Method of operating channel buffer block and devices including the channel buffer block

• US 9,240,234 B2
• Filed: 12/23/2014
• Issued: 01/19/2016
• Est. Priority Date: 06/10/2014
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Park, Hyun Sang, Kim, Kyung Chun
• Primary Examiner(s): HA, NATHAN W
• Application Number:
  US14/581,792
• Publication Number:
  US 20150357998A1
• Time in Patent Office: 392 Days
• Field of Search: 365/154, 327/536
• US Class Current: 1/1
• CPC Class Codes: G05F 3/02 Regulating voltage or current
• CPC Class Codes: G05F 3/16 being semiconductor devices
• CPC Class Codes: G05F 3/30 Regulators using the difference between the base-emitter voltages of two bipolar transistors operating at different current densities G05F3/26 takes precedence
• CPC Class Codes: G11C 11/419 Read-write [R-W] circuits
• CPC Class Codes: G11C 29/022 in I/O circuitry
• CPC Class Codes: G11C 29/023 in clock generator or timing circuitry
• CPC Class Codes: G11C 29/028 with adaption or trimming of parameters
• CPC Class Codes: G11C 7/222 Clock generating, synchronizing or distributing circuits within memory device
• CPC Class Codes: H01L 29/7801 DMOS transistors, i.e. MISFETs with a channel accommodating body or base region adjoining a drain drift region lateral high-voltage MISFETs with channel well and drain offset region H01L29/7835
• CPC Class Codes: H03M 1/06 Continuously compensating for, or preventing, undesired influence of physical parameters periodically, e.g. by using stored correction values, H03M1/10
• CPC Class Codes: H04N 23/00 Cameras or camera modules comprising electronic image sensors; Control thereof
• CPC Class Codes: H04N 25/00 Circuitry of solid-state image sensors [SSIS]; Control thereof

Abstract

A method of operating a channel buffer block is provided. The method includes changing bias voltages applied to bias lines in an input stage included in the channel buffer block using a coupling effect of coupling capacitors during a slewing interval and increasing bias currents in the input stage using input voltages and changed bias voltages.

Claims

1. A column driver integrated circuit (IC) having a channel buffer block, wherein the channel buffer block comprises:

a first differential amplifier having a first bias circuit configured to generate a first bias current inversely proportional to a first bias voltage and a first transistor pair configured to amplify a difference between input voltages using the first bias current;

a second differential amplifier having a second bias circuit configured to generate a second bias current proportional to a second bias voltage and a second transistor pair configured to amplify the difference between the input voltages using the second bias current;

a first coupling capacitor configured to decrease the first bias voltage using a first control voltage during a slewing interval; and

a second coupling capacitor configured to increase the second bias voltage using a second control voltage during the slewing interval.

2. The column driver IC of claim 1, wherein the first control voltage and the second control voltage are received from outside of the channel buffer block and a phase of the first control voltage is opposite to a phase of the second control voltage during the slewing interval.

3. The column driver IC of claim 2, further comprising a pulse width control circuit configured to control a pulse width of the first control voltage using a control code output from a timing controller.

4. The column driver IC of claim 1, wherein the first control voltage is a voltage of a first common node of the first bias circuit and the first transistor pair and the second control voltage is a voltage of a second common node of the second bias circuit and the second transistor pair.

5. The column driver IC of claim 4, wherein the voltage of the first common node decreases when one of the input voltages decreases and the voltage of the second common node increases when the one of the input voltages increases.

6. A display system comprising:

the column driver integrated circuit (IC) of claim 1; and

a timing controller configured to control operation of the column driver IC.

7. The display system of claim 6, wherein the first control voltage and the second control voltage are received from outside of the channel buffer block and a phase of the first control voltage is opposite to a phase of the second control voltage during the slewing interval.

8. The display system of claim 7, wherein the column driver IC further comprises a pulse width control circuit configured to control a pulse width of the first control voltage using a control code output from a timing controller.

9. The display system of claim 8, wherein the timing controller is configured to compare previous line data in display data with current line data in the display data and to generate the control code according to a comparison result.

10. The display system of claim 8, further comprising a serial interface connected between the column driver IC and the timing controller,

wherein the timing controller is configured to generate a data packet having the display data and the control code and to transmit the generated data packet to the column driver IC through the serial interface.

11. The display system of claim 6, wherein the first control voltage is a voltage of a first common node of the first bias circuit and the first transistor pair and the second control voltage is a voltage of a second common node of the second bias circuit and the second transistor pair.

12. An image processing system comprising:

a column driver integrated circuit (IC) having a channel buffer block;

a timing controller configured to control operation of the column driver IC; and

a processor configured to control operation of the timing controller,

wherein the channel buffer block comprises;

a first differential amplifier having a first bias circuit configured to generate a first bias current inversely proportional to a first bias voltage and a first transistor pair configured to amplify a difference between input voltages using the first bias current;

a second differential amplifier having a second bias circuit configured to generate a second bias current proportional to a second bias voltage and a second transistor pair configured to amplify the difference between the input voltages using the second bias current;

a first coupling capacitor configured to decrease the first bias voltage using a first control voltage during a slewing interval; and

a second coupling capacitor configured to increase the second bias voltage using a second control voltage during the slewing interval.

13. The image processing system of claim 12, wherein the first control voltage and the second control voltage are received from outside of the channel buffer block and a phase of the first control voltage is opposite to a phase of the second control voltage during the slewing interval.

14. The image processing system of claim 13, wherein the column driver IC further comprises a pulse width control circuit configured to control a pulse width of the first control voltage using a control code output from a timing controller.

15. The image processing system of claim 14, wherein the timing controller compares previous line data in display data with current line data in the display data and generates the control code according to a comparison result.

16. The image processing system of claim 15, further comprising a serial interface connected between the column driver IC and the timing controller,

wherein the timing controller is configured to generate a data packet having the display data and the control code and to transmit the generated data packet to the column driver IC through the serial interface.