R1211x SERIES
STEP-UP DC/DC CONTROLLER
NO.EA-088-0604
OUTLINE
The R1211x Series are CMOS-based PWM step-up DC/DC converter controllers with low supply current.
Each of the R1211x Series consists of an oscillator, a PWM control circuit, a reference voltage unit, an error
amplifier, a reference current unit, a protection circuit, and an under voltage lockout (UVLO) circuit. A low ripple,
high efficiency step-up DC/DC converter can be composed of this IC with some external components, or an
inductor, a diode, a power MOSFET, divider resisters, and capacitors.
Phase compensation has been made internally in the R1211x002B/D Series, while phase compensation can
be made externally as for R1211x002A/C Series. B/D version has stand-by mode.
Max duty cycle is internally fixed typically at 90%. Soft start function is built-in, and Soft-starting time is set
typically at 9ms(A/B, 700kHz version) or 10.5ms(C/D, 300kHz version). As for the protection circuit, after the
soft-starting time, if the maximum duty cycle is continued for a certain period, the R1211x Series latch the
external driver with its off state, or Latch-type protection circuit works.
The delay time for latch the state can be set with an external capacitor.
To release the protection circuit, restart with power-on (Voltage supplier is equal or less than UVLO detector
threshold level), or once after making the circuit be stand-by with chip enable pin and enable the circuit again.
FEATURES
•
•
•
•
•
•
•
•
Standby Current ................................................Typ. 0µA (for B/D version)
Input Voltage Range .........................................2.5V to 6.0V
Built-in Latch-type Protection Function (Output Delay Time can be set with an external capacitor)
Two Options of Basic Oscillator Frequency ......300kHz, 700kHz
Max Duty Cycle.................................................Typ. 90%
High Reference Voltage Accuracy ....................±1.5%
U.V.L.O. Threshold level ...................................Typ. 2.2V (Hysteresis Typ. 0.13V)
Small Packages ................................................SOT-23-6W or thin (package height Max. 0.85mm) SON-6
APPLICATIONS
•
Constant Voltage Power Source for portable equipment.
•
Constant Voltage Power Source for LCD and CCD.
1
R1211x
BLOCK DIAGRAMS
Version A/C
V
FB
AMPOUT
-
Vref
OSC
DTC
Version B/D
EXT
V
IN
-
OSC
V
FB
DTC
EXT
+
-
-
-
+
+
-
-
-
V
IN
GND
Vref
+
GND
UVLO
UVLO
CE
Chip
Enable
SELECTION GUIDE
In the R1211x Series, the oscillator frequency, the optional function, and the package type for the ICs can be
selected at the user's request.
The selection can be made with designating the part number as shown below;
R1211x002x-TR
↑
a
↑
b
←Part
Number
Code
a
Contents
Designation of Package Type:
D: SON-6
N: SOT23-6W
Designation of Optional Function
A : 700kHz, with AMPOUT pin (External Phase Compensation Type)
B : 700kHz, with CE pin (Internal Phase Compensation Type, with Stand-by)
C : 300kHz, with AMPOUT pin (External Phase Compensation Type)
D : 300kHz, with CE pin (Internal Phase Compensation Type, with Stand-by)
b
2
-
Latch
Latch
+
-
DELAY
+
-
+
+
-
DELAY
R1211x
PIN CONFIGURATIONS
SON-6
Top View
6
5
4
SOT-23-6W
6
5
4
4
5
6
Bottom View
EXT
GND
(MARK SIDE)
V
IN
DELAY AMPOUT/CE
V
FB
1
2
3
3
2
1
1
2
3
PIN DESCRIPTIONS
Pin No
SON6
1
2
3
4
5
6
SOT23-6W
1
5
6
4
3
2
DELAY
GND
EXT
V
IN
V
FB
AMPOUT or CE
Pin for External Capacitor
(for Setting Output Delay of Protection)
Ground Pin
External FET Drive Pin (CMOS Output)
Power Supply Pin
Feedback Pin for monitoring Output Voltage
Amplifier Output Pin(A/C Version) or
Chip Enable Pin(B/D Version, Active at "H")
Symbol
Pin Description
* Tab in the
parts have GND level. (They are connected to the reverse side of this IC.)
Do not connect to other wires or land patterns.
ABSOLUTE MAXIMUM RATINGS
Symbol
V
IN
V
EXT
V
DLY
V
AMP
V
CE
V
FB
I
AMP
I
EXT
P
D
Topt
Tstg
V
IN
Pin Voltage
EXT Pin Output Voltage
DELAY Pin Voltage
AMPOUT Pin Voltage
CE Pin Input Voltage
V
FB
Pin Voltage
AMPOUT Pin Current
EXT Pin Inductor Drive Output Current
Power Dissipation (SOT-23-6W)*
Power Dissipation (SON-6)*
Operating Temperature Range
Storage Temperature Range
Item
Rating
6.5
−0.3
~ V
IN
+0.3
−0.3
~ V
IN
+0.3
−0.3
~ V
IN
+0.3
−0.3
~ V
IN
+0.3
−0.3
~ V
IN
+0.3
±10
±50
430
500
−40
~
+85
−55
~
+125
mW
°C
°C
Unit
V
V
V
V
V
V
mA
mA
* ) For Power Dissipation, please refer to PACKAGE INFORMATION to be described.
3
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