Texas Instruments Corporation

Edward Mullins

Badri N Varadarajan

Anand Ganesh Dabak

Il Han Kim

Gerald William Steele

David Alexander Gammie

Jeffery B Parfenchuck

A transmitter path of a power line communication (PLC) device is described. In an embodiment, the transmitter path may include an amplifier, a capacitor coupled to the amplifier, a shared transformer coupled to the capacitor, and a plurality of line interface coupling circuits coupled to the shared transformer, where each of the line interface coupling circuits is configured to be connected to a different phase of an electrical power circuit.

Transmitter path for power line communication devices

Coupling circuits for power line communication (PLC) devices are described. In an embodiment, a PLC device may comprise a processor and a coupling circuit coupled to the processor. The coupling circuit may in turn comprise a transmitter path and a receiver path. In some implementations, the transmitter path may include a first amplifier, a first capacitor coupled to the first amplifier, a first transformer coupled to the first capacitor, and a plurality of line interface coupling circuits coupled to the first transformer, where each of the line interface coupling circuits is configured to be connected to a different phase of an electrical power circuit. Meanwhile, the receiver path may include a plurality of capacitors, where each of the plurality of capacitors coupled to a corresponding one of the line interface circuits, a filter network coupled to the plurality of capacitors, and a second amplifier coupled to the filter network.

Coupling circuits for power line communication devices

Systems and methods are disclosed for communicating on a pilot wire between Electric Vehicle Service Equipment (EVSE) and an Electric Vehicle (EV). The EVSE and EV exchange a Pulse Width Modulation (PWM) signal on the pilot wire to control charging operations of the EV. Data communications may also be transmitted on the pilot wire, such as between transmit and receive modems. The modems transmit communication signals either continuously, without regard to the state of the PWM signal, or only when the PWM is in an off-state. If transmitting while PWM is on, the modem needs a large coupling impedance and/or a large signal injection. To transmit only when the PWM is off, the modem may use a blocking diode in the coupling circuit or may synchronize to the pulses in the PWM signal.

Communication on a pilot wire

An integrated circuit current shunt amplifier (A) includes an amplifier () having a (+) input connected to a first terminal (A) of a shunt resistor (R). An output transistor () has a gate coupled to an output of the amplifier, a source coupled to a (&#x2212;) input of the amplifier, and a drain coupled to a first terminal of an output resistor (R). A gain resistor (R) is coupled between the (&#x2212;) input of the amplifier and a second terminal of the shunt resistor. The gain resistor has a temperature coefficient which is essentially the same as that of the shunt resistor. A voltage regulator () can be coupled between the second terminal of the shunt resistor and a low-side supply voltage terminal () of the amplifier. A charge pump () can provide a below-ground voltage on a second terminal of the output resistor. A difference amplifier () coupled to the drain and referenced to the below-ground voltage produces an output voltage (Vout) referenced to ground.

Amplifier topology and method for connecting to printed circuit board traces used as shunt resistors

An amplifier circuit includes first (A) and second (B) operational amplifiers connected in a parallel configuration. A first terminal () of a first input resistor () is coupled to one input of both of the first (A) and second (B) amplifiers. A first terminal () of a second input resistor () is coupled to another input of both of the first (A) and second (B) amplifiers. A differential input voltage is applied between the second terminals of the first and second input resistors. The output signals of the first (A) and second (B) operational amplifiers are combined to produce an output signal (AB) representative of feedback currents produced in the first () and second () input resistors. Upper and lower common mode input voltage ranges associated with the differential input voltage extend substantially above and below the upper and lower supply voltages, respectively, of the amplifier circuit.

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Sahuarita, AZ, United States of America

Edward Mullins