RP400x Series
Current Mode PWM/VFM Step-up DC/DC Converter
The RP400x Series are CMOS-based automatic switch PWM- or VFM-controlled step-up DC/DC converters. RP400x includes a soft
start circuit. By simply using an inductor, a capacitor, a diode, and (resistors) as external components, a high-efficiency step-up
DC/DC converter can be easily configured. Due to current mode PWM control, the RP400x provides a fast response and high
efficiency. Ceramic output capacitors can be used. The output voltage can be selected from the internally fixed or the externally
adjustment. The RP400x has an anti-ringing switch that prevents inductor current from ringing in PWM discontinuous mode. RP400x
switches automatically to VFM control in low output current, keeping high efficiency. In addition to SOT-23-5 package, a 1.8mm
×
2.0mm square DFN(PLP)1820-6 package is also available.
FEATURES
•
Supply Current (I
DD1
)······················· Typ. 300μA (V
SET
=3.0V, Switching)
•
Supply Current (I
DD2
)······················· Typ. 160μA (No switching)
•
Standby Current (I
standby
)·················· Max. 3μA (CE="L", only A Version)
•
Input Voltage Range (V
IN
) ··············· Max. 5.5V
•
Start-up Voltage (V
start
)···················· Max. 0.9V
•
Output Voltage Range (V
OUT
)·········· 1.8V to 5.0 V (Internally fixed) (xx1)
Externally adjustable (Feedback voltage : 0.6V) (001)
•
Output Voltage Accuracy·················± 2%
•
Oscillator Frequency (f
osc
) ···············700kHz
•
Oscillator Maximum Duty Cycle (Maxduty) ···Typ. 88%
•
Coil-current Limit Circuit ·················Current Limit Typ. 600mA
•
Soft Start Time (t
start
)························Typ. 0.7ms
•
Anti-ringing Switch ··························Internal EMI Suppression
•
Packages ········································DFN(PLP)1820-6,
SOT-23-5
BLOCK DIAGRAMS
RP400xxx1x
(Internally fixed output voltage type)
L
X
Startup
Circuit
Control
Logic
Startup
Circuit
Control
Logic
RP400K001x
(Externally adjustable output voltage type)
L
X
V
IN
Buffer
V
IN
Buffer
PWM
Control
Current
Sense
PWM
Control
Current
Sense
V
OUT
ErrorAmp
ErrorAmp
CE
Chip
Enable
fosc
OSC
V
OUT
CE
Chip
Enable
fosc
OSC
V
FB
VFM Control
Vref
VFM Control
Vref
GND
GND
SELECTION GUIDES
Halogen Free
Package
Q'ty per Reel
Part No.
DFN(PLP)1820-6 5,000 pcs RP400K
.xx.1.
∗
-TR
SOT-23-5
3,000 pcs RP400N
.yy.1.
∗
-TR-FE
TYPICAL APPLICATIONS
RP400xxx1A
(Internally fixed output Voltage type)
L10μH (6.8μH)
SD
V
IN
V
IN
C
IN
10μF
"H"active
RP400x
OUT
CE
V
OUT
C
OUT
10μF
"H"active
CE
GND
V
FB
R1
L
X
V
IN
C
IN
10μF
V
IN
L
X
RP400x001A
V
OUT
C
OUT
10μF
RP400x001A
(Externally adjustable output voltage type)
L10μH (6.8μH)
SD
V
OUT
1.8V to 5.0V
R2
.xx.
: Specify the output voltage within the range of
1.8V (.18.) to 5.0V (.50.) in 0.1V steps.
For the externally adjustable output voltage type (.00.).
yy. : Specify the output voltage within the range of
.
1.8V (.18.) to 5.0V (.50.) in 0.1V steps.
(The externally adjustable output voltage type is not available.)
.∗
: Select from (.A.) with CE pin or (.B.) without CE pin.
GND
PACKAGES
DFN(PLP)1820-6
Top View
6
5
4
TYPICAL CHARACTERISTIC
SOT-23-5
5
4
RP400x001A Efficiency vs. Output Current
100
90
V
OUT
=3.0V
Bottom View
4
5
6
∗
1
2
3
3
2
1
1
2
3
4
5
6
xx1A
V
IN
CE
GND
L
X
NC
V
OUT
001A
V
IN
CE
GND
L
X
V
FB
V
OUT
xx1B
V
IN
NC
GND
L
X
NC
V
OUT
001B
V
IN
NC
GND
L
X
V
FB
V
OUT
1
2
3
4
5
xx1A
CE
GND
V
IN
V
OUT
L
X
xx1B
NC
GND
V
IN
V
OUT
L
X
Efficiency
η
(%)
1
2
3
80
70
60
50
40
V
IN
=2.5V
V
IN
=1.8V
V
IN
=1.5V
V
IN
=0.8V
0
200
400
600
Output Current I
OUT
(mA)
800
∗
)
The tab is substrate level (GND).
APPLICATIONS
•
MP3 players and PDA
•
Digital cameras
No.EK-193-121001
•
LCD bias power supply
•
Personal medical equipment
•
Wireless Handset
•
GPS
Step-up DC/DC Converter
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.
Halogen Free
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.)
RICOH COMPANY, LTD.
Electronic Devices Company
http://www.ricoh.com/LSI/
RICOH COMPANY, LTD.
Electronic Devices Company
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