R1205x Series
Step-up DC / DC Converter with Overcurrent Protection
NO.EA-272-201211
OUTLINE
The R1205x is a PWM control type step-up DC/DC converter IC with low supply current. Each of these ICs
consists of an NMOS FET, a diode, an oscillator, a PWM comparator, a voltage reference unit, an error amplifier,
a current limit circuit, an under voltage lockout circuit (UVLO), an over-voltage protection circuit (OVP), a softstart circuit, a Maxduty limit circuit, and a thermal shutdown protection circuit. This step-up DC/DC converter
can be easily built with a few external components such as a coil, a resistor, and a capacitor. As the protection
functions, the R1205x has an Lx peak current limit function, an over voltage protection (OVP) function, an
under voltage lock out (UVLO) function and a thermal shutdown function.
The R1205x presents the R1205x8xxA version that is optimized for the constant voltage power source, and
the R1205x8xxB/C version that is optimized for driving the white LED with the constant current. The
R1205x8xxB/C is an adjustable version that can change the LED brightness dynamically by using a 200Hz to
300kHz PWM signal toward the CE pin.
The R1205x is available in DFN1616-6B and TSOT-23-6 packages.
FEATURES
Input Voltage Range ............................................. 2.3V to 5.5V (R1205x8xxA)
1.8V to 5.5V (R1205x8xxB/C)
Supply Current ...................................................... Typ. 800A
Standby Current .................................................... Max. 5A
Feedback Voltage ................................................. 1.0V15mV (R1205x8xxA)
0.2V10mV (R1205x8xxB)
0.4V10mV (R1205x8xxC)
Oscillator Frequency ............................................. Typ. 1.2MHz
Maximum Duty Cycle ............................................ Typ. 91%
UVLO Function ꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏ Typ.2.0V (Hys.Typ.0.2V) (R1205x8xxA)
Typ.1.6V (Hys.Typ.0.1V) (R1205x8xxB/C)
Selectable Lx Current Limit Function .................... Typ. 350mA / 700mA
Over Voltage Protection ........................................ Typ. 25V
LED dimming control (R1205x8xxB/C) ............... by external PWM signal (Frequency 200Hz to 300kHz)
Thermal Protection Function ................................. Typ.150ºC(Hys.Typ.50ºC)
Switch ON Resistance .......................................... Typ. 1.35Ω
Packages .............................................................. DFN1616-6B, TSOT-23-6
Ceramic capacitors are recommended
APPLICATION
Constant Voltage Power Source for portable equipment
OLED power supply for portable equipment
White LED Backlight for portable equipment
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R1205x
NO.EA-272-201211
SELECTION GUIDE
The OVP threshold voltage, current limit, package and VFB/Auto discharge are user-selectable options.
Product Name
R1205L8x1-TR
R1205N8x3-TR-FE
2
Package
Quantity per Reel
Pb Free
Halogen Free
DFN1616-6B
5,000 pcs
Yes
Yes
TSOT-23-6
3,000 pcs
Yes
Yes
x
: Designation of current limit.
(1) 350mA
(2) 700mA
: Designation of VFB.
(A) 1.0V
(B) 0.2V
(C) 0.4V
R1205x
NO.EA-272-201211
BLOCK DIAGRAMS
VIN
VFB
Err. Amp.
+
–
VOUT
UVLO
PWM Comp.
+
–
vref
LX
R
S
Q
Driver
Control
OVP
Oscillator
Soft-start
Slope Compensation
Current
Limit
Current
sense
Thermal
Shutdown
∑
CE
CE
R1205x8xxA
VIN
VFB
Err. Amp.
+
–
LX
UVLO
R
S
Q
Driver
Control
OVP
Oscillator
PWM
Cntrl
VOUT
PWM Comp.
+
–
vref
GND
EN
Slope Compensation
Shutdown
delay
∑
Current
Limit
Current
sense
Thermal
Shutdown
CE
CE
GND
R1205x8xxB/C
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R1205x
NO.EA-272-201211
PIN DESCRIPTIONS
DFN1616-6B
Top View
6
5
TSOT-23-6
Bottom View
4
4
5
6
2
3
3
2
4
6
1
5
(mark side)
1
1
2
3
DFN1616-6B
Pin No
Symbol
Pin Description
1
CE
Chip Enable Pin ("H" Active)
2
VFB
Feedback Pin
3
LX
4
GND
Ground Pin
5
VIN
Input Pin
6
VOUT
Switching Pin (Open Drain Output)
Output Pin
The tab is substrate level (GND). The tab is better to be connected to the GND, but leaving it open is also acceptable.
TSOT-23-6
4
Pin No
Symbol
Pin Description
1
CE
2
VOUT
3
VIN
Input Pin
4
LX
Switching Pin (Open Drain Output)
5
GND
Ground Pin
6
VFB
Feedback Pin
Chip Enable Pin ("H" Active)
Output Pin
R1205x
NO.EA-272-201211
ABSOLUTE MAXIMUM RATINGS
Symbol
Item
GND0V
Rating
Unit
VIN
VIN Pin Voltage
0.3 to 6.5
V
VCE
CE Pin Voltage
0.3 to 6.5
V
VFB
VFB Pin Voltage
0.3 to 6.5
V
VOUT
VOUT Pin Voltage
0.3 to 28
V
VLX
LX Pin Voltage
0.3 to 28
V
ILX
LX Pin Current
1000
mA
PD
Power Dissipation (1)
DFN1616-6B
(JEDEC STD. 51-7 Test Land Pattern)
TSOT-23-6
(Standard Test Land Pattern)
2400
mW
460
Tj
Junction Temperature Range
40 to 125
C
Tstg
Storage Temperature Range
55 to 125
C
ABSOLUTE MAXIMUM RATINGS
Electronic and mechanical stress momentarily exceeded absolute maximum ratings may cause permanent damage
and may degrade the life time and safety for both device and system using the device in the field.
The functional operation at or over these absolute maximum ratings are not assured.
RECOMMENDED OPERATING CONDITIONS
Symbol
VIN
Ta
Item
Rating
Input Voltage (R1205x8xxA)
2.3 to 5.5
Input Voltage (R1205x8xxB/C)
1.8 to 5.5
Operating Temperature Range
−40 to 85
Unit
V
°C
RECOMMENDED OPERATING CONDITIONS
All of electronic equipment should be designed that the mounted semiconductor devices operate within the
recommended operating conditions. The semiconductor devices cannot operate normally over the recommended
operating conditions, even if they are used over such ratings by momentary electronic noise or surge. And the
semiconductor devices may receive serious damage when they continue to operate over the recommended operating
conditions.
(1)
Refer to POWER DISSIPATION for detailed information.
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NO.EA-272-201211
ELECTRICAL CHARACTERISTICS
R1205x
Symbol
IDD
(Ta25C)
Item
Supply Current
Istandby Standby Current
Conditions
Typ.
Max.
Unit
VIN=5.5V, VFB=0V , LX at no load
0.8
1.2
mA
VIN=5.5V, VCE=0V
1.0
5.0
A
2.0
1.6
VUVLO1
+0.2
VUVLO1
+0.1
2.1
1.7
V
VUVLO1 UVLO Detector Threshold VIN falling
R1205x8xxA
R1205x8xxB/C
Min.
1.9
1.5
R1205x8xxA
VUVLO2
UVLO Released Voltage VIN rising
R1205x8xxB/C
VCEH
CE Input Voltage "H"
VCEL
CE Input Voltage "L"
RCE
CE Pull Down Resistance
VFB
VFB/
Ta
IFB
VFB Voltage Accuracy
VIN=5.5V
V
1200
VIN=3.6V
R1205x8xxA
R1205x8xxB
R1205x8xxC
VIN=5.5V, VFB=0V or 5.5V
Soft-start Time
RON
FET ON Resistance
ILX=100mA
IOFF
FET Leakage Current
VLX=24V
ILIM
FET Current Limit
VF
Diode Forward Voltage
fosc
0.985
0.19
0.39
1.000
0.2
0.4
-0.1
R1205x8xxA
2.0
1.015
0.21
0.41
0.1
A
3.0
ms
Ω
3.0
R1205x81xx
250
350
450
R1205x82xx
500
700
900
0.8
VOUT=24V, VLX=0V
VIN=3.6V, VFB=0V
1000
1200
Maxduty Maximum Duty Cycle
VIN=3.6V, VFB=0V
86
91
24.2
25
V
ppm
/°C
1.35
ISW=100mA
V
kΩ
150
Oscillator Frequency
A
mA
V
10
A
1400
kHz
%
25.8
VOVP1
OVP Detect Voltage
VIN=3.6V, VOUT rising
VOVP2
OVP Release Voltage
VIN=3.6V, VOUT falling
VOVP1
-1.8
V
VIN=3.6V
150
°C
VIN=3.6V
100
°C
TTSD
TTSR
6
1.8
0.5
tstart
IDIODEleak Diode Leakage Current
V
1.5
VFB Voltage Temperature
VIN=3.6V, 40C Ta 85C
Coefficient
VFB Input Current
2.3
Thermal Shutdown
Detect Temperature
Thermal Shutdown
Release Temperature
V
R1205x
NO.EA-272-201211
THEORY OF OPERATION
Operation of Step-Up DC/DC Converter and Output Current
i2
IOUT
VOUT
Diode
L
VIN
i1
Lx Tr
CL
GND
Discontinuous mode
Continuous mode
ILm ax
IL
IL
ILm ax
ILm in
ILm in
tope n
t
toff
ton
T =1/fosc
t
ton
toff
T =1/fosc
There are two operation modes of the step-up PWM control-DC/DC converter. That is the continuous mode
and discontinuous mode by the continuousness inductor.
When the transistor turns ON, the voltage of inductor L becomes equal to VIN voltage. The increase value of
inductor current (i1) will be
i1 = VIN ton / L ........................................................................................................... Formula 1
As the step-up circuit, during the OFF time (when the transistor turns OFF) the voltage is continually supply
from the power supply. The decrease value of inductor current (i2) will be
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NO.EA-272-201211
∆i2 = (VOUT − VIN) topen / L .......................................................................................... Formula 2
At the PWM control-method, the inductor current become continuously when topen=toff, the DC/DC converter
operate as the continuous mode.
In the continuous mode, the variation of current of i1 and i2 is same at regular condition.
VIN ton / L = (VOUT - VIN) toff / L .................................................................................. Formula 3
The duty at continuous mode will be
duty (%)= ton / (ton + toff) = (VOUT - VIN) / VOUT ................................................................ Formula 4
The average of inductor current at tf = toff will be
IL(Ave.) = VIN ton / (2 L) ........................................................................................... Formula 5
If the input voltage = output voltage, the IOUT will be
IOUT = VIN2 ton / (2 L VOUT) ...................................................................................... Formula 6
If the IOUT value is large than above the calculated value (Formula 6), it will become the continuous mode, at
this status, the peak current (ILmax) of inductor will be
ILmax = IOUT VOUT / VIN + VIN ton / (2 L) ................................................................... Formula 7
ILmax = IOUT VOUT / VIN + VIN T (VOUT - VIN) / (2 L VOUT) ..................................... Formula 8
The peak current value is larger than the IOUT value. In case of this, selecting the condition of the input and the
output and the external components by considering of ILmax value.
The explanation above is based on the ideal calculation, and the loss caused by LX switch and the external
components are not included.
The actual maximum output current will be between 50% and 80% by the above calculations. Especially, when
the IL is large or VIN is low, the loss of VIN is generated with on resistance of the switch. Moreover, it is necessary
to consider Vf of the diode (approximately 0.8V) about VOUT.
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Soft-Start (R1205x8xxA)
The output and referrence of the error amplifier start from 0V and the referrence gradually rises up to 1.0V.
After the softstart time (TSS), output voltage rise up to the setting voltage.
The output of the error amplifier starts from 0V and the inrush current is suppressed when starting by the CE
pin "H" input. Moreover, the inrush current can be suppressed by gradually enlarging Duty of the PWM signal
to the CE pin.
Current Limit Function
Current limit function monitors the over current and if it reaches the peak current, it will turn off the driver. When
the over current decreases, it will restart oscillation and will restart the monitoring.
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R1205x
NO.EA-272-201211
APPLICATION INFORMATION
Typical Applications
R1205x8xxA
R1205x8xxB/C
L1
10H
L1
10H
C1
1F
C1
1F
VIN
LX
CE
VOUT
R2
GND
VFB
C3
R3
C2
1F
VIN
LX
CE
VOUT
VFB
GND
R1
C2
0.22F
R1
Inductor Selection
The peak current of the inductor at normal mode can be estimated as the next formula when the efficiency is
80%.
ILmax = 1.25 × IOUT × VOUT / VIN + 0.5 × VIN × (VOUT − VIN) / (L × VOUT × fosc)
In the case of start-up or dimming control by CE pin, inductor transient current flows, and the peak current of
it must be equal or less than the current limit of the IC. The peak current should not beyond the rated current
of the inductor.
The recommended inductance value is 10H - 22H.
Table 1 Peak current value in each condition
VIN (V)
3
3
3
3
Condition
VOUT (V) IOUT (mA)
14
20
14
20
21
20
21
20
L (H)
10
22
10
22
ILmax (mA)
215
160
280
225
Table 2 Recommended inductors
L
(H)
10
10
10
10
22
22
22
10
Part No.
LQH32CN100K53
LQH2MC100K02
VLF3010A-100
VLS252010-100
LQH32CN220K53
LQH2MC220K02
VLF3010A-220
Rated
Current (mA)
450
225
490
520
250
185
330
Size
(mm)
3.2x2.5x1.55
2.0x1.6x0.9
2.8x2.6x0.9
2.5x2.0x1.0
3.2x2.5x1.55
2.0x1.6x0.9
2.8x2.6x0.9
R1205x
NO.EA-272-201211
Capacitor Selection
Set 1F or more value bypass capacitor C1 between VIN pin and GND pin as close as possible.
R1205xxxxA
Set 1F – 4.7F or more capacitor C2 between VOUT and GND pin.
Table 3-A Recommended components for R1205xxxxA
C1
C2
C3
R1
R2
R3
Rated voltage(V)
Part No.
6.3
25
25
CM105B105K06
GRM21BR11E105K
22pF
For VOUT Setting
For VOUT Setting
2kΩ
If the transient drop of output voltage by the load fluctuation is large and exceeds the allowable range in above
setting, refer to Table 3-B to change the capacitors of C2 and C3 for the response improvement and the
transient voltage drop reduction.
Table 3-B Recommended components for R1205xxxxA
C1
C2
C3
R1
R2
R3
Rated voltage(V)
Part No.
6.3
50
25
CM105B105K06
GRM31CR71H475M
220pF
For VOUT Setting
For VOUT Setting
2kΩ
R1205xxxxB/C
Set 0.22F or more capacitor C2 between VOUT and GND pin. (R1205x8xxB)
Set 0.47F or more capacitor C2 between VOUT and GND pin. (R1205x8xxC)
Note the VOUT that depends on LED used, and select the rating of VOUT or more.
Table 4 Recommended components for R1205xxxxB/C
Rated voltage(V)
Part No.
C1
6.3
25
CM105B105K06
GRM21BR11E224
C2
25
C2012X7R1E474K
50
GRM21BR71H224
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R1205x
NO.EA-272-201211
External Components Setting
If the VOUT spike noise is high, it may influence on the VFB pin to cause the operation of R1205x8xxA unstable.
To reduce the noise coming into VFB pin, please place a 1kΩ to 5kΩ resistor in R3 in Fig. 1.
Application of Using 5.5V or more Power Supply
Other than the IC power supply, if there is a power supply greater than 5.5V, the high power output can be
achieved by using the power supply as an inductor power supply. In this case, please place a capacitor
between an inductor power supply and GND (shown in Fig. 2) aside from a bypass capacitor between the VIN
pin and GND of the IC.
V2=12V
V2=12V
L1
L1
C4
V1=3.3V
C4
V1=3.3V
VIN
LX
CE
VOUT
C1
C1
R2
GND
C3
R3
VIN
LX
CE
VOUT
C2
C2
VFB
GND
VFB
R1
Fig. 1 R1205x8xxA
R1
Fig .2 R1205x8xxB/C
The Method of Output Voltage Setting (R1205x8xxA)
The output voltage (VOUT) can be calculated with divider resistors (R1 and R2) values as the following formula:
Output Voltage (VOUT)= VFB × (R1 R2) / R1
The total value of R1 and R2 should be equal or less than 300k. Make the VIN and GND line sufficient. The
large current flows through the VIN and GND line due to the switching. If this impedance (VIN and GND line) is
high, the internal voltage of the IC may shift by the switching current, and the operating may become unstable.
Moreover, when the built-in LX switch is turn OFF, the spike noise caused by the inductor may be generated.
LED Current setting (R1205x8xxB/C)
When CE pin input is "H" (Duty=100%), LED current can be set with feedback resistor (R1)
ILED = VFB / R1
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LED Dimming Control (R1205x8xxB/C)
The LED brightness can be controlled by inputting the PWM signal to the CE pin. If the CE pin input is "L" in
the fixed time (Typ.0.5ms), the IC becomes the standby mode and turns OFF LEDs.
The current of LEDs can be controlled by Duty of the PWM signal of the input CE pin. The current of LEDs
when High-Duty of the CE input is ”Hduty” reaches the value as calculatable following formula.
ILED = Hduty × VFB / R1
The frequency of the PWM signal is using the range between 200Hz to 300kHz.
When controlling the LED brightness by the PWM signal of 5kHz or less, R1205x8xxB/C are recomended to
avoide discharge function during dimming control.
When controlling the LED brightness by the PWM signal of 20kHz or less, the increasing or decreasing of the
inductor current might be make a sounds in the hearable sound wave area. In that case, please use the PWM
signal in the high frequency area.
CE
Hduty
VFB
R1
Dimming Control by CE Pin Input
ILED accuracy (R1205x8xxB / R1205x8xxC)
LED current (ILED) is affected by the offset voltage of the error amplifier in the DC/DC converter.
LED might turn off due to the offset voltage variation, when brightness is controlled by low PWM duty cycle.
In case of R1205x8xxB, it is recommended to input PWM signal that has 18.5% or more duty.
In case of lower duty cycle than 18.5%, it is recommended to use R1205x8xxC.
The table below shows the ILED accuracy of R1205x8xxC at low PWM duty cycle input (low brightness).
ILED accuracy when low PWM Duty is applied (R1 = 20 Ω)
PWM Duty applied to CE Pin
ILED Min.
R1205x8xxC
(1)
3.5% (Frequency = 20kHz to 300kHz)
(1)
0.01mA
ILED Max.
2.1mA(1)
Design guaranteed value (Ta = 25 ºC)
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TECHNICAL NOTES
Current Path on PCB
The current paths in an application circuit are shown in Fig. 3 and 4.
A current flows through the paths shown in Fig. 3 at the time of MOSFET-ON, and shown in Fig. 4 at the
time of MOSFET-OFF. In the paths pointed with red arrows in Fig. 4, current flows just in MOSFET-ON
period or just in MOSFET-OFF period. Parasitic impedance / inductance and the capacitance of these paths
influence stability of the system and cause noise outbreak. So please minimize this side effect. In addition,
please shorten the wiring of other current paths shown in Fig. 3 and 4 except for the paths of LED load.
Layout Guide for PCB
Please shorten the wiring of the input capacitor (C1) between VIN pin and GND pin of IC. The GND pin should
be connected to the strong GND plane.
The area of LX land pattern should be smaller.
Please put output capacitor (C2) close to the VOUT pin.
Please make the GND side of output capacitor (C2) close to the GND pin of IC.
14
MOSFET-ON
Load
Load
Fig. 3
Fig. 4
MOSFET-OFF
R1205x
NO.EA-272-201211
PCB Layout
PKG: DFN1616-6B pin
R1205LxxxA/xxxB/xxxC Typical Board Layout
Top Layer
Back Layer
・PKG:TSOT-23-6pin
R1205NxxxA/xxxB/xxxCTypical Board Layout
Top Layer
Back Layer
U1-● indicates the position of No.1 pin.
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TYIPICAL CHARACTERISTICS
1）Efficiency vs. Output Current Characteristics (R1205N823A)
VOUT=10V, L=22H (LQH32CN220K53)
90
90
85
85
80
80
Efficiency (%)
Efficiency (%)
VOUT=10V, L=10H (LQH32CN100K53)
75
70
65
Vin=3V
60
Vin=5V
5
10
15
65
Vin=3V
Vin=3.6V
Vin=4.2V
Vin=5V
55
50
50
0
70
60
Vin=3.6V
Vin=4.2V
55
75
0
20
5
Output Current (mA)
VOUT=15V, L=10H (LQH32CN100K53)
85
80
80
Efficiency (%)
85
Efficiency (%)
90
70
65
Vin=3V
60
Vin=3.6V
Vin=4.2V
55
Vin=5V
70
65
Vin=3V
Vin=3.6V
Vin=4.2V
Vin=5V
55
50
0
5
10
15
0
20
5
10
15
20
Output Current (mA)
Output Current (mA)
VOUT=20V, L=10H (LQH32CN100K53)
VOUT=20V, L=22H (LQH32CN220K53)
90
90
85
85
80
80
Efficiency (%)
Efficiency (%)
20
75
60
50
75
70
65
Vin=3V
Vin=3.6V
60
75
70
65
Vin=3V
60
Vin=4.2V
Vin=5V
55
Vin=3.6V
Vin=4.2V
55
Vin=5V
50
50
0
5
10
Output Current (mA)
16
15
VOUT=15V, L=22H (LQH32CN220K53)
90
75
10
Output Current (mA)
15
20
0
5
10
Output Current (mA)
15
20
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VOUT=20V, VIN=3.6V
85
80
Efficiency (%)
75
70
65
60
LQH32CN100k53L (3.2×2.5×1.55)
VLF3010AT-100MR33 (2.8×2.6×0.9)
55
LQH2MCN100K02 (2.0×1.6×0.9)
50
0
5
10
15
20
Output Current (mA)
Typical Applications with Using 5.5V or Greater
VOUT=20V, L=10H (LQH32CN100K53)
95
95
90
90
85
85
80
80
Efficiency (%)
Efficiency (%)
VOUT=15V, L=10H (LQH32CN100K53)
75
70
65
Vin(L)=7.2V
60
70
65
Vin(L)=7.2V
60
Vin(L)=9V
55
75
Vin(L)=9V
55
Vin(L)=12V
Vin(L)=12V
50
50
0
5
10
15
0
20
5
10
15
20
Output Current (mA)
Output Current (mA)
2）Efficiency vs. Output Current Characteristics (R1205N823B/C)
4LED, L=10H (LQH32CN100K53)
4LED, L=22H (LQH32CN220K53)
90
85
85
80
80
Efficiency (%)
Efficiency (%)
90
75
75
70
70
65
65
Vin=3V
Vin=3.6V
Vin=4.2V
Vin=5V
60
55
Vin=3V
Vin=3.6V
Vin=4.2V
Vin=5V
60
55
50
50
0
5
10
15
Output Current ILED (mA)
20
0
5
10
15
20
Output Current ILED (mA)
17
R1205x
NO.EA-272-201211
5LED, L=22H (LQH32CN220K53)
90
90
85
85
80
80
Efficiency (%)
Efficiency (%)
5LED, L=10H (LQH32CN100K53)
75
75
70
70
65
65
Vin=3V
Vin=3.6V
Vin=4.2V
Vin=5V
60
55
Vin=3V
Vin=3.6V
Vin=4.2V
Vin=5V
60
55
50
50
0
5
10
15
0
20
Output Current ILED (mA)
10
15
20
Output Current ILED (mA)
6LED, L=10H (LQH32CN100K53)
6LED, L=22H (LQH32CN220K53)
90
85
85
80
80
Efficiency (%)
Efficiency (%)
90
75
75
70
70
65
65
Vin=3V
Vin=3.6V
Vin=4.2V
Vin=5V
60
55
Vin=3V
Vin=3.6V
Vin=4.2V
Vin=5V
60
55
50
50
0
5
10
15
20
Output Current ILED (mA)
85
80
Efficiency (%)
75
70
65
60
LQH32CN100k53L (3.2×2.5×1.55)
VLF3010AT-100MR33 (2.8×2.6×0.9)
LQH2MCN100K02 (2.0×1.6×0.9)
55
50
0
5
10
0
5
10
15
Output Current ILED (mA)
6LED, VIN=3.6V
15
Output Current ILED (mA)
18
5
20
20
R1205x
NO.EA-272-201211
Typical Applications with Using 5.5V or Greater
6LED, VIN(IC)=3.6V
95
95
90
90
85
85
80
80
Efficiency (%)
Efficiency (%)
5LED, VIN(IC)=3.6V
75
70
65
Vin(L)=7.2V
Vin(L)=9V
60
55
75
70
65
Vin(L)=7.2V
Vin(L)=9V
60
55
Vin(L)=12V
Vin(L)=12V
50
50
0
5
10
15
0
20
5
10
15
20
Output Current ILED (mA)
Output Current ILED (mA)
3）Output Voltage vs. Output Current (R1205N823A)
VOUT=10V, L=10H (LQH32CN100K53)
VOUT=10V, L=22H (LQH32CN220K53)
10.4
Vin=3V
Vin=3.6V
Vin=4.2V
Vin=5V
10.3
Output Voltage (V)
10.3
Output Voltage (V)
10.4
Vin=3V
Vin=3.6V
Vin=4.2V
Vin=5V
10.2
10.1
10
10.2
10.1
10
9.9
9.9
9.8
9.8
0
50
100
150
0
200
50
VOUT=15V, L=10H (LQH32CN100K53)
150
200
VOUT=15V, L=22H (LQH32CN220K53)
16
16
Vin=3V
Vin=3.6V
Vin=4.2V
Vin=5V
15.4
Vin=3V
Vin=3.6V
Vin=4.2V
Vin=5V
15.7
Output Voltage (V)
15.7
Output Voltage (V)
100
Output Current (mA)
Output Current (mA)
15.1
14.8
14.5
15.4
15.1
14.8
14.5
14.2
14.2
0
35
70
Output Current (mA)
105
140
0
30
60
90
120
Output Current (mA)
19
R1205x
NO.EA-272-201211
VOUT=20V, L=10H (LQH32CN100K53)
VOUT=20V, L=22H (LQH32CN220K53)
21.4
21
Vin=3V
Vin=3.6V
20.6
Vin=4.2V
Vin=5V
Vin=3V
Vin=3.6V
Vin=4.2V
21
Output Voltage (V)
Output Voltage (V)
21.4
20.2
19.8
19.4
Vin=5V
20.6
20.2
19.8
19.4
19
19
0
20
40
60
80
100
0
20
40
Output Current (mA)
60
80
100
Output Current (mA)
VOUT=20V, VIN=3.6V
21
20.8
Output Voltage (V)
20.6
20.4
20.2
20
19.8
19.6
LQH32CN100k53L (3.2×2.5×1.55)
19.4
VLF3010AT-100MR33 (2.8×2.6×0.9)
19.2
LQH2MCN100K02 (2.0×1.6×0.9)
19
0
10
20
30
40
50
Output Current (mA)
Typical Applications with Using 5.5V or Greater
16
21
15.8
20.8
15.6
20.6
15.4
15.2
15
14.8
Vin(L)=7.2V
14.6
Vin(L)=9V
14.4
Vin(L)=12V
0
50
100
150
200
Output Current (mA)
250
20.4
20.2
20
19.8
Vin(L)=7.2V
19.6
Vin(L)=9V
19.4
Vin(L)=12V
19.2
14.2
20
VOUT=20V, L=10H (LQH32CN100K53)
Output Voltage (V)
Output Voltage (V)
VOUT=15V, L=10H (LQH32CN100K53)
300
0
50
100
Output Current (mA)
150
200
R1205x
NO.EA-272-201211
4）Duty vs. ILED
5）OVP Output Waveform
R1205N823B/C
R1205N823B/C
25
27
26
Output Voltage (V)
ILED (mA)
20
15
10
200Hz
10kHz
5
300kHz
20
40
60
80
24
23
22
0
0
25
100
21
-50
Duty (%)
-30
-10
10
Time (ms)
30
50
6）Waveform (6LED)
R1205N823B/C (CE Freq=200Hz)
55
CE
40
10
10
5
-5
0
-20
ILED (mA)
25
-5
-35
-5
0
Time (ms)
5
10
R1205N823B/C(CE Freq=300KHz)
25
Output Voltage (V)
CE Voltage (V)
10
10
5
-5
0
-20
-5
-500
25
10
10
5
-5
0
-20
-5
-35
0
Time [us]
0.5
1
ILED (mA)
15
-0.5
0
Time (us)
250
500
0.95
40
-1
-35
-250
7）Diode Forward Voltage vs. Temperature
ILED
20
40
25
Diode Forward Voltage (V)
CE
ILED
15
55
VOUT
CE
20
15
-10
55
VOUT
20
Output Voltage (V)
CE Voltage (V)
25
ILED
Output Voltage (V)
CE Voltage (V)
VOUT
ILED (mA)
25
R1205N823B/C (CE Freq=10KHz)
0.90
0.85
0.80
0.75
0.70
0.65
0.60
0.55
0.50
-40
-15
10
35
60
85
Temparature Ta (°C)
21
R1205x
NO.EA-272-201211
8）Standby Current vs. Temperature
9）Supply Current vs. Temperature
1000
Supplay Current Iin[uA]
Standby Current(uA)
1.0
0.8
0.6
0.4
0.2
900
800
700
600
500
400
300
200
100
0
0.0
-40
-15
10
35
60
Temperature Ta(°C)
85
-40
-15
10
35
60
85
Temparature Ta (°C)
10）UVLO Output Voltage vs. Temperature
R1205x8xxA
R1205x8xxB/C
1.75
2.25
1.70
2.15
UVLO Voltage(V)
UVLO Voltage (V)
2.20
2.10
2.05
2.00
1.95
1.60
1.55
1.50
1.90
1.85
1.45
-40
-15
10
35
Temparature Ta (°C)
22
1.65
60
85
-40
-15
10
35
Temparature Ta (°C)
60
85
R1205x
NO.EA-272-201211
11）VFB Voltage vs. Temperature
R1205x8xxA
R1205x8xxB
1.050
0.210
0.208
0.206
VFB Voltage (V)
VFB Voltage (V)
1.030
1.010
0.990
0.204
0.202
0.200
0.198
0.196
0.194
0.970
0.192
0.190
0.950
-40
-15
10
35
60
Temparature Ta (°C)
-40
85
-15
10
35
60
85
Temparature Ta (°C)
R1205x8xxC
0.410
0.408
VFB Voltage (V)
0.406
0.404
0.402
0.400
0.398
0.396
0.394
0.392
0.390
-40
-15
10
35
60
Temperature Ta (°C)
85
13）OVP Voltage vs. Temperature
1.9
28
1.7
27
1.5
OVP Voltage (V)
Switch ON Resistance RON (Ω)
12）Switch ON Resistance RON vs. Temperature
1.3
1.1
0.9
26
OVP Detect
25
24
OVP Release
23
0.7
0.5
-40
-15
10
35
Temparature Ta (°C)
60
85
22
-40
-15
10
35
60
85
Temparature Ta (°C)
23
R1205x
NO.EA-272-201211
14）LX Current Limit vs. Temperature
R1205x81xx
R1205x82xx
500
900
Vin=2.8V
Vin=5.5V
400
Vin=2.8V
850
Vin=3.6V
Lx Limit Current (mA)
Lx Limit Current (mA)
450
350
300
250
Vin=3.6V
800
Vin=5.5V
750
700
650
600
550
200
500
-40
-15
10
35
60
85
-40
-15
Temparature Ta (°C)
15）Oscillator Frequency vs. Temperature
Vin=1.8V
98
1300
Vin=3.6V
96
Vin=5.5V
1250
1200
1150
1100
MXDUTY (%)
Frequency fosc (kHz)
1350
85
90
88
86
84
35
60
85
Vin=5.5V
92
1000
10
Vin=3.6V
94
1050
-15
Vin=1.8V
-40
Temparature Ta (°C)
200
180
160
Thermal Shutdown Detect
140
120
100
Thermal Shutdown Release
80
60
2
2.5
3
3.5
4
Vin (V)
4.5
-15
10
35
Temparature Ta (°C)
17）Thermal Shutdown Detect / Release Temperature vs. Input Voltage
Temparature ( ℃)
60
100
-40
24
35
16）Maxduty vs. Temperature
1400
1.5
10
Temparature Ta (°C)
5
5.5
6
60
85
R1205x
NO.EA-272-201211
18) Load Transient Response
VIN = 3.6 V, VOUT = 15 V
IOUT = 0 mA ⇔ 30 mA
L = 10 µH
Setting：Table 3-A
L = 22 µH
Setting：Table 3-A
L =10 µH
Setting：Table 3-B
25
R1205x
NO.EA-272-201211
L = 22 µH
26
Setting：Table 3-B
POWER DISSIPATION
DFN1616-6B
Ver. A
The power dissipation of the package is dependent on PCB material, layout, and environmental conditions.
The following conditions are used in this measurement.
Measurement Conditions
Item
Measurement Conditions (JEDEC STD. 51-7)
Environment
Mounting on Board (Wind Velocity = 0 m/s)
Board Material
Glass Cloth Epoxy Plastic (Four-Layer Board)
Board Dimensions
76.2 mm × 114.3 mm × 0.8 mm
Copper Ratio
1st Layer: Less than 95% of 50 mm Square
2nd, 3rd, 4th Layers: Approx. 100% of 50 mm Square
Through-holes
φ 0.2 mm × 15 pcs
Measurement Result
(Ta = 25°C, Tjmax = 125°C)
Item
Measurement Result
Power Dissipation
2400 mW
Thermal Resistance (θja)
θja = 41°C/W
Thermal Characterization Parameter (ψjt)
ψjt = 11°C/W
θja: Junction-to–ambient thermal resistance.
ψjt: Junction–to-top of package thermal characterization parameter.
2500
2400
Power Dissipation PD (mW)
2000
1500
1000
500
0
0
25
50
75 85
100
125
Ambient Temperature (°C)
Power Dissipation vs. Ambient Temperature
Measurement Board Pattern
i
PACKAGE DIMENSIONS
DFN1616-6B
Ver. A
1.30±0.05
(3X0.15)
B
0.70±0.05
X4
1.60
0.05
4
6
∗
0.25±0.05
1.60
A
INDEX
0.4max.
0.1±0.05
3
0.5
0.20±0.05
1
0.05 M AB
Bottom View
S
0.05 S
DFN1616-6B Package Dimensions (Unit: mm)
*
∗ The tab on the bottom of the package shown by blue circle is a substrate potential (GND). It is recommended that this
tab be connected to the ground plane pin on the board but it is possible to leave the tab floating.
i
POWER DISSIPATION
TSOT-23-6
Ver. A
The power dissipation of the package is dependent on PCB material, layout, and environmental conditions.
The following conditions are used in this measurement.
Measurement Conditions
Standard Test Land Pattern
Environment
Mounting on Board (Wind Velocity = 0 m/s)
Board Material
Glass Cloth Epoxy Plastic (Double-Sided Board)
Board Dimensions
40 mm × 40 mm × 1.6 mm
Top Side: Approx. 50%
Copper Ratio
Bottom Side: Approx. 50%
φ 0.5 mm × 44 pcs
Through-holes
Measurement Result
(Ta = 25°C, Tjmax = 125°C)
Standard Test Land Pattern
Power Dissipation
460 mW
θja = (125 − 25°C) / 0.46 W = 217°C/W
Thermal Resistance
θjc = 40°C/W
Power Dissipation PD (mW)
600
500
460
Standard Test Land Pattern
400
300
200
100
0
0
25
50
75 85 100
125
Ambient Temperature (°C)
Power Dissipation vs. Ambient Temperature
150
IC Mount Area (mm)
Measurement Board Pattern
i
PACKAGE DIMENSIONS
TSOT-23-6
+0.100
0.125-0.025
2.9±0.2
5
4
2
3
+0.10
0.4-0.05
0.85±0.10
0.95
S
0.12 M
0 ∼ 0.1
1
2.8±0.2
+0.2
1.6-0.1
6
0.4±0.2
Ver. A
0.10 S
TSOT-23-6 Package Dimensions (Unit: mm)
0∼15°
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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consent of Ricoh.
3. Please be sure to take any necessary formalities under relevant laws or regulations before exporting or otherwise
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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.
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8. The X-ray exposure can influence functions and characteristics of the products. Confirm the product functions and
characteristics in the evaluation stage.
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characteristics of the products under operation or storage.
10. There can be variation in the marking when different AOI (Automated Optical Inspection) equipment is used. In the
case of recognizing the marking characteristic with AOI, please contact Ricoh sales or our distributor before attempting
to use AOI.
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the technical information.
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Ricoh has been providing RoHS compliant products since April 1, 2006 and Halogen-free products since
April 1, 2012.
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