PWM Step-up DC/DC Converter Controller
R1210Nxx2x SERIES
OUTLINE
NO. EA-064-071207
The R1210Nxx2C/xx2D Series are CMOS-based PWM step-up DC/DC Converter controllers, with high
accuracy, low supply current.
Each of the R1210Nxx2x Series consists of an oscillator, a PWM circuit, a reference voltage unit, an error
amplifier, phase compensation circuit, resistors for voltage detection, a chip enable circuit, a controller against
drastic load transient and an output voltage detector. A low ripple, high efficiency step-up DC/DC converter can
be composed of this IC with only four external components, or an inductor, a diode, a transistor and a capacitor.
The R1210Nxx2x Series can detect drastic change of output voltage with a circuit controller, the load transient
response is improved.
Each of the R1210Nxx2x Series has a driver pin, or ‘EXT’ pin for external transistor. By connecting a power
transistor with low ON-resistance to EXT pin, a large current flows through an inductor, thus, large output current
can be supplied.
The built-in chip enable circuit can make the standby mode with ultra low quiescent current.
Since the package for these ICs is small SOT-23-5, high density mounting of the ICs on board is possible.
FEATURES
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•
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•
•
•
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External Components .......................................Only an inductor, a diode, a capacitor, and a transistor
Standby Current ................................................Max. 0.5µA
Low Temperature-Drift Coefficient of Output Voltage Typ.
±100ppm/°C
Output Voltage ..................................................Stepwise Setting with a step of 0.1V in the range of
2.2V to 6.0V
Two choices of Basic Oscillator Frequency ......100kHz (xx2C), 180kHz (xx2D)
Output Voltage Accuracy...................................±2.5%
Small Package ..................................................SOT-23-5 (Mini-mold)
Low Ripple, Low Noise
Oscillator Start-up Voltage ................................Max. 0.8V
APPLICATIONS
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Power source for battery-powered equipment.
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Power source for portable communication appliances, cameras, VCRs
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Power source for appliances of which require higher voltage than battery voltage.
1
R1210Nxx2x
BLOCK DIAGRAMS
Vref Circuit
EXT
5
Buffer
PWM Controller
OSC
Phase Comp.
-
+
-
+
-
+
2
V
OUT
Chip Enable
4
GND
1
CE
SELECTION GUIDE
In the R1210N Series, the output voltage, the oscillator frequency, the optional function, and the taping type for
the ICs can be selected at the user’s request.
The selection can be made by designating the part number as shown below;
R1210Nxx2x-xx-F
↑ ↑ ↑↑ ↑ ↑
a bcd e f
←Part
Number
Code
a
b
c
d
e
f
Contents
Designation of Package Type:
N: SOT-23-5
Setting Output Voltage(V
OUT
):
Stepwise setting with a step of 0.1V in the range of 2.2V to 6.0V
Designation of Driver
2: External Tr. Driver
Designation of Oscillator Frequency
C: 100kHz
D: 180kHz
Designation of Taping Type:
Ex. TR (Refer to Taping Specifications; TR type is the standard direction.)
Designation of composition of pin plating:
-F: Lead free plating
2
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