2001.4.23
Step-up DC/DC Controller
R1211X Series
s
OUTLINE
The R1211X Series are PWM step-up DC/DC converter controllers with low supply current by CMOS process.
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 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 R1211XB Series, while phase compensation can be made
externally as for R1211XA Series. B 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(700kHz version) or 10.5ms(300kHz version).
As for the protection circuit, after the soft-starting time, if the maximum duty cycle is continued for a certain time, the
R1211X Series latch the external driver with its off state, or Latch-type protection circuit. 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.
s
FEATURES
q
Standby Current
• • • • • • • • • • • • • • • • •
TYP. 0µA (for B version)
q
Input Voltage Range
• • • • • • • • • • • • • • •
2.5V to 6.0V
q
Built-in Latch-type Protection Function (Output Delay Time can be set with an external capacitor)
q
Two choices of Basic Oscillator Frequency
• •
300kHz, 700kHz
q
Max Duty Cycle
• • • • • • • • • • • • • • • • • •
TYP. 90%
q
High Reference Voltage Accuracy
• • • • • • • ±1.5%
q
U.V.L.O. Threshold level
• • • • • • • • • • • • •
TYP. 2.2V (Hysteresis TYP. 0.13V)
q
Small Package
• • • • •
SOT-23-6W or thin (package thickness MAX. 0.85mm) SON-6 (Under Development)
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APPLICATIONS
q
Constant Voltage Power Source for portable equipment.
q
Constant Voltage Power Source for LCD and CCD.
Rev. 0.05
-1-
s
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
Code
a
↑
b
Contents
b
Designation of Package Type:
D: SON-6
N: SOT23-6W
Designation of Optional Function
A : 700kHz, with AMPOUT pin
B : 700 kHz, with CE pin
C : 300kHz, with AMPOUT pin
D : 300kHz, with CE pin
s
PIN CONFIGURATION
SON-6
6
SOT-23-6W
5
4
EXT
1
DELAY
AMPOUT/CE
(MARK SIDE)
6
GND
V
IN
2
GND
VFB
5
(MARK SIDE)
3
EXT
V
IN
4
DELAY
AMPOUT/CE
VFB
1
2
3
Rev. 0.05
-3-
s
PIN DESCRIPTION
Pin No.
SON6
1
2
3
4
5
6
SOT23-6W
1
5
6
4
3
2
DELAY Pin for External Capacitor (for Setting Output Delay of Protection)
GND
EXT
V
IN
V
FB
Ground Pin
External FET Drive Pin (CMOS Output)
Power Supply Pin
Feedback Pin for monitoring Output Voltage
Symbol
Description
AMPOUT Amp Output Pin(A/C Version) or Chip Enable Pin(B/D Version)
or CE
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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
VFB Pin Voltage
AMPOUT Pin Current
EXT Pin Inductor Drive Output Current
Power Dissipation
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
250
-40∼+85
-55∼+125
Unit
V
V
V
V
V
V
mA
mA
mW
°C
°C
Rev. 0.05
-4-
s
ELECTRICAL CHARACTERISTICS
qR1211X002A
Symbol
V
IN
V
FB
∆V
FB
/
∆T
I
FB
f
OSC
∆f
OSC
/
∆T
I
DD1
Item
Operating Input Voltage
V
FB
Voltage Tolerance
V
FB
Voltage
Temperature Coefficient
V
FB
Input Current
Oscillator Frequency
Oscillator Frequency
Temperature Coefficient
Supply Current 1
V
IN
=6V, V
DLY
=V
FB
=0V, EXT at no load
V
IN
=3.3V, EXT “H” side
V
IN
=3.3V, I
EXT
=-20mA
V
IN
=3.3V, I
EXT
=20mA
V
IN
=3.3V, V
DLY
=V
FB
=0V
V
IN
=V
FB
=2.5V, V
DLY
=0.1V
V
IN
=3.3V, V
FB
=0V, V
DLY
=0V→2V
V
IN
=3.3V at 90% of rising edge
2.5
2.5
0.95
4.5
2.1
0.08
0.45
30
82
600
90
5
3
5.0
5.5
1.00
9.0
2.2
0.13
0.90
60
900
94
10
6
7.5
9.0
1.05
13.5
2.3
0.18
1.50
90
µA
%
Ω
Ω
µA
mA
V
ms
V
V
mA
µA
V
IN
=6V, V
FB
=0V or 6V
V
IN
=3.3V, V
DLY
=V
FB
=0V
-40°C≤ Topt
≤
85°C
-0.1
595
700
±1.4
0.1
805
µA
kHz
kHz/°C
V
IN
=3.3V
-40°C≤ Topt
≤
85°C
Conditions
MIN.
2.5
0.985
1.000
±150
TYP.
(Topt=25°C)
MAX.
6.0
1.015
Unit
V
V
ppm/°C
maxdty
Maximum Duty Cycle
R
EXTH
R
EXTL
I
DLY1
I
DLY2
V
DLY
EXT “H” ON Resistance
EXT “L” ON Resistance
Delay Pin Charge Current
Delay Pin Discharge Current
Delay Pin Detector Threshold
T
START
Soft-start Time
V
UVLO1
UVLO Detector Threshold V
IN
=3.3V→0V, V
DLY
=V
FB
=0V
V
UVLO2
UVLO Detector Hysteresis V
IN
=0V→3.3V, V
DLY
=V
FB
=0V
I
AMP1
I
AMP2
AMP “H” Output Current
AMP “L” Output Current
V
IN
=3.3V, V
AMP
=1V, V
FB
=0.9V
V
IN
=3.3V, V
AMP
=1V, V
FB
=1.1V
Rev. 0.05
-5-
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