Abstract: A low power biasing circuit for powering up split-rail electronic circuits includes an intermediate voltage generator at each pad which is supplied by a temporary supply voltage to generate a temporary intermediate voltage only when a power signal indicates that all external voltage rails are not safe, thereby reducing power consumption.

Abstract: Methods and apparatus for matching voltages between two or more circuits within an integrated circuit is disclosed. The apparatus includes a comparator circuit, comparing supply voltages to first and second circuits. The comparator outputs a variable error voltage based on the comparison, the error voltage related to the difference in voltages. The error voltage is supplied to a variable current control circuit that variably sinks one of the supply voltages to a common potential in order to increase the IR drop in the circuit supplying voltage to one of the first and second circuits, thereby affording voltage adjustment in order to match the first and second circuits. A corresponding method is also disclosed.

Abstract: A low power biasing circuit for powering up split-rail electronic circuits includes an intermediate voltage generator at each pad which is supplied by a temporary supply voltage to generate a temporary intermediate voltage only when a power signal indicates that all external voltage rails are not safe, thereby reducing power consumption.

Abstract: A method and apparatus for powering up an integrated circuit having a plurality of power domains each coupled to receive power from one of a plurality of power sources, where each power domain includes an internal power detector which senses the power of a plurality of power domains (VDD1, VDD2, VDD3, . . . , VDDn) and compares them to a reference voltage to generate a combined power good (PG) signal. The PG signal is combined with an external system power ok signal at a plurality of AND gate circuits which are respectively powered by the plurality of power domains, thereby generating a plurality of power status signals (POWER_OK) on the destination power domains.

Abstract: Methods and apparatus provide for indicating multi-power rail status of integrated circuits by taking into account a clock signal provided by, for example, core logic, in addition to considering voltage levels of multiple power rails. In one example, the apparatus includes multi-power rail status indicating logic that provides a multi-power rail status signal. The multi-power rail status signal is synchronized for assertion with a clock signal of the integrated circuit, such as the core logic of the integrated circuit, in response to an assertion of an asynchronous multi-power rail voltage stability signal. The asynchronous multi-power rail voltage stability signal indicates a state of a plurality of voltage signals from a plurality of power rails supplied to the integrated circuit.

Abstract: Methods and apparatus provide for voltage level shifting with concurrent synchronization. The apparatus includes level shifting logic that in response to a non-level shifted clock signal from a first voltage domain, provides level shifted concurrently synchronous differential data signals in a second voltage domain based on pre-level shifted differential data signals from the first voltage domain. The first voltage domain may be, for example, a core logic voltage domain in which core logic operates. The second voltage domain may be, for example, an input/output (I/O) voltage domain in which an I/O buffer operates. The voltage level of the level shifted concurrently synchronous differential data signals is shifted from the pre-level shifted differential data signals, and the timing of the level shifted concurrently synchronous differential data signals is concurrently referenced to the non-level shifted clock signal.

Abstract: Methods and apparatus provide for voltage level shifting with concurrent synchronization. The apparatus includes level shifting logic that in response to a non-level shifted clock signal from a first voltage domain, provides level shifted concurrently synchronous differential data signals in a second voltage domain based on pre-level shifted differential data signals from the first voltage domain. The first voltage domain may be, for example, a core logic voltage domain in which core logic operates. The second voltage domain may be, for example, an input/output (I/O) voltage domain in which an I/O buffer operates. The voltage level of the level shifted concurrently synchronous differential data signals is shifted from the pre-level shifted differential data signals, and the timing of the level shifted concurrently synchronous differential data signals is concurrently referenced to the non-level shifted clock signal.

Abstract: Methods and apparatus provide for indicating multi-power rail status of integrated circuits by taking into account a clock signal provided by, for example, core logic, in addition to considering voltage levels of multiple power rails. In one example, the apparatus includes multi-power rail status indicating logic that provides a multi-power rail status signal. The multi-power rail status signal is synchronized for assertion with a clock signal of the integrated circuit, such as the core logic of the integrated circuit, in response to an assertion of an asynchronous multi-power rail voltage stability signal. The asynchronous multi-power rail voltage stability signal indicates a state of a plurality of voltage signals from a plurality of power rails supplied to the integrated circuit.

Abstract: The present disclosure relates to a differential signaling circuit including differential signaling circuitry having at least one output and one input, that can operate in multiple mode of operations while using a single, low voltage supply source. Two or more switches are included and configured to selectively couple a supply voltage to the output dependent on a mode of operation of the differential signaling circuitry. The circuit also includes a switch control biasing circuit operatively coupled to at least one of the switches and to the output of the differential signaling circuitry. The switch control biasing circuit provides a switch control biasing voltage to control a state of the switch based on a voltage level of the output. Further, a bulk biasing circuit is included and operatively coupled to the switch. The bulk biasing circuit selectively provides a bulk biasing voltage to the switch based on the voltage level of the output.

Abstract: The present disclosure relates to a differential signaling circuit including differential signaling circuitry having at least one output and one input, that can operate in multiple mode of operations while using a single, low voltage supply source. Two or more switches are included and configured to selectively couple a supply voltage to the output dependent on a mode of operation of the differential signaling circuitry. The circuit also includes a switch control biasing circuit operatively coupled to at least one of the switches and to the output of the differential signaling circuitry. The switch control biasing circuit provides a switch control biasing voltage to control a state of the switch based on a voltage level of the output. Further, a bulk biasing circuit is included and operatively coupled to the switch. The bulk biasing circuit selectively provides a bulk biasing voltage to the switch based on the voltage level of the output.

Abstract: The present disclosure relates to a differential signaling circuit including differential signaling circuitry having at least one output and one input, that can operate in multiple mode of operations while using a single, low voltage supply source. Two or more switches are included and configured to selectively couple a supply voltage to the output dependent on a mode of operation of the differential signaling circuitry. The circuit also includes a switch control biasing circuit operatively coupled to at least one of the switches and to the output of the differential signaling circuitry. The switch control biasing circuit provides a switch control biasing voltage to control a state of the switch based on a voltage level of the output. Further, a bulk biasing circuit is included and operatively coupled to the switch. The bulk biasing circuit selectively provides a bulk biasing voltage to the switch based on the voltage level of the output.

Abstract: The present disclosure relates to apparatus and methods for measurement of analog voltages in an integrated circuit. In particular, the apparatus includes an on-chip digital-to-analog converter configured to receive a variable digital input code and output a corresponding analog voltage corresponding to the variable digital input code. The apparatus also includes an on-chip comparator circuit configured to receive the analog voltage output by the digital-to-analog converter and a test analog voltage as inputs and to provide an output indicating the test analog voltage. Further, the apparatus includes an on-chip logic operative to determine the test analog voltage based on the output of the comparator circuit. A corresponding method is also disclosed.

Abstract: The present disclosure relates to a differential signaling circuit including differential signaling circuitry having at least one output and one input, that can operate in multiple mode of operations while using a single, low voltage supply source. Two or more switches are included and configured to selectively couple a supply voltage to the output dependent on a mode of operation of the differential signaling circuitry. The circuit also includes a switch control biasing circuit operatively coupled to at least one of the switches and to the output of the differential signaling circuitry. The switch control biasing circuit provides a switch control biasing voltage to control a state of the switch based on a voltage level of the output. Further, a bulk biasing circuit is included and operatively coupled to the switch. The bulk biasing circuit selectively provides a bulk biasing voltage to the switch based on the voltage level of the output.

Abstract: A multiphase clock generating circuit includes a multiphase clock generator that produces a plurality of multiphase output signals at a first frequency and a multiphase divider with delayed reset control. The multiphase divider with delayed reset control is operatively coupled to receive the plurality of multiphase output signals at the first frequency and further operative to produce a plurality of multiphase output signals at a second frequency based on reset control information. As a result, an interface can be supplied with and switch between multiphase clock at different frequencies within a short amount of time with reduced power consumption and circuit area.