R1203x/R1206N Series
PWM Step-up DC/DC Converter for White LED
The R1203x/R1206N Series are CMOS-based PWM step-up DC/DC converters, which are optimized to drive white LEDs with constant current.
R1203x/R1206N includes an under-voltage lockout circuit (UVLO), and over-voltage protection circuit (OVP). By simply using an inductor, a
resistor, capacitors and a diode as external components, white LEDs can be driven with constant current and high efficiency. The LED
current can be determined by the value of current setting resistor. The brightness of the LEDs can be adjusted quickly by applying a PWM
signal (200Hz to 300kHz) to the CE pin. Two different pin layout of SOT-23-6 package as R1203N and R1206N are available.
FEATURES
•
Supply Current (I
DD
) ··················· Typ. 500μA (No switching)
•
Standby Current (I
standby
) ·············· Typ. 1μA (CE="L")
•
Input Voltage Range (V
IN
) ············ 1.8V to 5.5V
•
Feedback Voltage (V
FB
) ················ 0.2V
•
Feedback Voltage Accuracy ·········
±
10mV
•
Oscillator Frequency (f
osc
) ············ 1.2MHz
•
Oscillator Maximum Duty Cycle (Maxduty) ·· Min. 86%, Typ. 91%
(Absolute maximum rating: 6.5V)
•
UVLO Detect Voltage (V
UVLO
) ······· Typ. 1.6V
•
Coil-current Limit Circuit ·············· Current limit Typ. 700mA
•
Over Voltage Protection Circuit (OVP) ··· 29.5V
•
LED High-speed Dimming Control
•
Packages ··································R1203x Series
DFN1616-6B, SOT-23-6
R1206N Series
SOT-23-6
BLOCK DIAGRAM
R1203x071B
R1206N071B
V
FB
V
IN
L
X
V
OUT
TYPICAL APPLICATION
R1203x071B
R1206N071B
L1
22μH
UVLO
Error Amp.
PWM Comp.
R
S
Vref
PWM
Cntrl
OSC
EN
Slope
Compensation
Current
Limit
Current
Sense
OVP
Q
Switch
Control
C1
1μF
C2
0.22μF
V
IN
L
X
CE
V
OUT
Shutdown
delay
Chip Enable
GND
V
FB
R1
10Ω
Σ
CE
GND
SELECTION GUIDES
Halogen Free
Package
DFN1616-6B
SOT-23-6
Q'ty per Reel
Part No.
5,000 pcs R1203L.071B -TR
R1203N.071B -TR-FE
3,000 pcs
R1206N.071B -TR-FE
.xxx
: Specify the OVP Voltage.
(.071.) 29.5V
PACKAGES
DFN1616-6B
Top View
6
5
4
TYPICAL CHARACTERISTIC
SOT-23-6
6
5
4
6
7LEDs
90
85
Efficiency vs. Output Current
Bottom View
4
5
Efficiency
η
(%)
∗
80
75
70
65
60
55
50
0
5
10
15
Output Current I
OUT
(mA)
20
V
IN
=5.0V
V
IN
=3.6V
V
IN
=2.8V
1
1
2
3
3
2
1
2
3
R1203N
1
2
3
4
5
6
CE
V
OUT
V
IN
Lx
GND
V
FB
R1206N
1
2
3
4
5
6
Lx
GND
V
FB
CE
V
OUT
V
IN
1
2
3
4
5
6
CE
V
FB
Lx
GND
V
IN
V
OUT
∗
) The tab is substrate level (GND).
APPLICATION
•
White LED driver for hand-held equipment
No.EK-207-140930
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.
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prior written consent of Ricoh.
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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, fire containment 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
Ricoh is committed to reducing the environmental loading materials in electrical devices
with a view to contributing to the protection of human health and the environment.
Ricoh has been providing RoHS compliant products since April 1, 2006 and Halogen-free products since
April 1, 2012.
http://www.e-devices.ricoh.co.jp/en/
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