R1245x Series
1.2
A, 30 V Step-D own DC/DC Converter
No. EA-269-170720
1
OUTLINE
The R1245x is a CMOS-based Step-down DC/DC converter with internal N-channel high side Tr. The ON
resistance of the built-in high-side transistor is 0.35 Ω and the R1245x can provide the maximum 1.2 A output
current. Each of the ICs consists of an oscillator, a PWM control circuit, a voltage reference unit, an error
amplifier, a phase compensation circuit, a slope compensation circuit, a soft-start circuit, protection circuits, an
internal voltage regulator, and a switch for bootstrap circuit. The ICs can make up a step-down DC/DC
converter with an inductor, resistors, a diode, and capacitors.
The R1245x is a current mode operating type DC/DC converter without an external current sense resistor, and
realizes fast response and high efficiency. As an output capacitor, a ceramic type capacitor can be used with
the R1245x. The options of the internal oscillator frequency are preset at 330 kHz for version A and B, 500
kHz for version C and D, 1000 kHz for version E and F, 2400 kHz for version G and H.
As for protection, an Lx peak current limit circuit cycle by cycle, a thermal shutdown function and an under
voltage lockout (UVLO) function are built in. Furthermore, there are two types for short protection, for A/C/E/G
version, a latch protection function which makes the output latch off if the output voltage keeps lower than the
set output voltage for a certain time after detecting current limit is built in, for B/D/F/H version, a fold-back
protection function which changes the oscillator frequency slower after detecting short circuit or equivalent.
As for the packages of the R1245x, HSOP-8E, DFN(PLP)2020-8, SOT23-6W are available.
FEATURES
• Operating Voltage ·········································· 4.5 V to 30 V
• Internal N-channel MOSFET Driver ······················ Typ. RON = 0.35 Ω
• Adjustable Output Voltage with External Resistor ···· 0.8 V or more
• Feedback Voltage and Tolerance ························· 0.8 V±1.0%
• Peak Current Limit ············································ Typ. 2.0 A
• UVLO Function Released Voltage ························ Typ. 4.0 V
• Operating Frequency ········································ 330 kHz (Ver. A/B), 500 kHz (Ver. C/D),
1000 kHz (Ver. E/F), 2400 kHz (Ver. G/H)
• Fold-back Protected Frequency ··························· 170 kHz (Ver. B/D), 250 kHz (Ver. F), 400 kHz (Ver. H)
• Latch Protection Delay Time ······························· Typ. 4 ms (Ver. A/C/E/G)
• Ceramic Capacitors Recommended for Input and Output.
• Stand-by Current ·············································· Typ. 0 µA
• Packages ······················································· SOT-23-6W, DFN(PLP)2020-8, HSOP-8E
R1245x
No. EA-269-170720
2
APPLICATIONS
• Digital Home Appliances: Digital TVs, DVD Players
• Office Equipment: Printers, Faxes
• 5V PSU or 2-cell or more Li-ion Battery Powered Communication Equipment, Cameras, VCRs, Camcorders
• High Voltage Battery-powered Equipment
SELECTIO N G UIDE
In the R1245x, the package, type of short protection (Latch or Fold-back), and the oscillator frequency can be
selected with the user’s request.
Selection Guide
Product code
Package
Quantity per Reel
Pb Free
Halogen Free
R1245S003∗-E2-FE
HSOP-8E
1,000 pcs
Ye s
Ye s
R1245K003
∗
-TR
DFN(PLP)2020-8 5,000 pcs Yes Yes
R1245N001
∗
-TR-FE
SOT-23-6W 3,000 pcs Yes Yes
∗: Designation of the oscillator frequency and the protection function option.
Symbol
Oscillator
Frequency
Latch
Protection
Fold-back
Protection
A
330 kHz
B
330 kHz
C
500 kHz
D
500 kHz
E 1000 kHz
F
1000 kHz
G
2400 kHz
H 2400 kHz
R1245x
No. EA-269-170720
3
BLOCK DI AGR AM
FB
CE
-
+
Oscillator
*1
BST
Regulator 5V
R
S D
SETPULSE
MAXDUTY
Current Slope
Circui
t
Reference
Soft Start
Circuit(1ms)
-
+
UVLO
0.8V
Regulator
Thermal Shutdown
Peak Current
Limit Circuit
Lx
VIN
GND
Limit Latch
Circuit (4ms)
Shutdown
*1
R1245x Block Diagram
*1
Version
Oscillator Frequency
Short Protection Type
A
330 kHz
330 kHz
B
330 kHz
330 kHz
C
500 kHz
500 kHz
D
500 kHz
500 kHz
E
1000 kHz
1000 kHz
F
1000 kHz
1000 kHz
G
2400 kHz
2400 kHz
H
2400 kHz
2400 kHz
R1245x
No. EA-269-170720
4
PIN DESCRIPTIONS
Top View Bottom View
8 7 6 5 5 6 7 8
1 2 3 4 4 3 2 1
DFN(PLP)2020-8 Pin Configuration
Top View Bottom View
8 7 6 5 5 6 7 8
1 2 3 4 4 3 2 1
Top View
6 5 4
1 2 3
HSOP-8E Pin Configuration
SOT-23-6W Pin Configuration
* Connect the backside heat radiation tub to GND or same as GND level (recommendation). The tub is
connected to the GND pin.
R1245x
No. EA-269-170720
5
R1245S Pin Description
Pin No. Symbol Description
1 Lx Lx Switching Pin
2 VIN Power Supply Pin
3 CE Chip Enable Pin, Active with ”H”
4 TEST TEST pin (must be open for user side.)
5 GND Ground Pin
6 FB Feedback Pin
7 NC No connection
8 BST Bootstrap Pin
* Connect the backside heat radiation tub to GND or same as GND level (recommendation). The tub is connected to the
GND pin.
R1245K Pin Description
Pin No. Symbol Description
1 Lx Lx Switching Pin
2 VIN Power Supply Pin
3 VIN Power Supply Pin
4 CE Chip Enable Pin, Active with ”H”
5 GND Ground Pin
6 FB Feedback Pin
7 TEST Test Pin (must be open for user side.)
8 BST Bootstrap Pin
* Connect the backside heat radiation tub to GND or same as GND level (recommendation). The tub is connected to the
GND pin.
R1245N Pin Description
Pin No. Symbol Description
1 BST Bootstrap Pin
2 GND Ground Pin
3 FB Feedback Pin
4 CE Chip Enable Pin, Active with ”H”
5 VIN Power Supply Pin
6 Lx Lx Switching Pin
R1245x
No. EA-269-170720
6
INTERNAL EQUIVALENT CIRCUIT FOR EACH PIN
<BST pin>
<Lx pin>
<FB pin>
<CE pin>
<TEST pin>
BST
L
X
Regulator
VIN
LX
Regulator
FB
VIN
CE
Regulator
TEST
R1245x
No. EA-269-170720
7
ABSOLUTE MAXMUM RATINGS
Absolute Maximum Ratings (GND = 0 V)
Symbol Item Rating Unit
VIN Input Voltage −0.3 V to 32 V V
VBST BST Pin Voltage VLX −0.3 V to VLX + 6 V V
VLX Lx Pin Voltage −0.3 V to VIN + 0.3 V
VCE CE Pin Input Voltage −0.3 V to VIN + 0.3 V
VFB Feedback Pin Voltage −0.3 V to 6 V V
PD Power
Dissipation*
HSOP-8E
Ultra High Wattage
Land Pattern
2900
mW
DFN(PLP)2020-8 Standard Land Pattern 880
SOT-23-6W Standard Land Pattern 430
Tj Junction Temperature Range −40 to 125 ºC
Tstg Storage Temperature Range −55 to 125 ºC
* Refer to POWER DISSIPATION for detailed information.
ABSOLUTE MAXIMUM RATINGS
Electronic and mechanical stress momentarily exceeded absolute maximum ratings may cause the permanent
damages and may degrade the lifetime and safety for both device and system using the device in the field.
The functional operation at or over these absolute maximum ratings is not assured.
RECOMMENDED OPERATING CONDITIONS
Recommended Operating Conditions
Symbol
Item
Rating
Unit
VIN Operating Input Voltage 4.5 to 30 V
Ta
Operating Temperature Range
−40 to 105
°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 when they are used over such conditions by momentary electronic noise or surge. And
the semiconductor devices may receive serious damage when they continue to operate over the recommended
operating conditions.
R1245x
No. EA-269-170720
8
ELECTRICAL CHARACTERISTICS
Electrical Characteristics (Unless otherwise noted, VIN = 12 V, Ta = 25ºC)
Symbol
Item
Conditions
Min.
Typ.
Max.
Unit
IIN Consumption Current VIN = 30 V, VFB = 1.0 V
0.5
1.0
mA
VUVLO1 UVLO Detect Voltage Specified VIN falling edge 3.6
V
UVLO2
−
0.2
V
UVLO2
−
0.1
V
VUVLO2 UVLO Released Voltage Specified rising edge
3.8
4.0
4.2
V
V
FB
VFB Voltage Tolerance
0.792
0.800
0.808
V
ΔVFB/ΔTa
VFB Voltage Temperature
Coefficient
−40ºC ≤ Ta ≤ 105ºC ±100
ppm/
ºC
fosc Oscillator Frequency
Ver. A/B
300
330
360
kHz
Ver. C/D
450
500
550
Ver. E/F
900
1000
1100
Ver. G/H
2200
2400
2600
fFLB Fold back Frequency VF B < 0.56 V
Ver. B/D
170
kHz
Ver. F
250
Ver. H
400
Maxduty
Oscillator Maximum
Duty Cycle
Ver. A/B/C/D
92
%
Ver. E/F
88
Ver. G/H
76
tstart
Soft-start Time
V
FB
= 0.72 V
1
ms
tDLY
Delay Time for Latch
Protection
Ver. A/C/E/G 4 ms
RLXH
Lx High Side Switch ON
Resistance
VBST − VLX = 4.5 V 0.35 Ω
ILXHOFF
Lx High Side Switch
Leakage Current
VIN = 30 V, VCE = 0 V 0 5 μA
ILIMLXH
Lx High Side Switch Limited
Current
VBST − VLX = 4.5 V 1.5 2.0 2.7 A
V
CEL
CE “L” Input Voltage
V
IN
= 30 V
0.3
V
V
CEH
CE “H” Input Voltage
V
IN
= 30 V
1.6
V
IFB VFB Input Current VIN = 30.0 V, VFB = 1.0 V −1.0 1.0 μA
ICEL CE “L” Input Current VIN = 30 V, VCE = 0 V −
1.0
1.0 μA
ICEH CE “H” Input Current VIN = 30 V, VCE = 30 V −1.0 1.0 μA
TTSD
Thermal Shutdown Detect
Temperature
Hysteresis 30ºC 160 ºC
Istandby
Standby Current
V
IN
= 30 V
0
5
μA
R1245x
No. EA-269-170720
9
OPERATING DESCRIPTIONS
OPERATION OF THE BUCK CONVERTER AND THE OUTPUT CURRENT
The DC/DC converter charges energy in the inductor when the switch turns on, and discharges the energy
from the inductor when the switch turns off and controls with less energy loss, so that a lower output voltage
than the input voltage is obtained. Refer to the following figures.
Basic Circuit
Current flowing through the Inductor
Step 1: The switch turns on and current IL (= i1) flows, and energy is charged into COUT. At this moment, IL
increases from ILmin (= 0) to reach ILmax in proportion to the on-time period (ton) of the switch.
Step 2: When the switch turns off, the diode turns on in order to maintain IL at ILmax, and current IL (= i2)
flows.
Step 3: IL (= i2) decreases gradually and reaches IL = ILmin = 0 after a time period of topen, and the diode
turns off. This case is called as discontinuous mode. If the output current becomes large, next switching cycle
starts before IL becomes 0 and the diode turns off. In this case, IL value increases from ILmin (> 0), and this
case is called continuous mode.
In the case of PWM control system, the output voltage is maintained by controlling the on-time period (ton),
with the oscillator frequency (fosc) being maintained constant.
Switch
L
Diode
VIN
i1
V
OUT
C
OUT
i2
GND
t=1/fosc
toff
topen
ILmin
ILmax
ton
IL
R1245x
No. EA-269-170720
10
APPLICATION INFORMATION
TYPICAL APPLICATION CIRCUIT
R1245x00xA/B Typical Application Circuit, 330 kHz, VOUT = 1.2 V, VIN = 24 V
R1245x00xC/D Typical Application Circuit, 500 kHz, VOUT = 3.3 V, VIN = 24 V
* TEST pin must be open.
R1245x
No. EA-269-170720
11
R1245x00xE/F Typical Application Circuit, 1000 kHz, VOUT = 3.3 V VIN = 12 V
R1245x00xG/H Typical Application Circuit, 2400 kHz, VOUT = 5. 0 V, VIN = 12 V
* TEST pin must be open.
R1245x
No. EA-269-170720
12
OUTPUT CURRENT AND SELECTION OF EXTERNAL COMPONENTS
The relation between the output current and external components is as follows:
When the switch of Lx turns on:
(Wherein, the peak to peak value of the ripple current is described as IRP, the ON resistance of the switch is
described as RONH, and the diode forward voltage as VF, and the DC resistance of the inductor is described as
RL, and on time of the switch is described as ton)
VIN = VOUT + (RONH + RL) × IOUT + L × IRP / ton ································································· Equation 1
When the switch turns off (the diode turns on) as toff:
L × IRP / toff = VF + VOUT + RL × IOUT ·············································································· Equation 2
Put Equation 2 to Equation 1 and solve for ON duty of the switch, ton / (toff + ton) = DON,
DON = (VOUT + VF + RL × IOUT) / (VIN + VF - RONH × IOUT) ······················································ Equation 3
Ripple Current is as follows:
IRP = (VIN − VOUT − RONH × IOUT − RL × IOUT) × DON / fosc / L ················································ Equation 4
wherein, peak current that flows through L, and the peak current ILmax is as follows:
ILmax = IOUT + IRP / 2 ································································································ Equation 5
As for the valley current ILmin,
ILmin = IOUT - IRP / 2 ·································································································· Equation 6
If ILmin < 0, the step-down DC/DC converter operation becomes current discontinuous mode.
Therefore the current condition of the current discontinuous mode, the next formula is true.
IOUT < IRP / 2 ············································································································ Equation 7
Consider ILmax and ILmin, conditions of input and output and select external components.
*The above explanation is based on the calculation in an ideal case in continuous mode.
R1245x
No. EA-269-170720
13
Ripple Current and Lx Current Limit
The ripple current of the inductor may change according to the various reasons. In the R1245x, as an Lx
current limit, Lx peak current limit is used. Therefore the upper limit of the inductor current is fixed.
The peak current limit is not the average current of the inductor (output current). If the ripple current is large,
peak current becomes also large. The characteristic is used for the fold-back current limit of version B/D/F/H.
In other words, the peak current limit is maintained and the switching frequency is reduced, as a result, the
average current of the inductor is reduced. To release this condition, at 170 kHz for version B/D, at 250 kHz
for version F, at 400 kHz for version H must not be beyond the peak current limit. In the fig.1, the sequence
of the Lx current limit function is described.
t
t
V
OUT
V
OUT
short
4msec
shutdown restart
(CE=0→"H")
short
open
open
FB<0.56V
V
OUT
I
OUT
V
OUT
I
OUT
FB<0.56V
Limit Latch
(R1245x00x
A/C/E/G)
Fold Back
(R1245x00x
B/D/F/H)
shutdown
4msec
Fig.1 LX Limit function sequence
Latch Protection Function for Version A/C/E/G
The latch function works after detecting current limit and if the output voltage becomes low for a certain time,
the output is latched off. Refer to the TECHNICAL NOTES.
Fold-back Protection Function for Version B/D/F/H
If FB voltage becomes lower than approximately 0.56 V, the fold-back protection function limits the oscillator
frequency to typically 170 kHz for version B/D, typically 250 kHz fir version F, typically 400 kHz for version
H. By reducing frequency, the ripple current increases. The R1245x has the peak current limit function,
therefore as in the equation 8, the Lx average current decreases by the increase of the ripple current.
IOUT = ILmax + IRP / 2………………………………………………………………………………………..Equation 8
If FB voltage becomes less than 0.56 V, the oscillator frequency is reduced. At heavy load, if the R1245x
becomes into the fold-back protection mode, the situation may not be released by increase the ripple current.
In terms of other notes on this protection function, refer to the TECHNICAL NOTES.
R1245x
No. EA-269-170720
14
MAXIMUM OUTPUT CURRENT
The output current of the R1245x is limit by the power dissipation PD of the package and the maximum
specification 1.2 A. The loss of the IC includes the switching loss, and it is difficult to estimate. To estimate
the maximum output, using the efficiency data is one method.
By using the efficiency data, the loss including the external components can be calculated with the equation,
(100 / efficiency (%) - 1) x (VOUT (V) x IOUT (A)). From this equation, by reducing the loss of external
components, the loss of the IC can be estimated. The main loss of the external components is composed
by the rectifier diode and DCR of the inductor. Supposed that the forward voltage of the diode is described
as VF, the loss of the diode can be described as follows:
(VIN (V) - RON (Ω) x IOUT (A) - VOUT (V) - VF (V))) / VIN (V) x VF (V) x IOUT (A)
The loss by the DCR of the inductor can be calculated by the formula DCR (Ω) x IOUT2 (A).
Thus,
The loss of the IC = (100 / efficiency (%) - 1) x (VOUT (V) x IOUT (A) - (VIN (V) - RON (Ω) x IOUT (A) - VOUT (V) -VF
(V)) / VIN (V) x VF (V) x IOUT (A) – DCR (Ω) x IOUT2 (A)
The efficiency of the R1245x at Ta = 25°C, VIN = 12 V, VOUT = 3.3 V, I OUT = 600 mA is approximately 89.5%
for version A/B (Oscillator frequency: 330 kHz). Supposed that the On resistance of the internal driver is
0.35 Ω, the DCR of the inductor is 65 mΩ, the VF of the rectifier diode is 0.3 V and applied to the formula
above,
The loss of the IC = (100% / 89.5% - 1) x (3.3 V x 0.6 A) - (12 V - 0.35 Ω x 0.6 A - 3.3 V - 0.3 V) / 12 V x 0.3
V x 0.6 A - 0.065 Ω x 0.62 A = 86 mW
The power dissipation PD of the package is specified at Ta = 25°C based on the Tjmax = 125°C. Thus the
thermal resistance of the package θja = (Tjmax (°C) - Ta(°C)) / PD (W), therefore the thermal resistance of
the each available package is as follows:
HSOP-8E: (125°C - 25°C) /2.9 W = 34.5°C/W
DFN(PLP)2020-8: (125°C - 25°C) / 0.88 W = 114°C/W
SOT-23-6W: (125°C - 25°C) / 0.43 W = 233°C/W
Due to the loss of the IC is 86mW for this example, therefore Tj increase of the each package is as follows:
HSOP-8E: 34.5°C/W x 86 mW = 2.96°C
DFN(PLP)2020-8: 114°C/W x 86 mW = 9.80°C
SOT-23-6W: 233°C/W x 86 mW = 20.0°C
For all the packages, even if the ambient temperature is at 105°C, Tj can be suppressed less than 125°C.
By the increase of the temperature, on resistance and switching loss increases, therefore, temperature
margin is not enough, measure the efficiency at the actual maximum temperature and recalculation is
necessary.
At the same condition, if the preset frequency is 2400 kHz, the efficiency will be down to approximately 81%.
The result of the loss calculation is 310 mW, therefore the Tj increase of each package is,
HSOP-8E: 34.5°C/W x 310 mW = 11°C
DFN(PLP)2020-8: 114°C/W x 310 mW = 35°C
SOT-23-6W: 233°C/W x 310 mW = 72°C
R1245x
No. EA-269-170720
15
HSOP-8E can be used at the ambient temperature 105°C, DFN(PLP)2020-8 can be used at the ambient
temperature up to 90°C, SOT-23-6W can be used at the ambient temperature up to 53°C. Note that the
result is different by the frequency.
The next graphs are the output current and estimated ambient temperature limit.
Maximum Output Current
VIN = 12 V, VOUT = 3.3 V, fosc = 330 kHz
Maximum Output Current
VIN = 12 V, VOUT = 3.3 V, fosc = 2400 kHz
0
200
400
600
800
1000
1200
1400
-50 0 50 100 150
Ta[°C]
IOUT[mA]
SOT-23-6W
DFN2020-8
HSOP-8E
-40°C
105°C
0
200
400
600
800
1000
1200
1400
-50 0 50 100 150
Ta[°C]
I
OUT
[mA]
SOT-23-6W
DFN2020-8
HSOP-8E
-40°C
105°C
R1245x
No. EA-269-170720
16
TECHNICAL NOTES
• External components must be connected as close as possible to the ICs and make wiring as short as
possible. Especially, the capacitor connected in between VIN pin and GND pin must be wiring the shortest.
If their impedance is high, internal voltage of the IC may shift by the switching current, and the operating
may be unstable. Make the power supply and GND lines sufficient. In the wiring of the power supply, GND,
LX, VOUT and the inductor, large current by switching may flow. To avoid the bad influence, the wiring
between the resistance, “RUP” for setting the output voltage and loading, and the wiring between the inductor
and loading must be separated.
• The ceramic capacitors have low ESR (Equivalent Series Resistance) and recommended for the ICs. The
recommendation of CIN capacitor between VIN and GND is 10 µF or more for A/B/C/D version, 4.7 µF or
more for E/F version, and 2.2 µF or more for G/H version. Verify the bias dependence and the
temperature characteristics of the ceramic capacitors. Recommendation conditions are written based on
the case which the recommendation parts are used with the R1245x.
• The R1245x is designed with the recommendation inductance value and ceramic capacitor value and
phase compensation has been made. If the inductance value is large, due to the lack of current sensing
amount of the current mode, unstable operation may result. On the contrary, if the inductance value is
small, the current sensing amount may increase too much, low frequency oscillation may occur when the
on duty ratio is beyond 50%. Not only that, if the inductance value is small, according to the increase of
the load current, the peak current of the switching may increase, as a result, the current may reach the
current limit value and the current limit may work.
• As for the diode, use the Schottky diode with small capacitance between terminals. The reference
characteristic of the capacitance between terminals is around 100 pF or less at 10 V. If the capacitance
between terminals is large, excess switching current may flow and the operation of the IC may be
unstable. If the capacitance between terminals of the Scottky diode is beyond 100 pF at 10 V or unknown,
verify the load regulation, line regulation, and the load transient response.
• Output voltage can be set by adjustment of the values of R1 and R2. The equation of setting the output
voltage is VOUT = VFB × (R1 + R2) / R2. If the values of R1 and R2 are large, the impedance of FB pin
increases, and pickup the noise may result. The recommendation value range of R2 is approximately
between 1.0 kΩ to 16 kΩ. If the operation may be unstable, reduce the impedance of FB pin.
• For the CE pin, as an ESD protection element, a diode to VIN pin is formed internal of the IC. If CE pin
voltage may become higher than VIN pin voltage, to prevent flowing large current from CE pin to VIN pin,
connect 10 kΩ or more resistor between CE and VIN pin.
• Connect the backside heat radiation tub of the DFN(PLP)2020-9/HSOP-8E to the GND. As for multi-layered
boards, to make better power dissipation, putting some thermal via on the thermal pad in the land pattern
and radiation of the heat to another layer is effective.
• After the soft-start operation, the latch function is enabled for version A/C/E/G. The latch protection starts
the internal counter when the internal current limit protection circuit detects the current limit. When the
internal counter counts up to the latch timer limit, typically 4 ms, the output is latched off. To reset the latch
function, make the CE pin “L”, or make VIN pin voltage lower than UVLO detector threshold. Then in the
case that the output voltage or FB voltage becomes setting voltage within the latch timer preset time,
counter is initialized. If the slew rate of the power supply is too slow and after the soft-start time, the output
voltage does not reach the set output voltage even if the latch timer preset time is over, the latch function
may work unexpectedly.
R1245x
No. EA-269-170720
17
• After the soft-start operation, fold-back protection function is enabled for version B/D/F/H. The fold-back
function will limit the oscillator frequency if the FB pin voltage becomes lower than typically 0.56 V. For B/D
version, the oscillator frequency will be reduced typically into 170 kHz, for F version, into 250 kHz, for H
version, into 400 kHz.
• If the slew rate of the power supply is too slow, and even after the soft-start time, the output voltage is still
less than 70% of the set output voltage, or FB pin voltage is less than typically 0.56 V, then this function
may work unexpectedly.
• The performance of power circuit using this IC largely depends on external components. Selection of
external components is very important, especially, do not exceed each rating value (voltage/current/power).
Table 1. Recommended Values for Each Output Voltage
R1245x00xA/B: 330 kHz
VOUT (V)
0.8 to 1.2
1.2 to 2.5
2.5 to 5.0
5.0 ≤
R1 (RUP) (kΩ) = (VOUT / 0.8 − 1) × R2
R2 (RBOT) (kΩ)
16
12
1.20
1.20
CSPD (pF)
open
470
2200
1000
COUT (µF)
47
47
22
22
L (µH)
4.7
10
15
33
R1245x00xC/D: 500 kHz
VOUT (V)
0.8 to 1.2
1.2 to 1.5
1.5 to 2.0
2.0 to 5.0
5.0 to 12.0
12.0 ≤
R1 (RUP) (kΩ) = (VOUT / 0.8 − 1) × R2
R2 (RBOT) (kΩ)
16
16
16
1.2
1.2
1.2
CSPD (pF)
open
100
100
1000
1000
470
COUT (µF)
100
100
22
22
22
22
L (µH)
4.7
4.7
10
10
15
15
R1245x00xE/F: 1000 kHz
VOUT (V)
0.8 to 1.0
1.0 to 1.2
1.2 to 1.5
1.5 to 2.5
2.5 to 5.0
5.0 ≤
R1 (RUP) (kΩ) = (VOUT / 0.8 − 1) × R2
R2 (RBOT) (kΩ)
16
16
16
16
1.2
1.2
CSPD (pF)
open
100
100
100
470
470
COUT (µF)
100
100
47
22
10
10
L (µH)
2.2
2.2
2.2
2.2
4.7
10
R1245x00xG/H: 2400 kHz
VOUT (V)
1.2 to 1.8
1.8 to 2.5
2.5 to 5.0
5.0 ≤
R1 (RUP) (kΩ) = (VOUT / 0.8 − 1) × R2
R2 (RBOT) (kΩ)
16
12
1.2
1.2
CSPD (pF)
100
100
470
470
COUT (µF)
10
10
4.7
4.7
L (µH)
1.0
1.5
2.2
4.7
R1245x
No. EA-269-170720
18
*1 Divider Resisters Values and Possible Setting Range of Input/ Output
VOUT
[V]
R1 (RUP)
[kΩ]
R2 (RBOT)
[kΩ]
Input Voltage Range [V]
Ver. A/B
Ver. C/D
Ver. E/F
Ver. G/H
0.8
0
open
4.5 to 20 4.5 to 13.5 4.5 to 7 -
0
16
1
4
16
4.5 to 25.5
4.5 to 17
4.5 to 8.5
-
1.2
8
16
4.5 to 30 4.5 to 20 4.5 to 10 -
6
12
1.5
10.5
12
4.5 to 30 4.5 to 25 4.5 to 12.5 4.5 to 5.5
14
16
1.8
20
16
4.5 to 30 4.5 to 30 4.5 to 15 4.5 to 6.5
15
12
2
24
16
4.5 to 30 4.5 to 30 4.5 to 17 4.5 to 7
1.8
1.2
2.5
34
16
4.5 to 30 4.5 to 30 4.5 to 21 4.5 to 9
25.5
12
2.55
1.2
3.3
3.75
1.2
4.5 to 30 4.5 to 30 4.5 to 27.5 4.5 to 12
5
6.3
1.2
5.5 to 30
5.5 to 30
6 to 30
7 to 18.5
6
7.8
1.2
6.5 to 30
6.5 to 30
7 to 30
8 to 20
9
12.3
1.2
10 to 30 10 to 30 11 to 30 12 to 30
12
16.8
1.2
13 to 30
13 to 30
14 to 30
16 to 30
15
21.3
1.2
16.5 to 30 16.5 to 30 17 to 30 20 to 30
24
34.8
1.2
26.5 to 30 26.5 to 30 27.5 to 30 30
R1245x
No. EA-269-170720
19
Table 2. Recommended External Components Ex ampl es (Considering All the Range)
Symbol
Condition
Value
Parts Name
MFR
CIN 50 V/ X5R
10
µ
F
UMK325BJ106MM-P TAIYO YUDEN
50 V/ X5R
10
µ
F
CGA6P3X7S1H106K TDK
50 V/ X7R
4.7
µ
F
GRM31CR71H475KA12L Murata
50 V/ X7R
2.2
µ
F
GRM31CR71H225KA88L Murata
C
OUT
50 V/ X5R
10
µ
F
UMK325BJ106MM-P
TAIYO YUDEN
50 V/ X5R
10 µF
CGA6P3X7S1H106K
TDK
50 V/ X7R
10
µ
F
KTS500B106M55N0T00 Nippon Chemi-Con
25 V/ X7R
10 µF
GRM31CR71E106K
Murata
10 V/ X7R
22
µ
F
GRM31CR71A226M
Murata
16 V/ B
47
µ
F
GRM32EB31C476KE15
Murata
10 V/ X7R
47
µ
F
GRM32ER71A476KE15 Murata
NOTE: The value of C
OUT
depends on
the setting output voltage.
C
BST
16 V/ X7R
0.47 µF
EMK212B7474KD-T
TAIYO YUDEN
L
1.8 A
10 µH
SLF6045T-100M1R6-3PF
TDK
1.65 A
4.7
µ
H
SLF7045T-4R7M2R0-PF TDK
1.7 A
4.7 µH
NR4018T-4R7M2R0-PF
TDK
2.4 A
4.7 µH
NR6020T4R7N
TAIYO YUDEN
1.9 A
10 µH
NR6028T100M
TAIYO YUDEN
2.3 A
15 µH
NR6045T150M
TAIYO YUDEN
1.9 A
22 µH
NR6045T220M
TAIYO YUDEN
1.9 A
33 µH
NR8040T330M
TAIYO YUDEN
1.7 A
2.2 µH
VLCF4020T-2R2N1R7
TDK
1.65 A
2.2 µH
NR4012T2R2M
TAIYO YUDEN
1.8 A
1.5 µH
NR3015T1R5N
TAIYO YUDEN
1.8 A
1.0 µH
NR4010T1R0N
TAIYO YUDEN
D
30 V/ 2.0 A
0.37 V
CMS06
TOSHIBA
40 V/ 2.0 A
0.55 V
CMS11
TOSHIBA
R
CE
An up diode is formed between the CE pin and the VIN pin as an ESD protection element.
If the CE pin may become higher than the voltage of the VIN pin, connect the 10 kΩ resistance
between the CE pin and VIN pin, to prevent a large current from flowing into the VIN pin from
the CE pin.
R1245x
No. EA-269-170720
20
THE NOTE OF LAYOUT PATTERN
1. The wire of Power line (VIN, GND) should be broad to minimize the parasitic inductance. The Bypass
capacitor (CIN) must be connected as close as possible in between VIN – GND.
2. The wire between Lx pin and the inductor as short as possible to minimize the parasitic inductance.
This evaluation board is designed for the product evaluation board. Therefore large inductors or
diodes can be set and the large space of Lx area has been secured. The evaluation board,
R1245K003x (2400 kHz) with the reduced mounting area including external components, is available
due to the small package of R1245K003G/H and the low recommended constant numbers including
inductors.
3. The ripple current flows through the output capacitor. If the GND side of the output capacitor is
connected very close to GND pin of the IC, the noise might have a bad impact on the IC. Therefore,
the GND side of the output capacitor is better to connect to the outside of the GND of the CIN, or
connect to the GND plain layer.
4. Rup, Rbot, Cspd, and Rspd should be mounted on the position as close as possible to the FB pin,
and away from the inductor and BST pin.
5. The feed-back must be made as close as possible from the Output capacitor (COUT).
R1245x
No. EA-269-170720
21
PCB LAYOUT
R1245N001x
TOP VIEW
BOTTOM VIEW
R1245S003x
TOP VIEW
BOTTOM VIEW
R1245x
No. EA-269-170720
22
R1245K003x
TOP VIEW
BOTTOM VIEW
R1245K003x (2400 kHz)
TOP VIEW
BOTTOM VIEW
R1245x
No. EA-269-170720
23
TYPICAL CH ARACTE RISTICS
Note: Typical Characteristics are intended to be used as reference data; they are not guaranteed.
1) FB voltage vs. Temperature 2) Driver On resistance vs. Temperature
3) Oscillator frequency vs. Temperature
R1245x00xx
(VIN=12V)
0.792
0.794
0.796
0.798
0.8
0.802
0.804
0.806
0.808
-50 -25 0 25 50 75 100 125
Ta (℃)
FB Voltage (V)
R1245x00xx
(VIN=12V)
200
250
300
350
400
450
500
-50 -25 0 25 50 75 100 125
T
a
(℃)
Driver On Resistance
(ｍΩ)
R1245x00xA/R1245x00xB
(VIN=12V)
300
310
320
330
340
350
360
-50 -25 0 25 50 75 100 125
Ta (℃)
Frequency (kHz)
R1245x00xC/R1245x00xD
(VIN=12V)
450
475
500
525
550
-50 -25 0 25 50 75 100 125
Ta (℃)
Frequency (kHz)
R1245x00xE/R1245x00xF
(VIN=12V)
900
950
1000
1050
1100
-50 -25 0 25 50 75 100 125
Ta (℃)
Frequency (kHz)
R1245x00xG/R1245x00xH
(VIN=12V)
2160
2240
2320
2400
2480
2560
2640
-50 -25 0 25 50 75 100 125
Ta (℃)
Frequency (kHz)
R1245x
No. EA-269-170720
24
4) Maximum duty cycle vs. Temperature
5) Fold back frequency vs. Temperature
R1245x00xA/R1245x00xB
(VIN=12V)
92
93
94
95
96
97
98
99
-50 -25 0 25 50 75 100 125
Ta (℃)
Maxduty (%)
R1245x00xC/R1245x00xD
(VIN=12V)
92
93
94
95
96
97
98
99
-50 -25 0 25 50 75 100 125
Ta (℃)
Maxduty (%)
R1245x00xE/R1245x00xF
(VIN=12V)
89
90
91
92
93
94
95
96
-50 -25 0 25 50 75 100 125
Ta (℃)
Maxduty (%)
R1245x00xG/R1245x00xH
(VIN=12V)
79
80
81
82
83
84
85
86
-50 -25 0 25 50 75 100 125
Ta (℃)
Maxduty (%)
R1245x00xB
(VIN=12V)
80
100
120
140
160
180
200
220
240
-50 -25 0 25 50 75 100 125
Ta (℃)
Fold back Frequency
(kHz)
R1245x00xD
(VIN=12V)
80
100
120
140
160
180
200
220
240
-50 -25 0 25 50 75 100 125
Ta (℃)
Fold back Frequency
(kHz)
R1245x
No. EA-269-170720
25
6) High si de switch current limit vs. Temperature
7) UVLO detector threshold vs. Temperature 8) UVLO released voltage vs. Temperature
R1245x00xF
(VIN=12V)
120
170
220
270
320
370
420
-50 -25 0 25 50 75 100 125
Ta (℃)
Fold back Frequency
(kHz)
R1245x00xH
(VIN=12V)
120
220
320
420
520
620
720
-50 -25 0 25 50 75 100 125
Ta (℃)
Fold back Frequency
(kHz)
R1245x00xx
(VIN=12V)
1.5
1.7
1.9
2.1
2.3
2.5
2.7
-50 -25 0 25 50 75 100 125
Ta (℃)
LX Current Limit (A)
R1245x00xx
3.6
3.7
3.8
3.9
4
4.1
-50 -25 0 25 50 75 100 125
Ta (℃)
UVLO
Detector Threshold (V)
R1245x00xx
3.8
3.9
4
4.1
4.2
-50 -25 0 25 50 75 100 125
Ta (℃)
UVLO
Released Voltage (V)
R1245x
No. EA-269-170720
26
9) Soft-start time vs. Temperature 10) Timer latch delay vs. Temperature
11) CE “H” Input voltage vs. Temperature 12) CE “L” Input voltage vs. Temperature
13) Soft-start waveform
R1245x00xA/R1245x00xB
VOUT=3.3V , VIN=12V , IOUT=0mA , Ta=25
°
C
R1245x00xA/R1245x00xB
VOUT=3.3V , VIN=12V , IOUT=600mA , Ta=25
°
C
R1245x00xx
(VIN=12V)
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
-50 -25 0 25 50 75 100 125
T
a
(℃)
Soft Start Time (ms)
R1245x00xx
(VIN=6V)
1
2
3
4
5
6
-50 -25 0 25 50 75 100 125
Ta (℃)
Delay Time For Latch
Protection (ms)
R1245x00xx
(VIN=12V)
0.5
1
1.5
2
2.5
-50 -25 0 25 50 75 100 125
Ta (℃)
CE "H" Voltage (V)
R1245x00xx
(V
IN
=12V)
0.5
1
1.5
2
2.5
-50 -25 0 25 50 75 100 125
T
a
(℃)
CE "L" Voltage (V)
V
CE
(5V/div)
I
LX
(200mA/div)
V
OUT
(1V/div)
V
LX
(10V/div)
V
CE
(5V/div)
I
LX
(200mA/div)
V
OUT
(1V/div)
V
LX
(10V/div)
V
CE
(5V/div)
I
LX
(200mA/div)
V
OUT
(1V/div)
V
LX
(10V/div) 200µs/div
V
CE
(5V/div)
I
LX
(200mA/div)
V
OUT
(1V/div)
V
LX
(10V/div)
V
CE
(5V/div)
I
LX
(200mA/div)
V
OUT
(1V/div)
V
LX
(10V/div)
V
CE
(5V/div)
I
LX
(200mA/div)
V
OUT
(1V/div)
V
LX
(10V/div) 200µs/div
VCE
(5V/div)
ILX
(200mA/div)
VOUT
(1V/div)
VLX
(10V/div) 200µs/div
VCE
(5V/div)
ILX
(200mA/div)
VOUT
(1V/div)
VLX
(10V/div)
VCE
(5V/div)
ILX
(200mA/div)
VOUT
(1V/div)
VLX
(10V/div)
VCE
(5V/div)
ILX
(200mA/div)
VOUT
(1V/div)
VLX
(10V/div) 200µs/div
VCE
(5V/div)
ILX
(200mA/div)
VOUT
(1V/div)
VLX
(10V/div)
VCE
(5V/div)
ILX
(200mA/div)
VOUT
(1V/div)
VLX
(10V/div)
R1245x
No. EA-269-170720
27
14) Switching operation waveform
R1245x00xA/R1245x00xB
VOUT=3.3V , VIN=12V , IOUT=0mA , Ta=25
°
C
R1245x00xA/R1245x00xB
VOUT=3.3V , VIN=12V , IOUT=600mA , Ta=25
°
C
R1245x00xG/R1245x00xH
VOUT=3.3V , VIN=12V , IOUT=20mA , Ta=25
°
C
R1245x00xG/R1245x00xH
VOUT=3.3V , VIN=12V , IOUT=600mA , Ta=25
°
C
15) Loaf tr ansient response waveform
R1245x00xA/R1245x00xB
VOUT=0.8V , VIN=12V , IOUT=600
⇔
1200mA , Ta=25
°
C
R1245x00XA/R1245x00xB
VOUT=3.3V , VIN=12V , IOUT=600
⇔
1200mA , Ta=25
°
C
I
LX
(200mA/div)
V
OUT
(AC)
(20mV/div)
V
LX
(5V/div)
2µs/div
I
LX
(200mA/div)
V
OUT
(AC)
(20mV/div)
V
LX
(5V/div)
I
LX
(200mA/div)
V
OUT
(AC)
(20mV/div)
V
LX
(5V/div)
2µs/div
I
LX
(200mA/div)
V
OUT
(AC)
(20mV/div)
V
LX
(5V/div)
V
OUT
(100mV/div)
I
OUT
(500mA/div)
100µs/div
V
OUT
(100mV/div)
I
OUT
(500mA/div)
100µs/div
R1245x
No. EA-269-170720
28
R1245x00xG/R1245x00xH
VOUT=1.5V , VIN=4.5V , IOUT=600
⇔
1200mA , Ta=25
°
C
R1245x00xG/R1245x00xH
VOUT=3.3V , VIN=12V , IOUT=600
⇔
1200mA , Ta=25
°
C
16) Limit latch operation waveform 17) Released waveform from limit latch
R1245x00xA
VOUT=3.3V , VIN=12V , ROUT=5.5Ω
→
0.05Ω, Ta=25
°
C
R1245x00xA
VOUT=3.3V , VIN=12V , ROUT=5.5Ω
→
0.05Ω
→
5.5Ω
, Ta=25
°
C
18) Fold back operation waveform 19) Released waveform from fold back
R1245x00xB
VOUT=3.3V , VIN=12V , ROUT=5.5Ω
→
0.05Ω
Ta=25
°
C
R1245x00xB
VOUT=3.3V , VIN=12V , ROUT=5.5Ω
→
0.05Ω
→
5.5Ω
Ta=25
°
C
V
OUT
(2V/div)
V
LX
(10V/div)
I
LX
(1A/div)
V
OUT
(2V/div)
V
LX
(10V/div)
I
LX
(1A/div)
V
OUT
(2V/div)
V
LX
(10V/div)
I
LX
(1A/div)
20µs/div
V
OUT
(2V/div)
V
LX
(10V/div)
I
LX
(1A/div)
V
OUT
(2V/div)
V
LX
(10V/div)
I
LX
(1A/div)
V
OUT
(2V/div)
V
LX
(10V/div)
I
LX
(1A/div)
V
OUT
(2V/div)
V
LX
(10V/div)
I
LX
(1A/div)
V
OUT
(2V/div)
V
LX
(10V/div)
I
LX
(1A/div)
V
OUT
(2V/div)
V
LX
(10V/div)
I
LX
(1A/div)
V
OUT
(2V/div)
V
LX
(10V/div)
I
LX
(1A/div)
V
OUT
(2V/div)
V
LX
(10V/div)
I
LX
(1A/div)
20µs/div
V
OUT
(2V/div)
V
LX
(10V/div)
I
LX
(1A/div)
V
OUT
(2V/div)
V
LX
(10V/div)
I
LX
(1A/div)
V
OUT
(2V/div)
V
LX
(10V/div)
I
LX
(1A/div)
V
OUT
(2V/div)
V
LX
(10V/div)
I
LX
(1A/div)
V
OUT
(2V/div)
V
LX
(10V/div)
I
LX
(1A/div)
V
OUT
(2V/div)
V
LX
(10V/div)
I
LX
(1A/div)
V
OUT
(2V/div)
V
LX
(10V/div)
I
LX
(1A/div)
V
OUT
(2V/div)
V
LX
(10V/div)
I
LX
(1A/div)
20µs/div
V
OUT
(2V/div)
V
LX
(10V/div)
I
LX
(1A/div)
V
OUT
(2V/div)
V
LX
(10V/div)
I
LX
(1A/div)
V
OUT
(2V/div)
V
LX
(10V/div)
I
LX
(1A/div)
V
OUT
(2V/div)
V
LX
(10V/div)
I
LX
(1A/div)
V
OUT
(2V/div)
V
LX
(10V/div)
I
LX
(1A/div)
V
OUT
(2V/div)
V
LX
(10V/div)
I
LX
(1A/div)
V
OUT
(2V/div)
V
LX
(10V/div)
I
LX
(1A/div)
V
OUT
(2V/div)
V
LX
(10V/div)
I
LX
(1A/div)
20µs/div
V
OUT
(2V/div)
V
LX
(10V/div)
I
LX
(1A/div)
V
OUT
(2V/div)
V
LX
(10V/div)
I
LX
(1A/div)
V
OUT
(2V/div)
V
LX
(10V/div)
I
LX
(1A/div)
V
OUT
(2V/div)
V
LX
(10V/div)
I
LX
(1A/div)
V
OUT
(2V/div)
V
LX
(10V/div)
I
LX
(1A/div)
R1245x
No. EA-269-170720
29
20) Switching waveform at fold back operation
R1245x00xB
VOUT=3.3V , VIN=12V , ROUT=0.05Ω, Ta=25
°
C
21) Output cur rent vs. Efficiency (Version A/B)
V
OUT
(2V/div)
V
LX
(10V/div)
I
LX
(1A/div)
2µs/div
V
OUT
(2V/div)
V
LX
(10V/div)
I
LX
(1A/div)
V
OUT
(2V/div)
V
LX
(10V/div)
I
LX
(1A/div)
V
OUT
(2V/div)
V
LX
(10V/div)
I
LX
(1A/div)
V
OUT
(2V/div)
V
LX
(10V/div)
I
LX
(1A/div)
2µs/div
V
OUT
(2V/div)
V
LX
(10V/div)
I
LX
(1A/div)
V
OUT
(2V/div)
V
LX
(10V/div)
I
LX
(1A/div)
V
OUT
(2V/div)
V
LX
(10V/div)
I
LX
(1A/div)
R1245x00xA/R1245x00xB
V
OUT
=0.8V
(Ta=25℃)
0
20
40
60
80
100
0.01 0.1 110 100 1000 10000
I
OUT
(m A)
Efficiency (%)
VIN = 4.5V
VIN = 6.0V
VIN = 18V
R1245x00xA/R1245x00xB
V
OUT
=3.3V
(Ta=25℃)
0
20
40
60
80
100
0.01 0.1 110 100 1000 10000
I
OUT
(m A)
Efficiency (%)
VIN = 4.5 V
VIN = 12 V
VIN = 24 V
R1245x00xA/R1245x00xB
V
OUT
=5.0V
(Ta=25℃)
0
20
40
60
80
100
0.01 0.1 110 100 1000 10000
I
OUT
(m A)
Efficiency (%)
VIN = 12V
VIN = 24V
VIN = 30V
R1245x00xA/R1245x00xB
V
OUT
=12V
(Ta=25℃)
0
20
40
60
80
100
0.01 0.1 110 100 1000 10000
I
OUT
(m A)
Efficiency (%)
VIN = 18V
VIN = 24V
VIN = 30V
R1245x
No. EA-269-170720
30
22) Output Current vs. Efficiency (Version C/D)
R1245x00xA/R1245x00xB
V
OUT
=15V
(Ta=25℃)
0
20
40
60
80
100
0.01 0.1 110 100 1000 10000
I
OUT
(m A)
Efficiency (%)
VIN = 24V
VIN = 30V
R1245x00xA/R1245x00xB
V
OUT
=24V
(Ta=25℃)
0
20
40
60
80
100
0.01 0.1 110 100 1000 10000
I
OUT
(m A)
Efficiency (%)
VIN=30V
R1245x00xC/R1245x00xD
V
OUT
=0.8V
(Ta=25℃)
0
20
40
60
80
100
0.01 0.1 110 100 1000 10000
I
OUT
(m A)
Efficiency (%)
VIN = 4.5V
VIN = 6.0V
VIN = 12V
R1245x00xC/R1245x00xD
V
OUT
=3.3V
(Ta=25℃)
0
20
40
60
80
100
0.01 0.1 110 100 1000 10000
I
OUT
(m A)
Efficiency (%)
VIN = 4.5V
VIN = 12V
VIN = 24V
R1245x00xC/R1245x00xD
V
OUT
=5.0V
(Ta=25℃)
0
20
40
60
80
100
0.01 0.1 110 100 1000 10000
I
OUT
(m A)
Efficiency (%)
VIN = 12V
VIN = 24V
VIN = 30V
R1245x00xC/R1245x00xD
V
OUT
=12V
(Ta=25℃)
0
20
40
60
80
100
0.01 0.1 110 100 1000 10000
I
OUT
(m A)
Efficiency (%)
VIN = 18V
VIN = 24V
VIN = 30V
R1245x
No. EA-269-170720
31
23) Output cur rent vs. Efficiency (Version E/F)
R1245x00xC/R1245x00xD
V
OUT
=15V
(Ta=25℃)
0
20
40
60
80
100
0.01 0.1 110 100 1000 10000
I
OUT
(m A)
Efficiency (%)
VIN = 24V
VIN = 30V
R1245x00xC/R1245x00xD
V
OUT
=24V
(Ta=25℃)
0
20
40
60
80
100
0.01 0.1 110 100 1000 10000
I
OUT
(m A)
Efficiency (%)
VIN = 30V
R1245x00xE/R1245x00xF
V
OUT
=0.8V
(Ta=25℃)
0
20
40
60
80
100
0.01 0.1 110 100 1000 10000
I
OUT
(m A)
Efficiency (%)
VIN = 4.5V
VIN = 6.0V
R1245x00xE/R1245x00xF
VOUT=3.3V
(Ta=25℃)
0
20
40
60
80
100
0.01 0.1 110 100 1000 10000
I
OUT
(m A)
Efficiency (%)
VIN = 4.5V
VIN = 12V
VIN = 24V
R1245x00xE/R1245x00xF
V
OUT
=5.0V
(Ta=25℃)
0
20
40
60
80
100
0.01 0.1 110 100 1000 10000
I
OUT
(m A)
Efficiency (%)
VIN = 12V
VIN = 24V
VIN = 30V
R1245x00xE/R1245x00xF
VOUT=12V
(Ta=25℃)
0
20
40
60
80
100
0.01 0.1 110 100 1000 10000
I
OUT
(m A)
Efficiency (%)
VIN = 24V
VIN = 30V
R1245x
No. EA-269-170720
32
24) Output cur rent vs. Efficiency (Version G/H)
R1245x00xE/R1245x00xF
V
OUT
=15V
(Ta=25℃)
0
20
40
60
80
100
0.01 0.1 110 100 1000 10000
IOUT
(m A)
Efficiency (%)
VIN = 24V
VIN = 30V
R1245x00xE/R1245x00xF
VOUT=24V
(Ta=25℃)
0
20
40
60
80
100
0.01 0.1 110 100 1000 10000
I
OUT
(m A)
Efficiency (%)
VIN = 30V
R1245x00xG/R1245x00xH
V
OUT
=1.5V
(Ta=25℃)
0
20
40
60
80
100
0.01 0.1 110 100 1000 10000
I
OUT
(m A)
Efficiency (%)
VIN = 4.5V
R1245x00xG/R1245x00xH
V
OUT
=3.3V
(Ta=25℃)
0
20
40
60
80
100
0.01 0.1 110 100 1000 10000
I
OUT
(m A)
Efficiency (%)
VIN = 6V
VIN = 10V
VIN = 12V
R1245x00xG/R1245x00xH
V
OUT
=5.0V
(Ta=25℃)
0
20
40
60
80
100
0.01 0.1 110 100 1000 10000
I
OUT
(m A)
Efficiency (%)
VIN = 8.0V
VIN = 12V
R1245x00xG/R1245x00xH
V
OUT
=12V
(Ta=25℃)
0
20
40
60
80
100
0.01 0.1 110 100 1000 10000
I
OUT
(m A)
Efficiency (%)
VIN = 24V
VIN = 30V
R1245x
No. EA-269-170720
33
25) Output cur rent vs Output voltage (Version A/B)
R1245x00xA/R1245x00xB
V
OUT
=0.8V
(Ta=25℃)
0.792
0.794
0.796
0.798
0.800
0.802
0.804
0.806
0.808
0200 400 600 800 1000 1200
I
OUT
(m A)
Output Voltage(V)
VIN=4.5V VIN=6.0V
VIN=18V
R1245x00xA/R1245x00xB
VOUT=3.3V
(Ta=25℃)
3.25
3.26
3.27
3.28
3.29
3.30
3.31
3.32
3.33
0200 400 600 800 1000 1200
I
OUT
(m A)
Output Voltage (V)
VIN = 4.5 V VIN = 12 V
VIN = 24 V
R1245x00xA/R1245x00xB
V
OUT
=5.0V
(Ta=25℃)
4.95
4.97
4.99
5.01
5.03
5.05
0200 400 600 800 1000 1200
I
OUT
(m A)
Output Voltage (V)
VIN = 12V VIN = 24V
VIN = 30V
R1245x00xA/R1245x00xB
VOUT=12V
(Ta=25℃)
11.90
12.00
12.10
12.20
12.30
0200 400 600 800 1000 1200
I
OUT
(m A)
Output Voltage (V)
VIN = 18V VIN = 24V
VIN = 30V
R1245x00xA/R1245x00xB
V
OUT
=15V
(Ta=25℃)
14.80
15.00
15.20
15.40
15.60
0200 400 600 800 1000 1200
I
OUT
(m A)
Output Voltage (V)
VIN = 24V
VIN = 30V
R1245x00xA/R1245x00xB
VOUT=24V
(Ta=25℃)
23.90
24.10
24.30
24.50
24.70
0200 400 600 800 1000 1200
IOUT (m A)
Output Voltage (V)
VIN = 30V
R1245x
No. EA-269-170720
34
26) Output cur rent vs. Output voltage (Version C/D)
R1245x00xC/R1245x00xD
V
OUT
=0.8V
(Ta=25℃)
0.792
0.794
0.796
0.798
0.800
0.802
0.804
0.806
0.808
0200 400 600 800 1000 1200
I
OUT
(m A)
Output Voltage (V)
VIN = 4.5V VIN = 6.0V
VIN = 12V
R1245x00xC/R1245x00xD
V
OUT
=3.3V
(Ta=25℃)
3.25
3.26
3.27
3.28
3.29
3.30
3.31
3.32
3.33
0200 400 600 800 1000 1200
I
OUT
(m A)
Output Voltage (V)
VIN = 4.5V VIN = 12V
VIN = 24V
R1245x00xC/R1245x00xD
V
OUT
=5.0V
(Ta=25℃)
4.95
4.97
4.99
5.01
5.03
5.05
0200 400 600 800 1000 1200
I
OUT
(m A)
Output Voltage (V)
VIN = 12V VIN = 24V
VIN = 30V
R1245x00xC/R1245x00xD
V
OUT
=12V
(Ta=25℃)
11.80
11.90
12.00
12.10
12.20
0200 400 600 800 1000 1200
I
OUT
(m A)
Output Voltage (V)
VIN = 18V VIN = 24V
VIN = 30V
R1245x00xC/R1245x00xD
V
OUT
=15V
(Ta=25℃)
14.60
14.80
15.00
15.20
15.40
0200 400 600 800 1000 1200
I
OUT
(m A)
Output Voltage (V)
VIN = 24V
VIN = 30V
R1245x00xC/R1245x00xD
V
OUT
=24V
(Ta=25℃)
23.60
23.80
24.00
24.20
24.40
0200 400 600 800 1000 1200
I
OUT
(m A)
Output Voltage (V)
VIN = 30V
R1245x
No. EA-269-170720
35
27) Output cur rent vs. Output voltage (Version E/F)
R1245x00xE/R1245x00xF
V
OUT
=0.8V
(Ta=25℃)
0.792
0.794
0.796
0.798
0.800
0.802
0.804
0.806
0.808
0200 400 600 800 1000 1200
I
OUT
(m A)
Output Voltage(V)
VIN = 4.5V
R1245x00xE/R1245x00xF
V
OUT
=3.3V
(Ta=25℃)
3.25
3.26
3.27
3.28
3.29
3.30
3.31
3.32
3.33
0200 400 600 800 1000 1200
I
OUT
(m A)
Output Voltage (V)
VIN = 4.5V VIN = 12V
VIN = 24V
R1245x00xE/R1245x00xF
V
OUT
=5.0V
(Ta=25℃)
4.95
4.97
4.99
5.01
5.03
5.05
0200 400 600 800 1000 1200
I
OUT
(m A)
Output Voltage (V)
VIN = 12V VIN = 24V
VIN = 30V
R1245x00xE/R1245x00xF
V
OUT
=12V
(Ta=25℃)
11.80
11.90
12.00
12.10
12.20
0200 400 600 800 1000 1200
I
OUT
(m A)
Output Voltage (V)
VIN = 24V VIN = 30V
R1245x00xE/R1245x00xF
V
OUT
=15V
(Ta=25℃)
14.80
15.00
15.20
15.40
15.60
0200 400 600 800 1000 1200
I
OUT
(m A)
Output Voltage (V)
VIN = 24V
VIN = 30V
R1245x00xE/R1245x00xF
V
OUT
=24V
(Ta=25℃)
23.60
23.80
24.00
24.20
24.40
0200 400 600 800 1000 1200
I
OUT
(m A)
Output Voltage (V)
VIN = 30V
R1245x
No. EA-269-170720
36
28) Output cur rent vs. Output voltage (Version G/H)
29) Input voltage vs. Output voltage (Version A /B)
R1245x00xG/R1245x00xH
V
OUT
=1.5V
(Ta=25℃)
1.485
1.490
1.495
1.500
1.505
1.510
1.515
0200 400 600 800 1000 1200
I
OUT
(m A)
Output Voltage (V)
VIN = 4.5V
R1245x00xG/R1245x00xH
V
OUT
=3.3V
(Ta=25℃)
3.25
3.26
3.27
3.28
3.29
3.30
3.31
3.32
3.33
0200 400 600 800 1000 1200
I
OUT
(m A)
Output Voltage (V)
VIN = 6V VIN = 10V
VIN = 12V
R1245x00xG/R1245x00xH
V
OUT
=5.0V
(Ta=25℃)
4.95
4.97
4.99
5.01
5.03
5.05
0200 400 600 800 1000 1200
I
OUT
(m A)
Output Voltage (V)
VIN = 8.0V VIN = 12V
R1245x00xG/R1245x00xH
V
OUT
=12V
(Ta=25℃)
11.80
11.90
12.00
12.10
12.20
0200 400 600 800 1000 1200
I
OUT
(m A)
Output Voltage (V)
VIN = 24V VIN = 30V
R1245x00xA/R1245x00xB
VOUT=0.8V
(Ta=25℃)
0.792
0.794
0.796
0.798
0.800
0.802
0.804
0.806
0.808
4 6 8 10 12 14 16 18
V
IN
(V)
Output Voltage (V)
IOUT=1m A IOUT=100mA
IOUT=500mA IOUT=1200mA
R1245x00xA/R1245x00xB
V
OUT
=3.3V
(Ta=25℃)
3.27
3.28
3.29
3.30
3.31
3.32
3.33
4 8 12 16 20 24 28
VIN
(V)
Output Voltage (V)
IOUT=1m A IOUT=10mA
IOUT=100mA IOUT=1200mA
R1245x
No. EA-269-170720
37
30) Input voltage vs. Output voltage (Version C/D)
R1245x00xA/R1245x00xB
VOUT=5.0V
(Ta=25℃)
4.95
4.97
4.99
5.01
5.03
5.05
46810 12 14 16 18 20 22 24 26 28 30
V
IN
(V)
Output Voltage (V)
IOUT=1m A IOUT=100mA
IOUT=500mA IOUT=1200mA
R1245x00xA/R1245x00xB
V
OUT
=12V
(Ta=25℃)
11.95
12.00
12.05
12.10
12.15
12.20
12 14 16 18 20 22 24 26 28 30
VIN
(V)
Output Voltage (V)
IOUT=100mA IOUT=500mA
IOUT=1200mA
R1245x00xA/R1245x00xB
VOUT=15V
(Ta=25℃)
14.90
15.00
15.10
15.20
15.30
14 16 18 20 22 24 26 28 30
V
IN
(V)
Output Voltage (V)
IOUT=100mA IOUT=500mA
IOUT=1200mA
R1245x00xA/R1245x00xB
V
OUT
=24V
(Ta=25℃)
23.80
23.90
24.00
24.10
24.20
24 25 26 27 28 29 30
VIN
(V)
Output Voltage (V)
IOUT=100mA IOUT=500mA
IOUT=1200mA
R1245x00xC/R1245x00xD
V
OUT
=0.8V
(Ta=25℃)
0.79
0.79
0.80
0.80
0.80
0.80
0.80
0.81
0.81
4.5 67.5 910.5 12 13.5
V
IN
(V)
Output Voltage (V)
1mA 100mA
500mA 1200mA
R1245x00xC/R1245x00xD
V
OUT
=3.3V
(Ta=25℃)
3.27
3.28
3.29
3.30
3.31
3.32
3.33
4 8 12 16 20 24 28
V
IN
(V)
Output Voltage (V)
1mA 100mA
500mA 1200mA
R1245x
No. EA-269-170720
38
31) Input voltage vs. Output voltage (Version E/F)
R1245x00xC/R1245x00xD
V
OUT
=5.0V
(Ta=25℃)
4.95
4.97
4.99
5.01
5.03
5.05
46810 12 14 16 18 20 22 24 26 28 30
V
IN
(V)
Output Voltage (V)
1mA 100mA
500mA 1200mA
R1245x00xC/R1245x00xD
V
OUT
=12V
(Ta=25℃)
11.80
11.90
12.00
12.10
12.20
12 14 16 18 20 22 24 26 28 30
V
IN
(V)
Output Voltage (V)
100mA 500mA
1200mA
R1245x00xC/R1245x00xD
V
OUT
=15V
(Ta=25℃)
14.60
14.70
14.80
14.90
15.00
15.10
15.20
15.30
15.40
14 16 18 20 22 24 26 28 30
V
IN
(V)
Output Voltage (V)
100mA 500mA
1200mA
R1245x00xC/R1245x00xD
V
OUT
=24V
(Ta=25℃)
23.80
23.90
24.00
24.10
24.20
24 25 26 27 28 29 30
V
IN
(V)
Output Voltage (V)
100mA 500mA
1200mA
R1245x00xE/R1245x00xF
V
OUT
=0.8V
(Ta=25℃)
0.792
0.794
0.796
0.798
0.800
0.802
0.804
0.806
0.808
4.5 55.5 66.5
V
IN
(V)
Output Voltage (V)
1mA 100mA
500mA 1200mA
R1245x00xE/R1245x00xF
VOUT=3.3V
(Ta=25℃)
3.27
3.28
3.29
3.30
3.31
3.32
3.33
4 8 12 16 20 24 28
V
IN
(V)
Output Voltage (V)
1mA 100mA
500mA 1200mA
R1245x
No. EA-269-170720
39
32) Input voltage vs. Output voltage (Version G/H)
R1245x00xE/R1245x00xF
V
OUT
=5.0V
(Ta=25℃)
4.95
4.97
4.99
5.01
5.03
5.05
510 15 20 25 30
V
IN
(V)
Output Voltage (V)
1mA 100mA
500mA 1200mA
R1245x00xE/R1245x00xF
VOUT=12V
(Ta=25℃)
11.80
11.90
12.00
12.10
12.20
12 14 16 18 20 22 24 26 28 30
V
IN
(V)
Output Voltage (V)
100mA 500mA
1200mA
R1245x00xE/R1245x00xF
VOUT=15V
(Ta=25℃)
14.60
14.80
15.00
15.20
15.40
16 18 20 22 24 26 28 30
V
IN
(V)
Output Voltage (V)
100mA 500mA
1200mA
R1245x00xE/R1245x00xF
VOUT=24V
(Ta=25℃)
23.60
23.80
24.00
24.20
24.40
26 27 28 29 30
V
IN
(V)
Output Voltage (V)
100mA 500mA
1200mA
R1245x00xG/R1245x00xH
V
OUT
=1.5V
(Ta=25℃)
1.485
1.490
1.495
1.500
1.505
1.510
1.515
4.5 4.7 4.9 5.1 5.3 5.5
V
IN
(V)
Output Voltage (V)
1mA 100mA
500mA 1200mA
R1245x00xG/R1245x00xH
V
OUT
=3.3V
(Ta=25℃)
3.27
3.28
3.29
3.30
3.31
3.32
3.33
4.5 5.5 6.5 7.5 8.5 9.5 10.5 11.5 12.5
V
IN
(V)
Output Voltage (V)
1mA 100mA
500mA 1200mA
R1245x
No. EA-269-170720
40
R1245x00xG/R1245x00xH
V
OUT
=5.0V
(Ta=25℃)
4.95
4.97
4.99
5.01
5.03
5.05
6 8 10 12 14 16 18
V
IN
(V)
Output Voltage (V)
1mA 100mA
500mA 1200mA
R1245x00xG/R1245x00xH
V
OUT
=12V
(Ta=25℃)
11.80
11.90
12.00
12.10
12.20
14 16 18 20 22 24 26 28 30
V
IN
(V)
Output Voltage (V)
100mA 500mA
1200mA
POWER DISSIPATION HSOP-8E
Ver. A
i
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
Ultra-High Wattage Land Pattern
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 Outer Layers (First and Fourth Layers): Approx. 95% of 50 mm Square
Inner Layers (Second and Third Layers): Approx. 100% of 50 mm Square
Through-holes φ 0.4 mm × 21 pcs
Measurement Resu lt (Ta = 25°C, Tjmax = 125°C)
Ultra-High Wattage Land Pattern
Power Dissipation 2.9 W
Thermal Resistance
θja = (125 − 25°C) / 2.9 W = 35°C/W
θjc = 10°C/W
IC Mount Area (mm)
Power Dissipation vs. Ambient Temperature
Measurement Board Pattern
Power Dissipation P
D
(W)
0
25 50 75 100 125 150
Ambient Temperature (°C)
4.0
3.0
2.0
1.0
0 105
Ultra-High Wattage Land Pattern
2.9
40
50
76.2
114.3
50
POWER DISSIPAT I ON DFN(PLP)2020-8
Ver. A
i
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
Copper Ratio Top Side: Approx. 50%
Bottom Side: Approx. 50%
Through-holes φ 0.54 mm × 30 pcs
Measurement Result ( Ta = 2 5 °C, Tjmax = 125°C)
Standard Test Land Pattern
Power Dissipation 880 mW
Thermal Resistance θja = (125 − 25°C) / 0.88 W = 114°C/W
IC Mount Area (mm)
Power Dissipation vs. Ambient Temperatur e
Measurement Board Pattern
Power Dissipation PD (mW)
1200
1000
800
600
400
200
0
0 25 50 75 100 125 150
Ambient Temperature (°C)
105
880
Standard Test Land Pattern
40
40
PACKAGE DIMENSIONS DFN (PLP) 2020-8
Ver. A
i
2.00
2.00
A
B
0.05
X4
INDEX
0.6MAX.
0.05 S
S
0.05min
0.25
±0.1
0.25
±0.1
0.5
1.8
±0.1
0.25
±0.1
0.05
M AB
1.0
±0.1
C0.2
※
58
41
Bottom View
DFN (PLP) 2020-8 Package Dimensions (Unit: mm)
*
∗ The tab on the bottom of the package is substrate level (GND). It is recommended that the tab be connected to the
ground plane on the board, or otherwise be left floating.
POWER DISSIPAT I ON SOT-23-6W
Ver. A
i
Power Dissipation PD (mW)
600
500
400
300
200
100
0
0 25 50 75
100
125
150
Ambient Temperature (°C)
105
Standard Test Land Pattern
430
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
Copper Ratio Top Side: Approx. 50%
Bottom Side: Approx. 50%
Through-holes φ 0.5 mm × 44 pcs
Measurement Result ( Ta = 2 5 °C, Tjmax = 125°C)
Standard Test Land Pattern
Power Dissipation 430 mW
Thermal Resistance θja = (125 − 25°C) / 0.43 W = 233°C/W
IC Mount Area (mm)
Power Dissipation vs. Ambient Temperatur e
Measurement Board Pattern
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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.
Halogen Free
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