RP500x SERIES
600mA∗ Step-down DC/DC Converter with Synchronous Rectifier
NO.EA-155-100802
1
OUTLINE
The RP500x Series are CMOS-based 600mA∗ step-down DC/DC Converters with synchronous rectifier.
Each of these ICs consists of an oscillator, a switching control circuit, a reference voltage unit, an error
amplifier, a soft-start circuit, protection circuits, UVLO circuit, switching transistors, and so on. A low ripple, high
efficiency step-down DC/DC converter can be easily composed of this IC with only an inductor and capacitors.
In terms of the output voltage, since the feedback resistances are built-in, the voltage is fixed internally. 0.1V
step output can be set by laser-trim and 1.5% or 24mV tolerance depending on the output voltage is guaranteed.
Mode alternative circuit works automatically for improving the efficiency. Considering fixed noise frequency,
PWM fixed control type is also available.
As protection circuits, the current limit circuit which limits peak current of Lx at each clock cycle, and the latch
type protection circuit which works if the term of the over-current condition keeps on a certain time exist. The
latch-type protection circuit works to latch an internal driver with keeping it disable. To release the condition of
the protection, after disabling this IC with a chip enable circuit, enable it again, or restart this IC with power-on or
make the supply voltage at UVLO detector threshold level or lower than UVLO.
Since packages are WLCSP-6-P2, DFN1616-6, DFN(PLP)1820-6, SOT-23-6W, high density mounting on
boards is possible. ∗)This is an approximate value, because output current depends on conditions and external parts.
FEATURES
• Supply Current ......................................................Typ. 400μA (at PWM mode)
Typ. 100μA (at VFM mode)
• Standby Current ....................................................Max. 5μA
• Input Voltage Range .............................................2.55V to 5.50V
• Output Voltage Range...........................................1.1V to 3.3V (0.1V steps)
(For other voltages, please refer to MARK INFORMATIONS.)
• Output Voltage Accuracy.......................................±1.5% (VOUT≥1.6V), ±24mV (VOUT<1.6V)
• Temperature-Drift Coefficient of Output Voltage ...Typ. ±100ppm/°C
• Oscillator Frequency .............................................Typ. 1.2MHz
• Oscillator Maximum Duty Cycle............................Min. 100%
• Built-in Driver ON Resistance ...............................Typ. Pch. 0.3Ω, Nch. 0.38Ω (VIN=3.6V)
• UVLO Detector Threshold.....................................Typ. 2.2V
• Soft Start Time.......................................................Typ. 120μs
• Lx Current Limit.....................................................Typ. 900mA
• Latch type Protection Circuit.................................Typ. 1.5ms
• Two choices of Switching Mode............................Automatic PWM/VFM mode change / PWM fixed
• Packages ..............................................................
WLCSP-6-P2, DFN1616-6, DFN(PLP)1820-6, SOT-23-6W
APPLICATIONS
• Power source for battery-powered equipment.
• Power source for hand-held communication equipment, cameras, VCRs, camcorders.
• Power source for HDD, portable equipment.
RP500x
2
BLOCK DIAGRAMS RP500xxx1A/2A
CE
V
IN
AGND
L
X
Chip
Enable
Ramp
Com
p
ensation
Current
Feedback
Current
Protection
Switching
Control
UVLO
OSC
Vref
V
OUT
PWM
Control
Soft Start
PGND
∗
∗) only RP500xxx1A for automatic PWM/VFM mode change
RP500xxx3A/4A
CE
V
IN
AGND
L
X
Chip
Enable
Ramp
Com
p
ensation
Current
Feedback
Current
Protection
Switching
Control
UVLO
OSC
Vref
V
OUT
PWM
Control
Soft Start
PGND
∗
∗) only RP500xxx3A for automatic PWM/VFM mode change
RP500x
3
SELECTION GUIDE
The output voltage, switching mode, and auto discharge function for the ICs can be selected at the user’s
request.
Product Name Package Quantity per Reel Pb Free Halogen Free
RP500Zxx∗A-E2-F WLCSP-6-P2 5,000 pcs Yes Yes
RP500Lxx∗A-TR DFN1616-6 5,000 pcs Yes Yes
RP500Kxx∗A-TR DFN(PLP)1820-6 5,000 pcs Yes Yes
RP500Nxx∗A-TR-FE SOT-23-6W 3,000 pcs Yes Yes
xx : The output voltage can be designated in the range from 1.1V(11) to 3.3V(33) in 0.1V steps∗1.
(For other voltages, please refer to MARK INFORMATIONS.)
∗ : The switching mode, and auto discharge function can be designated.
Code Modulation method Auto discharge function
1 PWM/VFM auto switching No
2 PWM fixed No
3 PWM/VFM auto switching Yes
4 PWM fixed Yes
(The RP500Kxx3A does not exist. Please use RP500Lxx3A.)
∗1) 0.05V step is also available as a custom code.
RP500x
4
PIN CONFIGURATIONS
• WLCSP-6-P2 • DFN1616-6
Mark Side
6 5 4
1 2 3
Bump Side
65 4
12 3
Top Vie w
3
4
2
5
1
6
Bottom Vi ew
1
6
2
5
3
4
∗
• DFN(PLP)1820-6 • SOT-23-6W
Top Vie w
6 5 4
1 2 3
Bottom Vi ew
4 56
3 2 1
654
123
(mark side)
PIN DESCRIPTIONS
• WLCSP-6-P2, SOT-23-6W
Pin No Symbol Pin Description
1 VOUT Output Pin
2 PGND Ground Pin
3 Lx Lx Switching Pin
4 VIN Input Pin
5 AGND Ground Pin
6 CE Chip Enable Pin ("H" Active)
• DFN1616-6, DFN(PLP)1820-6
Pin No Symbol Pin Description
1 CE Chip Enable Pin ("H" Active)
2 AGND Ground Pin
3 VIN Input Pin
4 Lx Lx Switching Pin
5 PGND Ground Pin
6 VOUT Output Pin
∗) Tab is GND level. (They are connected to the reverse side of this IC.)
The tab is better to be connected to the GND, but leaving it open is also acceptable.
RP500x
5
ABSOLUTE MAXIMUM RATINGS AGND=PGND=0V
Symbol Item Rating Unit
VIN Input Voltage −0.3 to 6.5 V
VLx Lx pin Voltage −0.3 to VIN+0.3 V
VCE CE Pin Input Voltage −0.3 to 6.5 V
VOUT Output Voltage −0.3 to 6.5 V
ILx Lx Pin Output Current 800 mA
Power Dissipation (WLCSP-6-P2) ∗ 650
Power Dissipation (DFN1616-6) ∗ 640
Power Dissipation (DFN(PLP)1820-6) ∗ 880
PD
Power Dissipation (SOT-23-6W) ∗ 430
mW
Topt Operating Temperature Range −40 to 85 °C
Tstg Storage Temperature Range −55 to 125 °C
∗) For Power Dissipation, please refer to PACKAGE INFORMATION.
ABSOLUTE MAXIMUM RATINGS
Electronic and mechanical stress momentarily exceeded absolute maximum ratings may cause the
permanent damages 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 is not assured.
RP500x
6
ELECTRICAL CHARACTERISTICS
• RP500x Topt=25°C
Symbol Item Conditions Min. Typ. Max. Unit
VIN Operating Input Voltage 2.55 5.5 V
VOUT ≥ 1.6V ×0.985 ×1.015 V
VOUT Output Voltage VIN=VCE=3.6V
or Set VOUT+1V VOUT < 1.6V −24 24 mV
ΔVOUT/ΔTopt Output Voltage Temperature
Coefficient −40°C≤Topt≤85°C ±100 ppm
/°C
fosc Oscillator Frequency VIN=VCE=3.6V or Set VOUT+1V 0.96 1.2 1.44 MHz
IDD1 Supply Current 1 VIN=VCE=5.5V, VOUT=0V 400 500
μA
PWM/VFM 100 160
IDD2 Supply Current 2 VIN=VCE=VOUT
=5.5V PWM fixed 400 500 μA
Istandby Standby Current VIN=5.5V, VCE=0V 0 5
μA
RONP ON Resistance of Pch Tr. VIN=3.6V, ILX=−100mA 0.3 Ω
RONN ON Resistance of Nch Tr. VIN=3.6V, ILX=−100mA 0.38 Ω
ILXleakH Lx Leakage Current "H" VIN=VLX=5.5V, VCE=0V −1 0 5
μA
ILXleakL Lx Leakage Current "L" VIN=5.5V, VCE=VLX=0V −5 0 1
μA
IVOUTH VOUT "H" Input Current ∗1 VIN=VOUT=5.5V, VCE=0V −1 0 1
μA
IVOUTL VOUT "L" Input Current VIN=5.5V, VCE=VOUT=0V −1 0 1
μA
ICEH CE "H" Input Current VIN=VCE=5.5V −1 0 1
μA
ICEL CE "L" Input Current VIN=5.5V, VCE=0V −1 0 1
μA
VCEH CE Input Voltage "H" VIN=5.5V 1.0 V
VCEL CE Input Voltage "L" VIN=5.5V 0.4 V
Maxduty
Oscillator Maximum Duty Cycle
100 %
tstart Soft-start Time VIN=VCE=3.6V or Set VOUT+1V 120 150
μs
ILXlim Lx Current Limit VIN=VCE=3.6V or Set VOUT+1V 600 900 mA
tprot Protection Delay Time VIN=VCE=3.6V or Set VOUT+1V 0.5 1.5 5.0 ms
VUVLO1 UVLO Detector Threshold VIN=VCE 2.1 2.2 2.3 V
VUVLO2 UVLO Released Voltage VIN=VCE 2.2 2.3 2.4 V
RLOW Low Output Nch Tr. ON
Resistance ∗2 VIN=3.6V, VCE=0V 80 Ω
Test circuit is "OPEN LOOP" and AGND=PGND=0V unless otherwise noted.
∗1) without auto discharge version only
∗2) with auto discharge version only
RECOMMENDED OPERATING CONDITIONS (ELECTRICAL CHARACTERISTICS)
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.
RP500x
7
TEST CIRCUITS
RP500x
Series
V
IN
CE
L
X
V
OUT
PGND
A
GND
OSCILLOSCOPE
RP500x
Series
V
IN
CE
L
X
V
OUT
PGND
A
GND
OSCILLOSCOPE
Output Voltage Oscillator Frequency
RP500x
Series
V
IN
CE
L
X
V
OUT
PGND
A
GND
A
RP500x
Series
V
IN
CE
L
X
V
OUT
PGND
A
GND
A
Supply Current 1,2 Standby Current
RP500x
Series
V
IN
CE
L
X
V
OUT
PGND
A
GND
A
RP500x
Series
V
IN
CE
L
X
V
OUT
PGND
A
GND
A
CE "H"/"L" Input Current VOUT "H"/"L" Current
RP500x
8
RP500x
Series
V
IN
CE
L
X
V
OUT
PGND
A
GND
A
RP500x
Series
V
IN
CE
L
X
V
OUT
PGND
A
GND
OSCILLOSCOPE
Lx Leakage Current CE Input Voltage
RP500x
Series
VIN
CE
LX
VOUT
PGND
A
GND
V
OSCILLOSCOPE
RP500x
Series
VIN
CE
LX
VOUT
PGND
A
GND
OSCILLOSCOPE
Pch • Nch transistor ON resistance / Soft-start T i me
Output Delay for Protection / Lx Current limit
RP500x
Series
VIN
CE
LX
VOUT
PGND
A
GND
OSCILLOSCOPE
UVLO Detector Threshold • Released Volt age
RP500x
9
TYPICAL APPLICATION
V
IN
CE
L
X
V
OUT
PGND
A
GND
V
IN
C
IN
10μF
C
OUT
10μF
V
OUT
4.7
μ
H
RP500x
Series
Symbol Parts Recommendation
CIN 10μF Ceramic C2012JB0J106K (TDK)
COUT 10μF Ceramic C2012JB0J106K (TDK)
L 4.7μH VLF3010AT-4R7MR30
TECHNICAL NOTES
When using these ICs, consider the following points:
⋅ Set the same level as AGND and PGND.
⋅ Set external components such as an inductor, CIN, COUT as close as possible to the IC, in particular, minimize
the wiring to VIN pin and PGND pin. Reinforce the VIN, PGND, and VOUT lines sufficiently. Large switching
current may flow in these lines. If the impedance of VIN and PGND lines is too large, the internal voltage level in
this IC may shift caused by the switching current, and the operation might be unstable. The wiring between
VOUT and load and between L and VOUT should be separated.
⋅ Use an external capacitor CIN between VIN and GND, and COUT with a capacity of 10µF or more ceramic type.
⋅ Choose an inductor with inductance range from 4.7μH to 10μH. The phase compensation has been made by
these values with output capacitors. The recommendation characteristics of the inductor are low DC resistance,
large enough permissible current, and strong against the magnetic saturation. Inductance value may shift
depending on an inductor. If the inductance value at an actual load current is low, Lx peak current may
increase and may overlap the Lx current limit. As a result, over current protection may work.
⋅ Over current protection circuit may be affected by self-heating and heat radiation environment.
∗The performance of power source circuits using these ICs extremely depends upon the peripheral circuits.
Pay attention in the selection of the peripheral circuits. In particular, design the peripheral circuits in a way that
the values such as voltage, current, and power of each component, PCB patterns and the IC do not exceed
their respected rated values. (such as the voltage, current, and power)
RP500x
10
Operation of step-down DC/DC converter and Output Current
The DC/DC converter charges energy in the inductor when LX transistor is ON, and discharges the energy
from the inductor when LX transistor is OFF and controls with less energy loss, so that a lower output voltage
than the input voltage is obtained. The operation will be explained with reference to the following diagrams:
<Basic Circuit> <Current through L>
Pch T
r
L
Nch T
r
V
IN
i1
V
OUT
CL
i2
GND
T=1/fosc
ton toff
topen
ILmin
ILmax
IL
i1 i2
⋅ Step 1 : Pch Tr. turns on and current IL (=i1) flows, and energy is charged into CL. At this moment, IL increases
from ILmin (=0) to reach ILmax in proportion to the on-time period (ton) of Pch Tr.
⋅ Step 2 : When Pch Tr. turns off, Synchronous rectifier Nch Tr. turns on in order that L maintains 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 Nch Tr. turns off.
Provided that in the continuous mode, next cycle starts before IL becomes to 0 because toff time is not
enough. In this case, IL value increases from this ILmin (>0).
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.
The maximum value (ILmax) and the minimum value (ILmin) of the current flowing through the inductor are the
same as those when Pch Tr. turns on and off.
The difference between ILmax and ILmin, which is represented by ΔI:
∆I = ILmax − ILmin = VOUT × topen / L = (VIN − VOUT) × ton / L ..........................................Equation 1
wherein,
T = 1 / fosc = ton + toff
duty (%) = ton / T × 100 = ton × fosc × 100
topen ≤ toff
In Equation 1, VOUT × topen / L and (VIN − VOUT) × ton / L respectively show the change of the current at "ON", and
the change of the current at "OFF".
RP500x
11
Discontinuous mode and Continuous mode
When the output current (IOUT) is relatively small, topen < toff as illustrated in the following diagram. In this case,
the energy is charged in the inductor during the time period of ton and is discharged in its entirely during the time
period of toff, therefore ILmin becomes to zero (ILmin=0). When IOUT is gradually increased, eventually, topen
becomes to toff (topen=toff), and when IOUT is further increased, ILmin becomes larger than zero (ILmin>0). The
former mode is referred to as the discontinuous mode and the latter mode is referred to as continuous mode.
Discontinuous mode Continuous mode
ILmax
ILmin
ton toff
T=1/fosc
topen
IL
t
ILmax
ILmin
ton toff
T=1/fosc
IL
Iconst
t
In the continuous mode, when Equation 1 is solved for ton and assumed that the solution is tonc,
tonc = T × VOUT / VIN ....................................................................................................... Equation 2
When ton<tonc, the mode is the discontinuous mode, and when ton=tonc, the mode is the continuous mode.
Output Current and selection of External components
The relation between the output current and external components is as follows:
When Pch Tr. of LX is ON:
(Wherein, Ripple Current p-p value is described as IRP, ON resistance of Pch Tr. and Nch Tr. of LX are
respectively described as RONP and RONN, and the DC resistor of the inductor is described as RL.)
VIN = VOUT + (RONP + RL) × IOUT + L × IRP / ton.................................................................. Equation 3
When Pch Tr. of LX is "OFF" (Nch Tr. is "ON"):
L × IRP / toff = RONN × IOUT + VOUT + RL × IOUT ................................................................ Equation 4
Put Equation 4 to Equation 3 and solve for ON duty of Pch transistor, DON = ton / (toff + ton),
DON = (VOUT + RONN × IOUT + RL × IOUT) / (VIN + RONN × IOUT − RONP × IOUT) ....................... Equation 5
RP500x
12
Ripple Current is as follows:
IRP = (VIN − VOUT − RONP × IOUT − RL × IOUT) × DON / fosc / L..............................................Equation 6
wherein, peak current that flows through L, and LX Tr. is as follows:
ILxmax = IOUT + IRP / 2 .....................................................................................................Equation 7
Consider ILxmax, condition of input and output and select external components.
∗The above explanation is directed to the calculation in an ideal case in continuous mode.
RP500x
13
TIMING CHART
(1) Soft Start Time
• In the case of starting this IC with CE
In the case of starting this IC with CE, the operation can be as in the timing chart below.
When the voltage of CE pin (VCE) is beyond the threshold level, the operation of the IC starts. The threshold
voltage of CE pin is in between CE "H" input voltage (VCEH) and CE "L" input voltage (VCEL) described in the
electrical characteristics table. Soft-start circuit operates, and after the certain time, the reference voltage
inside the IC (VREF) is rising gradually up to the constant value.
V
CEH
Soft-start Time
IC Internal Voltage
Reference
V
CEL
Threshold Level
Lx Voltage
(V
CE
)
(V
REF
)
Soft-start Circuit
operating
(
V
LX
)
Depending on Power supply,
Load Current, External Components
(V
OUT
)
Output Voltage
CE Pin
Input Voltage
PWM mode operating
during the Soft-start Time
Soft-start time is the time interval from soft start circuit starting point to the reference voltage level reaching
point up to this constant level.
∗Soft start time is not always equal to the turn-on speed of DC/DC converter.
The power supply capacity for this IC, load current, inductance and capacitance values affect the turn-on
speed.
• In the case of starting with power supply
In the case of starting with power supply, when the input voltage (VIN) is larger than UVLO released voltage
(VUVLO2), soft start circuit operates, and after that, the same explanation above is applied to the operation.
Soft-start time is the time interval from soft start circuit starting point to the reference voltage level reaching
point up to this constant level.
Output Voltage
Input Voltage
V
UVLO2
IC Internal Voltage
Reference
V
UVLO1
Lx Voltage
Set V
OUT
Set V
OUT
Soft-start Time
Depending on Power supply,
Load Current, External Components
PWM mode operating during the Soft-start Time
(V
OUT
)
(V
IN
)
(V
REF
)
(V
LX
)
∗ Turn-on speed is affected by next conditions;
(a) Input Voltage (VIN) rising speed depending on the power supplier to the IC and input capacitor CIN.
(b) Output Capacitor COUT value and load current value.
RP500x
14
(2) Under Voltage Lockout (UVLO) Circuit
The step-down DC/DC converter stops and ON duty becomes 100%, if input voltage (VIN) becomes less
than the set output voltage (Set VOUT), the output voltage (VOUT) gradually drops according to the input
voltage (VIN). If the input voltage drops more and becomes less than UVLO detector threshold (VUVLO1), the
under voltage lockout circuit (UVLO) operates, the IC internal reference voltage (VREF) stops, switching
transistors turn off and the output voltage drops according to the load and output capacitor COUT value.
To restart the normal operation, the input voltage (VIN) must be more than the UVLO released voltage
(VUVLO2).
The timing chart below describes the operation with varying the input voltage (VIN).
V
UVLO2
V
UVLO1
Set V
OUT
Set V
OUT
Output Voltage
Input Voltage
IC Internal Voltage
Reference
Lx Voltage
Soft-start Time
Depending on Power supply,
Load Current, External Components
(V
OUT
)
(V
IN
)
(V
REF
)
(V
LX
)
∗Actually, the waveform of VOUT at UVLO working and releasing varies depending on the initial voltage of
COUT and load current situation.
RP500x
15
(3) Over Current Protection Circuit, Latch Type Protection Circuit
Over current protection circuit supervises the coil peak current (the current flowing Pch transistor) at each
switching cycle, and if the current beyond the Lx current limit (ILXlim), Pch transistor is turned off. the Lx
current limit of RP500x is Typ.900mA.
Further, if the over current status continues equal or longer than protection delay time, or, when the Lx limit
current is exceeded even once when the driver operates by duty 100%, a built-in driver is latched in the
OFF state and the operation of DC/DC converter stops.
∗ Lx current limit and protection delay time is affected by self-heating and ambient environment. If the output
is short and the input voltage (VIN) is drastically dropped or becomes unstable, the protection operation
and delay time may vary.
Protection Delay Time (t
prot
)
Lx Current Limit (I
LX
lim
)
Lx Current
Pch Tr. Current
Lx Voltage
(V
LX
)
To release the condition of latch type protection, restart this IC by inputting "L" signal to CE pin, or restart
this IC with power-on or make the supply voltage lower than UVLO detector threshold (VUVLO1) level.
The timing chart shown below describes the changing process of input voltage rising, stable operating,
operating with large current, reset with CE pin, stable operating, input voltage falling, input voltage
recovering, and stable operating.
If too large current flows through the circuit because of short or other reasons, after the delay time of latch
type protection a built-in driver is latched in the OFF state and VLX signal will be "L", then output will turn off.
At the point (1), release the latch type protection is realized with CE reset as changed CE signal from "L" to
"H".
At the point (2), release the latch type protection is realized with UVLO reset as make the supply voltage
lower than UVLO detector threshold (VUVLO1) level.
Input Voltage
(V
IN
)
Set VOUT
UVLO Detect Voltage (VUVLO1)
CE Pin
Input Voltage
(V
CE
)
Set VOUT
Threshold Level
Lx Voltage
(V
LX
)
Set VOUT
Output Voltage
(V
OUT
)
UVLO Release Voltage (VUVLO2)
1 2
Soft-start Time
Set VOUT
Soft-start Time Soft-start Time
Stable
operation
Protection Delay Time Protection Delay Time
UVLO Reset
CE Reset
Latch-type Protection Latch-type Protection
Stable
operation
Stable
operation
RP500x
16
TYPICAL CHARACTERISTICS
1) Output Voltage vs. Output Current
RP500x121A/123A RP500x181A/183A
1.0
1.1
1.4
1.2
1.3
Output Current I
OUT
(mA)
Output Voltage V
OUT
(V)
10 1001 1000
V
IN
=5V
V
IN
=3.6V
1.6
1.7
2.0
1.8
1.9
Output Current I
OUT
(mA)
Output Voltage V
OUT
(V)
10 1001 1000
V
IN
=5V
V
IN
=3.6V
RP500x251A/253A RP500x331A/333A
2.3
2.4
2.7
2.5
2.6
Output Current I
OUT
(mA)
Output Voltage V
OUT
(V)
10 1001 1000
V
IN
=5V
V
IN
=3.6V
3.1
3.2
3.5
3.3
3.4
Output Current I
OUT
(mA)
Output Voltage V
OUT
(V)
10 1001 1000
V
IN
=5V
V
IN
=4.3V
RP500x152A/154A
1.3
1.4
1.7
1.5
1.6
Output Current I
OUT
(mA)
Output Voltage V
OUT
(V)
10 1001 1000
V
IN
=5V
V
IN
=3.6V
RP500x
17
2) Output Voltage vs. Input Voltage
RP500x121A/123A RP500x251A/253A
3.0 5.04.54.03.5 5.5
Input Voltage V
IN
(V)
Output Voltage V
OUT
(V)
1.17
1.23
1.19
1.18
1.21
1.20
1.22 I
OUT
=1mA
I
OUT
=50mA
I
OUT
=200mA
2.6 4.64.13.63.1 5.1
Input Voltage V
IN
(V)
Output Voltage V
OUT
(V)
2.44
2.56
2.48
2.46
2.52
2.50
2.54 I
OUT
=1mA
I
OUT
=50mA
I
OUT
=200mA
RP500x331A/333A RP500x152A/154A
3.0 5.04.54.03.5 5.5
Input Voltage V
IN
(V)
Output Voltage V
OUT
(V)
3.24
3.36
3.28
3.26
3.32
3.30
3.34 I
OUT
=1mA
I
OUT
=50mA
I
OUT
=200mA
3.0 5.04.54.03.5 5.5
Input Voltage V
IN
(V)
Output Voltage V
OUT
(V)
1.47
1.53
1.49
1.48
1.51
1.50
1.52 I
OUT
=1mA
I
OUT
=50mA
I
OUT
=200mA
3) Efficiency vs. Output Current
RP500x121A/123A RP500x181A/183A
40
50
100
70
90
60
80
Output Current I
OUT
(mA)
10 1001 1000
V
IN
=2.5V
V
IN
=3.6V
V
IN
=5V
Efficiency (%)
40
50
100
70
90
60
80
Output Current I
OUT
(mA)
10 1001 1000
Efficiency (%)
V
IN
=5V
V
IN
=3.6V
RP500x
18
RP500x251A/253A RP500x331A/333A
40
50
100
70
90
60
80
Output Current I
OUT
(mA)
10 1001 1000
Efficiency (%)
V
IN
=5V
V
IN
=3.6V
40
50
100
70
90
60
80
Output Current I
OUT
(mA)
10 1001 1000
Efficiency (%)
V
IN
=5V
V
IN
=4.3V
RP500x152A/154A
40
50
100
70
90
60
80
Output Current I
OUT
(mA)
10 1001 1000
Efficiency (%)
V
IN
=5V
V
IN
=3.6V
4) Supply Current 1, 2 vs. Temperature 5) Supply Current 1, 2 vs. Input Voltage
RP500x15xA RP500x15xA
0
500
300
400
100
200
-40 7550025-25 85
Temperature Topt (°C)
VIN=VCE=5.5V
Supply Current IDD (μA)
IDD1
IDD2
IDD1
IDD2
2.5 4.53.5 5.5
Input Voltage VIN (V)
Supply Current IDD (μA)
0
500
300
100
400
200
RP500x
19
6) DC/DC Output Waveform (CIN=COUT=10μF, L=4.7μH)
RP500x121A/123A RP500x12xA
0 0.5 1.51.0
Time t
(ms)
Output Voltage V
OUT
(V)
1.14
1.26
1.22
1.18
1.24
1.20
1.16
I
OUT
=1mA
01 32
Time t
(μs)
Output Voltage V
OUT
(V)
1.16
1.24
1.22
1.18
1.20
I
OUT
=200mA
RP500x251A/253A RP500x25xA
0 0.5 1.51.0
Time t
(ms)
Output Voltage V
OUT
(V)
2.44
2.56
2.52
2.48
2.54
2.50
2.46
I
OUT
=1mA
01 32
Time t
(μs)
Output Voltage V
OUT
(V)
2.46
2.54
2.52
2.48
2.50
I
OUT
=200mA
RP500x331A/333A RP500x33xA
0 0.5 1.51.0
Time t
(ms)
Output Voltage V
OUT
(V)
3.24
3.36
3.32
3.28
3.34
3.30
3.26
I
OUT
=1mA
01 32
Time t
(μs)
Output Voltage V
OUT
(V)
3.26
3.34
3.32
3.28
3.30
I
OUT
=200mA
RP500x
20
7) Output Voltage vs. Temperature
RP500x15xA RP500x33xA
1.47
1.53
1.49
1.51
1.48
1.50
1.52
-40 7550025-25 85
Temperature Topt (°C)
Output Voltage V
OUT
(V)
3.24
3.36
3.28
3.32
3.26
3.30
3.34
-40 7550025-25 85
Temperature Topt (°C)
Output Voltage V
OUT
(V)
8) Oscillator Frequency vs. Temperature 9) Oscillator Frequency vs. Input Voltage
RP500x15xA RP500x15xA
1050
1350
1150
1250
1100
1200
1300
-40 7550025-25 85
Temperature Topt (°C)
Frequency f
OSC
(kHz)
V
IN
=3.6V
1050
1350
1150
1250
1100
1200
1300
2.5 4.53.5 5.5
Input Voltage V
IN
(V)
Frequency f
OSC
(kHz)
I
OUT
=-40°C
I
OUT
=25°C
I
OUT
=85°C
10) Soft-start Time vs. Temperature 11) UVLO Detector Threshold/
Released Voltage vs. Temperature
RP500x16xA RP500x15xA
100
160
120
140
110
130
150
-40 7550025-25 85
Temperature Topt (°C)
Soft Start Time t
start
(μs)
UVLO Detector Threshold
UVLO Released Voltage
2.1
2.5
2.3
2.2
2.4
-40 7550025-25 85
Temperature Topt (°C)
UVLO Voltage V
UVLO
(V)
RP500x
21
12) CE Input vs. Temperature 13) Lx Current Limit vs. Temperature
RP500x15xA RP500x15xA
0
1.0
0.4
0.8
0.2
0.6
-40 7550025-25 85
Temperature Topt (°C)
CE Input Threshold Voltage V
CE
(V)
600
1000
700
900
800
-40 7550025-25 85
Temperature Topt (°C)
L
X
Limit Current I
LXLimit
(mA)
14) Nch Tr. ON Resistance vs. Temperature 15) Pch Tr. ON Resistance vs. Temperature
RP500x15xA RP500x15xA
0
0.6
0.2
0.4
0.5
0.1
0.3
-40 7550025-25 85
Temperature Topt (°C)
NchTr. ON Resistance R
ONN
(Ω)
0
0.6
0.2
0.4
0.5
0.1
0.3
-40 7550025-25 85
Temperature Topt (°C)
PchTr. ON Resistance R
ONP
(Ω)
16) Turn on speed with CE pin (CIN=COUT=Ceramic 10μF, L=4.7μH)
RP500x111A/113A (IOUT=1.1mA) RP500x251A/253A (IOUT=2.5mA)
2
0
0 400100 300200
Output Voltage V
OUT
(V)
Output Voltage
0
0.4
0.6
0.8
1.2
1.0
0.2
4
Time t (μs)
CE Input Voltage
CE Input Voltage V
CE
(V)
V
IN
=3.6V
3
0
0
400100 300200
Output Voltage VOUT (V)
Output Voltage
0
1.0
1.5
2.0
3.0
2.5
0.5
6
Time t (μs)
CE Input Voltage
CE Input Voltage VCE (V)
VIN=5V
RP500x
22
RP500x331A/333A (IOUT=3.3mA) RP500x152A/154A (IOUT=1.5mA)
3
0
0 400100 300200
Output Voltage VOUT (V)
Output Voltage
0
1
2
4
3
6
Time t (μs)
CE Input Voltage
CE Input Voltage VCE (V)
VIN=5V
2
0
0 400100 300200
Output Voltage V
OUT
(V)
Output Voltage
0
0.5
1.0
2.0
1.5
4
Time t (μs)
CE Input Voltage
CE Input Voltage V
CE
(V)
V
IN
=3.6V
17) Load Transient Response (CIN=COUT=Ceramic 10μF, L=4.7μH)
RP500x121A/123A RP500x121A/123A
1.20
1.15
0 10020 60 8040
Output Voltage V
OUT
(V)
Output Voltage
0
200
1.25
1.10
Time t (μs)
Output Current I
OUT
(mA)
V
IN
=3.6V
Output Current
0mA 200mA
1.25
1.20
0 1000200 600 800400
Output Voltage V
OUT
(V)
Output Voltage
0
200
1.30
1.15
Time t (μs)
Output Current I
OUT
(mA)
V
IN
=3.6V
Output Current
200mA 0mA
RP500x12xA RP500x12xA
1.20
1.15
0 10020 60 8040
Output Voltage V
OUT
(V)
Output Voltage
0
200
400
1.25
Time t (μs)
Output Current I
OUT
(mA)
V
IN
=3.6V
Output Current
100mA 400mA
1.25
1.20
0 10020 60 8040
Output Voltage V
OUT
(V)
Output Voltage
0
200
400
1.30
1.15
Time t (μs)
Output Current I
OUT
(mA)
V
IN
=3.6V
Output Current
400mA 100mA
RP500x
23
RP500x251A/253A RP500x251A/253A
2.50
2.45
0 10020 60 8040
Output Voltage V
OUT
(V)
Output Voltage
0
200
2.55
2.40
Time t (μs)
Output Current I
OUT
(mA)
V
IN
=5.0V
Output Current
0mA 200mA
2.55
2.50
0 1000200 600 800400
Output Voltage V
OUT
(V)
Output Voltage
0
200
2.60
2.45
Time t (μs)
Output Current I
OUT
(mA)
V
IN
=5.0V
Output Current
200mA 0mA
RP500x25xA RP500x25xA
2.50
2.45
0 10020 60 8040
Output Voltage V
OUT
(V)
Output Voltage
0
200
400
2.55
Time t (μs)
Output Current I
OUT
(mA)
V
IN
=5.0V
Output Current
100mA 400mA
2.50
2.45
0 10020 60 8040
Output Voltage V
OUT
(V)
Output Voltage
0
200
400
2.55
Time t (μs)
Output Current I
OUT
(mA)
V
IN
=5.0V
Output Current
400mA 100mA
RP500x331A/333A RP500x331A/333A
3.30
3.25
0 10020 60 8040
Output Voltage V
OUT
(V)
Output Voltage
0
200
400
3.35
3.20
Time t (μs)
Output Current I
OUT
(mA)
V
IN
=5.0V
Output Current
0mA 200mA
3.35
3.30
0 1000200 600 800400
Output Voltage V
OUT
(V)
Output Voltage
0
200
3.40
3.25
Time t (μs)
Output Current I
OUT
(mA)
V
IN
=5.0V
Output Current
200mA 0mA
RP500x
24
RP500x33xA RP500x33xA
3.30
3.25
0 10020 60 8040
Output Voltage V
OUT
(V)
Output Voltage
0
200
400
3.35
Time t (μs)
Output Current I
OUT
(mA)
V
IN
=5.0V
Output Current
100mA 400mA
3.30
3.25
0 10020 60 8040
Output Voltage V
OUT
(V)
Output Voltage
0
200
400
3.35
Time t (μs)
Output Current I
OUT
(mA)
V
IN
=5.0V
Output Current
400mA 100mA
RP500x152A/154A RP500x152A/154A
1.50
1.45
0 10020 60 8040
Output Voltage V
OUT
(V)
Output Voltage
0
200
1.55
1.40
Time t (μs)
Output Current I
OUT
(mA)
V
IN
=3.6V
Output Current
0mA 200mA
1.55
1.50
0 1000200 600 800400
Output Voltage V
OUT
(V)
Output Voltage
0
200
1.60
1.45
Time t (μs)
Output Current I
OUT
(mA)
V
IN
=3.6V
Output Current
200mA 0mA
RP500x15xA RP500x15xA
1.50
1.45
0 10020 60 8040
Output Voltage V
OUT
(V)
Output Voltage
0
200
400
1.55
Time t (μs)
Output Current I
OUT
(mA)
V
IN
=3.6V
Output Current
100mA 400mA
1.50
1.45
0 10020 60 8040
Output Voltage V
OUT
(V)
Output Voltage
0
200
400
1.55
Time t (μs)
Output Current I
OUT
(mA)
V
IN
=3.6V
Output Current
400mA 100mA