The present disclosure relates to the generation and control of signal supply voltages for use in a data transmission system.
In a communication system, data or other information may be transmitted from one integrated circuit (IC) device to another IC device as electric signals over one or more wires. For example, a memory controller may transmit (during a “memory write” operation) data as data signals to a memory device over one or more data communication channels, while the memory device may transmit (during a “memory read” operation) data as data signals to the memory controller using the same or different data communication channels. In many instances, a signal from a transmitting device would have one or more characteristics (e.g., a signal swing) that are dependent on one or more regulated signal supply voltages. Conventionally, each IC device in a communication system obtains a power supply voltage from an external voltage regulation device. That power supply voltage is often used directly, but in some cases is regulated again, internal to the chip, to generate a signal supply voltage that determines the one or more characteristics of the signals sent to other devices. In the above example involving the memory controller and the memory device, the memory controller would include a set of internal voltage regulation circuitry to generate the regulated voltage(s) for forming the write data signals while the memory device would include another set of internal voltage regulation circuitry to generate the regulated voltage(s) for forming the read data signals.
Such arrangement would have several drawbacks. First, on-chip, internal voltage regulators or generators require relatively complex circuitry (e.g., charge pumps) and/or involve relatively large circuit components (e.g., on-chip capacitors), and thus add to the size and manufacturing cost of the IC device. Second, when the communicating IC devices have independent voltage regulators to generate their own signal supply voltage(s), the IC devices that transmit the signal would not have information to adjust one or more signal characteristics of the signal to suit the IC device receiving the signal.