RP502x SERIES
Step-down DC/DC Converter with Synchronous Rectifier
NO.EA-189-110315
1
OUTLINE
The RP502x Series are CMOS-based step-down DC/DC converters with synchronous rectifier.
Each of these ICs consists of an oscillator, a reference voltage unit, an error amplifier, a switching control
circuit, a soft-start circuit, protection circuits, an UVLO circuit, and switching transistors. By adopting the
synchronous rectification with built-in switching transistors, high efficient step-down DC/DC converter can be
composed of only an inductor and capacitors.
As protection circuits, the current limit circuit and the latch protection circuit are built into the ICs. The current
limit circuit controls the peak current of LX at each clock cycle. Latch protection circuit maintains the built-in driver
in OFF state if the load current exceeds the limit value for a certain period of time. To cancel the latch protection,
disable the ICs with a chip enable circuit and then enable it again or make the power supply voltage lower than
UVLO.
The setting voltage for the RP502x Series is the output voltage fixed type with built-in feedback resistance that
is adjustable in 0.1V step with the accuracy of ± 1.5% or ±24mV. The packages for the ICs are WLCSP-6-P2
and DFN1616-6, which enable the high-density mounting. The switching mode for the ICs is selectable from the
PWM/VFM auto switching type, which achieves the high efficiency at the light load condition or PWM fixed type,
which switches at the fixed frequency.
FEATURES
• Supply Current ......................................................Typ. 750μA (at normal)
Typ. 180μA (at light road)
• Input Voltage Range .............................................2.5V to 5.5V(VOUT≥1.0V)
2.5V to 4.5V(VOUT<1.0V)
• Absolute Maximum Ratings ..................................6.0V
• Output Voltage Range...........................................0.8V to 3.3V (0.1V steps)
• Output Voltage Accuracy.......................................±1.5% (VOUT≥1.6V)
±24mV (VOUT<1.6V)
• Oscillator Frequency .............................................Typ. 3.3MHz
• Maximum Duty ......................................................Min. 100%
• Built-in Driver ON Resistance ...............................Typ. Pch. 0.5Ω, Nch. 0.5Ω(VIN=3.6V)
• UVLO Detector Threshold.....................................Typ. 2.2V
• Soft Start Time.......................................................Typ. 0.12ms
• Lx Current Limit.....................................................Typ. 900mA(VOUT≥1.2V)
Typ. 800mA(VOUT<1.2V)
• Latch type Protection Circuit.................................Typ. 1.5ms
• Chip Enable Function............................................"H" Active
• Packages ..............................................................WLCSP-6-P2, DFN1616-6
APPLICATIONS
• Power source for battery-powered equipments.
• Power source for hand-held communication equipments, cameras, VCRs, camcorders.
• Power source for HDDs, portable equipments.
RP502x
2
BLOCK DIAGRAMS RP502xxx1B
RP502xxx2B
SWITCHING
CONTROL
CURRENT
PROTECTION
SOFT
START
VREF
L
X
VOUT
VIN
CE
PGND
OSCILLATO
R
PWM
CURREN
T
FEEDBACK
RAM
P
COMPENSATION
UVL
O
AGND
CHIP
ENABLE
S
WIT
C
HIN
G
CONTROL
CURREN
T
PROTE CTI ON
SOF
START
VREF
L
X
VOUT
VIN
C
E
PGND
OSC ILLATOR
PW
M
CURRENT
FEEDBACK
RAM
P
COMPENSATION
UVL
O
AGND
CHI
P
ENAB LE
RP502x
3
RP502xxx3B
RP502xxx4B
S
WIT
C
HIN
G
CONTROL
CURREN
T
PROTE CTI ON
SOF
START
VREF
L
X
VOUT
VIN
C
E
PGND
OSC ILLATOR
PW
M
CURRENT
FEEDBACK
RAM
P
COMPENSATION
UVLO
AGND
CHI
P
ENAB LE
S
WIT
C
HIN
G
CONTROL
CURREN
T
PROTE CTI ON
SOF
START
VREF
L
X
VOUT
VIN
C
E
PGND
OSC ILLATOR
PW
M
CURRENT
FEEDBACK
RAM
P
COMPENSATION
UVLO
AGND
CHI
P
ENAB LE
RP502x
4
SELECTION GUIDE
In the RP502 Series, output voltage, switching mode, and auto discharge function for the ICs are selectable at
the user’s request.
Product Name Package Quantity per Reel Pb Free Halogen Free
RP502Zxx∗B-E2-F WLCSP-6-P2 5,000 pcs Yes Yes
RP502Lxx∗B-TR DFN1616-6 5,000 pcs Yes Yes
xx : The output voltage can be designated in the range of 0.8V(08) 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 as shown below.
Code PWM/VFM auto switching Auto discharge function
1 Yes No
2 No No
3 Yes Yes
4 No Yes
Auto-discharge function quickly lowers the output voltage to 0V, when the chip enable signal is switched from the active
mode to the standby mode, by releasing the electrical charge accumulated in the external capacitor.
∗1) 0.05V step is also available as a custom code.
RP502x
5
PIN CONFIGURATIONS
• WLCSP-6-P2 • DFN1616-6
Mark Side
6 5 4
1 2 3
Bump Side
65 4
12 3
Top View
3
4
2
5
1
6
Bottom Vi ew
1
6
2
5
3
4
∗
PIN DESCRIPTIONS
• WLCSP-6-P2
Pin No Symbol Pin Description
1 VOUT Output Pin
2 PGND Ground Pin
3 LX L
X Switching Pin
4 VIN Input Pin
5 AGND Ground Pin
6 CE Chip Enable Pin ("H" Active)
• DFN1616-6
Pin No Symbol Pin Description
1 CE Chip Enable Pin ("H" Active)
2 AGND Ground Pin
3 VIN Input Pin
4 LX L
X 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.
RP502x
6
ABSOLUTE MAXIMUM RATINGS AGND=PGND=0V
Symbol Item Rating Unit
VIN Input Voltage -0.3 to 6.0 V
VLX LX pin Voltage -0.3 to VIN + 0.3 V
VCE CE Pin Input Voltage -0.3 to 6.0 V
VOUT Output Voltage -0.3 to 6.0 V
ILX L
X Pin Output Current 900 mA
Power Dissipation (WLCSP-6-P2) ∗ 650
PD
Power Dissipation (DFN1616-6) ∗ 640
mW
Ta 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 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 (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.
RP502x
7
ELECTRICAL CHARACTERISTICS
• RP502xxxxB (Ta=25°C)
Symbol Item Conditions MIN. TYP. MAX. Unit
VOUT ≥1.0 2.5 5.5
VIN Operating Input Voltage VOUT <1.0 2.5 4.5 V
VOUT ≥1.6 -1.5% +1.5%
VOUT Output Voltage VIN = VCE =3.6V
or VSET +1V VOUT <1.6 -0.024 +0.024 V
∆VOUT/∆Ta Output Voltage
Temperature Coefficient -40°C
<
=
Ta
<
=
85°C ±100 ppm/
°C
fosc Oscillator Frequency VIN = VCE =3.6V or VSET +1V 2.64 3.3 3.96 MHz
IDD1 Supply Current 1 VIN = VCE =5.5V, VOUT =0V 750 900 μA
PWM/VFM 180 240
IDD2 Supply Current 2 VIN = VCE =
VOUT =5.5V PWM fixed 750 900 μA
Istandby Standby Current VIN = 5.5V, VCE = 0V 0 5 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
IVOUTH VOUT “H” Input Current∗1 VIN = VOUT = 5.5V, VCE = 0V -1 0 1 μA
IVOUTL V
OUT “L” Input Current VIN = 5.5V, VCE = VOUT = 0V -1 0 1 μA
RLOW Low Output Nch Tr. ON
Resistance∗2 VIN = 3.6V, VCE =0V 40 Ω
ILXLEAKH L
X Leakage Current “H” VIN = VLX = 5.5V, VCE = 0V -1 0 1 μA
ILXLEAKL L
X Leakage Current “L” VIN = 5.5V, VCE = VLX = 0V -5 0 5 μA
VCEH CE Input Voltage “H” VIN = 5.5V 1.0 V
VCEL CE Input Voltage “L” VIN = 2.5V 0.4 V
RONP ON Resistance of Pch Tr. VIN = 3.6V, ILX = -100mA 0.5 Ω
RONN ON Resistance of Nch Tr. VIN = 3.6V, ILX = -100mA 0.5 Ω
Maxduty Maximum Duty 100 %
tSTART Soft-start Time VIN = VCE =3.6V or VSET +1V 120 150 μs
VOUT ≥1.2 600 900
ILXLIM L
X Current Limit VIN = VCE =3.6V
or VSET +1V VOUT <1.2 500 800 mA
tPROT Protection Delay Time VIN = VCE =3.6V or VSET +1V 0.5 1.5 5 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
Test circuit is "OPEN LOOP" and AGND=PGND=0V unless otherwise noted.
∗1) without auto discharge function
∗2) with auto discharge function
RP502x
8
TEST CIRCUITS
RP502x
Series
VIN
CE
LX
VOUT
PGND
A
GND
OSCILLOSCOPE
RP502x
Series
VIN
CE
LX
VOUT
PGND
A
GND
OSCILLOSCOPE
Output Voltage Oscillator Frequency
RP502x
Series
VIN
CE
LX
VOUT
PGND
A
GND
A
RP502x
Series
VIN
CE
LX
VOUT
PGND
A
GND
A
Supply Current 1,2 Standby Current
RP502x
Series
VIN
CE
LX
VOUT
PGND
A
GND
A
RP502x
Series
VIN
CE
LX
VOUT
PGND
A
GND
A
CE "H"/"L" Input Current VOUT "H"/"L" Current
RP502x
9
RP502x
Series
VIN
CE
LX
VOUT
PGND
A
GND
A
RP502x
Series
VIN
CE
LX
VOUT
PGND
A
GND
OSCILLOSCOPE
LX Leakage Current CE Input Voltage
RP502x
Series
VIN
CE
LX
VOUT
PGND
A
GND
V
OSCILLOSCOPE
RP502x
Series
VIN
CE
LX
VOUT
PGND
A
GND
OSCILLOSCOPE
Pch • Nch Tr. ON resistance /
Output Delay for Protection / LX Current limit Soft-start Time
RP502x
Series
VIN
CE
LX
VOUT
PGND
A
GND
OSCILLOSCOPE
UVLO Detector Threshold • Released Voltage
RP502x
10
TYPICAL APPLICATION
Symbol Parts Recommendation
CIN 4.7μF Ceramic JMK107BJ475MA (TAIYO YUDEN)
COUT 4.7μF Ceramic JMK107BJ475MA (TAIYO YUDEN)
L 2.2μH NR 3010T 2R2M (TAIYO YUDEN) ,1.0μH MIPS 2520 D1R0 (FDK)
VIN
CE
LX
VOUT
PGNDAGND
VIN
CIN
4.7μF
COUT
4.7μF
VOUT
2.2μH/1.0μH
RP502x
Series
RP502x
11
TECHNICAL NOTES
When using the R502x Series, consider the following points:
⋅ Set AGND in the same level as PGND.
⋅ Set external components such as an inductor, CIN, and COUT as close as possible to the ICs. VIN, CIN and
PGND have to be wired as close as possible. If the impedances of VIN line and PGND line are high, the
switching current will fluctuate the electric potential of the inside the ICs. As a result, the operation may
become unstable. The impedances of power supply line and PGND line must be as low as possible. Please
note that a large current caused by the switching current flows into VIN, PGND, Inductor, LX, and VOUT.
Separate the wiring between VOUT pin and inductor from the wiring of load.
⋅ For CIN, use a ceramic capacitor with a low ESR. The recommended condenser capacity for CIN is 4.7µF or
more. Also, the recommended condenser capacity for COUT is 4.7µF.
⋅ Choose an inductor from the range of 1.0 to 2.2µH. The internal phase compensation has been determined
based on the above-mentioned inductor value and the COUT value. For stable operation, these conditions are
necessary. Choose an inductor that is low DC resistance, has enough permissive current, and is strong
against magnetic saturation. Decide the inductance value with consideration of the load current under the
condition of use. If the inductance value is low, the peak value of LX current may increase along with the
increase of the load current. As a result, the peak value of LX may reach to the “LX Limit Current” and may
trigger the overcurrent protection circuit.
⋅ Please note that overcurrent protection circuit may be affected by self-heating and heat radiation
environment.
∗ The performance of power source circuits using these ICs largely depends upon the peripheral circuits.
Pay attention to the setting of the peripheral components. In particular, when designing the peripheral circuit,
the constant values (voltage, current and power) for each part, PCB pattern and the ICs should not be
exceeded.
RP502x
12
Operation of step-down DC/DC converter and Output Current
The step-down DC/DC converter charges energy in the inductor when the Lx transistor is turned on, and
discharges the energy when the Lx transistor is turned off. The step-down DC/DC converter also controls with
the less energy loss and supplies the lower output voltage than the input voltage. The operation of the DC/DC
converter will be explained with the following diagrams:
<Basic Circuit> <Inductor Current >
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. Then, L and CL are charged with energy. At this moment, IL
(=i1) increases from ILmin (=0) to 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 and IL(=i2) flows in order to maintain IL
at ILmax.
⋅ Step 3: IL (=i2) starts to decrease gradually when topen time period starts. IL reaches to ILmin (IL=ILmin=0)
when topen time period ends and then Nch Tr. turns off. In the continuous mode, toff time period runs
out before IL becomes ILmin (IL=ILmin=0). The next cycle starts. Pch Tr. turns on and Nch Tr, turns off.
Since toff time period runs out before IL becomes ILmin (IL=ILmin=0), ILmin (>0) is still remaining. In
this case, IL starts increasing from ILmin (>0).
In the case of PWM control system, the output voltage is maintained constant by keeping the switching time
(fosc) per unit constant, and by controlling the On-time period (ton).
When the step-down operation is constant and stable, as shown in the above “Inductor Current”, the maximum
inductor current (ILmax) will be same as the on-time period of Pch Tr. (ton) and the minimum inductor current
(ILmin) will be same as the on-time period of Pch Tr. (toff).
The difference between ILmax and ILmin is described as ΔI:
∆I = ILmax – ILmin = VOUT x topen / L = (VIN – VOUT) x ton / L ....................................Equation 1
Wherein,
T = 1 / fosc = ton + toff
duty (%)= ton / T x 100 = ton x fosc x 100
topen
<
=
toff
In Equation 1, “VOUT x topen / L” shows the amount of current change at the on-time. “(VIN – VOUT) x ton / L”
shows the amount of current change at the off-time”.
RP502x
13
Discontinuous mode and Continuous mode
As the following diagram shows, when the output current (IOUT) is relatively small, topen will be smaller than
toff (topen < toff). In this case, the all energy charged in the inductor during the time period of ton will be
discharged during the time period of toff. As a result, IL will be ILmin (=0). If IOUT is gradually increased,
eventually topen will be equal to toff (topen=toff). If IOUT is further increased, ILmin will be larger than zero
(ILmin>0). The former mode (topen<toff) is referred to as “discontinuous mode” and the latter mode (topen=toff)
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, solve the equation 1 for ton, and assume that the solution is tonc.
tonc = T x VOUT / VIN ..................................................................................................... Equation 2
If ton is smaller than tonc (ton<tonc), it is discontinuous mode. If ton is equal to tonc (ton=tonc), it is continuous
mode.
RP502x
14
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 turned on:
(Ripple Current p-p value is described as IRP, On Resistances of Pch Tr. and Nch Tr. are respectively described
as RONP and RONN. Also, the DC resistor of the inductor is described as RL.)
The time period of LX Pch Tr. being “ON” is described as ton.
VIN = VOUT + (RONP + RL) x IOUT + L x IRP / ton ...............................................................Equation 3
The time period of Lx Pch Tr. being "OFF" is described as toff. (Nch Tr. is "ON"):
L x IRP / toff = RONN x IOUT + VOUT + RL x IOUT .............................................................Equation 4
Substitute Equation 4 into Equation 3 to solve for ON duty of Pch Tr.: (DON = ton / (toff + ton).
DON = (VOUT + RONN x IOUT + RL x IOUT) / (VIN + RONN x IOUT – RONP x IOUT) ....................Equation 5
Ripple Current is solved by the following equation:
IRP = (VIN – VOUT – RONP x IOUT – RL x IOUT) x DON / fosc / L ..........................................Equation 6
Wherein, peak current that flows through L and LX Tr. is solved by the following equation:
ILxmax = IOUT + IRP / 2...................................................................................................Equation 7
It is necessary to consider ILxmax when deciding the input/output conditions and selecting the peripheral
components.
∗The above calculation is based on the ideal operation of the ICs in continuous mode.
RP502x
15
TIMING CHART
(1) Soft-Start Time
• In the case of starting the ICs with CE
The ICs start to operate when the CE pin voltage (VCE) exceeds the threshold voltage. The threshold voltage
is set between CE “H” input voltage (VCEH) and CE ”L” input voltage (VCEL).
When the ICs start to operate, the soft-start circuit also starts to operate. After a certain period of time, the
reference voltage (VREF) of the inside the ICs gradually rise up to the specified value.
VCEH
Soft-start Time
IC Internal Voltage
Reference
VCEL
Threshold Level
LX Voltage
(VCE)
(VREF) Soft-Start Circuit
starts to operate
(VLX)
Influences by Power supply,
Load Current, External Components
(VOUT)
Output Voltage
CE Pin
Input Voltage
Operate with PWM mode
during the Soft-start Time
Soft-start time is the time period from when the soft-start circuit started to when the reference voltage
reached to the specified value.
∗ Soft-start time may not always equal to the actual start-up time of DC/DC converter.
Start-up peed could be affected by the power supply capacity, the output current value, the inductor value
and capacitor value.
• In the case of starting with power supply
After starting up with power supply, the ICs starts to operate when the input voltage (VIN) exceeds the
UVLO released voltage (VUVL02). The soft-start circuit starts to operate and then the reference voltage (VREF)
of the inside the ICs gradually rise up to the specified value.
Soft-start time is the time period from when the soft-start circuit started to when the reference voltage
reached to the specified value.
Output Voltage
Input Voltage
VUVLO2
IC Internal Voltage
Reference
VUVLO1
LX Voltage
Set VOUT
Set VOUT
Soft-start Time
Influences by Power supply,
Load Current, External Components
Operate with PWM mode during the Soft-start Time
(VOUT)
(VIN)
(VREF)
(VLX)
∗The start-up speed of the output voltage could be affected by the following elements.
(a) The start-up speed of the input voltage (VIN), which is determined by the power supply for the ICs and
also by the input capacitor (CIN).
(b) The output capacitor (COUT) value and the output current value.
RP502x
16
(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).
VUVLO2
VUVLO1
Set VOUT
Set VOUT
Output Voltage
Input Voltage
IC Internal Voltage
Reference
LX Voltage
Soft-start Time
Influences by Power supply,
Load Current, External Components
(VOUT)
(VIN)
(VREF)
(VLX)
* The start-up speeds of VOUT at operation and recovery or the default voltage and the output current of COUT.
Could affect on the waveform in the above chart. Therefore, the actual waveform could be slightly different
from the waveform in the above chart.
RP502x
17
(3) Overcurrent Protection Circuit, Latch Type Protection Circuit
Overcurrent protection circuit supervises the peak current of the inductor (The current passing through
Pch Tr.) at each switching cycle. If the peak current exceeds the LX current limit (ILXLIM), the overcurrent
protection circuit turns off the Pch transistor. The LX current limit of the RP502x Series is set at Typ. 900mA
(VOUT≥1.2V), and Typ. 800mA (VOUT<1.2V).
Latch type protection circuit latches the built-in driver in OFF state to stop the operation of the ICs if the
overcurrent status continues more than the protection delay time (tprot).
∗LX limit current (ILXLIM) and the protection delay time (tprot) could be easily affected by self-heating and
ambient environment. The drastic drop of input voltage (VIN) or the unstable input voltage caused by the
short-circuiting in the output (VOUT) may affect on the protection operation and the delay time.
Protection Delay Time (t
prot
)
L
X
Current Limit (I
LXLIM
)
L
X
Current
Pch Tr. Current
L
X
Voltage
(V
LX
)
To release the latch type protection circuit, reset the ICs by inputting “L” into CE pin or make the input
voltage lower than the UVLO detector threshold (VUVL01).
As the following timing chart shows, the changing process of input voltage flows as follows: start-up,
stable operation, high load condition, CE reset, stable operation, input voltage drop, input voltage recovery,
and stable operation.
If the ICs enters the high load condition due to short-circuit or such, after the protection delay time (tprot),
the built-in driver is latched in OFF state. VLX becomes “L” and then the output voltage turns off. There are
two ways of releasing the latch type protection: CE reset and UVLO reset.
(1) CE reset makes the CE signal to “L” once and then turns the CE signal back to “H” again.
(2) UVLO rest makes the input voltage lower than the UVLO voltage (VUVL01).
Input Voltage
(V
IN
)
Set VOUT
UVLO Detect Voltage (VUVLO1)
CE Pin
Input Voltage
(V
CE
)
Set VOUT
Threshold Level
L
X
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
RP502x
18
TYPICAL CHARACTERISTICS
1
)
出力電圧対出力電流特性例
RP502x081B/083B RP502x121B/123B
RP502x181B/183B RP502x291B/293B
RP502x182B/184B RP502x332B/334B
0.700
0.725
0.750
0.775
0.800
0.825
0.850
0.875
0.900
1 10 100 1000
Output Current I
OUT
(mA)
Output Voltage V
OUT
(V)
VIN=3.6V
VIN=4.5V
1.100
1.125
1.150
1.175
1.200
1.225
1.250
1.275
1.300
1 10 100 1000
Output Current I
OUT
(mA)
Output Voltage V
OUT
(V)
VIN=3.6V
VIN=5.0V
1.700
1.725
1.750
1.775
1.800
1.825
1.850
1.875
1.900
1 10 100 1000
Output Current I
OUT
(mA)
Output Voltage V
OUT
(V)
VIN=3.6V
VIN=5.0V
1.700
1.725
1.750
1.775
1.800
1.825
1.850
1.875
1.900
1 10 100 1000
Output Current I
OUT
(mA)
Output Voltage V
OUT
(V)
VIN=3.6V
VIN=5.0V
3.200
3.225
3.250
3.275
3.300
3.325
3.350
3.375
3.400
1 10 100 1000
Output Current I
OUT
(mA)
Output Voltage V
OUT
(V)
VIN=4.3V
VIN=5.0V
2.800
2.825
2.850
2.875
2.900
2.925
2.950
2.975
3.000
1 10 100 1000
Output Current I
OUT
(mA)
Output Voltage V
OUT
(V)
VIN=3.9V
VIN=5.0V
1) Outp ut Voltage vs. Ou tput Current
RP502x
19
2
)
出力電圧対入力電圧特性例
RP502x121B/123B RP502x181B/183B
RP502x291B/293B RP502x182B/184B
3
)
出力電圧対周囲温度特性例
RP502x332B/334B RP502x16xB
V
IN
=3.6V
1.100
1.125
1.150
1.175
1.200
1.225
1.250
1.275
1.300
2.5 3.0 3.5 4.0 4.5 5.0 5.5
Input Voltage V
IN
(V)
Output Voltage V
OUT
(V)
IOUT=1mA
IOUT=50mA
IOUT=250mA
2.800
2.825
2.850
2.875
2.900
2.925
2.950
2.975
3.000
3.4 3.9 4.4 4.9 5.4
Input Voltage V
IN
(V)
Output Voltage V
OUT
(V)
IOUT=1mA
IOUT=50mA
IOUT=250mA
3.200
3.225
3.250
3.275
3.300
3.325
3.350
3.375
3.400
3.8 4.3 4.8 5.3
Input Voltage V
IN
(V)
Output Voltage V
OUT
(V)
IOUT=1mA
IOUT=50mA
IOUT=250mA
1.500
1.525
1.550
1.575
1.600
1.625
1.650
1.675
1.700
-50 -25 0 25 50 75 100
Temperature Ta(°C)
Output Voltage V
OUT
(V)
VOUT=1.6V
1.700
1.725
1.750
1.775
1.800
1.825
1.850
1.875
1.900
2.5 3.0 3.5 4.0 4.5 5.0 5.5
Input Voltage V
IN
(V)
Output Voltage V
OUT
(V)
IOUT=1mA
IOUT=50mA
IOUT=250mA
1.700
1.725
1.750
1.775
1.800
1.825
1.850
1.875
1.900
2.5 3.0 3.5 4.0 4.5 5.0 5.5
Input Voltage V
IN
(V)
Output Voltage V
OUT
(V)
IOUT=1mA
IOUT=50mA
IOUT=250mA
2) Output Voltage vs. Input Voltage
3) Output Voltage vs. Temperature
RP502x
20
4
)
効率対出力電流特性例
RP502x081B/083B RP502x121B/123B
RP502x181B/182B RP502x291B/293B
RP502x182B/184B RP502x332B/334B
20
30
40
50
60
70
80
90
100
1 10 100 1000
Output Current I
OUT
(mA)
Efficiency (%)
VIN=3.6V
VIN=4.5V
20
30
40
50
60
70
80
90
100
1 10 100 1000
Output Current I
OUT
(mA)
Efficiency (%)
VIN=3.6V
VIN=5.0V
20
30
40
50
60
70
80
90
100
1 10 100 1000
Output Current I
OUT
(mA)
Efficiency (%)
VIN=3.6V
VIN=5.0V
20
30
40
50
60
70
80
90
100
1 10 100 1000
Output Current I
OUT
(mA)
Efficiency (%)
VIN=3.6V
VIN=5.0V
20
30
40
50
60
70
80
90
100
1 10 100 1000
Output Current I
OUT
(mA)
Efficiency (%)
VIN=4.3V
VIN=5.0V
20
30
40
50
60
70
80
90
100
1 10 100 1000
Output Current I
OUT
(mA)
Efficiency (%)
VIN=3.9V
VIN=5.0V
4
)
Efficienc
y
vs. Output current
RP502x181B/183B
RP502x
21
5
)
Su
pp
l
y
Current 1
,
2 vs.Te m
p
erature 6) Supp ly Curren t 1, 2 vs. Input Volta ge
RP502x15xB RP502x15xB
VIN=5.5V
7) DC/DC Out pu t Wa v eform
RP502x081B/083B RP502x081B/083B
RP502x121B/123B RP502x121B/123B
0
100
200
300
400
500
600
700
800
900
1000
-50 -25 0 25 50 75 100
Temperature Ta (°C)
Supply Curren t (µA)
IDD1
IDD2
0
100
200
300
400
500
600
700
800
900
1000
2.5 3.5 4.5 5.5
Input Voltage VIN (V)
Supply Current (µA)
IDD1
IDD2
VIN=3.6V,IOUT=1mA
0.00
0.02
0.04
0.06
0.08
0.10
0 100 200 300 400
Tim e t (µ s)
Output Ripple Volt age(AC)
Vripple (V)
-100
0
100
Inductor Current IL (mA)
Output Voltage
IL
VIN=3.6V,IOU T =25 0m A
0.00
0.02
0.04
0.06
0.08
0.10
0246810
Time t (µs)
Output Ripple Voltage(AC)
Vripple (V)
0
100
200
300
400
Inductor Current IL (mA)
Output Voltage
IL
VIN=3.6V,IOUT=1mA
0.00
0.02
0.04
0.06
0.08
0.10
0 100 200 300 400
Tim e t (µ s)
Out put Ripple Volt age(AC)
Vripple (V)
-100
0
100
Inductor Current IL (mA)
Output Voltage
IL
VIN=3.6V,IOU T =25 0m A
0.00
0.02
0.04
0.06
0.08
0.10
0246810
Time t (µs)
Out put Ripple Voltage(AC)
Vripple (V)
0
100
200
300
400
Inductor Current IL (mA)
Output Voltage
IL
RP502x
22
RP502x181B/183B RP502x181B/183B
RP502x182B/184B RP502x182B/184B
RP502x332B/334B RP502x332B/334B
V
IN
=3.6V,I
OUT
=1mA
0.00
0.02
0.04
0.06
0.08
0.10
0 100 200 300 400
Time t (µs)
Output Ripple Voltage(AC)
Vripple (V)
-100
0
100
Inductor Current IL (mA)
Output Voltage
IL
V
IN
=3.6V,I
OUT
=250mA
0.00
0.02
0.04
0.06
0.08
0.10
0246810
Time t (µs)
Output Ripple Voltage(AC)
Vripple (V)
0
100
200
300
400
Inductor Current IL (mA)
Output Voltage
IL
V
IN
=3.6V,I
OUT
=1mA
0.00
0.02
0.04
0.06
0.08
0.10
0.00.51.01.52.0
Time t (µs)
Output Ripple Voltage(AC)
Vripple (V)
-100
0
100
Inductor Current IL (mA)
Output Voltage
IL
V
IN
=3.6V,I
OUT
=250mA
0.00
0.02
0.04
0.06
0.08
0.10
0246810
Time t (µs)
Output Ripple Voltage(AC)
Vripple (V)
0
100
200
300
400
Inductor Current IL (mA)
Output Voltage
IL
V
IN
=5.0V,I
OUT
=1mA
0.00
0.02
0.04
0.06
0.08
0.10
0.00.51.01.52.0
Time t (µs)
Output Ripple Voltage(AC)
Vripple (V)
-100
0
100
Inductor Current IL (mA)
Output Voltage
IL
V
IN
=5.0V,I
OUT
=250mA
0.00
0.02
0.04
0.06
0.08
0.10
0246810
Time t (µs)
Output Ripple Voltage(AC)
Vripple (V)
0
100
200
300
400
Inductor Current IL (mA)
Output Voltage
IL
RP502x
23
8) Oscillat or Frequency vs. Tempera ture 9) Oscillator Frequency vs. Input Voltage
RP502x12xB RP502x12xB
VIN=3.6V,IOUT=250ｍA
10) Soft- s tart T i me vs. Temperature
RP502x15xB
11) UVLO Detector T hresh old / Released Voltage vs. Temper ature
RP502x15xB RP502x15xB
IOUT=250ｍA
UVLO Detect or Threshold Released Voltage
2.9
3.0
3.1
3.2
3.3
3.4
3.5
3.6
3.7
-50 -25 0 25 50 75 100
Temperature Ta (°C)
Frequency fosc (MHz)
VIN=3. 6V
2.9
3.0
3.1
3.2
3.3
3.4
3.5
3.6
3.7
2.5 3.5 4.5 5.5
Input Voltage VIN (V)
Frequency fosc (MHz)
-40°C
25°C
85°C
80
90
100
110
120
130
140
-50-25 0 25 50 75100
Temperature Ta (°C)
Soft Start Time tstart (µs)
2.1
2.2
2.3
2.4
-50-25 0 25 50 75100
Temperature Ta (°C)
UVLO Voltage V UVLO1 (V)
2.1
2.2
2.3
2.4
-50 -25 0 25 50 75 100
Temperature Ta(°C)
UVLO Voltage V UVLO2 (V)
RP502x
24
12) CE I npu t Voltage vs . Temperature
RP502x16xB RP502x16xB
VIN=5 .5V VIN=2.5V
13)
L
X Current Lim it vs. Temperature
RP502x15xB
14) Nch Tr. ON Resistance vs. Temperat ure 15) Pch Tr. ON Resistance vs.Temperature
CE "H" Input Voltage CE "L" Inpu t Voltage
0.0
0.2
0.4
0.6
0.8
1.0
-50-25 0 25 50 75100
Temperature Ta (°C)
CE Input Voltage V CE (V)
0.0
0.2
0.4
0.6
0.8
1.0
-50-25 0 25 50 75100
Temperature Ta(°C)
CE Input Voltage V CE (V)
800
850
900
950
1000
1050
1100
-50-250 255075100
Temperature Ta (°C)
LX Current Limit Ilim (mA)
0.0
0.1
0.2
0.3
0.4
0.5
0.6
-50-25 0 25 50 75100
Temperature Ta (°C)
Nch Tr. ONResistance R ON (Ω)
0.0
0.1
0.2
0.3
0.4
0.5
0.6
-50-25 0 25 50 75100
Temperature Ta(°C)
Nch Tr . ONResistance R ON (Ω)
RP502x
25
16
)
CE応答特性例
RP502x081B/083B RP502x121B/123B
RP502x181B/183B RP502x291B/293B
RP502x182B/184B RP502x332B/334B
V
IN
=3.6V,R
OUT
=1kΩ
0.0
0.2
0.4
0.6
0.8
1.0
0 100 200 300 400
Time t (µs)
Output Voltage V
OUT
(V)
0
3
6
CE Input Voltage V
CE
(V)
CE Input
Output Voltage
V
IN
=3.6V,R
OUT
=1kΩ
0.0
0.2
0.4
0.6
0.8
1.0
1.2
0 100 200 300 400
Time t (µs)
Output Voltage V
OUT
(V)
0
3
6
CE Input Voltage V
CE
(V)
CE Input
Output Voltage
V
IN
=5.0V,R
OUT
=1kΩ
0.0
0.5
1.0
1.5
2.0
2.5
3.0
0 100 200 300 400
Time t (µs)
Output Voltage V
OUT
(V)
0
3
6
CE Input Voltage V
CE
(V)
CE Input
Output Voltage
V
IN
=3.6V,R
OUT
=1kΩ
0.0
0.5
1.0
1.5
2.0
0 100 200 300 400
Time t (µs)
Output Voltage V
OUT
(V)
0
3
6
CE Input Voltage V
CE
(V)
CE Input
Output Voltage
V
IN
=5.0V,R
OUT
=1kΩ
0.0
1.0
2.0
3.0
0 100 200 300 400
Time t (µs)
Output Voltage V
OUT
(V)
0
3
6
CE Input Voltage V
CE
(V)
CE Input
Output Voltage
V
IN
=3.6V,R
OUT
=1kΩ
0.0
0.5
1.0
1.5
2.0
0 100 200 300 400
Time t (µs)
Output Voltage V
OUT
(V)
0
3
6
CE Input Voltage V
CE
(V)
CE Input
Output Voltage
16) Turn on speed with CE pin
RP502x
26
17) Load Transien t Response
RP502x081B/083B RP502x081B/083B
VIN=3.6V VIN=3.6V
RP502x081B/083B RP502x081B/083B
VIN=3.6V VIN=3.6V
RP502x121B/123B RP502x121B/123B
VIN=3.6V VIN=3.6V
0.70
0.75
0.80
0.85
0 20406080100
Time t (µs)
Output Voltage V OUT (V)
0
200
400
Output Current I OUT (mA)
Output Current 1mA --> 300mA
Output Voltage
0.70
0.75
0.80
0.85
0.90
0 200 400 60 0 800 1000
Time t (µs)
Output Voltage V OUT (V)
0
200
400
Output Current I OUT (mA)
Output Current 300mA --> 1mA
Output Voltage
0.70
0.75
0.80
0.85
0 20406080100
Time t (µs)
Output Voltage V OUT (V)
0
200
400
600
Output Current I OUT (mA)
Output Current 200mA --> 500mA
Output Voltage
0.70
0.75
0.80
0.85
0.90
0 200 400 600 800 1000
Time t (µs)
Output Voltage V OUT (V)
0
200
400
600
Output Current I OUT (mA)
Output Current 500mA --> 200mA
Output Voltage
1.10
1.15
1.20
1.25
0 20406080100
Time t (µs)
Output Voltage V OUT (V)
0
200
400
Output Current I OUT (mA)
Output Current 1mA --> 300mA
Output Voltage
1.10
1.15
1.20
1.25
1.30
0 200 400 600 800 1000
Time t (µs)
Output Voltage V OUT (V )
0
200
400
Output Current I OUT (mA)
Output Current 300mA --> 1mA
Output Voltage
RP502x
27
RP502x121B/123B RP502x121B/123B
V
IN
=3.6V V
IN
=3.6V
RP502x181B/183B RP502x181B/183B
V
IN
=3.6V V
IN
=3.6V
RP502x181B/183B RP502x181B/183B
V
IN
=3.6V V
IN
=3.6V
1.10
1.15
1.20
1.25
0 20 40 60 80 100
Time t (µs)
Output Voltage V
OUT
(V)
0
200
400
600
Output Current I
OUT
(mA)
Output Current 200mA --> 500mA
Output Voltage
1.10
1.15
1.20
1.25
1.30
0 200 400 600 800 1000
Time t (µs)
Output Voltage V
OUT
(V)
0
200
400
600
Output Current I
OUT
(mA)
Output Current 500mA --> 200mA
Output Voltage
1.70
1.75
1.80
1.85
1.90
0 20 40 60 80 100
Time t (µs)
Output Voltage V
OUT
(V)
0
200
400
Output Current I
OUT
(mA)
Output Current 1mA --> 300mA
Output Voltage
1.70
1.75
1.80
1.85
1.90
0 200 400 600 800 1000
Time t (µs)
Output Voltage V
OUT
(V)
0
200
400
Output Current I
OUT
(mA)
Output Current 300mA --> 1mA
Output Voltage
1.70
1.75
1.80
1.85
1.90
0 20 40 60 80 100
Time t (µs)
Output Voltage V
OUT
(V)
0
200
400
600
Output Current I
OUT
(mA)
Output Current 200mA --> 500mA
Output Voltage
1.70
1.75
1.80
1.85
1.90
0 20406080100
Time t (µs)
Output Voltage V
OUT
(V)
0
200
400
600
Output Current I
OUT
(mA)
Output Current 500mA --> 200mA
Output Voltage
RP502x
28
RP502x182B/184B RP502x182B/184B
V
IN
=3.6V V
IN
=3.6V
RP502x182B/184B RP502x182B/184B
V
IN
=3.6V V
IN
=3.6V
RP502x332B/334B RP502x332B/334B
V
IN
=5.0V V
IN
=5.0V
1.70
1.75
1.80
1.85
1.90
0 20 40 60 80 100
Time t (µs)
Output Voltage V
OUT
(V)
0
200
400
Output Current I
OUT
(mA)
Output Current 1mA --> 300mA
Output Voltage
1.70
1.75
1.80
1.85
1.90
0 200 400 600 800 1000
Time t (µs)
Output Voltage V
OUT
(V)
0
200
400
Output Current I
OUT
(mA)
Output Current 300mA --> 1mA
Output Voltage
1.70
1.75
1.80
1.85
1.90
0 20 40 60 80 100
Time t (µs)
Output Voltage V
OUT
(V)
0
200
400
600
Output Current I
OUT
(mA)
Output Current 200mA --> 500mA
Output Voltage
1.70
1.75
1.80
1.85
1.90
020406080100
Time t (µs)
Output Voltage V
OUT
(V)
0
200
400
600
Output Current I
OUT
(mA)
Output Current 500mA --> 200mA
Output Voltage
3.10
3.15
3.20
3.25
3.30
3.35
0 20 40 60 80 100
Time t (µs)
Output Voltage V
OUT
(V)
0
200
400
Output Current I
OUT
(mA)
Output Current 1mA --> 300mA
Output Voltage
3.10
3.15
3.20
3.25
3.30
3.35
0 200 400 600 800 1000
Time t (µs)
Output Voltage V
OUT
(V)
0
200
400
Output Current I
OUT
(mA)
Output Current 300mA --> 1mA
Output Voltage
RP502x
29
RP502x332B/334B RP502x332B/334B
V
IN
=5.0V V
IN
=5.0V
3.10
3.15
3.20
3.25
3.30
3.35
0 20 40 60 80 100
Time t (µs)
Output Voltage V
OUT
(V)
0
200
400
600
Output Current I
OUT
(mA)
Output Current 200mA --> 500mA
Output Voltage
3.10
3.15
3.20
3.25
3.30
3.35
020406080100
Time t (µs)
Output Voltage V
OUT
(V)
0
200
400
600
Output Current I
OUT
(mA)
Output Current 500mA --> 200mA
Output Voltage
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informationthereon.
2.Thematerialsinthisdocumentmaynotbecopiedorotherwisereproducedinwholeorinpart
withoutpriorwrittenconsentofRicoh.
3.Pleasebesuretotakeanynecessaryformalitiesunderrelevantlawsorregulationsbefore
exportingorotherwisetakingoutofyourcountrytheproductsorthetechnicalinformation
describedherein.
4.Thetechnicalinformationdescribedinthisdocumentshowstypicalcharacteristicsofand
exampleapplicationcircuitsfortheproducts.Thereleaseofsuchinformationisnottobe
construedasawarrantyoforagrantoflicenseunderRicoh'soranythirdparty'sintellectual
propertyrightsoranyotherrights.
5.
Theproductslistedinthisdocumentareintendedanddesignedforuseasgeneralelectronic
componentsinstandardapplications(officeequipment,telecommunicationequipment,
measuringinstruments,consumerelectronicproducts,amusementequipmentetc.).Those
customersintendingtouse
aproductinanapplicationrequiringextremequalityandreliability,
forexample,inahighlyspecificapplicationwherethefailureormisoperationoftheproduct
couldresultinhumaninjuryordeath(aircraft,spacevehicle,nuclearreactorcontrolsystem,
trafficcontrolsystem,automotiveand
transportationequipment,combustionequipment,safety
devices,lifesupportsystemetc.)shouldfirstcontactus.
6.Wearemakingourcontinuousefforttoimprovethequalityandreliabilityofourproducts,but
semiconductorproductsarelikelytofailwithcertainprobability.Inordertopreventanyinjuryto
personsordamagestopropertyresultingfromsuchfailure,customersshouldbecarefulenough
toincorporatesafetymeasuresintheirdesign,suchasredundancyfeature,firecontainment
featureandfail-safefeature.Wedonotassumeanyliability
orresponsibilityforanylossor
damagearisingfrommisuseorinappropriateuseoftheproducts.
7.Anti-radiationdesignisnotimplementedintheproductsdescribedinthisdocument.
8.
PleasecontactRicohsalesrepresentativesshouldyouhaveanyquestionsorcomments
concerningtheproductsorthetechnicalinformation.
RICOHCOMPANY.,LTD.ElectronicDevicesCompany
■
Ricoh presented with the Japan Management Quality Award for 1999
.
Ricoh continually strives to promote customer satisfaction, and shares the achievements
of its management quality improvement program with people and society.
■Ricoh awarded ISO 14001 certification.
The Ricoh Group was awarded ISO 14001 certification, which is an international standard for
environmental management systems, at both its domestic and overseas production facilities.
Our current aim is to obtain ISO 14001 certification for all of our business offices.
Ricoh completed the organization of the Lead-free production for all of our products.
After Apr. 1, 2006, we will ship out the lead free products only. Thus, all products that
will be shipped from now on comply with RoHS Directive.