Low power multilevel driver
First Claim
1. An apparatus comprising:
- a voltage termination node connected to a plurality of transmission lines via a plurality of termination impedance elements, the voltage termination node having a termination voltage corresponding to a summation of a plurality of currents flowing through the plurality of termination impedance elements, each current of the plurality of currents corresponding to a respective symbol of a plurality of symbols of a balanced codeword of a vector signaling code, each symbol of the plurality of symbols of the balanced codeword having a symbol value selected from a set of at least three symbol values;
a plurality of multi-level drivers, each multi-level driver connected to a respective transmission line of the plurality of transmission lines and to the voltage termination node via a respective termination impedance element of the plurality of termination impedance elements, each multi-level driver configured to generate a corresponding current of the plurality of currents, each multi-level driver comprising;
at least one current source connected to the respective transmission line, each current source selectively enabled to source current to the respective transmission line to drive a line voltage above the termination voltage of the termination voltage node connected to the transmission line via the respective termination impedance element of the plurality of termination impedance elements, wherein each of the at least one current sources has an output impedance different than a characteristic impedance of the transmission line; and
at least one current sink connected to the respective transmission line, each current sink selectively enabled to sink current from the transmission line to drive a line voltage below the termination voltage, each of the at least one current sinks having an output impedance different than the characteristic impedance of the transmission line.
2 Assignments
0 Petitions
Accused Products
Abstract
A driver for transmitting multi-level signals on a multi-wire bus is described that includes at least one current source connected to a transmission line, each current source selectively enabled to source current to the transmission line to drive a line voltage above a termination voltage of a termination voltage source connected to the transmission line via a termination impedance element, wherein each of the at least one current sources has an output impedance different than a characteristic impedance of the transmission line, and at least one current sink connected to the transmission line, each current sink selectively enabled to sink current from the transmission line to drive a line voltage below the termination voltage, each of the at least one current sinks having an output impedance different than the characteristic impedance of the transmission line.
402 Citations
16 Claims
-
1. An apparatus comprising:
-
a voltage termination node connected to a plurality of transmission lines via a plurality of termination impedance elements, the voltage termination node having a termination voltage corresponding to a summation of a plurality of currents flowing through the plurality of termination impedance elements, each current of the plurality of currents corresponding to a respective symbol of a plurality of symbols of a balanced codeword of a vector signaling code, each symbol of the plurality of symbols of the balanced codeword having a symbol value selected from a set of at least three symbol values; a plurality of multi-level drivers, each multi-level driver connected to a respective transmission line of the plurality of transmission lines and to the voltage termination node via a respective termination impedance element of the plurality of termination impedance elements, each multi-level driver configured to generate a corresponding current of the plurality of currents, each multi-level driver comprising; at least one current source connected to the respective transmission line, each current source selectively enabled to source current to the respective transmission line to drive a line voltage above the termination voltage of the termination voltage node connected to the transmission line via the respective termination impedance element of the plurality of termination impedance elements, wherein each of the at least one current sources has an output impedance different than a characteristic impedance of the transmission line; and at least one current sink connected to the respective transmission line, each current sink selectively enabled to sink current from the transmission line to drive a line voltage below the termination voltage, each of the at least one current sinks having an output impedance different than the characteristic impedance of the transmission line. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
-
-
9. A method comprising:
-
obtaining a plurality of control bits identifying a plurality of symbols of a balanced codeword of a vector signaling code, each symbol of the plurality of symbols of the balanced codeword having a symbol value selected from a set of at least three symbol values; in response to obtaining the plurality of control bits, setting a line voltage on a plurality of transmission lines connected to a voltage termination node via a plurality of termination impedance elements, the voltage termination node having a termination voltage corresponding to a summation of a plurality of currents flowing through the plurality of termination impedance elements, each current of the plurality of currents corresponding to a respective symbol of the plurality of symbols of the balanced codeword, wherein setting the line voltage on each respective transmission line of the plurality of transmission lines comprises; selectively sourcing current via at least one current source to the respective transmission line to drive the line voltage above the termination voltage of the termination voltage node connected to the respective transmission line via a respective termination impedance element of the plurality of termination impedance elements, wherein each of the at least one current sources has an output impedance different than a characteristic impedance of the transmission line; and selectively sinking current via at least one current sink from the respective transmission line to drive the line voltage below the termination voltage, each of the at least one current sinks having an output impedance different than the characteristic impedance of the respective transmission line. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16)
-
Specification