RP508K Series
600 mA 6 MHz Synchronous Step-down DC/DC Converter
NO. EA-318-171106
OUTLINE
The RP508K is a low supply current PWM/VFM step-down DC/DC converter with synchronous rectifier
featuring 600 mA(1) output current. Internally, a single converter consists of an oscillator, a reference voltage
unit, an error amplifier, a switching control circuit, a mode control circuit, a soft-start circuit, an under-voltage
lockout (UVLO) circuit, an over current protection circuit, a thermal shutdown circuit and switching transistors.
By the adoption of the synchronous rectification circuit with built-in switching transistors, the RP508K works as
efficient step-down DC/DC converter, without connecting external diodes. Using synchronous rectification not
only increases circuit performance but also allows a design to reduce parts count.
Power controlling method can be selected from forced PWM control type or PWM/VFM auto switching control
type by inputting a signal to the MODE pin. In low output current, forced PWM control switches at fixed
frequency rate in order to reduce noise. Likewise, in low output current, PWM/VFM auto switching control
automatically switches from PWM mode to VFM mode in order to achieve high efficiency.
Output voltage is internally fixed type which allows output voltages that range from 0.8 V to 3.3 V in 0.1 V step.
The output voltage accuracy is as high as ±1.5% or ±18 mV.
Protection circuits included in the RP508K are over current protection circuit and thermal shutdown circuit.
Over current protection circuit supervises the inductor peak current in each switching cycle, and if the current
exceeds the LX current limit (ILXLIM), it turns off P-channel Tr. Thermal shutdown circuit detects overheating of
the converter if the output pin is shorted to the ground pin (GND) etc. and stops the converter operation to
protect it from damage if the junction temperature exceeds the specified temperature.
The RP508K is offered in a small and thin 6-pin DFN(PLP)1212-6F package which achieves the smallest
possible footprint solution on boards where area is limited.
For an input capacitor (CIN) and an output capacitor (COUT), the smaller sized 0402/1005 (inch/mm) capacitor
can be used. For an inductor (L), the smaller sized 0603/1608 or 1005/2012 (inch/mm) inductor can be used.
FEATURES
• Input Voltage Range (VIN) ····································· 2.3 V to 5.5 V (Absolute Maximum Ratings: 6.5 V)
• Output Voltage Range (VOUT) ································· 0.8 V to 3.3 V (Adjustable in 0.1 V steps)
• Supply Current (IDD2) ············································ Typ. 15 µA (VFM Mode with No-load)
• Standby Current (Istandby) ··································· Typ. 0 µA
• Output Voltage Temperature Coefficient (∆VOUT/Ta) ······ Typ. ±100 ppm/°C
• Oscillator Frequency (fosc)···································· Typ. 6.0 MHz
• Maximum Duty Cycle (Maxduty) ····························· 100%
• Built-in Driver ON Resistance (RONP, RONN) ··············· Typ. Pch. 0.33 Ω, Nch. 0.24 Ω (VIN = 3.6 V)
• UVLO Detector Threshold (VUVLO01) ························· Typ. 2.0 V
• Soft-start Time (tstart) ·········································· Typ. 90 µs
(1)
This is an approximate value. The output current is dependent on conditions and external components.
1
RP508K
NO. EA-318-171106
• LX Current Limit Circuit (ILXLIM) ································ Typ. 1.1 A
• Output Voltage Accuracy ······································ ±1.5% (VOUT ≥ 1.2 V) or ±18 mV (VOUT < 1.2 V)
• Package
························································ DFN(PLP)1212-6F
APPLICATIONS
• Cellular Phones
• Smartphones
• Digital Still Camera
• Notebook PCs, PDA’s
• Li-ion Battery-used Equipment
SELECTION GUIDE
The set output voltage and the auto discharge(1) function are user-selectable options.
Selection Guide
Product Name
Package
Quantity per Reel
Pb Free
Halogen Free
RP508Kxx1$-TR
DFN(PLP)1212-6F
5,000 pcs
Yes
Yes
xx: Specify the set output voltage (VSET) within the range of 0.8 V (08) to 3.3 V (33) in 0.1 V steps(2).
If the set output voltage includes the 3rd digit, indicate the digit of 0.01.
(1.05 V, 1.25 V, 1.35 V)
Ex. If the set output voltage is 1.05 V: RP508K101$5
If the set output voltage is 1.25 V: RP508K121$5
If the set output voltage is 1.35 V: RP508K131$5
$: Specify the auto-discharge option.
A: Fixed output voltage type
B: Fixed output voltage type, auto-discharge function in shutdown mode
(1)
(2)
2
Auto-discharge function quickly lowers the output voltage to 0 V, 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.
0.05 V step is also available as a custom code.
RP508K
NO. EA-318-171106
BLOCK DIAGRAM
VIN
UVLO
Clock
Generator
Delay
Control
Thermal
Protection
Soft Start
Current
Detector
Vref
Switching
Control
Delay
Mode
Control
MODE
OSC
Chip
Enable
CE
LX
VOUT
+
RIPPLE
Control
GND
RP508Kxx1A Block Diagram
VIN
UVLO
Clock
Generator
Delay
Control
Thermal
Protection
Soft Start
Current
Detector
Vref
CE
Switching
Control
Delay
Mode
Control
MODE
LX
OSC
Chip
Enable
VOUT
+
RIPPLE
Control
GND
RP508Kxx1B Block Diagram
3
RP508K
NO. EA-318-171106
PIN DESCRIPTION
Top View
Bottom View
6
5
4
4
5
6
1
2
3
3
2
1
DFN(PLP)1212-6F Pin Configurations
Pin Description
Pin No.
Symbol
4
Pin Description
1
VOUT
Output Pin
2
MODE
3
CE
Chip Enable Pin ("H" active)
4
VIN
Input Pin
5
LX
LX Switching Pin
6
GND
Mode Control Pin
(“H” forced PWM control, “L” PWM/VFM auto switching control)
Ground Pin
RP508K
NO. EA-318-171106
ABSOLUTE MAXIMUM RATINGS
Absolute Maximum Ratings
Symbol
Item
Rating
Unit
−0.3 to 6.5
V
−0.3 to VIN +0.3
V
VIN
VIN Input Voltage
VLX
LX Pin Voltage
VCE
CE Pin Input Voltage
−0.3 to 6.5
V
VMODE
MODE Pin Input Voltage
−0.3 to 6.5
V
VOUT
VOUT Pin Voltage
−0.3 to 6.5
V
ILX
LX Pin Output Current
1300
mA
PD
Power Dissipation(1) (JEDEC STD 51-7 Test Land Pattern )
666
mW
Tj
Junction Temperature Range
−40 to 125
°C
Tstg
Storage Temperature Range
−55 to 125
°C
ABSOLUTE MAXIMUM RATINGS
Electronic and mechanical stress momentarily exceeded absolute maximum ratings may cause 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 are not assured.
RECOMMENDED OPERATING CONDITIONS
Symbol
Item
Rating
Unit
VIN
Input Voltage
2.3 to 5.5
V
Ta
Operating Temperature Range
−40 to 85
°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.
(1)
Refer to POWER DISSIPATION for detailed information.
5
RP508K
NO. EA-318-171106
ELECTRICAL CHARACTERISTICS
RP508K Electrical Characteristics
Symbol
Item
VOUT
Conditions
Typ.
VSET ≥ 1.2 V
x0.985
x1.015
V
VSET < 1.2 V
−0.018
+0.018
V
6.0
6.6
MHz
1000
1300
µA
15
25
µA
1000
1300
µA
0
5
µA
Output Voltage
VIN = VCE = 3.6 V
fosc
Oscillator Frequency
VIN = VCE = 3.6 V (VSET ≤ 2.6 V),
VIN = VCE = VSET + 1 V (VSET > 2.6 V)
IDD1
Supply Current 1
VIN = VCE = 5.5 V,
VOUT = VSET × 0.8
IDD2
Supply Current 2
VIN = VCE = VOUT
= 5.5 V
Istandby Standby Current
Min.
(Ta = 25°C)
Max. Unit
5.4
VMODE = 0 V
VMODE = 5.5 V
VIN = 5.5 V, VCE = 0 V
ICEH
CE “H” Input Current
VIN = VCE = 5.5 V
−1
0
1
µA
ICEL
CE “L” Input Current
VIN = 5.5 V, VCE = 0 V
−1
0
1
µA
IMODEH
Mode “H” Input Current
VIN = VMODE = 5.5 V, VCE = 0 V
−1
0
1
µA
IMODEL
Mode “L” Input Current
VIN = 5.5 V, VCE = VMODE = 0 V
−1
0
1
µA
VIN = VOUT = 5.5 V, VCE = 0 V
−1
0
1
µA
−1
0
1
µA
Current( 1)
IVOUTH
VOUT “H” Input
IVOUTL
VOUT “L” Input Current
VIN = 5.5 V, VCE = VOUT = 0 V
RLOW
On Resistance for
Auto Discharge(2)
VIN = 3.6 V, VCE = 0 V
ILXLEAKH
LX Leakage Current “H”
VIN = VLX = 5.5 V, VCE = 0 V
−1
0
5
µA
ILXLEAKL
LX Leakage Current “L”
VIN = 5.5 V, VCE = VLX = 0 V
−5
0
1
µA
VCEH
CE “H” Input Voltage
VIN = 5.5 V
1.0
VCEL
Ω
30
V
CE “L” Input Voltage
VIN = 2.3 V
VMODEH
Mode ”H” Input Voltage
VIN = VCE = 5.5 V
VMODEL
Mode ”L” Input Voltage
VIN = VCE = 2.3 V
RONP
On Resistance of Pch Tr.
VIN = 3.6 V, ILX = −100 mA
0.33
Ω
RONN
On Resistance of Nch Tr.
VIN = 3.6 V, ILX = −100 mA
0.24
Ω
Maxduty
Maximum Duty Cycle
tstart
Soft-start Time
ILXLIM
LX Current Limit
0.4
1.0
V
0.4
100
Soft-start Time is between the rising
edge of CE pin and VOUT ≥ VSET x 0.9.
V
V
%
90
150
µs
900
1100
VUVLO1
UVLO Detector Threshold
VIN = VCE
1.9
2.0
2.1
V
VUVLO2
UVLO Released Voltage
VIN = VCE
2.0
2.1
2.2
V
TTSD
TTSR
Thermal Shutdown
Junction Temperature
Temperature
Thermal Shutdown Released
Junction Temperature
Temperature
mA
140
°C
100
°C
All test items listed under ELECTRICAL CHARACTERISTICS are done under the pulse load condition (Tj ≈ Ta = 25°C)
except Output Voltage Temperature Coefficient.
(1)
(2)
6
RP508Kxx1A only
RP508Kxx1B only
RP508K
NO. EA-318-171106
THEORY OF OPERATION
Fast Frequency and Fast Response
VIN
UVLO
Clock
Generator
4.7uF
Delay
Control
LX
Thermal
Protection
Current
Detector
Vref
Soft Start
Switching
Control
Delay
0.47uH or 1.0uH
MODE
MODE Control
Mode
Control
CE
CE Control
VIN
OSC
VOUT
Chip
Enable
VOUT
+
RIPPLE
Control
GND
4.7uF
*
∗ Ripple is added and easy to detect and stabilize the system.
There are the following advantages when it operates at fast frequency (6 MHz).
- Inductance value can be reduced.
- The fluctuation of energy in one cycle is fast and small, as a result, the capacitance value of COUT can be also
reduced.
- Small LC value reduced the feedback delay, then response frequency band can be wide and transient
response is much improved compared with conventional line-up.
Maximum Frequency (6 MHz) Lock
VIN
UVLO
Clock
Generator
4.7uF
Delay
Control
LX
Thermal
Protection
Soft Start
*
Vref
Current
Detector
Switching
Control
Delay
0.47uH or 1.0uH
MODE
MODE Control
CE Control
Mode
Control
CE
VIN
OSC
VOUT
Chip
Enable
VOUT
+
4.7uF
GND
RIPPLE
Control
∗ The frequency goes faster and faster without this.
7
RP508K
NO. EA-318-171106
Switching frequency in order to become reference frequency (6 MHz), delay time is included the output voltage
feedback loop and locked the frequency (6 MHz).
Frequency Control for Minimum On/Off Time
Minimum on/off time/Minimum off time is set. (But 100% duty is available.) In the 6 MHz, based on the
calculation of input/ output relation, on/off time can be calculated, and if it is not satisfy the minimum on time /
minimum off time, the reference frequency must be reduced and switching frequency is reduced.
(Ex.) Min On Time (40 ns)
(Ex.) Min Off Time (40 ns)
VIN = 3.6 V VOUT = 1.0 V
VIN = 5.0 V VOUT = 3.3 V
1/6 MHz × 1.0 V / 3.6 V ≈ 46 ns > Min On Time (= 40 ns)
1/6 MHz × ( 1 - 3.3 V / 5.0 V ) ≈ 57 ns > Min Off Time (=
→6 MHz Switching OK
40 ns)
→6 MHz Switching OK
VIN =5.5V Vout=1.0V
1/6 MHz × 1.0 V / 5.5 V ≈ 30 ns < Min On Time (= 40 ns)
VIN =4.2 V VOUT = 3.3 V
→It must be slow down from 6 MHz
1/6 MHz × ( 1 - 3.3 V / 4.2 V ) ≈ 36 ns < Min Off Time (=
40 ns)
→It must be slow down from 6 MHz
LX Waveform
LX Waveform
46 ns
57 ns
166 ns (= 1/6 MHz)
166 ns (= 1/6 MHz)
Min On Time
(= 40 ns)
Min Off Time
(= 40 ns)
(166 +α) ns > 1/6 MHz
(166 +α) ns > 1/6 MHz
Cycle time becomes long in order to satisfy Min. on
Cycle time becomes long in order to satisfy Min. off
time. It is suitable with keeping the duty.
time. It is suitable with keeping the duty.
8
RP508K
NO. EA-318-171106
Operation of Step-Down DC/DC Converter and Output Current
The step-down DC/DC converter charges energy in the inductor when LX Tr. turns “ON”, and discharges the
energy from the inductor when LX Tr. turns “OFF” and operates with less energy loss, so that a lower output
voltage (VOUT) than the input voltage (VIN) can be obtained.
The operation of the step-down DC/DC converter is explained in the following figures.
IL
ILMAX
i1
VIN
Pch Tr
Nch Tr
ILMIN
VOUT
L
topen
i1
i2
i2
CL
GND
Figure 1. Basic Circuit
Step1.
ton
toff
T = 1 / fosc
Figure 2. Inductor Current (IL) flowing through Inductor
P-channel Tr. turns “ON” and the inductor current (IL = i1) flows, L is charged with energy. At this
moment, i1 increases from the minimum inductor current (ILMIN), which is 0 A, and reaches the
maximum inductor current (ILMAX) in proportion to the on-time period (ton) of P-channel Tr.
Step2.
When P-channel Tr. turns “OFF”, L tries to maintain IL at ILMAX, so L turns N-channel Tr. “ON” and the
inductor current (IL = i2) flows into L.
Step3.
i2 decreases gradually and reaches ILMIN after the open-time period (topen) of N-channel Tr., and then
N-channel Tr. turns “OFF”. This is called discontinuous current mode.
As the output current (IOUT) increases, the off-time period (toff) of P-channel Tr. runs out before IL
reaches ILMIN. The next cycle starts, and P-channel Tr. turns “ON” and N-channel Tr. turns “OFF”,
which means IL starts increasing from ILMIN. This is called continuous current mode.
In the case of PWM mode, VOUT is maintained by controlling ton. During the PWM mode, the oscillator
frequency (fosc) is constantly maintained.
As shown in Figure 2., when the step-down DC/DC operation is constant, ILMIN and ILMAX during ton of P-channel
Tr. is same as the P-channel Tr. during toff.
The current differential between ILMAX and ILMIN is described as ∆I.
∆I = ILMAX − ILMIN = VOUT × topen / L = (VIN − VOUT) × ton / L ·································· Equation 1
However,
T = 1 / fosc = ton + toff
Duty (%) = ton / T × 100 = ton × fosc × 100
topen ≤ toff
In Equation 1, “VOUT × topen / L” shows the amount of current change in “OFF” state. Also, “(VIN − VOUT) × ton
/ L” shows the amount of current change at “ON” state.
9
RP508K
NO. EA-318-171106
Discontinuous Mode and Continuous Mode
As illustrated in Figure 3. when IOUT is relatively small, topen < toff. In this case, the energy charged into L
during ton will be completely discharged during toff, as a result, ILMIN = 0. This is called discontinuous mode.
When IOUT is gradually increased, eventually topen = toff and when IOUT is increased further, eventually ILMIN >
0. This is called continuous mode.
IL
ILMAX
IL
ILMAX
ILMIN
ILMIN
topen
t
ICONST
t
ton
toff
ton
T = 1 / fosc
Figure 3. Discontinuous Mode
toff
T = 1 / fosc
Figure 4. Continuous Mode
In the continuous mode, the solution of Equation 1 is described as tonc.
tonc = T × VOUT / VIN ··························································································· Equation 2
When ton < tonc, it indicates discontinuous mode, and when ton ≥ tonc, it indicates continuous mode.
10
RP508K
NO. EA-318-171106
Forced PWM Mode
By setting the MODE pin to “H”, the RP508K switches on/off at the fixed frequency to reduce noise even under
the light load. When IOUT is ∆IL / 2 or less, ILMIN becomes less than 0. That is, the accumulated electricity in
CL is discharged through the IC side at IL increase period from ILMIN to "0" during ton and at IL decrease
period from "0" to ILMIN during toff.
ILMAX
IL
ΔIL
IOUT
0
ILMIN
t
ton
toff
T = 1 / fosc
Forced PWM Mode
VFM MODE
By setting the MODE pin to “L”, in low output current, the IC automatically switches into VFM mode in order to
achieve high efficiency. In VFM mode, a value of ton is determined by VIN and VOUT.
ILMAX
IL
0
ILMIN
t
ton
toff
VFM Mode
11
RP508K
NO. EA-318-171106
Timing Chart
1. Soft-Start Time
Starting-up with CE Pin
The IC starts to operate when the CE pin voltage (VCE) exceeds the threshold voltage. The threshold voltage
is preset between CE “H” input voltage (VCEH) and CE “L” input voltage (VCEL).
After the start-up of the IC, soft-start circuit starts to operate. Then, after a certain period of time, the reference
voltage (VREF) in the IC gradually increases up to the specified value.
CE Pin Input Voltage
(VCE)
IC Internal Reference Voltage
(VREF)
Lx Voltage
(VLX)
VCEH
Threshold Level
VCEL
Soft-start Time
Soft-start Circuit
operation starts.
IC operates with PWM mode
during Soft-start time.
Output Voltage
(VOUT)
Depending on Power Supply,
Load Current, External Components
Soft-start time starts when soft-start circuit is activated, and ends when the reference voltage reaches the
specified voltage. Soft start time is not always equal to the turn-on speed of the step-down DC/DC converter.
Note that the turn-on speed could be affected by the power supply capacity, the output current, the inductance
value and the COUT value.
Starting-up with Power Supply
After the power-on, when VIN exceeds the UVLO released voltage (VUVLO2), the IC starts to operate. Then, softstart circuit starts to operate and after a certain period of time, VREF gradually increases up to the specified
value. Soft-start time starts when soft-start circuit is activated, and ends when VREF reaches the specified
voltage.
VSET
VUVLO2
Input Voltage
(VIN)
VUVLO1
Soft-start Time
IC Internal Reference Voltage
(VREF)
Lx Voltage
(VLX)
IC operates with PWM mode during Soft-start time.
VSET
Output Voltage
(VOUT)
12
Depending on Power Supply, Load Current,
External Components
RP508K
NO. EA-318-171106
Note that the turn-on speed of VOUT could be affected by the power supply capacity, the output current, the
inductance value, the COUT value and the turn-on speed of VIN determined by CIN.
2.
Under Voltage Lockout (UVLO) Circuit
If VIN becomes lower than VSET, the step-down DC/DC converter stops the switching operation and ON duty
becomes 100%, and then VOUT gradually drops according to VIN.
If the VIN becomes lower than the UVLO detector threshold (VUVLO1), the UVLO circuit starts to operate, VREF
stops, and P-channel and N-channel built-in switch transistors turn “OFF”. As a result, VOUT drops according
to the COUT capacitance value and the load.
To restart the operation, VIN needs to be higher than VUVLO2. The timing chart below shows the voltage shifts
of VREF, VLX and VOUT when VIN value is varied.
Input Voltage
(VIN)
VSET
VUVLO2
VUVLO1
Soft-start Time
IC Internal Reference Voltage
(VREF)
Lx Voltage
(VLX)
Output Voltage
(VOUT)
VSET
Depending on Power Supply, Load Current,
External Components
Falling edge (operating) and rising edge (releasing) waveforms of VOUT could be affected by the initial voltage
of COUT and the output current of VOUT.
13
RP508K
NO. EA-318-171106
3.
Over Current Protection Circuit
Over current protection circuit supervises the inductor peak current (the peak current flowing through Pchannel Tr.) in each switching cycle. If the current exceeds the LX current limit (ILXLIM) of 1100 mA (Typ.), Pchannel Tr. is turned off.
ILXLIM could be easily affected by self-heating or ambient environment. If the VIN drops dramatically or becomes
unstable due to short-circuit, protection operation could be affected.
Over Current Protection
LX Current
Pch Tr. Current
LX Voltage
(VLX)
14
LX Current Limit
(ILXLIM)
RP508K
NO. EA-318-171106
APPLICATION INFORMATION
Typical Application
GND
V OUT
RP508x
Load
LX
COUT 4.7μF
MODE
Control
L 0.47μH
or 1.0μH
V IN
V IN
CE
Control
CIN 2.2μF or 4.7μF
RP508K Typical Application
Recommended Components
Symbol
Size
Type
Manufacturer
2.2 µF
Ceramic
C1005JB0J225K (TDK)
4.7 µF
Ceramic
C1005JB0J475K (TDK)
4.7 µF
Ceramic
C1005JB0J475K (TDK)
0.47 µH (0.5 µH)
Inductor
CIN
COUT
MIPSZ2012D0R5 (FDK)
MDT1608CHR47N (TOKO)
L
MIPSZ2012D1R0 (FDK)
1.0 µH
Inductor
MDT1608CH1R0N (TOKO)
15
RP508K
NO. EA-318-171106
Cautions in Selecting External Components
•
Ensure the VIN and GND lines are sufficiently robust. A large switching current flows through the GND
lines, the VDD line, the VOUT line, an inductor, and LX. If their impedance is too high, noise pickup or
unstable operation may result. Set the external components as close as possible to the IC and minimize
the wiring between the components and the IC, especially between a capacitor (CIN) and the VIN pin. The
wiring between VOUT and load and between L and VOUT should be separated.
•
Choose a low ESR ceramic capacitor. The capacitance of CIN should be more than or equal to 2.2 µF.
The capacitance of a capacitor (COUT) should be between 4.7 µF to 10 µF.
•
The Inductance value should be set within the range of 0.47 µH to 1.0 µH. However, the inductance value
is limited by output voltage. Refer to the table below. The phase compensation of this IC is designed
according to the COUT and L values. Choose an inductor that has small DC resistance, has enough
allowable current and is hard to cause magnetic saturation. If the inductance value of an inductor is
extremely small, the peak current of LX may increase. The increased LX peak current reaches “LX limit
current” to trigger over current protection circuit even if the load current is less than 600 mA.
Set Output Voltage Range vs. Inductance Range
Set Output Voltage (V)
Input Voltage (V)
VSET
VIN
L = 0.47 μH
L = 1.0 μH
0.8 to 1.2
up to 5.5
Recommended
Acceptable
up to 4.5
Recommended
Acceptable
4.5 to 5.5
Acceptable
Recommended
up to 3.6
Recommended
Acceptable
up to 4.5
Acceptable
Recommended
4.5 to 5.5
-
Recommended
up to 4.5
Recommended
Acceptable
4.5 to 5.5
-
Recommended
1.3 to 1.5
1.6 to 2.6
2.7 to 3.3
•
•
Inductance
Over current protection circuit may be affected by self-heating or power dissipation environment.
The performance of power source circuits using this IC largely depends on the peripheral circuits. When
selecting the peripheral components, consider the conditions of use. Do not allow each component, PCB
pattern and the IC to exceed their respected rated values (voltage, current and power) when designing
the peripheral circuits.
16
RP508K
NO. EA-318-171106
Output Current and Selection of External Components
The following equations explain the relationship between output current and peripheral components used in
the diagrams in TYPICAL APPLICATIONS.
Ripple Current P-P value is described as IRP, ON resistance of P-channel Tr. is described as RONP, ON
resistance of N-channel Tr. is described as RONN, and DC resistor of the inductor is described as RL.
First, when P-channel Tr. Is “ON”, the following equation is satisfied.
VIN = VOUT + (RONP + RL) × IOUT + L × IRP / ton ··················································· Equation 3
Second, when P-channel Tr. is “OFF” (N-channel Tr. Is “ON”), the following equation is satisfied.
L × IRP / toff = RONN × IOUT + VOUT + RL × IOUT ···················································· Equation 4
Put Equation 4 into Equation 3 to solve ON duty of P-channel Tr. (DON = ton / (toff + ton)):
DON = (VOUT + RONN × IOUT + RL × IOUT) / (VIN + RONN × IOUT − RONP × IOUT) ··············· Equation 5
Ripple Current is described as follows:
IRP = (VIN − VOUT − RONP × IOUT − RL × IOUT) × DON / fosc / L ································· Equation 6
Peak current that flows through L, and LX Tr. is described as follows:
ILXMAX = IOUT + IRP / 2 ·················································································· Equation 7
Consider ILXMAX when setting conditions of input and output, as well as selecting the external components.
The above calculation formulas are based on the ideal operation of the ICS in continuous mode.
17
RP508K
NO. EA-318-171106
TECHNICAL NOTES
The performance of power source circuits using this IC largely depends on the peripheral circuits. When
selecting the peripheral components, consider the conditions of use. Do not allow each component, PCB
pattern and the IC to exceed their respected rated values (voltage, current and power) when designing the
peripheral circuits.
•
Ensure the VIN and GND lines are sufficiently robust. A large switching current flows through the GND
lines, the VDD line, the VOUT line, an inductor, and LX. If their impedance is too high, noise pickup or
unstable operation may result. Set the external components as close as possible to the IC and minimize
the wiring between the components and the IC, especially between a capacitor (CIN) and the VIN pin. The
wiring between VOUT and load and between L and VOUT should be separated.
Reference PCB Layout
Topside
Backside
DFN1212-6 Typical Board Layout
18
RP508K
NO. EA-318-171106
TYPICAL CHARACTERISTICS
Note: Typical Characteristics are intended to be used as reference data; they are not guaranteed.
01) Output Voltage vs. Output Current
RP508K081x, VOUT = 0.8 V
MODE = "L" PWM/VFM auto switching control
RP508K081x, VOUT = 0.8 V
MODE = "H" forced PWM control
0.820
0.815
VIN=3.6V
0.810
VIN=5.0V
0.805
0.800
0.795
0.790
0.785
0.780
0.01
0.1
1
10
100
Output Voltage V OUT (V)
Output Voltage V OUT (V)
0.820
0.815
0.810
0.805
0.800
0.795
0.790
VIN=3.6V
0.785
VIN=5.0V
0.780
0.01
1000
Output Current IOUT (mA)
1.015
Output Voltage V OUT (V)
Output Voltage V OUT (V)
1.020
1.015
1.010
1.005
1.000
0.990
VIN=5.0V
0.985
0.980
0.01
0.1
1
10
100
1.000
0.995
0.990
VIN=3.6V
0.985
VIN=5.0V
1.215
Output Voltage V OUT (V)
Output Voltage V OUT (V)
1.220
1.210
1.205
1.200
1.185
1.180
0.01
0.1
1
10
100
Output Current IOUT (mA)
1
10
100
1000
RP508K121x, VOUT = 1.2 V
MODE = "H" forced PWM control
1.215
VIN=5.0V
0.1
Output Current IOUT (mA)
1.220
1.190
1000
1.005
0.980
0.01
1000
RP508K121x, VOUT = 1.2 V
MODE = "L" PWM/VFM auto switching control
VIN=3.6V
100
1.010
Output Current IOUT (mA)
1.195
10
RP508K101x, VOUT = 1.0 V
MODE = "H" forced PWM control
1.020
VIN=3.6V
1
Output Current IOUT (mA)
RP508K101x, VOUT = 1.0 V
MODE = "L" PWM/VFM auto switching control
0.995
0.1
1000
1.210
1.205
1.200
1.195
1.190
VIN=3.6V
1.185
VIN=5.0V
1.180
0.01
0.1
1
10
100
1000
Output Current IOUT (mA)
19
RP508K
NO. EA-318-171106
RP508K181x, VOUT = 1.8 V
MODE = "L" PWM/VFM auto switching control
RP508K181x, VOUT = 1.8 V
MODE = "H" forced PWM control
1.830
Output Voltage V OUT (V)
Output Voltage V OUT (V)
1.830
1.820
1.810
1.800
VIN=3.6V
1.790
VIN=5.0V
1.780
1.770
0.01
0.1
1
10
100
1.820
1.810
1.800
1.790
1.780
VIN=5.0V
1.770
0.01
1000
Output Current IOUT (mA)
1
10
Output Voltage VOUT (V)
Output Voltage V OUT (V)
100
1000
3.400
3.380
3.360
3.340
3.320
3.300
3.280
3.260
3.240
3.220
3.200
0.01
100
1000
VIN=4.3V
VIN=5.0V
0.1
1
10
100
1000
RP508K101x, VOUT = 1.0 V
MODE = "H" forced PWM control
0.820
1.020
0.815
1.015
0.810
0.805
0.800
0.795
Iout=1mA
0.790
Iout=50mA
Iout=250mA
Output Voltage VOUT(V)
Output Voltage VOUT(V)
02) Output Voltage vs. Input Voltage
RP508K081x, VOUT = 0.8 V
MODE = "H" forced PWM control
1.010
1.005
1.000
0.995
Iout=1mA
0.990
Iout=50mA
0.985
Iout=250mA
0.980
0.780
2.3
3.3
4.3
Input Voltage Vin(V)
20
10
Output Current IOUT (mA)
Output Current IOUT (mA)
0.785
1
RP508K331x, VOUT = 3.3 V
MODE = "H" forced PWM control
VIN=5.0V
0.1
0.1
Output Current IOUT (mA)
RP508K331x, VOUT = 3.3 V
MODE = "L" PWM/VFM auto switching control
3.400
3.380
3.360
3.340
3.320
3.300
3.280
3.260
3.240
3.220
3.200
0.01
VIN=3.6V
5.3
2.3
3.3
4.3
Input Voltage Vin(V)
5.3
RP508K
NO. EA-318-171106
RP508K181x, VOUT = 1.8 V
MODE = "H" forced PWM control
1.220
1.820
1.215
1.815
1.210
1.205
1.200
1.195
Iout=1mA
1.190
Iout=50mA
1.185
Iout=250mA
Output Voltage VOUT(V)
Output Voltage VOUT(V)
RP508K121x, VOUT = 1.2 V
MODE = "H" forced PWM control
1.810
1.805
1.800
1.795
Iout=1mA
1.790
Iout=50mA
1.785
Iout=250mA
1.780
1.180
2.3
3.3
4.3
Input Voltage Vin(V)
5.3
2.3
3.3
4.3
5.3
Input Voltage Vin(V)
RP508K331x, VOUT = 3.3 V
MODE = "H" forced PWM control
Output Voltage VOUT(V)
3.320
3.310
3.300
3.290
Iout=1mA
3.280
Iout=50mA
3.270
Iout=250mA
3.260
3.8
4.3
4.8
5.3
Input Voltage Vin(V)
03) Output Voltage vs. Temperature
1.83
Output Voltage V OUT (V)
1.82
Vin=3.6V
1.81
1.8
1.79
1.78
1.77
-50
-25
0
25
50
75
100
Temperature Ta (ﾟC)
21
RP508K
NO. EA-318-171106
04) Efficiency vs. Output Current
RP508K081x, VOUT = 0.8 V
L = MIPSZ2012D0R5 (2012size_0.5 µH)
RP508K101x, VOUT = 1.0 V
L = MIPSZ2012D0R5 (2012size_0.5 µH)
100
100
VIN = 3.6 V, VMODE = 0 V
90
80
80
70
70
60
50
40
VIN = VMODE = 5.0 V
30
Efficiency (%)
Efficiency (%)
90
VIN = 5.0 V, VMODE = 0 V
50
40
10
VIN = VMODE = 3.6 V
0
0.01
0.1
1
10
Output Current IOUT (mA)
100
VIN = VMODE = 3.6 V
0
0.01
1000
RP508K121x, VOUT = 1.2 V
L = MIPSZ2012D0R5 (2012size_0.5 µH)
0.1
1
10
Output Current IOUT (mA)
100
VIN = 3.6 V, VMODE = 0 V
VIN = 5.0 V, VMODE = 0 V
90
80
70
70
60
50
40
VIN = VMODE = 5.0 V
20
1000
VIN = 3.6 V, VMODE = 0 V
VIN = 5.0 V, VMODE = 0 V
60
50
40
VIN = VMODE = 5.0 V
30
20
10
0
0.01
Efficiency (%)
80
30
100
RP508K181x, VOUT = 1.8 V
L = MIPSZ2012D0R5 (2012size_0.5 µH)
100
10
VIN = VMODE = 3.6 V
0.1
1
10
Output Current IOUT (mA)
100
1000
RP508K331x, VOUT = 3.3 V
L = MIPSZ2012D1R0 (2012size_1.0 µH)
VIN = 5.0 V, VMODE = 0 V
VIN = VMODE = 5.0 V
VIN = VMODE = 4.3 V
22
VIN = VMODE = 5.0 V
20
10
Efficiency (%)
60
30
20
90
VIN = 5.0 V, VMODE = 0 V
VIN = 3.6 V, VMODE = 0 V
0
0.01
VIN = VMODE = 3.6 V
0.1
1
10
Output Current IOUT (mA)
100
1000
RP508K
NO. EA-318-171106
RP508K081x, VOUT = 0.8 V
L = MDT1608CHR47N (1608size_0.47 µH)
RP508K101x, VOUT = 1.0 V
L = MDT1608CHR47N (1608size_0.47 µH)
100
100
VIN = 5.0 V, VMODE = 0 V
80
80
70
70
60
50
40
30
60
50
40
VIN = VMODE = 5.0 V
20
10
10
VIN = VMODE = 3.6 V
0
0.01
0.1
1
10
Output Current IOUT (mA)
100
VIN = VMODE = 3.6 V
0
0.01
1000
RP508K121x, VOUT = 1.2 V
L = MDT1608CHR47N (1608size_0.47 µH)
0.1
1
10
Output Current IOUT (mA)
100
VIN = 5.0 V, VMODE = 0 V
90
VIN = 3.6 V, VMODE = 0 V
80
70
70
Efficiency (%)
80
60
50
40
30
VIN = VMODE = 5.0 V
20
1000
VIN = 5.0 V, VMODE = 0 V
VIN = 3.6 V, VMODE = 0 V
60
50
40
30
VIN = VMODE = 5.0 V
20
10
0
0.01
100
RP508K181x, VOUT = 1.8 V
L = MDT1608CHR47N (1608size_0.47 µH)
100
Efficiency (%)
VIN = 3.6 V, VMODE = 0 V
30
VIN = VMODE = 5.0 V
20
90
VIN = 5.0 V, VMODE = 0 V
90
VIN = 3.6 V, VMODE = 0 V
Efficiency (%)
Efficiency (%)
90
10
VIN = VMODE = 3.6 V
0.1
1
10
Output Current IOUT (mA)
100
1000
0
0.01
VIN = VMODE = 3.6 V
0.1
1
10
Output Current IOUT (mA)
100
1000
RP508K331x, VOUT = 3.3 V
L = MDT1608CH1R0N (1608size_1.0 µH)
VIN = 5.0 V, VMODE = 0 V
VIN = VMODE = 5.0 V
VIN = VMODE = 4.3 V
23
RP508K
NO. EA-318-171106
05) Supply Current vs. Temperature
RP508K181x, VOUT = 1.8 V (VIN = 5.5 V)
MODE = "L" PWM/VFM auto switching control
06) Supply Current vs. Input Voltage
RP508K181x, VOUT = 1.8 V
MODE = "L" PWM/VFM auto switching control
Vin=5.5V
40.0
40.0
Closed Loop
Open Loop
30.0
Supply Current (uA)
20.0
10.0
Open Loop
20.0
10.0
0.0
0.0
0
50
Temperature Ta (°C)
100
3.3
3.8
4.3
4.8
IOUT =10mA
0.06
300
0.06
300
0.05
200
0.05
200
0.04
100
0.04
100
0.03
0
0.03
0
0.02
-100
0.02
-100
0.01
-200
0.01
-200
0.00
-300
0.00
-300
-0.01
-400
Output Voltage
IL
-0.03
-10
-5
0
Time t (us)
5
-0.02
-600
-0.03
-400
Output Voltage
-500
IL
-1.0
10
IOUT =10mA
-0.5
0.0
Time t (us)
-600
0.5
1.0
RP508K121x, VOUT = 1.2 V (VIN = 3.6 V)
MODE = H" forced PWM control
IOUT =10mA
400
0.07
0.06
300
0.06
300
0.05
200
0.05
200
0.04
100
0.04
100
0.03
0
0.03
0
0.02
-100
0.02
-100
0.01
-200
0.01
-200
0.00
-300
0.00
-300
-0.01
-400
Output Voltage
-0.02
IL
-0.03
-10
-5
0
Time t (us)
5
10
Inductor Current IL (mA)
0.07
-0.01
-500
RP508K121x, VOUT = 1.2 V (VIN = 3.6 V)
MODE = "L" PWM/VFM auto switching control
400
Inductor Current IL (mA)
0.07
Output Voltage VOUT(V)
400
-0.02
5.3
RP508K081x, VOUT = 0.8 V (VIN = 3.6 V)
MODE = "H" forced PWM control
0.07
Inductor Current IL (mA)
Output Voltage VOUT(V)
2.8
Input Voltage VIN (V)
07) Output Voltage Waveform
RP508K081x, VOUT = 0.8 V (VIN = 3.6 V)
MODE = "L" PWM/VFM auto switching control
Output Voltage VOUT(V)
2.3
-0.01
-500
-0.02
-600
-0.03
400
-400
Output Voltage
IL
-500
-600
-1.0
-0.5
0.0
Time t (us)
0.5
1.0
Inductor Current IL (mA)
-50
24
30.0
Output Voltage VOUT(V)
Supply Current (uA)
Closed Loop
RP508K
NO. EA-318-171106
IOUT =10mA
IOUT =10mA
0.07
0.06
300
0.06
300
0.05
200
0.05
200
0.04
100
0.04
100
0.03
0
0.03
0
0.02
-100
0.02
-100
0.01
-200
0.01
-200
0.00
-300
0.00
-300
-0.01
-400
Output Voltage
-0.02
IL
-0.03
-10
-5
0
Time t (us)
5
Output Voltage VOUT(V)
400
Inductor Current IL (mA)
Output Voltage VOUT(V)
0.07
RP508K181x, VOUT = 1.8 V (VIN = 3.6 V)
MODE = "H" forced PWM control
-0.01
-500
-0.02
-600
-0.03
10
400
-400
Output Voltage
IL
-1.0
-0.5
0.0
Time t (us)
Inductor Current IL (mA)
RP508K181x, VOUT = 1.8 V (VIN = 3.6 V)
MODE = "L" PWM/VFM auto switching control
-500
-600
0.5
1.0
RP508K331x, VOUT = 3.3 V (VIN = 4.3 V)
MODE = "H" forced PWM control
Output Voltage VOUT(V)
400
0.06
300
0.05
200
0.04
100
0.03
0
0.02
-100
0.01
-200
0.00
-300
-0.01
-400
Output Voltage
-0.02
IL
-0.03
Inductor Current IL (mA)
IOUT =10mA
0.07
-500
-600
-1.0
-0.5
0.0
Time t (us)
0.5
1.0
08) Frequency vs. Input Voltage
RP508K181x, VOUT = 1.8 V
MODE = "H" forced PWM control
7.0
Frequency (MHz)
6.0
5.0
4.0
3.0
0A@25ﾟC
0A@-40ﾟC
2.0
0A@85ﾟC
1.0
2.0
2.5
3.0
3.5
4.0
4.5
5.0
5.5
Input Voltage (V)
25
RP508K
NO. EA-318-171106
7.0
7.0
6.0
6.0
Frequency (MHz)
Frequency (MHz)
09) Frequency vs. Input Voltage with Various Output Currents
RP508K121x, VOUT = 1.2 V
RP508K181x, VOUT = 1.8 V
MODE = "H" forced PWM control
MODE = "H" forced PWM control
5.0
4.0
0A@25ﾟC
3.0
5.0
4.0
0A@25ﾟC
3.0
0.1A@25ﾟC
0.1A@25ﾟC
0.3A@25ﾟC
2.0
0.3A@25ﾟC
2.0
0.6A@25ﾟC
0.6A@25ﾟC
1.0
1.0
2.0
2.5
3.0
3.5
4.0
4.5
5.0
2.0
5.5
2.5
3.0
3.5
10) VFM Frequency vs. Output Current
RP508K121x, VOUT = 1.2 V
MODE = "L" PWM/VFM auto switching control
4.5
2000
2000
1800
1800
1600
1600
1400
1400
1200
1000
800
2.3V@25ﾟC
600
1000
800
2.3V@25ﾟC
3.6V@25ﾟC
400
5.0V@25ﾟC
5.0V@25ﾟC
200
200
0
0
0
25
50
75
100
125
150
11) Soft-start Time vs. Temperature
120
110
100
90
80
70
60
-50
-25
0
25
50
Temperature Ta (ﾟC)
0
25
50
75
100
Output Current (mA)
Output Current (mA)
Soft Start Time Tstart (us)
5.5
1200
600
3.6V@25ﾟC
400
26
5.0
RP508K181x, VOUT = 1.8 V
MODE = "L" PWM/VFM auto switching control
Frequency (kHz)
Frequency (kHz)
4.0
Input Voltage (V)
Input Voltage (V)
75
100
125
150
RP508K
NO. EA-318-171106
12) UVLO Detector Threshold/ Released Voltage vs. Temperature
UVLO Detector Threshold
UVLO Release Voltage
2.3
UVLO検出電圧 UVLO1 (V)
UVLO検出電圧 UVLO1 (V)
2.3
2.2
2.1
2
1.9
-50
-25
0
25
50
75
2.2
2.1
2
1.9
-50
100
-25
0
Temperature Ta (ﾟC)
25
50
75
100
75
100
Temperature Ta (ﾟC)
13) CE Input Voltage vs. Temperature
CE = "H" Input Voltage (VIN = 2.3 V)
1
1
0.9
0.9
CE-L入力電圧 VCEL (V)
CE-H入力電圧 VCEH (V)
CE = "H" Input Voltage (VIN = 5.5 V)
0.8
0.7
0.6
0.5
0.4
-50
0.8
0.7
0.6
0.5
-25
0
25
50
75
0.4
-50
100
-25
0
Temperature Ta (ﾟC)
25
50
Temperature Ta (ﾟC)
14) LX Current Limit vs. Temperature
15) Standby Current vs. Temperature
1
1300
Standby Current ISTANDBY (uA)
LX Current Limit ILXlim (mA)
0.9
1200
1100
1000
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
900
-50
-25
0
25
50
Temperature Ta (ﾟC)
75
100
0
-50
-25
0
25
50
75
100
Temperature Ta (ﾟC)
27
RP508K
NO. EA-318-171106
16) Nch Transistor On Resistance vs. Temperature
17) Pch Transistor On Resistance vs. Temperature
0.6
On Resistance of Pch Tr ( Ω)
On Resistance of Nch Tr ( Ω)
0.6
0.5
0.4
0.3
0.2
0.1
0.0
0.5
0.4
0.3
0.2
0.1
0.0
-50
-25
0
25
50
75
100
-50
-25
0
Temperature (°C)
25
50
Temperature (°C)
75
100
18) Load Transient Response (COUT = 4.7 µF, C1005X5R0J475M)
RP508K081x (VIN = 3.6 V, VOUT = 0.8 V)
RP508K081x (VIN = 3.6 V, VOUT = 0.8 V)
L = MIPSZ2012D0R5 (2012size_0.5 µH)
L = MIPSZ2012D0R5 (2012size_0.5 µH)
MODE = "H" forced PWM control
MODE = "H" forced PWM control
600
600
0.90
Output Voltage
0.85
0.80
400
Output Current
300 mA --> 1 mA
200
0
0.90
Output Voltage
0.85
0.80
0.75
0.75
0
4
8
12
16
-4
0
4
Time t (us)
8
12
16
Time t (us)
RP508K081x (VIN = 3.6 V, VOUT = 0.8 V)
L = MIPSZ2012D0R5 (2012size_0.5 µH)
MODE = "H" forced PWM control
RP508K081x (VIN = 3.6 V, VOUT = 0.8 V)
L = MIPSZ2012D0R5 (2012size_0.5 µH)
MODE = "H" forced PWM control
800
800
Output Current
200 mA --> 500 mA
200
0
0.90
Output Voltage
0.85
0.80
Output Voltage V OUT (V)
400
Output Current IOUT (mA)
Output Voltage V OUT (V)
600
600
Output Current
500 mA --> 200 mA
400
200
0
0.90
Output Voltage
0.85
0.80
0.75
0.75
-4
0
4
8
Time t (us)
12
16
-4
0
4
8
Time t (us)
12
16
Output Current IOUT (mA)
-4
28
Output Current IOUT (mA)
0
Output Voltage V OUT (V)
200
Output Current
1 mA --> 300 mA
Output Current IOUT (mA)
Output Voltage V OUT (V)
400
RP508K
NO. EA-318-171106
RP508K121x (VIN = 3.6 V, VOUT = 1.2 V)
L = MIPSZ2012D0R5 (2012size_0.5 µH)
MODE = "H" forced PWM control
RP508K121x (VIN = 3.6 V, VOUT = 1.2 V)
L = MIPSZ2012D0R5 (2012size_0.5 µH)
MODE = "H" forced PWM control
600
600
1.30
Output Voltage
1.25
1.20
400
Output Current
300 mA --> 1 mA
200
0
1.30
1.25
Output Voltage
1.20
1.15
1.15
0
4
8
12
16
-4
0
4
Time t (us)
8
12
16
Time t (us)
RP508K121x (VIN = 3.6 V, VOUT = 1.2 V)
L = MIPSZ2012D0R5 (2012size_0.5 µH)
MODE = "H" forced PWM control
RP508K121x (VIN = 3.6 V, VOUT = 1.2 V)
L = MIPSZ2012D0R5 (2012size_0.5 µH)
MODE = "H" forced PWM control
800
800
Output Current
500 mA --> 200 mA
200
0
1.30
Output Voltage
1.25
Output Voltage V OUT (V)
400
Output Current
200 mA --> 500 mA
Output Current IOUT (mA)
600
400
200
0
1.30
Output Voltage
1.25
1.20
1.20
1.15
1.15
-4
0
4
8
12
-4
16
0
4
8
12
16
Time t (us)
Time t (us)
RP508K181x (VIN = 3.6 V, VOUT = 1.8 V)
L = MIPSZ2012D0R5 (2012size_0.5 µH)
MODE = "H" forced PWM control
RP508K181x (VIN = 3.6 V, VOUT = 1.8 V)
L = MIPSZ2012D0R5 (2012size_0.5 µH)
MODE = "H" forced PWM control
600
600
0
1.90
Output Voltage
1.85
1.80
Output Voltage V OUT (V)
200
Output Current IOUT (mA)
400
Output Current
1 mA --> 300 mA
400
Output Current
300 mA --> 1 mA
200
0
1.90
Output Voltage
1.85
Output Current IOUT (mA)
Output Voltage V OUT (V)
600
Output Current IOUT (mA)
-4
Output Voltage V OUT (V)
Output Current IOUT (mA)
0
Output Voltage V OUT (V)
200
Output Current
1 mA --> 300 mA
Output Current IOUT (mA)
Output Voltage V OUT (V)
400
1.80
1.75
1.75
-4
0
4
8
Time t (us)
12
16
-4
0
4
8
12
16
Time t (us)
29
RP508K
NO. EA-318-171106
RP508K181x (VIN = 3.6 V, VOUT = 1.8 V)
L = MIPSZ2012D0R5 (2012size_0.5 µH)
MODE = "H" forced PWM control
RP508K181x (VIN = 3.6 V, VOUT = 1.8 V)
L = MIPSZ2012D0R5 (2012size_0.5 µH)
MODE = "H" forced PWM control
800
800
200
0
1.90
1.85
Output Voltage
600
Output Current
500 mA --> 200 mA
400
200
0
1.90
Output Voltage
1.85
1.80
1.80
1.75
1.75
0
4
8
12
-4
16
0
4
Time t (us)
8
12
16
Time t (us)
RP508K331x (VIN = 5.0 V, VOUT = 3.3 V)
L = MIPSZ2012D1R0 (2012size_1.0 µH)
MODE = "H" forced PWM control
RP508K331x (VIN = 5.0 V, VOUT = 3.3 V)
L = MIPSZ2012D1R0 (2012size_1.0 µH)
MODE = "H" forced PWM control
600
600
0
3.40
3.35
Output Voltage
Output Voltage V OUT (V)
200
Output Current
1 mA --> 300 mA
Output Current IOUT (mA)
3.30
400
Output Current
300 mA --> 1 mA
200
0
3.40
Output Voltage
3.35
3.30
3.25
3.25
-4
0
4
8
12
16
-4
0
4
Time t (us)
8
12
16
Time t (us)
RP508K331x (VIN = 5.0 V, VOUT = 3.3 V)
L = MIPSZ2012D1R0 (2012size_1.0 µH)
MODE = "H" forced PWM control
RP508K331x (VIN = 5.0 V, VOUT = 3.3 V)
L = MIPSZ2012D1R0 (2012size_1.0 µH)
MODE = "H" forced PWM control
800
800
200
0
3.40
3.35
Output Voltage
3.30
Output Voltage V OUT (V)
400
Output Current
200 mA --> 500
Output Current IOUT (mA)
Output Voltage V OUT (V)
600
600
Output Current
500 mA --> 200 mA
400
200
0
3.40
3.35
Output Voltage
3.30
3.25
3.25
-4
0
4
8
Time t (us)
12
16
-4
0
4
8
Time t (us)
12
16
Output Current IOUT (mA)
Output Voltage V OUT (V)
400
Output Current IOUT (mA)
-4
30
Output Current IOUT (mA)
Output Current
200 mA --> 500 mA
Output Voltage V OUT (V)
400
Output Current IOUT (mA)
Output Voltage V OUT (V)
600
RP508K
NO. EA-318-171106
Load Transient Response (COUT = 4.7µF, C1005X5R0J475M)
RP508K081x (VIN = 3.6 V, VOUT = 0.8 V)
RP508K081x (VIN = 3.6 V, VOUT = 0.8 V)
L = MIPSZ2012D0R5 (2012size_0.5 µH)
L = MIPSZ2012D0R5 (2012size_0.5 µH)
MODE = "L" PWM/VFM auto switching control
MODE = "L" PWM/VFM auto switching control
600
600
Output Current
300 mA --> 1 mA
0.90
0.85
10
0.90
0.85
0.80
Output Voltage
0
0
Output Voltage
20
30
0.75
-100
40
0
100
Time t (us)
200
300
RP508K121x (VIN = 3.6 V, VOUT = 1.2 V)
L = MIPSZ2012D0R5 (2012size_0.5 µH)
MODE = "L" PWM/VFM auto switching control
RP508K121x (VIN = 3.6 V, VOUT = 1.2 V)
L = MIPSZ2012D0R5 (2012size_0.5 µH)
MODE = "L" PWM/VFM auto switching control
600
600
400
0
1.30
Output Voltage
Output Voltage V OUT (V)
200
Output Current
1 mA --> 300 mA
Output Current IOUT (mA)
Output Voltage V OUT (V)
400
1.25
1.20
1.15
-10
Output Current
300 mA --> 1 mA
200
0
1.30
Output Voltage
1.25
1.20
0
10
20
30
1.15
-100
40
0
100
200
300
RP508K181x (VIN = 3.6 V, VOUT = 1.8 V)
L = MIPSZ2012D0R5 (2012size_0.5 µH)
MODE = "L" PWM/VFM auto switching control
RP508K181x (VIN = 3.6 V, VOUT = 1.8 V)
L = MIPSZ2012D0R5 (2012size_0.5 µH)
MODE = "L" PWM/VFM auto switching control
600
600
0
1.90
Output Voltage
1.80
Output Voltage V OUT (V)
200
Output Current
1 mA --> 300 mA
Output Current IOUT (mA)
Output Voltage V OUT (V)
400
1.85
400
Time t (us)
Time t (us)
1.75
-10
400
Time t (us)
400
Output Current
300 mA --> 1 mA
200
0
1.90
1.85
Output Voltage
Output Current IOUT (mA)
0.75
-10
200
Output Current IOUT (mA)
0.80
400
Output Current IOUT (mA)
0
Output Voltage V OUT (V)
200
Output Current
1 mA --> 300 mA
Output Current IOUT (mA)
Output Voltage V OUT (V)
400
1.80
0
10
20
Time t (us)
30
40
1.75
-100
0
100
200
300
400
Time t (us)
31
RP508K
NO. EA-318-171106
RP508K331x (VIN = 5.0 V, VOUT = 3.3 V)
L = MIPSZ2012D1R0 (2012size_1.0 µH)
MODE = "L" PWM/VFM auto switching control
RP508K331x (VIN = 5.0 V, VOUT = 3.3 V)
L = MIPSZ2012D1R0 (2012size_1.0 µH)
MODE = "L" PWM/VFM auto switching control
600
600
3.40
Output Voltage
3.35
Output Voltage V OUT (V)
0
Output Current IOUT (mA)
Output Voltage V OUT (V)
200
Output Current
300 mA --> 1 mA
200
0
3.40
Output Voltage
3.35
Output Current IOUT (mA)
400
400
Output Current
1 mA --> 300 mA
3.30
3.30
3.25
-10
0
10
20
30
3.25
-100
40
0
100
200
300
400
Time t (us)
Time t (us)
Load Transient Response (COUT = 4.7 µF, C1005X5R0J475M)
RP508K081x (VIN = 3.6 V, VOUT = 0.8 V)
RP508K081x (VIN = 3.6 V, VOUT = 0.8 V)
L = MDT1608CHR47N (1608size_0.47 µH)
L = MDT1608CHR47N (1608size_0.47 µH)
MODE = "H" forced PWM control
MODE = "H" forced PWM control
600
600
0.90
Output Voltage
0.85
0.80
Output Current
300 mA --> 1 mA
200
0
0.90
Output Voltage
0.85
0.80
0.75
0.75
0
4
8
12
16
-4
0
4
Time t (us)
8
12
16
Time t (us)
RP508K081x (VIN = 3.6 V, VOUT = 0.8 V)
L = MDT1608CHR47N (1608size_0.47 µH)
MODE = "H" forced PWM control
RP508K081x (VIN = 3.6 V, VOUT = 0.8 V)
L = MDT1608CHR47N (1608size_0.47 µH)
MODE = "H" forced PWM control
800
800
200
0.90
0
0.85
Output Voltage
0.80
Output Voltage V OUT (V)
400
Output Current IOUT (mA)
Output Voltage V OUT (V)
600
Output Current
200 mA --> 500 mA
600
Output Current
500 mA --> 200 mA
400
200
0.90
0
Output Voltage
0.85
0.80
0.75
0.75
-4
0
4
8
Time t (us)
12
16
-4
0
4
8
Time t (us)
12
16
Output Current IOUT (mA)
-4
32
Output Current IOUT (mA)
0
Output Voltage V OUT (V)
200
Output Current
1 mA --> 300 mA
400
Output Current IOUT (mA)
Output Voltage V OUT (V)
400
RP508K
NO. EA-318-171106
RP508K121x (VIN = 3.6 V, VOUT = 1.2 V)
L = MDT1608CHR47N (1608size_0.47 µH)
MODE = "H" forced PWM control
RP508K121x (VIN = 3.6 V, VOUT = 1.2 V)
L = MDT1608CHR47N (1608size_0.47 µH)
MODE = "H" forced PWM control
600
600
1.30
Output Voltage
1.25
1.20
Output Current
300 mA --> 1 mA
200
0
1.30
1.25
Output
V lt
1.20
1.15
1.15
0
4
8
12
16
-4
0
4
Time t (us)
8
12
16
Time t (us)
RP508K121x (VIN = 3.6 V, VOUT = 1.2 V)
L = MDT1608CHR47N (1608size_0.47 µH)
MODE = "H" forced PWM control
RP508K121x (VIN = 3.6 V, VOUT = 1.2 V)
L = MDT1608CHR47N (1608size_0.47 µH)
MODE = "H" forced PWM control
800
800
Output Current
200 mA --> 500 mA
200
0
1.30
Output Voltage
1.25
600
Output Voltage V OUT (V)
400
Output Current IOUT (mA)
1.20
Output Current
500 mA --> 200 mA
400
200
0
1.30
Output Voltage
1.25
1.20
1.15
1.15
-4
0
4
8
12
16
-4
0
4
Time t (us)
8
12
16
Time t (us)
RP508K181x (VIN = 3.6 V, VOUT = 1.8 V)
L = MDT1608CHR47N (1608size_0.47 µH)
MODE = "H" forced PWM control
RP508K181x (VIN = 3.6 V, VOUT = 1.8 V)
L = MDT1608CHR47N (1608size_0.47 µH)
MODE = "H" forced PWM control
600
600
400
1.90
1.85
Output Voltage
1.80
Output Voltage V OUT (V)
0
Output Current IOUT (mA)
200
Output Current
1 mA --> 300 mA
400
Output Current
300 mA --> 1 mA
200
0
1.90
1.85
Output Voltage
Output Current IOUT (mA)
Output Voltage V OUT (V)
600
Output Current IOUT (mA)
-4
Output Voltage V OUT (V)
Output Current IOUT (mA)
0
400
Output Voltage V OUT (V)
200
Output Current
1 mA --> 300 mA
Output Current IOUT (mA)
Output Voltage V OUT (V)
400
1.80
1.75
1.75
-4
0
4
8
Time t (us)
12
16
-4
0
4
8
12
16
Time t (us)
33
RP508K
NO. EA-318-171106
RP508K181x (VIN = 3.6 V, VOUT = 1.8 V)
L = MDT1608CHR47N (1608size_0.47 µH)
MODE = "H" forced PWM control
RP508K181x (VIN = 3.6 V, VOUT = 1.8 V)
L = MDT1608CHR47N (1608size_0.47 µH)
MODE = "H" forced PWM control
800
800
200
0
1.90
1.85
Output Voltage
1.80
Output Current
500 mA --> 200 mA
400
200
0
1.90
Output Voltage
1.85
1.80
1.75
1.75
0
4
8
12
16
-4
0
4
Time t (us)
8
12
16
Time t (us)
RP508K331x (VIN = 5.0 V, VOUT = 3.3 V)
L = MDT1608CH1R0N(1608size_1.0 µH)
MODE = "H" forced PWM control
RP508K331x (VIN = 5.0 V, VOUT = 3.3 V)
L = MDT1608CH1R0N (1608size_1.0 µH)
MODE = "H" forced PWM control
600
600
Output Current
1 mA --> 300 mA
0
3.40
Output Voltage
3.35
400
Output Voltage V OUT (V)
200
Output Current IOUT (mA)
3.30
Output Current
300 mA --> 1 mA
200
0
3.40
Output Voltage
3.35
3.30
3.25
3.25
-4
0
4
8
12
16
-4
0
4
Time t (us)
8
12
16
Time t (us)
RP508K331x (VIN = 5.0 V, VOUT = 3.3 V)
L = MDT1608CH1R0N (1608size_1.0 µH)
MODE = "H" forced PWM control
RP508K331x (VIN = 5.0 V, VOUT = 3.3 V)
L = MDT1608CH1R0N (1608size_1.0 µH)
MODE = "H" forced PWM control
800
800
200
0
3.40
3.35
Output Voltage
3.30
Output Voltage V OUT (V)
400
Output Current
200 mA --> 500 mA
600
Output Current IOUT (mA)
Output Voltage V OUT (V)
600
Output Current
500 mA --> 200 mA
400
200
0
3.40
3.35
Output Voltage
3.30
3.25
3.25
-4
0
4
8
Time t (us)
12
16
-4
0
4
8
Time t (us)
12
16
Output Current IOUT (mA)
Output Voltage V OUT (V)
400
Output Current IOUT (mA)
-4
34
Output Current IOUT (mA)
Output Current
200 mA --> 500 mA
600
Output Voltage V OUT (V)
400
Output Current IOUT (mA)
Output Voltage V OUT (V)
600
RP508K
NO. EA-318-171106
Load Transient Response (COUT = 4.7µF, C1005X5R0J475M)
RP508K081x (VIN = 3.6 V, VOUT = 0.8 V)
RP508K081x (VIN = 3.6V, VOUT = 0.8 V)
L = MDT1608CHR47N (1608size_0.47 µH)
L = MDT1608CHR47N (1608size_0.47 µH)
MODE = "L" PWM/VFM auto switching control
MODE = "L" PWM/VFM auto switching control
600
600
Output Current
300 mA --> 1 mA
0.90
0.85
0.80
200
0
0.90
0.85
0.80
Output Voltage
10
20
30
40
0
100
Time t (us)
200
300
400
Time t (us)
RP508K121x (VIN = 3.6 V, VOUT = 1.2 V)
L = MDT1608CHR47N (1608size_0.47 µH)
MODE = "L" PWM/VFM auto switching control
RP508K121x (VIN = 3.6 V, VOUT = 1.2 V)
L = MDT1608CHR47N (1608size_0.47 µH)
MODE = "L" PWM/VFM auto switching control
600
600
0
1.30
Output Voltage
1.25
Output Voltage V OUT (V)
200
Output Current
1 mA --> 300 mA
400
Output Current IOUT (mA)
Output Voltage V OUT (V)
400
1.20
1.15
-10
Output Current
300 mA --> 1 mA
200
0
1.30
Output Voltage
1.25
1.20
0
10
20
30
1.15
-100
40
0
100
Time t (us)
200
300
RP508K181x (VIN = 3.6 V, VOUT = 1.8 V)
L = MDT1608CHR47N (1608size_0.47 µH)
MODE = "L" PWM/VFM auto switching control
600
600
0
1.90
Output Voltage
1.80
Output Voltage V OUT (V)
200
Output Current
1 mA --> 300 mA
Output Current IOUT (mA)
Output Voltage V OUT (V)
400
1.85
400
Time t (us)
RP508K181x (VIN = 3.6 V, VOUT = 1.8 V)
L = MDT1608CHR47N (1608size_0.47 µH)
MODE = "L" PWM/VFM auto switching control
1.75
-10
Output Current IOUT (mA)
0
Output Voltage
0.75
-100
400
Output Current
300 mA --> 1 mA
200
0
1.90
1.85
Output Voltage
Output Current IOUT (mA)
0.75
-10
400
Output Current IOUT (mA)
0
Output Voltage V OUT (V)
200
Output Current
1 mA --> 300 mA
Output Current IOUT (mA)
Output Voltage V OUT (V)
400
1.80
0
10
20
Time t (us)
30
40
1.75
-100
0
100
200
300
400
Time t (us)
35
RP508K
NO. EA-318-171106
RP508K331x (VIN = 5.0 V, VOUT = 3.3 V)
L = MDT1608CH1R0N (1608size_1.0 µH)
MODE = "L" PWM/VFM auto switching control
RP508K331x (VIN = 5.0 V, VOUT = 3.3 V)
L = MDT1608CH1R0N (1608size_1.0 µH)
MODE = "L" PWM/VFM auto switching control
600
600
3.40
Output Voltage
3.35
Output Voltage V OUT (V)
0
Output Current IOUT (mA)
Output Current
300 mA --> 1 mA
200
0
3.40
Output Voltage
3.35
3.30
3.30
0
10
20
30
3.25
-100
40
0
100
200
300
19) Mode Switching Waveform
RP508K121x (VIN = 3.6 V, VOUT = 1.2 V, IOUT = 1 mA)
MODE = "L" → MODE = "H"
RP508K121x (VIN = 3.6 V, VOUT = 1.2 V, IOUT = 1 mA)
MODE = "H" → MODE = "L"
6
2
0
1.30
1.25
1.20
0
100
200
300
4
Output Voltage VOUT (V)
Output Voltage VOUT (V)
4
Mode Input Voltage VMODE (V)
6
1.15
-100
2
0
1.30
1.25
1.20
1.15
-100
400
0
1.80
36
400
Output Voltage VOUT (V)
1.85
300
RP508K181x (VIN = 3.6V, VOUT = 1.8 V, IOUT = 1 mA)
MODE = "H" → MODE = "L"
4
1.90
Time t (us)
400
4
0
200
300
6
2
100
200
6
Mode Input Voltage VMODE (V)
Output Voltage VOUT (V)
RP508K181x (VIN = 3.6 V, VOUT = 1.8 V, IOUT = 1 mA)
MODE = "L" → MODE = "H"
0
100
Time t (us)
Time t (us)
1.75
-100
400
Time t (us)
Time t (us)
Mode Input Voltage VMODE (V)
3.25
-10
2
0
1.90
1.85
1.80
1.75
-100
0
100
200
Time t (us)
300
400
Mode Input Voltage VMODE (V)
Output Voltage V OUT (V)
200
Output Current IOUT (mA)
400
400
Output Current
1 mA --> 300 mA
POWER DISSIPATION
DFN(PLP)1212-6F
Ver. A
The power dissipation of the package is dependent on PCB material, layout, and environmental conditions.
The following conditions are used in this measurement.
Measurement Conditions
JEDEC STD.51-7 Test 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 × 1.6 mm
Copper Ratio
Outer Layers (First and Fourth Layers): Less than 10% of 60 mm Square
Inner Layers (Second and Third Layers): 100% of 74.2 mm Square
Through-holes
φ 0.85 mm × 44 pcs
Measurement Result
(Ta = 25°C, Tjmax = 125°C)
JEDEC STD.51-7 Test Land Pattern
Power Dissipation
666 mW
Thermal Resistance
θja = (125 − 25°C) / 0.666 W = 150°C/W
θjc = 28°C/W
76.2
60
750
666
40
900
JEDEC STD.51-7
Test Land Pattern
60
600
450
300
114.3
Power Dissipation PD
(mW)
1050
150
0
0
25
85
50
75
100
125
Ambient Temperature (°C)
基板レイアウト
Measurement
Board Pattern
IC Mount Area (mm)
Power Dissipation vs. Ambient Temperature
Measurement Board Pattern
i
PACKAGE DIMENSIONS
DFN(PLP)1212-6F
A
1.20
B
0.425±0.05
Ver. A
X4
4
6
0.05
0.4Max.
INDEX
0.25±0.05
1.20
C0.05
3
0.4
1
0.18±0.05
0.05 M AB
Bottom View
S
0.05 S
DFN(PLP)1212-6F Package Dimensions (Unit: mm)
i
1. The products and the product specifications described in this document are subject to change or discontinuation of
production without notice for reasons such as improvement. Therefore, before deciding to use the products, please
refer to Ricoh sales representatives for the latest information thereon.
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
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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, fire containment 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. The X-ray exposure can influence functions and characteristics of the products. Confirm the product functions and
characteristics in the evaluation stage.
9. WLCSP products should be used in light shielded environments. The light exposure can influence functions and
characteristics of the products under operation or storage.
10. There can be variation in the marking when different AOI (Automated Optical Inspection) equipment is used. In the
case of recognizing the marking characteristic with AOI, please contact Ricoh sales or our distributor before attempting
to use AOI.
11. Please contact Ricoh sales representatives should you have any questions or comments concerning the products or
the technical information.
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Ricoh is committed to reducing the environmental loading materials in electrical devices
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.
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