Ricoh RV5VH Manual Do Utilizador

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CSW

FB1

V

DD

EXT1

D

OUT

FB2

EXT2

GND

C2

L2

R3

R1

R2

C3

SBD3

C1

PNP Tr.

SBD1

R6

R5

C5

L1

R4

C4

NMOS

PMOS

V

IN

SBD2

Output DC/DC 2

Output DC/DC 1

R1 : 820k

Ω

, R2 : 820k

Ω

, R3 : 100k

Ω

, R4 : 1k

Ω

, R5 : 750k

Ω 

(AdjustabIe)

R6 : 100k

Ω

L1 : 68µH, L2 : 27µH
C1 : 22µF, C2 : 22µF, C3 : 1000pF, C4 : 2200pF, C5 : 1000pF
PMOS : 2SJ238, NMOS : 2SK1470, PNPTr. : 2SB1120F

The V

DD

voltage can be supplied from another source than battery output and a reference voltage for DC/DC2 is

supplied by the output of DC/DC1.

The PMOS transistor can operate as a switch when the CSW is “L”.

• Step up DC/DC converter : DC/DC1

The oscillator can operate when CSW is “H”.   When the CSW is “L” the EXT1 outputs GND.

The output voltage can be adjusted by R5 and R6 with FB1 of two volt.

• Invering DC/DC converter : DC/DC2

The oscillator can operate when CSW is “H”.  When the CSW is “L” the EXT2 outputs V

DD

.

The output voltage can be adjusted by R1 and R2 with FB2 of zero volt.

• VoItage Detector

V

DD

pin can be monitored.  This could be operated all the time by V

DD

.

The D

OUT

pin outputs “L” when low voltage is detected with Nch open-drain output.