Data processing apparatus

• US 8,243,865 B2
• Filed: 06/15/2007
• Issued: 08/14/2012
• Est. Priority Date: 06/21/2006
• Status: Active Grant

• Current Assignee: Ricoh Company Limited
• Original Assignee: Ricoh Company Limited
• Inventors: Tsukamoto, Nobunari, Ema, Hidetoshi
• Primary Examiner(s): PATEL, DHAVAL V
• Application Number:
  US11/763,663
• Publication Number:
  US 20070297548A1
• Time in Patent Office: 1,887 Days
• Field of Search: 375/354, 375/147, 375/213, 375/316, 375/355, 375/357, 375/360, 375/364, 375/373, 375/374, 375/375, 375/376, 370/503
• US Class Current: 375/354
• CPC Class Codes: H03M 7/3048 Conversion to or from one-bit differential modulation only, e.g. delta modulation [DM] H03M7/3004 takes precedence

Abstract

A disclosed data processing apparatus includes: a binarization unit binarizing input data based on a threshold voltage; a capture unit capturing data from a binary output binarized by the binarization unit; a duty cycle detection unit detecting a duty cycle of the binary output; and a control unit controlling a level of the input data based on the duty cycle detected by the duty cycle detection unit.

Claims

1. A data processing apparatus comprising:

a binarization unit binarizing input data based on a threshold voltage and configured to output only a binary output from a single connection point between a drain of a PMOS transistor and a drain of a NMOS transistor;

a capture unit capturing data from the binary output binarized by the binarization unit;

a duty cycle detection unit detecting a duty cycle of the binary output; and

a control unit, implemented via a processor, controlling a level of the input data based on the duty cycle detected by the duty cycle detection unit and configured to output only a single control signal directly into a gate of another PMOS transistor of the binarization unit, wherein a drain current value of the another PMOS transistor is varied in accordance with a change of the single control signal,

wherein the duty cycle detection unit is configured to detect the duty cycle of the binary output from an average value of the binary output and pulse values when the binary output is at a high (H) level and at a low (L) level.

2. The data processing apparatus according to claim 1, wherein the capture unit includes:

a clock generation unit generating a clock for determining a time when data is captured from the binary output binarized by the binarization unit; and

a data capture unit capturing data from the binary output in synchronization with the clock generated by the clock generation unit.

3. The data processing apparatus according to claim 2, wherein

the clock generation unit generates a synchronous clock synchronized with the binary output binarized by the binarization unit.

4. The data processing apparatus according to claim 1, wherein the capture unit includes:

a polyphase clock generation unit generating a polyphase clock for determining a time when data is captured from the binary output binarized by the binarization unit;

a polyphase data capture unit capturing polyphase data from the binary output in synchronization with the polyphase clock generated by the polyphase clock generation unit; and

a data recovery unit restoring the data captured from the binary output using the polyphase clock generated by the polyphase clock generation unit and the polyphase data captured by the polyphase data capture unit.

5. The data processing apparatus according to claim 1, wherein the control unit controls the level of the input data such that the duty cycle is 50%.

6. The data processing apparatus according to claim 1, wherein

the binarization unit includes:

a differential amplifier circuit receiving the input data;

a variable current source connected to an output of the differential amplifier circuit; and

an amplitude-limiting unit limiting amplitude of a voltage at a connection point between the output of the differential amplifier circuit and the variable current source.

7. The data processing apparatus according to claim 1, wherein the duty cycle detection unit includes a low-pass filter.

8. A data processing apparatus comprising:

a binarization unit binarizing input data based on a threshold voltage and configured to output only a binary output from a single connection point between a drain of a PMOS transistor and a drain of a NMOS transistor;

a capture unit capturing data from the binary output binarized by the binarization unit;

a simulated pulse generation unit generating simulated pulses of the binary output to be captured in the capture unit;

a duty cycle detection unit detecting a duty cycle of the simulated pulses generated by the simulated pulse generation unit; and

a control unit, implemented via a processor, controlling a level of the input data based on the duty cycle detected by the duty cycle detection unit and configured to output only a single control signal directly into a gate of another PMOS transistor of the binarization unit, wherein a drain current value of the another PMOS transistor is varied in accordance with a change of the single control signal,

wherein the duty cycle detection unit is configured to detect the duty cycle of the simulated pulses of the binary output from an average value of the simulated pulses and pulse values when the simulated pulses are at a high (H) level and at a low (L) level.

9. The data processing apparatus according to claim 8, wherein

the capture unit includes:

a clock generation unit generating a clock for determining a time when data is captured from the binary output binarized by the binarization unit; and

a data capture unit capturing data from the binary output in synchronization with the clock generated by the clock generation unit.

10. The data processing apparatus according to claim 9, wherein

the clock generation unit generates a synchronous clock synchronized with the binary output binarized by the binarization unit.

11. A data processing apparatus comprising:

a binarization unit binarizing input data based on a threshold voltage and configured to output only a binary output from a single connection point between a drain of a PMOS transistor and a drain of a NMOS transistor;

a capture unit capturing data from the binary output binarized by the binarization unit;

an average value detection unit detecting an average value of the binary output; and

a control unit, implemented via a processor, controlling a level of the input data based on the average value detected by the average value detection unit and configured to output only a single control signal directly into a gate of another PMOS transistor of the binarization unit, wherein a drain current value of the another PMOS transistor is varied in accordance with a change of the single control signal,

wherein a duty cycle of the binary output is detected from the average value of the binary output and pulse values when the binary output is at a high (H) level and at a low (L) level.

12. The data processing apparatus according to claim 11, wherein the capture unit includes:

a polyphase clock generation unit generating a polyphase clock for determining a time when data is captured from the binary output binarized by the binarization unit; and

a polyphase data capture unit capturing polyphase data from the binary output in synchronization with the polyphase clock generated by the polyphase clock generation unit, and

the average value detection unit detects an average value of the polyphase data captured by the polyphase data capture unit.

13. The data processing apparatus according to claim 11, including:

a D/A conversion unit receiving an output signal of the control unit, wherein

the average value detection unit and the control unit are configured using a digital circuit, and

the level of the input data is controlled based on an analog value signal converted by the D/A conversion unit.

14. The data processing apparatus according to claim 12, including:

a D/A conversion unit receiving an output signal of the control unit, wherein

the average value detection unit and the control unit are configured using a digital circuit, and

the level of the input data is controlled based on an analog value signal converted by the D/A conversion unit.