circuit, that is turned on and off to transmit the power supply voltage of the high side circuit to a low side circuit that operates with a second potential lower than the first potential as a reference potential;

a voltage conversion circuit, provided in the low side circuit, that converts the power supply voltage transmitted via the switch element into a pulse signal of a predetermined voltage with the second potential as a reference potential; and

a signal analysis circuit that analyzes the pulse signal obtained via the power conversion circuit and restores the plurality of signals.

2. The signal transmission circuit according to claim 1, wherein the plurality of signals are a plurality of kinds of abnormality detection signal.

3. The signal transmission circuit according to claim 1, wherein

the output circuit selectively generates a plurality of kinds of pulse signal that alternatively cause a plurality of the switch element provided in parallel to be turned on,

the voltage conversion circuit converts each of the voltages selectively transmitted via the switch elements into a pulse signal of a predetermined voltage, with the second potential as a reference potential, and outputs the plurality of kinds of pulse signal in parallel, and

the signal analysis circuit includes in parallel multiple stage latch circuits that sequentially latch the plurality of kinds of pulse signal category by category in synchronization with a clock signal generated from the plurality of kinds of pulse signal output in parallel from the voltage conversion circuit, analyzes the signal level held in each of the latch circuits, and restores the plurality of signals.

4. The signal transmission circuit according to claim 3, wherein the clock signal is generated as a signal synchronized with the inversion timing of one of the plurality of kinds of pulse signal output in parallel from the voltage conversion circuit.

5. The signal transmission circuit according to claim 3, wherein the signal analysis circuit determines that there is a reception error when the signal level held in each of the latch circuits indicates that the plurality of switch elements are simultaneously in an on-state.

6. The signal transmission circuit according to claim 1, wherein

the output circuit turns the switch element on and off by generating pulse signals of differing pulse widths in accordance with signal category in accordance with the level of priority of the plurality of signals,

the voltage conversion circuit converts the voltage selectively transmitted via each switch element into a pulse signal with the second potential in the low side circuit as a reference potential and charges a capacitor for the duration of the pulse signal, and

the signal analysis circuit determines the charge voltage of the capacitor and restores the plurality of signals.

7. The signal transmission circuit according to claim 1, wherein

the output circuit turns the switch element on and off by generating pulse signal trains of differing pulse numbers in accordance with signal category in accordance with the level of priority of the plurality of signals,

the voltage conversion circuit converts the voltage selectively transmitted via each switch element into a pulse signal with the second potential in the low side circuit as a reference potential and charges a capacitor each time the pulse signal is detected for a certain time, and

the signal analysis circuit determines the charge voltage of the capacitor after the certain time and restores the plurality of signals.