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 - forced 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
forced 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 (2.2
μ
H) 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
× 1.6mm DFN(PLP)1216-6B package is also available.
FEATURES
• Supply Current (IDD1)·······················Typ. 400μA (Switching)
• Supply Current (IDD2)·······················Typ. 25μA (No switching, VFM)
• Supply Current (IDD2)·······················Typ. 400μA (No switching, PWM)
•
UVLO
)··············Typ. 2.0V
• USVofLtOStDaertteTcitmVeolt(atsgtaert (V
)························Typ. 0.15ms
• 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": forced PWM control
"L": PWM/VFM auto switching control
• Standby Current (Istandby)··················Max. 5μA (CE="L")
• Input Voltage Range (VIN)···············2.3V to 5.5V (VSET≥1.0V)
• Output Voltage Range (VOUT)··········0.8V to 3.3V (Internally fixed)
• Output Voltage Accuracy ················± 1.5%
• Output Current (IOUT)·······················600mA∗
(RP504N does not have MODE pin)
• Oscillator Frequency (fosc)···············2.25MHz
• Packages········································DFN(PLP)1216-6F,
•
Oscillator Maximum Duty Cycle (Maxduty) ···Min. 100%
DFN1616-6B, SOT-23-5
) This is an approximate value, because output current depending on conditions and external parts.
∗
BLOCK DIAGRAM
TYPICAL APPLICATION
RP504x
RP504L/K
PVIN
L
VIN
VOUT
V
IN
VIN
LX
2.2μH
Slope
Current
Chip
CE
Compensation
Feedback
Enable
CE
VOUT
C
IN
C
OUT
2.2μF
4.7μF
∗2
∗3
OSC
Current
Protection
L
X
MODE
GND
Vref
PWM
Control
Switching
Control
Soft Start
V
OUT
UVLO
L
: MIPSZ2520D2R2, MIPS2520D2R2 (FDK),
MLP2520S2R2M, VLS252010T-2R2M (TDK)
CKP2520-2R2M (TAIYO YUDEN)
MODE∗1
GND
CIN
: 2.2 F: C1608JB0J225K (TDK),
μ
2.2 F 2: C1005JB0J225K (TDK), JMK105BJ225MV (TAIYO YUDEN)
μ ×
1) MODE pin exists in RP504K and RP504L only. MODE="H": forced PWM control,
MODE="L": PWM/VFM auto switching control.
∗
4.7 F: C1005X5R0J475M (TDK), JMK105BJ475MV (TAIYO YUDEN)
μ
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,
.
xx.
1.∗-E2
$ : Select from (
.
B
.
) PWM/VFM auto switching control,
.
.
DFN1616-6B
SOT-23-5
5,000 pcs RP504K
3,000 pcs RP504N
.
xx
.
1.∗-TR
without auto-discharge function,
.
xx
.
1$-TR-FE
.
.
(.
C
.
) forced PWM control, without auto-discharge function.
.
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
RP504x331x Efficiency vs. Output Current
DFN(PLP)1216-6F
DFN1616-6B
SOT-23-5
6
5
4
5
4
6
5
4
100
90
80
70
60
50
40
∗
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
1
2
3
4
5
VOUT
GND
LX
VIN
CE
MODE
VIN
30
20
10
0
VIN=4.3V, PWM/VFM
VIN=5.0V, PWM/VFM
VIN=4.3V, forced PWM
VIN=5.0V, forced PWM
LX
GND
VOUT
1
10
100
1000
) The tab is substrate level (GND).
∗
Output Current IOUT (mA)
APPLICATIONS
• Power source for battery-powered equipment
• Power source for hand-held communication equipment, cameras, and VCRs
• Power source for compact HDD
No.EK-259-121001
Step-down DC/DC Converter