R1225N Datasheet, PDF (1/31 Pages) RICOH electronics devices division – PWM/VFM step-down DC/DC Converter

51 6(5,(6
PWM/VFM step-down DC/DC Converter
NO. EA-097-0212
OUTLINE
7KH 51 6HULHV DUH &026EDVHG 3:0 VWHSGRZQ '&'& &RQYHUWHU FRQWUROOHUV ZLWK ORZ VXSSO\ FXUUHQW
(DFK RI WKHVH ,&V FRQVLVWV RI DQ RVFLOODWRU D 3:0 FRQWURO FLUFXLW D UHIHUHQFH YROWDJH XQLW DQ HUURU DPSOLILHU D VRIW
VWDUW FLUFXLW D ODWFKW\SH SURWHFWLRQ FLUFXLW D 3:09)0 DOWHUQDWLYH FLUFXLW D FKLS HQDEOH FLUFXLW D SKDVH FRPSHQVD
WLRQ FLUFXLW DQG DQ LQSXW YROWDJH GHWHFW FLUFXLW )XUWKHU SURWHFWLRQ FLUFXLW GHOD\ WLPH DGMXVWHU FLUFXLW DQG UHVLVWRUV IRU
YROWDJH GHWHFWLRQ DUH LQFOXGHG $ ORZ ULSSOH KLJK HIILFLHQF\ VWHSGRZQ '&'& FRQYHUWHU FDQ EH HDVLO\ FRPSRVHG RI
WKLV ,& ZLWK VRPH H[WHUQDO FRPSRQHQWV RU D SRZHUWUDQVLVWRU DQ LQGXFWRU D GLRGH DQG FDSDFLWRUV
:LWK D 3:09)0 DOWHUQDWLYH FLUFXLW ZKHQ WKH ORDG FXUUHQW LV VPDOO WKH RSHUDWLRQ LV DXWRPDWLFDOO\ VZLWFKLQJ LQWR WKH
9)0 RVFLOODWRU IURP 3:0 RVFLOODWRU WKHUHIRUH WKH HIILFLHQF\ DW VPDOO ORDG FXUUHQW LV LPSURYHG 7KH 51[[[&'.
W\SHV ZKLFK DUH ZLWKRXW D 3:09)0 DOWHUQDWLYH FLUFXLW DUH DOVR DYDLODEOH
,I WKH WHUP RI PD[LPXP GXW\ F\FOH NHHSV RQ D FHUWDLQ WLPH WKH HPEHGGHG SURWHFWLRQ FLUFXLW ZRUNV ,W LV ODWFKW\SH
SURWHFWLRQ FLUFXLW DQG LW ZRUNV WR ODWFK DQ H[WHUQDO 3RZHU 026)(7 ZLWK NHHSLQJ LW RII 7R UHOHDVH WKH FRQGLWLRQ RI
SURWHFWLRQ DIWHU GLVDEOH WKLV ,& ZLWK D FKLS HQDEOH FLUFXLW HQDEOH LW DJDLQ RU UHVWDUW WKLV ,& ZLWK SRZHURQ 'HOD\ 7LPH
IRU SURWHFWLRQ FLUFXLW LV DGMXVWDEOH ZLWK DQ H[WHUQDO FDSDFLWRU :LWK D EXLOWLQ 89/2 IXQFWLRQ ZKHQ WKH LQSXW YROWDJH LV
89/2 WKUHVKROG RU OHVV WKLV ,& NHHSV VWDQGE\ VWDWH DQG VDYHV LWV FRQVXPSWLRQ FXUUHQW DQG DYRLGV PLVVRSHUDWLRQ
)XUWKHU LI WKH VHW RXWSXW YROWDJH LV HTXDO RU PRUH WKDQ 9 ZLWK D EXLOWLQ VWDUWXS IXQFWLRQ DW WKH SRZHURQ PRPHQW
XQWLO WKH LQSXW YROWDJH EHFRPHV PRUH WKDQ WKH VHW RXWSXW YROWDJH '&'& RSHUDWLRQ LV KDOWHG DQG DYRLGV PLVVRSHUDWLRQ
FEATURES
• :LGH 5DQJH RI ,QSXW 9ROWDJH9a9
• %XLOWLQ 6RIWVWDUW )XQFWLRQ DQG /DWFKW\SH 3URWHFWLRQ )XQFWLRQ
• 7KUHH RSWLRQV RI 2VFLOODWRU )UHTXHQF\N+] N+] N+]
• +LJK (IILFLHQF\ 7\S 
• 2XWSXW 9ROWDJH6WHSZLVH 6HWWLQJ ZLWK D VWHS RI 9 LQ WKH UDQJH RI
9 a 9
• 6WDQGE\ &XUUHQW 7\S —$
• +LJK $FFXUDF\ 2XWSXW 9ROWDJH “
• /RZ 7HPSHUDWXUH'ULIW &RHIILFLHQW RI 2XWSXW 9ROWDJH7\S “SSPƒ&
APPLICATIONS
• 3RZHU VRXUFH IRU KDQGKHOG FRPPXQLFDWLRQ HTXLSPHQW FDPHUDV YLGHR LQVWUXPHQWV VXFK DV 9&5V FDPFRUGHUV
• 3RZHU VRXUFH IRU EDWWHU\SRZHUHG HTXLSPHQW
• 3RZHU VRXUFH IRU KRXVHKROG HOHFWULFDO DSSOLDQFHV
1