Application circuits, Rh5rh – Ricoh RH5RH13B User Manual
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V
IN
Inductor
Diode
OUT
Vss
V
OUT
+
Capacitor
EXT
ZD:6.8V
RH5RH502B
Tr
Cb
R
ZD
Rb
Starter Circuit
(Note) When the Output Current is small or the Output Voltage is unstable,use the Rzd for flowing the bias current through the Zener diode ZD.
FIG. 6
V
IN
Inductor
Diode
OUT
Vss
V
OUT
+
Capacitor
RH5RH
××
1A
Tr
PNP
Lx
Rb1
Rb2
Starter Circuit
(Note) When the L
X
pin Voltage is over the rating at the time PNP Tr is OFF,use a RH5RH
××
2B and drive the PNP Tr. by the external NPN Tr.
FIG. 7
APPLICATION CIRCUITS
• 12V Step-up Circuit
RH5RH
• Step-down Circuit