Apparatus and method for generating ramp signal

Patent metadata

Field	Value
Publication number	US-9496856-B2
Application number	US-201514688483-A
Country	US
Kind code	B2
Filing date	Apr 16, 2015
Priority date	Sep 15, 2014
Publication date	Nov 15, 2016
Grant date	Nov 15, 2016

Abstract

Provided is a ramp signal generating apparatus. The ramp signal generating apparatus includes N (N is a natural number) ramp signal generating cells that are connected in series to each other. Each of the ramp signal generating cells includes a power voltage unit for supplying current source, a latch unit for latching an output voltage of the power voltage unit, and a switch unit for outputting the voltage latched by the latch unit as an output voltage in response to an input signal.

First claim

What is claimed is:

1. A ramp signal generating apparatus comprising an N (N is a natural number) number of ramp signal generating cells that are connected in series to each other,
each of the ramp signal generating cells comprising:
a power voltage unit supplying a current source;
a latch unit latching an output voltage of the power voltage unit; and
a switch unit outputting the voltage latched by the latch unit as an output voltage of the switch unit in response to an input signal, wherein the ramp signal generating apparatus outputs an output signal of an N th ramp signal generating cell as a ramp signal.

2. The ramp signal generating apparatus according to claim 1 , wherein the power voltage unit supplies a constant current as the current source.

3. The ramp signal generating apparatus according to claim 1 , wherein the latch unit comprises a plurality of switches that are connected in a cross-coupled configuration.

4. The ramp signal generating apparatus according to claim 1 , wherein the switch unit comprises at least one capacitor and controls charging and discharging of the at least one capacitor in response to the input signal.

5. A ramp signal generating method comprising:
generating a constant current from a reference voltage generator, wherein the reference voltage generator generates a constant reference voltage;
latching a voltage generated in response to the constant current; and
outputting the latched voltage in response to an input signal;
charging a predetermined capacitor according to the latched voltage; and
outputting the charged voltage when the charged voltage reaches a preset level.

Assignees

• Univ Korea Res & Bus Found

Inventors

• Kim Chul Woo
• Shim Min Seob
• Jung Jun Won
• Kim Jung Moon
• Maeng Jun Young

Classifications

• H03K4/502 Primary

  the capacitor being charged from a constant-current source · CPC title

• H03K3/0322

  with differential cells · CPC title

• H03K3/12

  bistable · CPC title