RH5RH301A Datasheet, PDF (27/29 Pages) RICOH electronics devices division – PWM STEP-UP DC/DC CONVERTER

RH5RH
APPLICATION CIRCUITS
• 12V Step-up Circuit
Inductor
Diode
RH5RH502B
Cb
OUT
VIN
EXT
Vss
Rb
Tr
VOUT
ZD:6.8V
RZD
+
Capacitor
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
• Step-down Circuit
Rb2
VIN
PNP Tr
Inductor
Diode
RH5RH××1A
Lx
OUT
Rb1
Vss
VOUT
+
Capacitor
Starter Circuit
(Note) When the LX 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
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