2001.8.30
Step-up DC/DC Controller
R1211X Series
s
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.
s
FEATURES
q
Standby Current
• • • • • • • • • • • • • • • • •
TYP. 0µA (for B/D 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 Options 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 height MAX. 0.85mm) SON-6 (Under Development)
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APPLICATIONS
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Constant Voltage Power Source for portable equipment.
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Constant Voltage Power Source for LCD and CCD.
Rev. 1.10
-1-
s
BLOCK DIAGRAMS
Version A
V
FB
OSC
DTC
EXT
AMPOUT
Vref
V
IN
UVLO
GND
Latch
DELAY
Version B
V
FB
OSC
DTC
EXT
V
IN
Vref
UVLO
GND
CE
Chip
Enable
Latch
DELAY
Rev. 1.10
-2-
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 (External Phase Compensation Type)
B : 700 kHz, 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)
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PIN CONFIGURATIONS
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. 1.10
-3-
s
PIN DESCRIPTIONS
Pin No.
SON6
1
2
3
4
5
6
Symbol
SOT23-6W
1
DELAY
5
GND
6
EXT
4
V
IN
3
V
FB
2
AMPOUT
or CE
Description
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”)
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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
Item
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
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. 1.10
-4-
s
ELECTRICAL CHARACTERISTICS
qR1211X002A
Symbol
Item
V
IN
Operating Input Voltage
V
FB
V
FB
Voltage Tolerance
∆V
FB
/ V
FB
Voltage
Temperature Coefficient
∆T
I
FB
V
FB
Input Current
f
OSC
Oscillator Frequency
∆f
OSC
/ Oscillator Frequency
Temperature Coefficient
∆T
I
DD1
Supply Current 1
maxdty
Maximum Duty Cycle
R
EXTH
EXT “H” ON Resistance
R
EXTL
I
DLY1
I
DLY2
V
DLY
T
START
V
UVLO1
V
UVLO2
I
AMP1
I
AMP2
EXT “L” ON Resistance
Delay Pin Charge Current
Delay Pin Discharge Current
Delay Pin Detector Threshold
Conditions
V
IN
=3.3V
-40°C≤ Topt
≤
85°C
V
IN
=6V, V
FB
=0V or 6V
V
IN
=3.3V, V
DLY
=V
FB
=0V
-40°C≤ Topt
≤
85°C
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
MIN.
2.5
0.985
TYP.
1.000
±150
(Topt=25°C)
MAX.
Unit
6.0
V
1.015
V
ppm/°C
0.1
805
µA
kHz
kHz/°C
µA
%
Ω
Ω
µA
mA
V
ms
V
V
mA
µA
-0.1
595
700
±1.4
600
90
5
3
82
900
94
10
6
7.5
9.0
1.05
13.5
2.3
0.18
1.50
90
2.5
2.5
0.95
4.5
2.1
0.08
0.45
30
5.0
5.5
1.00
9.0
2.2
0.13
0.90
60
V
IN
=3.3V, V
FB
=0V, V
DLY
=0V→2V
Soft-start Time
V
IN
=3.3V at 90% of rising edge
UVLO Detector Threshold V
IN
=3.3V→0V, V
DLY
=V
FB
=0V
UVLO Detector Hysteresis V
IN
=0V→3.3V, V
DLY
=V
FB
=0V
AMP “H” Output Current
V
IN
=3.3V, V
AMP
=1V, V
FB
=0.9V
AMP “L” Output Current
V
IN
=3.3V, V
AMP
=1V, V
FB
=1.1V
Rev. 1.10
-5-
