RP504x Series
600mA∗ PWM/VFM Step-down DC/DC Converter with Synchronous Rectifier
The RP504x Series are low supply current CMOS-based PWM/VFM step-down DC/DC converters with synchronous rectifier.
RP504K/L 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. (RP504N Series can be
selected from fixed PWM control or PWM/VFM auto switching control.) RP504x includes a soft start circuit, an under-voltage lockout
circuit (UVLO), and a latch protection circuit. By simply using an inductor and capacitors as external components, a high-efficiency
step-down DC/DC converter can be easily configured. The small inductor (2.2μH) and output capacitor (4.7μH) can be used by the
switching of 2.25MHz. In addition to SOT-23-5 and DFN1616-6B packages, a 1.2mm
available.
× 1.6mm DFN(PLP)1216-6B package is also
FEATURES
• Supply Current (IDD1)·······················Typ. 400μA (VIN=VCE=5.5V, VOUT=VSET
×
0.8)
•
UVLO
) ·············Typ. 2.0V
• Supply Current (IDD2)·······················Typ. 25μA (VIN=VCE=VOUT=5.5V)
• USVofLtOStDaertteTcitmVeolt(atsgtaert (V
)························Typ. 0.15ms
• Standby Current (Istandby
)
··················Max. 5μA (VIN=5.5V, VCE=0V)
• Coil-current Limit Circuit·················Current limit Typ. 900mA
• Latch Protection Circuit ··················Delay time for protection Typ. 1.5ms
• Auto-Discharge Function················D Version
• MODE pin·······································“H”: PWM/VFM auto switching,
“L”: fixed PWM
• Input Voltage Range (VIN)···············2.3V to 5.5V
• Output Voltage Range (VOUT)··········0.8V to 3.3V (internally fixed)
• Output Voltage Accuracy ················± 1.5%
• Output Current (IOUT)·······················600mA∗
• Oscillator Frequency (fosc)···············2.25MHz
(RP504N does not have MODE pin)
•
Oscillator Maximum Duty Cycle (Maxduty)··Min. 100%
• Packages········································DFN(PLP)1216-6F,
DFN1616-6B, SOT-23-5
) This is an approximate value, because output current depending on conditions and external parts.
∗
BLOCK DIAGRAM
TYPICAL APPLICATION
RP504L/K
RP504L/K
PVIN
L
VIN
VOUT
VIN
LX
VIN
2.2μH
Slope
Compensation
Current
Feedback
Chip
Enable
CE
VOUT
C
2.2μF
IN
C
4.7μF
OUT
CE
OSC
Current
Protection
MODE
GND
LX
Vref
1
PWM∗
Control
Switching
Control
Soft Start
VOUT
L
: MIPSZ2520D2R2 MIPS2520D2R2 (FDK)
、 、
UVLO
MLP2520S2R2M VLS252010T-2R2M (TDK)
CKP2520-2R2M (TAIYO YUDEN)
、
MODE
GND
IN
C
: 2.2 F: C1608JB0J225K (TDK)
、
μ
2.2 F 2: C1005JB0J225K (TDK) JMK105BJ225MV (TAIYO YUDEN)
、
μ ×
4.7 F: C1005X5R0J475M (TDK) JMK105BJ475MV (TAIYO YUDEN)
、
μ
*1) MODE="H": PWM/VFM auto switching MODE="L": fixed PWM
Blue Line : only RP504Kxx1D, RP504Lxx1D
、
COUT : C1608JB0J475K (TDK)、GRM155B30J475KE18 (MURATA)
SELECTION GUIDES
.
:
Select from (
.
A
.
) With MODE pin, without auto-discharge function,
.
∗
Package
DFN(PLP)1216-6F 5,000 pcs RP504L
Halogen Free
Q'ty per Reel
Part No.
(.
D
.
) With MODE pin, with auto-discharge function,
.
xx1∗-E2
$ : Select from (
.
B
.
) PWM/VFM auto switching, without auto-discharge function,
DFN1616-6B
SOT-23-5
5,000 pcs RP504K
3,000 pcs RP504N
.
xx1∗ -TR
(.
C
.
) Fixed PWM, without auto-discharge function,
.
xx1$-TR-FE
.
xx.
: Specify the output voltage within the range of
0.8V (
.
08
.
) to 3.3V (
.
33
.
) in 0.1V steps.
PACKAGES (Top View)
TYPICAL CHARACTERISTIC
RP504x (VOUT=3.3V) Efficiency vs. Output Current
DFN(PLP)1216-6F
DFN1616-6B
SOT-23-5
5 4
6
5
4
6
5
4
V
IN=5.0V, VMODE=0V
100
90
80
70
60
50
40
30
20
10
0
V
IN=4.3V, VMODE=0V
∗
1
2
3
1
2
3
1
2
3
1
2
3
4
5
6
VIN
MODE
CE
VOUT
GND
LX
1
2
3
4
5
6
CE
MODE
VIN
LX
GND
VOUT
1
2
3
4
5
VOUT
GND
LX
VIN
CE
V
IN=VMODE=4.3V
V
IN=VMODE=3.6V
0.01
0.1
1
10
100
1000
Output Current IOUT (mA)
) The tab is substrate level (GND).
∗
APPLICATIONS
• Power source for battery-powered equipment
• Power source for hand-held communication equipment, cameras, and VCRs
• Power source for compact HDD
No.EK-259-110607
Step-down DC/DC Converter