R1243x Series
2A
∗
30V Input PWM Step-down DC/DC Converter
No.EK-206-130716 Step-down DC/DC Converter
The R1243x Series are 30V input, CMOS-based PWM step-down DC/DC converters featuring 2A∗ output current. R1243x includes a
soft start circuit and a latch or fold-back protection circuit. By simply using an inductor , resistors, a diode, and capacitors as external
components, a high-efficiency step-down DC/DC con verter can be easily configured. Due t o current mode PWM control, the R1243x
provides a fast response and high efficiency. Ceramic output capacitors can be used.
FEATURES
• Supply Current (IDD)························Typ. 0.7mA (No switching)
• Standby Current (Istandby) ·················Max. 10μA (CE="L")
• Input Voltage Range (VIN)···············4.5V to 30.0V
• Output Voltage Range (VOUT)··········0.8V to 18.0V (Externally adjustable)
(Feedback voltage : 0.5V)
• Feedback Voltage Accuracy···········± 1.4%
• Output Current (IOUT)·······················2A∗
• Oscillator Frequency (fosc)···············Select from 1MHz or 330kHz
•
Oscillator Maximum Duty Cycle (Maxduty)
···Min. 85%, Typ. 90%
• UVLO Detect Voltage (VUVLO) ·········Typ. 3.8V
• Soft Start Time (tstart)·······················Typ. 0.4ms ~
(Adjustable by an external capacitor)
• High Side Switch Limit Current·······Typ. 3.8A
• Thermal Shutdown Circuit··············Stops at 160°C
• Latch Protection Circuit··················Delay time for protection
Typ. 2ms (Ver. A/C) , 0.08ms (Ver. E)
• Fold-back Protection Circuit ···········Fold-back frequency
Typ. 250kHz (Ver. B)
Typ. 82.5kHz (Ver. D)
•
FLG pin (Nch. Open drain output)
·····FLG "OFF" Delay Time Typ. 0.25ms
• Packages········································DFN(PLP)2527-10, HSOP-8E
∗) This is an approximate value, because output current depending on conditions and external parts.
BLOCK DIAGRAM TYPICAL APPLICATION
R1243x001C/D
(VOUT=5.0V, Soft Start Time 12ms, Flag Function using)
BST
V
IN
L
X
V
FB
CE
TSS
"H"active
GND
L10
μ
H
C
IN
10μF
C
BST
0.47μF
V
IN
C
SS
0.1μF
V
FLGIN
5.0V
R
FLG
47kΩ
FLAG
R
CE
47kΩ
VOUT
5.0V
C
OUT
22μF
R
UP
18kΩ R
BOT
2.0kΩ
FLG
C
SPD
220pF
24.0V
R1243x
∗1) Latch / Fold-back Selectable
CIN, COUT: Ceramic capacitors can be used.
CBST: Bo otstrap Capaci tor
CSS: Capacitor for setting soft start time
SELECTION GUIDES
Halogen Free
Package
Q'ty per Reel
Part No.
DFN(PLP)2527-10 5,000 pcs R1243K001
.
∗
-TR
HSOP-8E 1,000 pcs
R1243S001
.
∗
-E2-FE
.
∗
:
Specify a combination of the osci llator frequency and the protection circuit.
.
A
.
: 1MHz, Latch type (2ms)
.
B
.
: 1MHz, Fold-back type
.
C
.
: 330kHz, Latch type (2ms)
.
D
.
: 330kHz, Fold-back type
E
.
: 1MHz, Latch type (0.08ms/ only HSOP-8E)
PACKAGES TYPICAL CHARACTERISTICS
DFN(PLP)2527-10 HSOP-8E
Bottom View Top View 6 10 7 8 9
5 1 4 3 2
10 6 9 8 7
1 5 2 3 4
∗
Top View Bottom View
5 86
4 2 13
86 5 7
13 4 2
7
∗
1 Lx 6 CE
2 Lx 7 TSS
3 GND 8 BST
4 VFB 9 VIN
5 FLG∗∗ 10 VIN
1 BST 5 VFB
2 VIN 6 FLG∗∗
3 Lx 7 CE
4 GND 8 TSS
Efficiency vs. Output Current
R1243x001A/B, R1243S001E R1243x001C/D
∗
) The tab is substrate level (GND), must be connected to GND level.
∗∗
) The FLG pin connected to the GND level or should be open when FLG is not used.
APPLICATIONS
• Power source for digital home appliances such as digital TVs and DVD players
• Power source for hand-held communication equipment, cameras, and VCRs
• Power source for office automation equipment such as printers and fax machines
• Power source for battery-powered equipment
0
20
10
100 V
OUT
=3.3V, Topt=25C°
60
80
40
30
70
90
50
1 10 1000100 10000
Output Current I
OUT
(mA)
V
IN
=12.0V
V
IN
=24.0V
V
IN
=5.0V
Efficiency η
(%)
0
20
10
100 V
OUT
=3.3V, Topt=25C°
60
80
40
30
70
90
50
1 10 1000100 10000
Output Current I
OUT
(mA)
V
IN
=5.0V
V
IN
=12.0V
Efficiency η
(%)
RICOHCOMPANY,LTD.
ElectronicDevicesCompany
http://www.ricoh.com/LSI/
For the conservation of the global environment, Ricoh is advancing the decrease of the negative environmental impact material.
After Apr. 1, 2006, we will ship out the lead free products only. Thus, all products that will be shipped from now on comply with RoHS Directive.
Basically after Apr. 1, 2012, we will ship out the Power Management ICs of the Halogen Free products only. (Ricoh Halogen Free products are
also Antimony Free.)
Halogen Free
RICOHCOMPANY,LTD.
ElectronicDevicesCompany
●Higashi-ShinagawaOffice(InternationalSales)
3-32-3,Higashi-Shinagawa,Shinagawa-ku,Tokyo140-8655,Japan
Phone:+81-3-5479-2857Fax:+81-3-5479-0502
RICOHEUROPE(NETHERLANDS)B.V.
●SemiconductorSupportCentre
NieuwKronenburgProf.W.H.Keesomlaan1,1183DJ,Amstelveen,TheNetherlands
P.O.Box114,1180ACAmstelveen
Phone:+31-20-5474-309Fax:+31-20-5474-791
RICOHELECTRONICDEVICESKOREACo.,Ltd.
11floor,Haesung1building,942,Daechidong,Gangnamgu,Seoul,Korea
Phone:+82-2-2135-5700Fax:+82-2-2135-5705
RICOHELECTRONICDEVICESSHANGHAICo.,Ltd.
Room403,No.2Building,690#BiBoRoad,PuDongNewdistrict,Shanghai201203,
People'sRepublicofChina
Phone:+86-21-5027-3200Fax:+86-21-5027-3299
RICOHCOMPANY,LTD.
ElectronicDevicesCompany
●Taipeioffice
Room109,10F-1,No.51,HengyangRd.,TaipeiCity,Taiwan(R.O.C.)
Phone:+886-2-2313-1621/1622Fax:+886-2-2313-1623
1.Theproductsandtheproductspecificationsdescribedinthisdocumentaresubjecttochangeor
discontinuationofproductionwithoutnoticeforreasons
suchasimprovement.Therefore,before
decidingtousetheproducts,pleaserefertoRicohsalesrepresentativesforthelatest
informationthereon.
2.Thematerialsinthisdocumentmaynotbecopiedorotherwisereproducedinwholeorinpart
withoutpriorwrittenconsentofRicoh.
3.Pleasebesuretotakeanynecessaryformalitiesunderrelevantlawsorregulationsbefore
exportingorotherwisetakingoutofyourcountrytheproductsorthetechnicalinformation
describedherein.
4.Thetechnicalinformationdescribedinthisdocumentshowstypicalcharacteristicsofand
exampleapplicationcircuitsfortheproducts.Thereleaseofsuchinformationisnottobe
construedasawarrantyoforagrantoflicenseunderRicoh'soranythirdparty'sintellectual
propertyrightsoranyotherrights.
5.
Theproductslistedinthisdocumentareintendedanddesignedforuseasgeneralelectronic
componentsinstandardapplications(officeequipment,telecommunicationequipment,
measuringinstruments,consumerelectronicproducts,amusementequipmentetc.).Those
customersintendingtouse
aproductinanapplicationrequiringextremequalityandreliability,
forexample,inahighlyspecificapplicationwherethefailureormisoperationoftheproduct
couldresultinhumaninjuryordeath(aircraft,spacevehicle,nuclearreactorcontrolsystem,
trafficcontrolsystem,automotiveand
transportationequipment,combustionequipment,safety
devices,lifesupportsystemetc.)shouldfirstcontactus.
6.Wearemakingourcontinuousefforttoimprovethequalityandreliabilityofourproducts,but
semiconductorproductsarelikelytofailwithcertainprobability.Inordertopreventanyinjuryto
personsordamagestopropertyresultingfromsuchfailure,customersshouldbecarefulenough
toincorporatesafetymeasuresintheirdesign,suchasredundancyfeature,firecontainment
featureandfail-safefeature.Wedonotassumeanyliability
orresponsibilityforanylossor
damagearisingfrommisuseorinappropriateuseoftheproducts.
7.Anti-radiationdesignisnotimplementedintheproductsdescribedinthisdocument.
8.
PleasecontactRicohsalesrepresentativesshouldyouhaveanyquestionsorcomments
concerningtheproductsorthetechnicalinformation.