PWM Step-up DC/DC Converter
R1210N××1× Series
OUTLINE
process.
phase compensation circuit, resistors for voltage detection, a chip enable circuit. Further, includes a controller
The R1210N××1× Series are PWM step-up DC/DC Converter, with high accuracy, low supply current by
Each of the R1210N××1× Series consists of an oscillator, a PWM circuit, a reference voltage unit, an error am
drastic load transient, a control transistor with low ON-Resistance, ‘L
X
switch’, and a protection circuit for L
X
A low ripple, high efficiency step-up DC/DC converter can be composed of this IC with only three external
nents, or an inductor, a diode and a capacitor.
and an output voltage detector. R1210N××1A Series contain further a circuit for changeover oscillator frequenc
The R1210N Series can detect drastic change of output voltage with a circuit controller. The load transi
sponse is improved compared with current model, furthermore the R1210N××1A Series have another function,
TYP 100kHz to 35kHz, therefore, supply current is reduced.
.
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.
when the load current is small, oscillator frequency is decreased by a circuit for switching oscillator frequenc
FEATURES
•
External Components ................................................................. Only an inductor, a diode, and a capacitor
•
Standby Current ......................................................................... TYP 0µA
.
•
Low Temperature-Drift Coefficient of Output Voltage.............. TYP ±100ppm/°C
.
2.2V to 6.0V (××1C/D)
2.2V to 3.5V (××1A)
•
Two choices of Basic Oscillator Frequency................................ 100kHz (××1A/C), 180kHz (××1D)
•
Small Package .............................................................................. SOT-23-5 (Mini-mold)
•
High Efficiency ............................................................................ TYP 88%
.
•
Low Ripple, Low Noise
•
Built-in a driver transistor with low on-resistance
•
Start-up Voltage........................................................................... MAX. 0.9V
•
Basic Frequency change-over circuit (only for
××1A
type)....... from TYP. 100kHz to 35kHz
•
Output Voltage............................................................................. Stepwise Setting with a step of 0.1V in the rang
(V
IN
=Set Output Voltage×0.6 [V], I
OUT
=10mA)
APPLICATIONS
•
Power source for battery-powered equipment.
•
Power source for portable communication appliances, cameras, VCRs
•
Power source for appliances of which require higher voltage than battery voltage.
BLOCK DIAGRAM
Vref Circuit
L
X
5
V
LX
limiter
Buffer
PWM Controller
OSC
fosc Control
Phase Comp.
2 V
OUT
4 GND
Chip Enable
1
CE
SELECTION GUIDE
ICs can be selected at the user’s request.
The selection can be made by designating the part number as shown below ;
R1210N××1×-××
↑ ↑ ↑
a b c
Code
Setting Output Voltage (V
OUT
) :
a
Stepwise setting with a step of 0.1V in the range of 2.2V to 6.0V (for
××1C/D
version) or
2.2V to 3.5V (for
××1A
version) is possible.
Designation of Oscillator Frequency
b
A : 100kHz with a Frequency Change-over circuit
C : 100kHz without a Frequency Change-over circuit
D : 180kHz without a Frequency Change-over circuit
c
Designation of Taping Type; Ex. :TR, TL (refer to Taping Specification)
“TR” is prescribed as a standard.
Contents
In the R1210N Series, the output voltage, the oscillator frequency, the optional function, and the taping type for the
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