R×5RL
• CURRENT BOOST CIRCUIT
Output current of 60mA or more can be obtained by
the current boost circuit constructed as shown in this cir-
cuit diagram.
Tr.1
VIN
VOUT
R×5RL
SERIES
VIN
VOUT
GND
+
+
C2
C1
GND
GND
• CURRENT BOOST CIRCUIT WITH OVERCURRENT LIMIT CIRCUIT
A circuit for protecting Tr.1 from the destruction
Tr.1
R2
caused by output short-circuit or overcurrent is shown in
this circuit diagram.
Vbe2
Tr.2
IOUT
When the voltage reduction caused by the current ( aa
IOUT) which flows through R2 reaches Vbe2 of Tr.2 by
additionally providing the current boost circuit with Tr.2
and R2, Tr.2 is turned ON and the base current of Tr.1 is
increased, so that the output current is limited.
Current limit of Overcurrent Limit Circuit is obtained
as follows :
VIN
VOUT
R×5RL
SERIES
VIN
R1
VOUT
+
+
C1
C2
GND
GND
GND
IOUT
Vbe2/R2
• CURRENT SOURCE
A current source with the structure as shown in this
circuit diagram can be used. Output Current IOUT is
obtained as follows :
IOUT
VIN
VOUT
R×5RL
SERIES
VIN
R
1
*
IOUT= Vreg /R + ISS
GND
+
ISS
C1
Take care that Output Current IOUT does not exceed
its allowable current.
1) Vreg : Set Output Voltage of R×5RL Series.
*
17
RICOH [ RICOH ELECTRONICS DEVICES DIVISION ]
