Title:
CONSTANT CURRENT CIRCUIT
Document Type and Number:
Japanese Patent JPS616715
Kind Code:
A
Abstract:
PURPOSE:To obtain a constant current output having no power supply dependence by obtaining a stabilized voltage from a super-low voltage power supply and driving an output transistor (TR) on the basis of the stabilized voltage to form a stabilized output current. CONSTITUTION:In the constant current circuit, an output voltage Vs is fed back by a pnp TR Q9 to stabilize the voltage Vs by an output current I0 and output TRs Q1-Q3 are driven by the voltage stabilized by said output current I0 and said output voltage to obtain stabilized output currents I1-I3. The addition of the TR Q9 makes it possible to reduce the Early's effect of the TRs Q11-Q14 and the stabilized output voltage Vs from a super-low voltage power supply is applied to a resistor R11 independently of the variation of a power supply Vcc. Consequently, load currents Z1, Z2 execute stabilize circuit operation without dependence of the stabilized output currents I1, I2 upon the variation of a power supply voltage Vcc.
Inventors:
WAKAZAKURA MASAO
OOKUBO YUUICHI
OOKUBO YUUICHI
Application Number:
JP12516784A
Publication Date:
January 13, 1986
Filing Date:
June 20, 1984
Export Citation:
Assignee:
HITACHI LTD
International Classes:
G05F3/30; G05F3/26; (IPC1-7): G05F1/565
Attorney, Agent or Firm:
Katsuo Ogawa (1 person outside)
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