Title:
DC/DC CONVERTER CIRCUIT AND RS-232 INTERFACE CIRCUIT EMPLOYING SAME
Document Type and Number:
Japanese Patent JPH05268763
Kind Code:
A
Abstract:
PURPOSE: To realize serial communication on a voltage defined by S-232 interface communication regulation when two type of voltages are employed individually in the host side circuit.
CONSTITUTION: Variation of DC input voltage VIN to host side circuit is detected and a voltage boosted at an appropriate rate is created thus obtaining positive and negative DC output voltages VDD, VSS conformable to RS-232 interface communication regulation regardless of variation of power supply voltage. In other words, a voltage Vo2 boosted by a factor of 2 from the voltage of a DC/DC converter circuit is selected for 5V operation whereas a Vo3 boosted by a factor of 3 is selected for 3V operation thus obtaining an DC output voltage.
Inventors:
Kohei Okamoto
Application Number:
JP6058792A
Publication Date:
October 15, 1993
Filing Date:
March 17, 1992
Export Citation:
Assignee:
NEC
International Classes:
G06F3/00; H02M1/10; H02M3/07; H02M3/155; (IPC1-7): H02M3/155; G06F3/00; H02M1/10
Attorney, Agent or Firm:
Yosuke Goto (2 outside)