RP500x SERIES
step-down DC/DC Converters with synchronous rectifier
NO.EA-155-080522
OUTLINE
The RP500X Series are CMOS-based step-down DC/DC Converters with synchronous rectifier.
Each of these ICs consists of an oscillator, a switching control circuit, a reference voltage unit, an error
amplifier, a soft-start circuit, protection circuits, UVLO circuit, switching transistors, and so on. A low ripple, high
efficiency step-down DC/DC converter can be easily composed of this IC with only an inductor and capacitors. In
terms of the output voltage, since the feedback resistances are built-in, the voltage is fixed internally.
50mV(custom-made) step output can be set by laser-trim and 1.5% or 24mV tolerance depending on the output
voltage is guaranteed.
Mode alternative circuit works automatically for improving the efficiency. Considering fixed noise frequency,
PWM fixed control type is also available. As protection circuits, the current limit circuit which limits peak current
of Lx at each clock cycle, and the latch type protection circuit which works if the term of the over-current
condition keeps on a certain time exist. The latch-type protection circuit works to latch an internal driver with
keeping it disable. To release the condition of the protection, after disabling this IC with a chip enable circuit,
enable it again, or restart this IC with power-on or make the supply voltage at UVLO detector threshold level or
lower than UVLO.
Since packages are DFN(PLP)1820-6, SOT23-6, WLCSP-6 (0.16φ), high density mounting on boards is
possible.
FEATURES
z
Input Voltage Range.............................................. 2.55V to 5.50V
z
Output Voltage....................................................... 1.1V to 3.3V
(It is possible in the range from1.1V to 3.3V with a step 0.1V)
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High Accuracy Output Voltage .............................. ±1.5% (Vout≥1.6V)
±24mV (Vout<1.6V)
z
Supply Current
......................................................... Typ.400
µA(at
PWM mode)
Typ.100
µA(at
PFM mode)
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Oscillator Frequency ............................................. Typ. 1.2MHz
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Built-in Soft start Function ..................................... Typ.0.1ms
z
Built-in Latch type Protection ................................ Typ.1.5ms
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Built-in UVLO Function.......................................... Typ. 2.2V
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Two choices of Switching Mode ............................ Automatic PWM/PFM mode change / PWM fixed
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Packages............................................................... DFN(PLP)1820-6, SOT23-6W, WLCSP-6 (0.16φ)
APPLICATIONS
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Power source for portable equipment such as cellular, PDA, DSC, Notebook PC
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Power source for HDD
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Power source for Li-ion battery-used equipment
1
RP500X
ABSOLUTE MAXIMUM RATINGS
Symbol
V
IN
V
LX
V
CE
V
OUT
I
LX
Item
V
IN
Supply Voltage
Lx Pin Voltage
CE Pin Input Voltage
Vout Pin Voltage
Lx Pin Output Current
Rating
6.5
-0.3 to V
IN
+0.3
-0.3 to V
IN
+0.3
-0.3 to V
IN
+0.3
800
DFN(PLP)
880
SOT
430
WLCSP
650
-40 to 85
-55 to 125
AGND=PGND=0V
Unit
V
V
V
V
mA
mW
°
C
°
C
P
D
Topt
Tstg
Power Dissipation
Operating Temp. Range
Storage Temp. Range
ABSOLUTE MAXIMUM RATINGS
Absolute Maximum ratings are threshold limit values that must not be exceeded ever for an instant
under any conditions. Moreover, such values for any two items must not be reached simultaneously.
Operation above these absolute maximum ratings may cause degradation or permanent damage to
the device. These are stress ratings only and do not necessarily imply functional operation these
limits.
SELECTION GUIDE
In the RP500 series, output voltage, function options, etc. can be designated with user's request.
Part number can be designated as follows:
RP500X xx x x - xx
a
Code
a
Designation of the package
K: DFN(PLP)1820-6
N: SOT-23-6W
Z: WL-CSP-6
b c d
e
←
Part Number
Contents
Designation of output voltage
Designation is possible in the range from 1.1V to 3.3V with a step of 0.1V
Designation of the function (with or without PWM/PFM Alternative function, auto
discharge function)
1:with PWM/PFM alternative, without auto discharge
c
2:without PWM/PFM alternative, without auto discharge
4:without PWM/PFM alternative function, with auto discharge function
Frequency
d
A: 1.2MHz
e
Designation of the taping type
TR:SOT23-6W / DFN(PLP)1820-6
E2:WLCSP-6
*0.05V step is also available as a custom code.
b
4