RP401x Series
PWM/VFM Step-up DC/DC Converter
The RP401x Series are CMOS-based PWM/VFM step-up DC/DC converters which can start-up from Typ. 0.6V. RP401K can be switched from
two control types by inputting signal to the MODE pin - fixed PWM control or PWM/VFM auto switching control in which mode automatically
switches to high-efficiency VFM mode in low output current. (RP401N Series can be selected from fixed PWM control or PWM/VFM auto
switching control.) RP401x includes a soft start circuit. By simply using an inductor, a capacitor, (resisters for adjustable type), and a diode
as external components, a high-efficiency step-up DC/DC converter can be easily configured. The output voltage can be selected from the
internally fixed or the externally adjustment. In addition to SOT-23-5 package, a 1.8mm × 2.0mm square DFN(PLP)1820-6 package is also
available.
FEATURES
• Supply Current (IDD1) ················· Typ. 400μA (VSET=3.0V, Switching)
• Supply Current (IDD2) ·················· Typ. 130μA (No switching, VFM)
• Supply Current (IDD2) ·················· Typ. 230μA (No switching, PWM)
• Standby Current (Istandby) ·············· Typ. 0.15μA (CE="L")
• Input Voltage Range (VIN) ············ 0.6V to 5.5V (Absolute maximum rating : 6.5V)
• Hold-on Voltage (VHOLD) ·············· Min. 0.6V
• Output Voltage Range (VOUT) ······· 1.8V to 5.5V (Internally fixed) (xx1)
•
•
Externally adjustable (Feedback voltage : 0.6V) (001C/D)
Output Voltage Accuracy ············· ± 2%
Oscillator Frequency (fosc) ············ 1.2MHz
• Oscillator Maximum Duty Cycle (Maxduty) ·· Min. 80%, Typ. 88%
• Coil-current Limit Circuit ············ Current Limit Typ.1A∗
• Soft Start Time (tstart) ··················· Typ. 0.7ms
• Latch Protection Circuit ··············· Delay time for protection
Typ. 3.3ms (A Version only)
• MODE pin ································ "H" : fixed PWM control,
•
"L" : PWM/VFM auto switching
control (A/B Version)
Packages ································· DFN(PLP)1820-6, SOT-23-5
∗) This is an approximate value, because ON duty depends on conditions
BLOCK DIAGRAMS
RP401Kxx1A/B
RP401K001C/D
RP401Nxx1C/D
(Internally fixed output voltage type)
(Ext. adjustable output voltage type)
(Internally fixed output voltage type)
VIN
VIN
VFM Control
Startup
Circuit
OSC
Vref
Current
Protection
Vref
Switching
Control
PWM
VIN
VFM Control ∗
LX
Startup
Circuit
Current
Protection
VFM Control ∗
LX
Ramp
Compensation
CE
VOUT
LX
Switching
Control
PWM
Soft
Start
Current
Feedback
Ramp
Compensation
Chip
Enable
Current
Protection
Error Amp.
Soft
Start
Current
Feedback
Startup
Circuit
OSC
Vref
Switching
Control
PWM
Error Amp.
Error Amp.
Soft
Start
CE
OSC
Current
Feedback
Ramp
Compensation
Chip
Enable
Chip
Enable
CE
VOUT
VOUT
VFB
MODE
Mode Control
GND
GND
GND
∗) only RP401K001C (PWM/VFM auto switching control)
SELECTION GUIDES
Package
TYPICAL APPLICATIONS
DFN(PLP)1820-6
SOT-23-5
Part No.
RP401K.xx.1.∗ -TR
5,000 pcs
RP401K.00.1.$.-TR
3,000 pcs RP401N.xx.1.$.-TR-FE
PACKAGES
5
4
5
CIN
10μF
5
4
VOUT
RP401K
xx1A/B
CE
VOUT
MODE
RP401K001x
VOUT
CE
Control
CE
VOUT
1.8V to 5.0V
COUT
COUT
10μF×2
GND
LX
CIN
10μF
1.8V to 5.0V
R2
10μF×2
VFB
R1
GND
CIN : C1608JB0J106M, (10μF, TDK)
COUT : C1608JB0J106M x 2, (10μF x 2, TDK)
Efficiency vs. Output Current
PWM/VFM auto switching control
3
xx1A/B
VIN
CE
GND
LX
MODE
VOUT
3
2
2
3
1
001C/D
VIN
CE
GND
LX
VFB
VOUT
∗) The tab is substrate level (GND).
1
2
3
4
5
xx1C/D
CE
GND
VIN
VOUT
LX
Efficiency η (%)
1
2
3
4
5
6
CE
Control
MODE
Control
VIN
RP401x331x / RP401K001x (VOUT=3.3V)
SOT-23-5
6
1
2
SD
SD
LX
Bottom View
4
∗
1
L4.7μH
L4.7μH
TYPICAL CHARACTERISTICS
DFN(PLP)1820-6
Top View
RP401K001C/D
(Externally adjustable output voltage type)
VIN
.xx. : Specify the output voltage within the range of
1.8V (.18.) to 5.5V (.55.) in 0.1V steps.
.00. : Specify the output voltage external adjustable within
the recommendation range of 1.8V to 5.5V.
.∗ : Select from (.A.) with MODE pin, with Latch protection circuit,
(.B.) with MODE pin, without Latch protection circuit.
.$. : Select from (.C.) PWM/VFM auto switching, without Latch
protection circuit, (.D.) fixed PWM, without Latch protection circuit.
6
RP401Kxx1A/B
(Internally fixed output Voltage type)
Q'ty per Reel
100
90
80
70
60
50
40
30
20
10
0
VIN=3.0V
VIN=2.5V
VIN=2.0V
VIN=1.5V
VIN=1.2V
VIN=0.8V
VIN=0.7V
1
10
100
Output Current IOUT (mA)
Fixed PWM control
Efficiency η (%)
Halogen Free
∗) only RP401Nxx1C (PWM/VFM auto switching control)
1000
100
90
80
70
60
50
40
30
20
10
0
VIN=3.0V
VIN=2.5V
VIN=2.0V
VIN=1.5V
VIN=1.2V
VIN=0.8V
VIN=0.7V
1
10
100
Output Current IOUT (mA)
1000
APPLICATIONS
• MP3 players and PDA
No.EK-260-140930
• LCD bias power supply
• Wireless Handset
Step-up DC/DC Converter
RP401x Series
Step-up DC/DC Converter
PWM/VFM Step-up DC/DC Converter
• Digital cameras
• Personal medical equipment
• GPS
RP401x Series / RP400x Series
Step-up DC/DC Converter Comparison
RP401x Series
A/B Version
Control
C Version
Fixed PWM⇔
PWM/VFM
PWM/VFM auto switching
auto switching
(It can be switched by MODE pin)
Lx Current limit *
D Version
PWM/VFM auto switching
Fixed PWM
1A
600mA
0.6V to 5.5V
0.7V to 5.5V (A/B Version)
1.2V to 5.5V (C Version)
1.8V to 5.5V
or
Externally adjustable (only DFN)
1.8V to 5.0V
or
Externally adjustable (only DFN)
Input Voltage Range
Output Voltage Range
RP400x Series
±2% (±12mV)
±2% (±12mV)
1.2MHz
700kHz
Oscillator Maximum
Duty Cycle (Min.)
80%
80%
Soft-start Time (Typ.)
0.7ms
0.7ms
3.3ms (only A Version)
－
Output Voltage Accuracy
Oscillator Frequency (Typ.)
Latch Protection Circuit
(Protection Delay Time)(Typ.)
Package
Others
DFN(PLP)1820-6
DFN(PLP)1820-6 (Ext. adjustable type)
DFN(PLP)1820-6
SOT-23-5 (Fixed output Voltage type) SOT-23-5 (Fixed output Voltage type only)
Built- in Anti-Ringing Switch
*) Will change according to the duty cycle.
The currently available information as of September 2014 is provided in this New Product News.
EK-260-140930