Transmission line drivers and serial interface data transmission devices including the same

• US 20080024178A1
• Filed: 07/23/2007
• Published: 01/31/2008
• Est. Priority Date: 07/25/2006
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Kim, Chi, Kwak, Myoung, Park, Jae, Yang, Seung, Shin, Jong, Kim, Ji Young, Kim, Hyun-Goo
• Granted Patent: US 7,701,262 B2
• Time in Patent Office: Days
• US Class Current: 327/108
• CPC Class Codes: H03K 19/0016 by using a control or a clock signal, e.g. in order to apply power supply
• CPC Class Codes: H03K 19/018528 with at least one differential stage
• CPC Class Codes: H04L 25/0276 Arrangements for coupling common mode signals
• CPC Class Codes: H04L 25/028 Arrangements specific to the transmitter end

Abstract

A transmission line driver and a serial interface data transmission device including the same are provided. The transmission line driver includes a pre-driver configured to generate and output differential input data signals based on a serial transmission data signal, a differential amplifier configured to receive the differential input data signals and to output differential output data signals, and a common mode controller configured to drive the differential output data signals to a predetermined common mode voltage in an idle mode. Accordingly, power consumption can be reduced and a common mode specification can be supported.

Claims

1. A transmission line driver, comprising:

a pre-driver configured to generate and output differential input data signals based on a serial transmission data signal;

a differential amplifier configured to receive the differential input data signals and to output differential output data signals; and

a common mode controller configured to drive the differential output data signals to a predetermined common mode voltage in an idle mode.

2. The transmission line driver of claim 1, further comprising a bias unit configured to control a magnitude of the differential output data signals.

3. The transmission line driver of claim 2, wherein the differential amplifier comprises:

a first switch pair connected to the bias unit and a first output terminal and a second output terminal, which respectively output the differential output data signals, and responsive to the differential input data signals;

a second switch pair connected to a first power supply terminal and the first and second output terminals and responsive to the differential input data signals; and

a first resistor connected between the first output terminal and the second output terminal.

4. The transmission line driver of claim 3, wherein the common mode controller comprises a third switch pair connected to the first power supply terminal and the first and second output terminals and responsive to an idle mode signal;

wherein the third switch pair is connected to the first and second output terminals via a second resistor and a third resistor, respectively.

5. The transmission line driver of claim 4, wherein the second resistor and the third resistor have about the same resistance value as a resistance value of a transmission line connected to the first and second output terminals;

wherein the first resistor has a resistance value that is about double that of the resistance value of the transmission line.

6. The transmission line driver of claim 4, wherein the first switch pair comprises switches implemented by NMOS transistors, and

wherein the second switch pair and the third switch pair comprise switches implemented by PMOS transistors.

7. The transmission line driver of claim 6, wherein the bias unit comprises a plurality of bias supply transistors each comprising a first terminal connected to a terminal of the first switch pair, a second terminal connected to a second power supply terminal, and a third terminal that receives a bias voltage based on a corresponding control signal among a plurality of predetermined control signals.

8. The transmission line driver of claim 6, wherein a channel width to length ratio of the second switch pair PMOS transistors is about double that of a channel width to length ratio of the third switch pair PMOS transistors.

9. The transmission line driver of claim 3, wherein the common mode controller comprises:

N logic operation elements configured to perform a NAND operation with respect to an idle mode signal and a plurality of predetermined control signals, respectively, and to output operation result signals; and

N switch pairs responsive to the operation result signals, respectively.

10. The transmission line driver of claim 9, wherein the first resistor has a resistance value that is about double that of a resistance value of a transmission line connected to the first output terminal and the second output terminal.

11. The transmission line driver of claim 9, wherein the first switch pair comprises switches implemented by NMOS transistors, and

wherein the second switch pair and the N switch pairs comprise switches implemented by PMOS transistors.

12. The transmission line driver of claim 11, wherein the bias unit comprises N bias supply transistors each comprising a first terminal connected to a terminal of the first switch pair, a second terminal connected to a second power supply terminal, and a third terminal that receives a bias voltage based on a corresponding control signal among a plurality of predetermined control signals.

13. The transmission line driver of claim 12, wherein a channel width to length ratio of the N switch pairs PMOS transistors is proportional to a channel width to length ratio of a corresponding bias supply transistor among the N bias supply transistors.

14. A serial interface data transmission device, comprising:

a serial converter configured to convert and output parallel data to be transmitted as serial transmission data signals; and

a transmission line driver configured to generate and output differential output data signals having a predetermined common mode voltage responsive to the serial transmission data signals and an idle mode signal,

wherein the transmission line driver comprises;

a pre-driver configured to generate and output differential input data signals based on the serial transmission data signal;

a differential amplifier configured to receive the differential input data signals and to output differential output data signals; and

a common mode controller configured to drive the differential output data signals to the predetermined common mode voltage in an idle mode.

15. The serial interface data transmission device of claim 14, wherein the transmission line driver further comprises a bias unit configured to control a magnitude of the differential output data signals.