Title:
COMPARATOR CIRCUIT WITH INTEGRATOR AND INFRARED LIGHT RECEPTION EQUIPMENT
Document Type and Number:
Japanese Patent JP3450975
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To suitably operate a comparator circuit with integrator over wide temperature range.
SOLUTION: When an infrared remote control signal is inputted from a BPF, an integration capacitor 15 is charged with a fixed current by a constant current source switching block 13 and when that signal is not inputted, the integration capacitor 15 is discharged with the fixed current. When the terminal voltage of integration capacitor 15 gets higher than a clamp voltage Vc1, a PNP transistor Tr2 is conducted between an emitter and a collector and the increase of terminal voltage is suppressed. The clamp voltage Vc1 is determined according to the base voltage of transistor Tr2 applied from a clamp voltage generating circuit. A threshold voltage Vth of comparator 16 and the clamp voltage Vc1 become the codes of similar temperature change characteristics and are generated so as to satisfy the conditions, the clamp voltage Vc1 is higher than the threshold voltage Vth within a fixed range, over wide temperature range.
Inventors:
Fumitaka Nakamura
Application Number:
JP34847896A
Publication Date:
September 29, 2003
Filing Date:
December 26, 1996
Export Citation:
Assignee:
Sharp Corporation
International Classes:
G06G7/18; H03F3/45; H03G11/00; H03K5/153; H04B10/07; H04B10/116; H04B10/40; H04B10/50; H04B10/60; H04B10/69; H04Q9/00; (IPC1-7): G06G7/18; H03F3/45; H03K5/153; H04Q9/00
Domestic Patent References:
| JP4343243A | ||||
| JP58141681U |
Attorney, Agent or Firm:
Keiichiro Saikyo