|
|
PDF R1218X Data sheet ( Hoja de datos )
| Número de pieza | R1218X | |
| Descripción | Step Up DC/DC Converter | |
| Fabricantes | Ricoh Corporation | |
| Logotipo |  |
|
Hay una vista previa y un enlace de descarga de R1218X (archivo pdf) en la parte inferior de esta página. Total 14 Páginas | ||
|
No Preview Available !
www.DataSheet4U.com
R1218x SERIES
Step-up DC/DC converter for Whilte LED Backlight
NO.EA-006-1025
OUTLINE
The R1218X Series are PWM control type step-up DC/DC converter ICs with low supply current. The R1218X
is fully dedicated to drive White LED with constant current. Each of these ICs consists of an NMOS FET, an
oscillator, a PWM comparator, a voltage reference unit, an error amplifier, an under voltage lockout circuit
(UVLO), an over-voltage protection circuit (OVP), and so on. The R1218X can drive white LEDs with high
efficiency with low supply current. A diode is built-in the R1218XXX1A, therefore it is possible to drive up to
4LEDs without an external diode. The R1218XXX2A, an external diode is necessary, however, up to 6 serial
LEDs can be driven with the R1218XXX2A.
Constant current can be set with an external resistance value. Dimming control is possible by PWM signal for
CE pin. Feedback voltage is 0.2V, therefore power loss by current setting resistance is small and efficiency is
good. Maximum duty cycle is internally fixed, Typ. 91%. LEDs can be driven from low voltage. Protection circuits
are the current limit of Lx peak current, the over voltage limit of output, and the under voltage lockout function.
Packages are standard SOT23-6 and very tiny PLP1820-6.
FEATURES
• Operating voltage ............................................. 1.8V to 5.5V
• Built-in 400mA, 1.5Ω, 20V Nch MOSFET (R1218XXX1A)
• Built-in 400mA, 1.5Ω, 29V Nch MOSFET (R1218XXX2A)
• High Frequency PWM control .......................... Oscillator Frequency 1.2MHz
• Maximum Duty Cycle ....................................... Typ. 91%
• Low Feedback Voltage ..................................... Typ. 0.2V
• UVLO Threshold Voltage.................................. Typ. 1.6V (Hysteresis Typ. 0.1V)
• Lx Current limit Protection ................................ Typ. 700mA
• Over Voltage Protection (OVP) Threshold ....... Typ. 9.5V(R1218X02XA)
.......................................................................... Typ. 14.0V(R1218X03XA)
.......................................................................... Typ. 18.5V(R1218X04XA)
.......................................................................... Typ. 23.0V(R1218X052A)
.......................................................................... Typ. 27.5V(R1218X062A)
• LED dimming control .....................................by external PWM signal (Frequency 500Hz to 5kHz) to CE pin
.......................................................................by feedback voltage and filtered PWM signal (high frequency)
• Packages.......................................................... SOT23-6 or PLP1820-6
APPLICATION
• White LED Backlight for portable equipment
DataSheet4 U .com
1
1 page  
www.DataSheet4U.com
R1218X
Symbol
VFB
∆VFB/∆T
IFB
RON
Item
VFB Voltage Tolerance
VFB Voltage Temperature
Coefficient
VFB Input Current
Switch On Resistance
IOFF Switch Leakage Current
ILIM
fOSC
Maxduty
Switch Current Limit
Oscillator Frequency
Maximum Duty Cycle
VOVP1 OVP Detector Threshold
VOVP2 OVP Released Voltage
• R1218XXX1A
Conditions
VIN=3.6V
VIN=3.6V, -40°C≤Topt≤85°C
VIN=5.5V, VFB=0V or 5.5V
VIN=3.6V, ISW=100mA
R1218XXX1A VLX=20V
R1218XXX2A VLX=29V
VIN=3.6V
VIN=3.6V, VOUT=VFB=0V
VIN=3.6V, VOUT=VFB=0V
R1218X021A
VIN=3.6V
VOUT rising
R1218X031A
R1218X041A
R1218X052A
R1218X062A
R1218X021A
VIN=3.6V
VOUT falling
R1218X031A
R1218X041A
R1218X052A
R1218X062A
MIN.
0.19
TYP.
0.20
±150
-0.1
1.5
0.0
400
1000
86
8.5
13.0
17.0
21.5
26.0
0.0
700
1200
91
9.5
14.0
18.5
23.0
27.5
VOVP1-0.5
VOVP1-0.75
VOVP1-1.0
VOVP1-1.25
VOVP1-1.5
MAX.
0.21
0.1
3.0
3.0
1000
1400
10.5
15.0
20.0
24.5
29.0
Unit
V
ppm
/°C
µA
Ω
µΑ
µΑ
mA
kHz
%
V
V
V
V
V
V
V
V
V
V
Symbol
VF
IR
Item
Diode Forward Voltage
Diode Leakage Current
TEST CIRCUITS
Supply Current Test Circuit
Conditions
IDIODE=100mA
VOUT=20V, VLX=0V
MIN.
TYP.
0.8
10
MAX.
Unit
V
µA
UVLO Detector Threshold/ UVLO Released Voltage
VIN
CE
GND
V FB
VIN
CE
GND
LX
V FB
DataSheet4 U .com
5
5 Page 
www.DataSheet4U.com
5-2. Output Voltage Waveform (Topt=25°C)
25 R1218X021A
Fosc=200Hz
CE Input Voltage
20
10
5
15 0
10 Output Voltage
5
0
0 0.8 1.6Time (m2s.4) 3.2 4
6. PWM Dimming Control (4 LED) VIN=3.6V, R1=10Ω
6-1. Duty vs. LED Current (Topt=25°C)
25
22.5
20
17.5
15
12.5
10
7.5
5
2.5
0
0
R1218X041A
5kHz
1kHz
200Hz
20 40 60 80 100
DUTY (%)
6-2. Output Voltage Waveform
50 R1218X041A
Fosc=200Hz
CE Input Voltage
40
10
5
30 0
20 Output Voltage
10
0
0 0.8 1.6 2.4 3.2 4
Time (ms)
R1218X
R1218X021A
25
CE Input Voltage
20
15
10 Output Voltage
5
0
Fosc=5kHz
10
5
0
0 0.04 0.08 0.12 0.16 0.2
Time (ms)
50
R1218X041A
Fosc=5kH
10
CE Input Voltage
40
5
30 0
20 Output Voltage
10
0
0 0.04 0.08 0.12 0.16 0.2
Time (ms)
DataSheet4 U .com
11
11 Page | ||
| Páginas | Total 14 Páginas | |
| PDF Descargar | [ Datasheet R1218X.PDF ] | |
Hoja de datos destacado
| Número de pieza | Descripción | Fabricantes |
| R1218X | Step Up DC/DC Converter | Ricoh Corporation |
| Número de pieza | Descripción | Fabricantes |
| SLA6805M | High Voltage 3 phase Motor Driver IC. |
 Sanken |
| SDC1742 | 12- and 14-Bit Hybrid Synchro / Resolver-to-Digital Converters. |
 Analog Devices |
|
DataSheet.es es una pagina web que funciona como un repositorio de manuales o hoja de datos de muchos de los productos más populares, |
| DataSheet.es | 2020 | Privacy Policy | Contacto | Buscar |