R1211N002C-TR [RICOH]
Step-up DC/DC Controller; 升压型DC / DC控制器
| 型号： | R1211N002C-TR |
| 厂家： | 
RICOH ELECTRONICS DEVICES DIVISION |
| 描述： | Step-up DC/DC Controller |
| 文件： | 总33页 (文件大小：374K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
2001.8.30
Step-up DC/DC Controller
R1211X Series
ꢀ 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 Package • • • • • SOT-23-6W or thin (package height MAX. 0.85mm) SON-6 (Under Development)
ꢀ APPLICATIONS
ꢀ Constant Voltage Power Source for portable equipment.
ꢀ Constant Voltage Power Source for LCD and CCD.
Rev. 1.10
- 1 -
ꢀ BLOCK DIAGRAMS
Version A
VFB
OSC
EXT
VIN
DTC
AMPOUT
Vref
GND
UVLO
Latch
DELAY
Version B
VFB
OSC
EXT
DTC
VIN
Vref
GND
UVLO
CE
Chip
Enable
Latch
DELAY
Rev. 1.10
- 2 -
ꢀ 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
Code
a
Contents
Designation of Package Type:
D: SON-6
N: SOT23-6W
b
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)
ꢀ PIN CONFIGURATIONS
SON-6
SOT-23-6W
6
5
4
GND
EXT
IN
V
DELAY
GND
AMPOUT/CE
1
2
6
5
(MARK SIDE)
AMPOUT/CE
(MARK SIDE)
VFB
IN
V
3
4
EXT
DELAY
1
VFB
3
2
Rev. 1.10
- 3 -
ꢀ PIN DESCRIPTIONS
Symbol
Description
Pin No.
SON6 SOT23-6W
1
2
3
4
5
6
1
5
6
4
3
2
DELAY Pin for External Capacitor (for Setting Output Delay of Protection)
GND
EXT
Ground Pin
External FET Drive Pin (CMOS Output)
Power Supply Pin
V
IN
V
FB
Feedback Pin for monitoring Output Voltage
AMPOUT Amplifier Output Pin(A/C Version) or Chip Enable Pin(B/D
or CE Version, Active at “H”)
ꢀ ABSOLUTE MAXIMUM RATINGS
Symbol
Item
Rating
6.5
Unit
V
V
IN
V
IN
Pin Voltage
V
V
V
EXT Pin Output Voltage
DELAY Pin Voltage
AMPOUT Pin Voltage
V
V
V
EXT
DLY
AMP
-0.3 V +0.3
IN
-0.3 V +0.3
IN
-0.3 V +0.3
IN
V
CE
CE Pin Input Voltage
V
-0.3 V +0.3
IN
V
FB
VFB Pin Voltage
V
-0.3 V +0.3
IN
I
I
AMPOUT Pin Current
EXT Pin Inductor Drive Output Current
Power Dissipation
Operating Temperature Range
Storage Temperature Range
mA
mA
mW
°C
°C
AMP
±10
±50
250
EXT
P
D
Topt
Tstg
-40 +85
-55 +125
Rev. 1.10
- 4 -
ꢀ ELECTRICAL CHARACTERISTICS
ꢀR1211X002A
(Topt=25°C)
TYP. MAX. Unit
6.0
Symbol
Item
Conditions
MIN.
2.5
V
IN
Operating Input Voltage
V
V
∆V
∆T
V
V
Voltage Tolerance
Voltage
V =3.3V
-40°C≤ Topt ≤ 85°C
0.985
1.000 1.015
±150
V
FB
FB
IN
FB
/
ppm/°C
FB
Temperature Coefficient
I
V
Input Current
V =6V, V =0V or 6V
-0.1
595
0.1
805
FB
FB
IN
FB
µA
kHz
kHz/°C
f
Oscillator Frequency
Oscillator Frequency
Temperature Coefficient
V =3.3V, V =V =0V
700
±1.4
OSC
IN
DLY
FB
∆f
/
-40°C≤ Topt ≤ 85°C
OSC
∆T
I
Supply Current 1
Maximum Duty Cycle
V =6V, V =V =0V, EXT at no load
600
90
5
900
94
10
DD1
IN
DLY
FB
µA
%
Ω
maxdty
V =3.3V, EXT “H” side
82
IN
R
EXT “H” ON Resistance
V =3.3V, I
=-20mA
EXTH
IN
EXT
R
EXT “L” ON Resistance
V =3.3V, I
=20mA
3
6
EXTL
DLY1
DLY2
IN
EXT
Ω
I
I
Delay Pin Charge Current V =3.3V, V =V =0V
2.5
2.5
5.0
5.5
7.5
9.0
IN
DLY
FB
µA
mA
Delay Pin Discharge Current
Delay Pin Detector Threshold
V =V =2.5V, V =0.1V
IN
FB
DLY
V
0.95
4.5
2.1
0.08
0.45
30
1.00
9.0
2.2
0.13
0.90
60
1.05
13.5
2.3
0.18
1.50
90
V
ms
V
V
mA
µA
DLY
V =3.3V, V =0V, V =0V→2V
IN
FB
DLY
T
Soft-start Time
V =3.3V at 90% of rising edge
IN
START
UVLO1
UVLO2
AMP1
V
V
I
UVLO Detector Threshold
UVLO Detector Hysteresis
AMP “H” Output Current
AMP “L” Output Current
V =3.3V→0V, V
=V =0V
FB
IN
DLY
V =0V→3.3V, V
=V =0V
FB
IN
DLY
V =3.3V, V
=1V, V =0.9V
IN
AMP
FB
I
V =3.3V, V
IN
=1V, V =1.1V
AMP2
AMP
FB
Rev. 1.10
- 5 -
ꢀR1211X002B
Symbol
(Topt=25°C)
TYP. MAX. Unit
Item
Conditions
MIN.
2.5
V
IN
Operating Input Voltage
6.0
1.000 1.015
±150
V
V
V
V
V
Voltage Tolerance
Voltage
V =3.3V
0.985
FB
FB
IN
FB
∆V
∆T
/
-40°C≤ Topt ≤ 85°C
V =6V, V =0V or 6V
ppm/°C
FB
Temperature Coefficient
I
FB
V
FB
Input Current
-0.1
595
0.1
IN
FB
µA
f
Oscillator Frequency
V =3.3V, V =V =0V
700
805
kHz
OSC
IN
DLY
FB
Oscillator Frequency
Temperature Coefficient
∆f
∆T
/
-40°C≤ Topt ≤ 85°C
±1.4
kHz/°C
OSC
I
Supply Current 1
V =6V, V =V =0V, EXT at no load
600
90
5
900
94
10
6
DD1
IN
DLY
FB
µA
Maximum Duty Cycle
maxdty
V =3.3V, EXT “H” side
IN
82
%
R
EXT “H” ON Resistance V =3.3V, I
=-20mA
=20mA
EXTH
IN
EXT
Ω
Ω
R
EXT “L” ON Resistance
V =3.3V, I
IN
3
EXTL
EXT
I
I
Delay Pin Charge Current V =3.3V, V =V =0V
2.5
2.5
5.0
5.5
7.5
9.0
DLY1
IN
DLY
FB
µA
mA
Delay Pin Discharge Current
V =V =2.5V, V =0.1V
DLY2
IN
FB
DLY
Delay Pin Detector Threshold
V
DLY
0.95
1.00
1.05
V
V =3.3V, V =0V, V =0V→2V
IN
FB
DLY
T
V
V
Soft-start Time
V =3.3V
4.5
2.1
0.08
9.0
2.2
0.13
0
13.5
2.3
0.18
1
0.5
0.5
ms
V
V
µA
µA
µA
V
START
UVLO1
UVLO2
IN
UVLO Detector Threshold
UVLO Detector Hysteresis
Standby Current
CE “H” Input Current
CE “L” Input Current
CE “H” Input Voltage
CE “L” Input Voltage
V =3.3V→0V, V
=V =0V
FB
=V =0V
FB
IN
DLY
V =0V→3.3V, V
IN
DLY
I
V =6V, V =0V
IN CE
STB
I
V =6V, V =6V
-0.5
-0.5
1.5
CEH
IN
CE
I
V =6V, V =0V
IN CE
CEL
V
V
CEH
V =6V, V =0V→6V
IN
CE
0.3
V
CEL
V =2.5V, V =2V→0V
IN
CE
Rev. 1.10
- 6 -
ꢀR1211X002C
Symbol
(Topt=25°C)
TYP. MAX. Unit
6.0
Item
Conditions
MIN.
2.5
V
IN
Operating Input Voltage
V
V
∆V
∆T
V
V
Voltage Tolerance
Voltage
V =3.3V
-40°C≤ Topt ≤ 85°C
0.985
1.000 1.015
±150
V
FB
FB
IN
FB
/
ppm/°C
FB
Temperature Coefficient
I
V
Input Current
V =6V, V =0V or 6V
-0.1
240
0.1
360
FB
FB
IN
FB
µA
kHz
kHz/°C
f
Oscillator Frequency
Oscillator Frequency
Temperature Coefficient
V =3.3V, V =V =0V
300
±0.6
OSC
IN
DLY
FB
∆f
/
-40°C≤ Topt ≤ 85°C
OSC
∆T
I
Supply Current 1
Maximum Duty Cycle
V =6V, V =V =0V, EXT at no load
300
90
5
500
94
10
DD1
IN
DLY
FB
µA
%
Ω
maxdty
V =3.3V, EXT “H” side
82
IN
R
EXT “H” ON Resistance
V =3.3V, I
=-20mA
EXTH
IN
EXT
R
EXT “L” ON Resistance
V =3.3V, I
=20mA
3
6
EXTL
DLY1
DLY2
IN
EXT
Ω
I
I
Delay Pin Charge Current V =3.3V, V =V =0V
2.0
2.5
4.5
5.5
7.0
9.0
IN
DLY
FB
µA
mA
Delay Pin Discharge Current
Delay Pin Detector Threshold
V =V =2.5V, V =0.1V
IN
FB
DLY
V
0.95
5.0
2.1
0.08
0.45
25
1.00
10.5
2.2
0.13
0.90
50
1.05
16.0
2.3
0.18
1.50
75
V
ms
V
V
mA
µA
DLY
V =3.3V, V =0V, V =0V→2V
IN
FB
DLY
T
Soft-start Time
V =3.3V
IN
START
UVLO1
UVLO2
AMP1
V
V
I
UVLO Detector Threshold
UVLO Detector Hysteresis
AMP “H” Output Current
AMP “L” Output Current
V =3.3V→0V, V
=V =0V
FB
IN
DLY
V =0V→3.3V, V
=V =0V
FB
IN
DLY
V =3.3V, V
=1V, V =0.9V
IN
AMP
FB
I
V =3.3V, V
IN
=1V, V =1.1V
AMP2
AMP
FB
Rev. 1.10
- 7 -
ꢀR1211X002D
Symbol
Item
Conditions
MIN.
2.5
TYP. MAX.
6.0
Unit
V
V
IN
Operating Input Voltage
V
V
V
Voltage Tolerance
Voltage
V =3.3V
0.985
1.000 1.015
V
FB
FB
IN
FB
∆V
∆T
/
-40°C≤ Topt ≤ 85°C
V =6V, V =0V or 6V
±150
ppm/°C
FB
Temperature Coefficient
I
FB
V
FB
Input Current
-0.1
240
0.1
IN
FB
µA
f
Oscillator Frequency
V =3.3V, V =V =0V
IN
300
360
kHz
OSC
DLY
FB
Oscillator Frequency
Temperature Coefficient
∆f
∆T
/
-40°C≤ Topt ≤ 85°C
±0.6
kHz/°C
OSC
I
Supply Current 1
V =6V, V =V =0V, EXT at no load
300
90
5
500
94
10
6
DD1
IN
DLY
FB
µA
Maximum Duty Cycle
maxdty
V =3.3V, EXT “H” side
IN
82
%
R
EXT “H” ON Resistance V =3.3V, I
=-20mA
=20mA
EXTH
IN
EXT
Ω
Ω
R
EXT “L” ON Resistance
V =3.3V, I
IN
3
EXTL
EXT
I
I
Delay Pin Charge Current V =3.3V, V =V =0V
2.0
2.5
4.5
5.5
7.0
9.0
DLY1
IN
DLY
FB
µA
mA
Delay Pin Discharge Current
V =V =2.5V, V =0.1V
DLY2
IN
FB
DLY
Delay Pin Detector Threshold
V
DLY
0.95
1.00
1.05
V
V =3.3V, V =0V, V =0V→2V
IN
FB
DLY
T
V
Soft-start Time
UVLO Detector Threshold
V =3.3V
V =3.3V→0V, V
IN
5.0
2.1
10.5
2.2
16.0
2.3
ms
V
START
UVLO1
IN
=V =0V
FB
DLY
V
UVLO Detector Hysteresis
Standby Current
CE “H” Input Current
CE “L” Input Current
CE “H” Input Voltage
CE “L” Input Voltage
0.08
0.13
0
0.18
1
0.5
0.5
V
µA
µA
µA
V
UVLO2
V =0V→3.3V, V
V =6V, V =0V
IN CE
=V =0V
FB
IN
DLY
I
STB
I
V =6V, V =6V
-0.5
-0.5
1.5
CEH
IN
CE
I
V =6V, V =0V
IN CE
CEL
V
V
CEH
V =6V, V =0V→6V
IN
CE
0.3
V
CEL
V =2.5V, V =2V→0V
IN
CE
Rev. 1.10
- 8 -
ꢀ TYPICAL APPLICATIONS AND TECHNICAL NOTES
<R1211X002A/R1211X002C>
Inductor
Diode
VIN
EXT
VFB
C4
NMOS
R1
R2
C3
C1
DELAY
C2
R3
GND AMPOUT
C5 R4
NMOS: IRF7601 (International Rectifier)
Inductor : LDR655312T-100 10µH (TDK) for R1211X002A
: LDR655312T-220 22µH (TDK) for R1211X002C
Diode: CRS02 (Toshiba)
C1: 4.7µF (Ceramic)
C2: 0.22µF (Ceramic)
C3: 10µF (Ceramic)
C4: 680pF(Ceramic)
C5: 2200pF(Ceramic)
R1: Output Voltage Setting Resistor 1
R2: Output Voltage Setting Resistor 2
R3: 30kΩ
R4: 30kΩ
<R1211X002B/R1211X002D>
Inductor
Diode
C4
R1
VIN
EXT
VFB
CE
NMOS
C3
C1
DELAY
GND
C2
R3
R2
CE Control
NMOS: IRF7601 (International Rectifier)
Inductor: LDR655312T-100 10µH (TDK) for R1211X002B
LDR655312T-220 22µH (TDK) for R1211X002D
Diode: CRS02 (Toshiba)
C1: 4.7µF (Ceramic)
C2: 0.22µF (Ceramic)
C3: 10µF (Ceramic)
C4: 680pF(Ceramic)
R1: Setting Output Voltage Resistor1
R2: Setting Output Voltage Resistor2
R3 : 30kΩ
[Note] These example circuits may be applied to the output voltage requirement is 15V or less. If the output voltage
requirement is 15V or more, ratings of NMOS and diode as shown above is over the limit, therefore, choose other
external components.
Rev. 1.10
- 9 -
ꢀ Use a 1µF or more capacitance value of bypass capacitor between VIN pin and GND, C1 as shown in the typical
applications above.
ꢀ In terms of the capacitor for setting delay time of the latch protection, C2 as shown in typical applications of the
previous page, connect between Delay pin and GND pin of the IC with the minimum wiring distance.
ꢀ Connect a 1µF or more value of capacitor between VOUT and GND, C3 as shown in typical applications of the
previous page. (Recommended value is from 10µF to 22µF.) If the operation of the composed DC/DC converter may
be unstable, use a tantalum type capacitor instead of ceramic type.
ꢀ Connect a capacitor between VOUT and the dividing point, C4 as shown in typical applications of the previous page.
The capacitance value of C4 depends on divider resistors for output voltage setting. Typical value is between 100pF
and 1000pF.
ꢀ Output Voltage can be set with divider resistors for voltage setting, R1 and R2 as shown in typical applications of
the previous page. Refer to the next formula.
Output Voltage = VFB×(R1+R2)/R2
R1+R2=100kΩ is recommended range of resistances.
ꢀ The operation of Latch protection circuit is as follows: When the IC detects maximum duty cycle, charge to an
external capacitor, C2 of DELAY pin starts. And maximum duty cycle continues and the voltage of DELAY pin
reaches delay voltage detector threshold, VDLY, outputs “L” to EXT pin and turns off the external power MOSFET.
To release the latch protection operation, make the IC be standby mode with CE pin and make it active in terms of
B/D version. Otherwise, restart with power on.
The delay time of latch protection can be calculated with C2, VDLY, and Delay Pin Charge Current, IDLY1, as in the
next formula.
t=C2×VDLY/IDLY1
Once after the maximum duty is detected and released before delay time, charge to the capacitor is halt and delay
pin outputs “L”.
ꢀ As for R1211X002A/C version, the values and positioning of C4, C5, R3, and R4 shown in the above diagram are
just an example combination. These are for making phase compensation. If the spike noise of VOUT may be large,
the spike noise may be picked into VFB pin and make the operation unstable. In this case, a resistor R3, shown in
typical applications of the previous page. The recommended resistance value of R3 is in the range from 10kΩ to
50kΩ. Then, noise level will be decreased.
ꢀ As for R1211X002B/D version, EXT pin outputs GND level at standby mode.
ꢀ Select the Power MOSFET, the diode, and the inductor within ratings (Voltage, Current, Power) of this IC. Choose
the power MOSFET with low threshold voltage depending on Input Voltage to be able to turn on the FET completely.
Choose the diode with low VF such as Shottky type, and with low reverse current IR, and with fast switching speed.
When an external transistor is switching, spike voltage may be generated caused by an inductor, therefore
recommended voltage tolerance of capacitor connected to VOUT is three times of setting voltage or more.
ꢀThe performance of power circuit with using this IC depends on external components. Choose the most suitable
components for your application.
Rev. 1.10
- 10 -
ꢀ Output Current and Selection of External Components
<Basic Circuit>
i2
Inductor
Diode
IOUT
VOUT
VIN
CL
i1
Lx Tr
GND
<Current through L>
Discontinuous Mode
Continuous Mode
ILxmax
IL
IL
ILxmax
ILxmin
ILxmin
Tf
Iconst
t
t
Ton
Toff
Ton
T=1/fosc
Toff
T=1/fosc
There are two modes, or discontinuous mode and continuous mode for the PWM step-up switching regulator
depending on the continuous characteristic of inductor current.
During on time of the transistor, when the voltage added on to the inductor is described as VIN, the current is VIN ×t/L.
Therefore, the electric power, PON, which is supplied with input side, can be described as in next formula.
ON
T
2
PON=∫VIN ×t/L dt
Formula 1
0
With the step-up circuit, electric power is supplied from power source also during off time. In this case, input current is
described as (VOUT-VIN)×t/L, therefore electric power, POFF is described as in next formula.
Tf
POFF=∫VIN×(VOUT-VIN)×t/L dt
Formula 2
0
In this formula, Tf means the time of which the energy saved in the inductance is being emitted. Thus average
electric power, PAV is described as in the next formula.
ON
T
Tf
2
PAV=1/(Ton+Toff)×{∫VIN ×t/L dt + ∫VIN×(VOUT-VIN)×t/L dt} Formula 3
0
0
In PWM control, when Tf=Toff is true, the inductor current becomes continuos, then the operation of switching
regulator becomes continuous mode.
In the continuous mode, the deviation of the current is equal between on time and off time.
VIN×Ton/L=(VOUT-VIN)×Toff/L
Formula 4
Further, the electric power, PAV is equal to output electric power, VOUT×IOUT, thus,
2
2
2
IOUT = fOSC × VIN ×TON /{2×L ×(VOUT-VIN)}=VIN ×TON/(2×L×VOUT)
Formula 5
When IOUT becomes more than formula 5, the current flows through the inductor, then the mode becomes
Rev. 1.10
- 11 -
continuous. The continuous current through the inductor is described as Iconst, then,
2
2
IOUT = fOSC ×VIN ×tON /(2×L×(VOUT-VIN))+VIN×Iconst/VOUT
Formula 6
In this moment, the peak current, ILxmax flowing through the inductor and the driver Tr. is described as follows:
ILxmax = Iconst +VIN×Ton/L
Formula 7
Formula 8
With the formula 4,6, and ILxmax is,
ILxmax = VOUT/VIN×IOUT+VIN×Ton/(2×L)
Therefore, peak current is more than IOUT. Considering the value of ILxmax, the condition of input and output, and
external components should be selected.
In the formula 7, peak current ILxmax at discontinuous mode can be calculated. Put Iconst=0 in the formula.
The explanation above is based on the ideal calculation, and the loss caused by Lx switch and external components
is not included. The actual maximum output current is between 50% and 80% of the calculation. Especially, when the
ILx is large, or VIN is low, the loss of VIN is generated with the on resistance of the switch. As for VOUT, Vf (as much as
0.3V) of the diode should be considered.
ꢀ TIMING CHART
ꢀ
R1211X002A/R1211X002C
DTC
VREF
SS
EXT
AMPOUT
OP AMP
VOUT
VFB
R1
EXT
R2
PWM Comparator
ꢀ
R1211X002B/R1211X002D
DTC
VREF
SS
EXT
AMPOUT
VOUT
VFB
R1
EXT
R2
PWM Comparator
OP AMP
<Soft-start Operation>
Soft-start operation is starting from power-on as follows:
(Step1)
The voltage level of SS is rising gradually by constant current circuit of the IC and a capacitor. VREF level which is
input to OP AMP is also gradually rising. VOUT is rising up to input voltage level just after the power-on, therefore, VFB
voltage is rising up to the setting voltage with input voltage and the ration of R1 and R2. AMPOUT is at “L”, and
switching does not start.
(Step2)
Rev. 1.10
- 12 -
When the voltage level of SS becomes the setting voltage with the ration of R1 and R2 or more, switching operation
starts. VREF level gradually increases together with SS level. VOUT is also rising with balancing VREF and VFB. Duty
cycle depends on the lowest level among AMPOUT, SS, and DTC of the 4 input terminals in the PWM comparator.
(Step3)
When SS reaches 1V, soft-start operation finishes. VREF becomes constant voltage (=1V). Then the switching
operation becomes normal mode.
SS
VFB,VREF
SS,VREF
VFB
DTC
AMPOUT
AMPOUT
Step1
Step2
VOUT
VIN
<Latch Protection Operation>
The operation of Latch protection circuit is as follows: When AMPOUT becomes “H” and the IC detects maximum
duty cycle, charge to an external capacitor, C2 of DELAY pin starts. And maximum duty cycle continues and the
voltage of DELAY pin reaches delay voltage detector threshold, VDLY, outputs “L” to EXT pin and turns off the
external power MOSFET.
To release the latch protection operation, make the IC be standby mode with CE pin and make it active in terms of
R1211X002B/D version. Otherwise, make supply voltage down to UVLO detector threshold or lower, and make it rise
up to the normal input voltage.
During the soft-start time, if the duty cycle may be the maximum, protection circuit does not work and DELAY pin is
fixed at GND level.
The delay time of latch protection can be calculated with C2, VDLY, and Delay Pin Charge Current, IDLY1, as in the
next formula.
t=C2×VDLY/IDLY1
Once after the maximum duty is detected and released before delay time, charge to the capacitor is halt and delay
pin outputs “L”.
Output Short
AMPOUT
AMPOUT
Normal
VDLY
DTC
DELAY
maxduty
Operation
Latched
EXT
Rev. 1.10
- 13 -
ꢀ TEST CIRCUITS
ꢀ
R1211X002A/R1211X002C
*Oscillator Frequency, Maximum Duty Cycle, VFB Voltage Test *Consumption Current Test
3.3V
6V
A
EXT
FB
IN
V
IN
OSCILLOSCOPE
V
F
B
V
GND DELAY
GND DELAY
*EXT “H” ON Resistance
*EXT “L” ON Resistance
3.3V
3.3V
EXT
EXT
V
IN
V
IN
150Ω
OSCILLOSCOPE
V
150Ω
V
FB
FB
V
GND
GND
DELAY
DELAY
*DELAY Pin Charge Current
*DELAY PIn Discharge Current
3.3V
2.5V
IN
V
V
IN
FB
FB
V
DELAY
GND
GND
A
DELAY
A
0.1V
Rev. 1.10
- 14 -
*DELAY Pin Detector Threshold Voltage Test
*AMP “H” Output Current/”L” Output Current Test
3.3V
3.3V
V
IN
EXT
FB
V
IN
OSCILLOSC
AMPOUT
A
OPE
1V
V
FB
V
DELAY
GND
DELAY
GND
*UVLO Detector Threshold/Hysteresis Range Test
V
IN
EXT
OSCILLOSC OPE
FB
V
DELAY
GND
*Soft-start Time Test
Coil
Diode
OUT
V
C2
C 5
NMOS
V
IN
OSCILLOSCOPE
EXT
Rout
AMPOUT
C1
C3
R1
C4
R4
V
FB
R3
GND
DELAY
R2
<Components>
Inductor (L)
Diode (SD)
Capacitors
: 22µH (TDK LDR655312T-220)
: CRS02 (Toshiba)
C1: 680pF(Ceramic), C2: 22µF (Tantalum)+2.2µF (Ceramic),
C3: 68µF (Tantalum)+2.2µF (Ceramic), C4: 2200pF(Ceramic), C5: 22µF(Tantalum)
NMOS Transistor : IRF7601 (International Rectifier)
Resistors : R1: 90kΩ, R2:10kΩ, R3:30kΩ, R4:30kΩ, Rout:1kΩ/330Ω
Rev. 1.10
- 15 -
ꢀ
R1211X002B/R1211X002D
*Oscillator Frequency, Maximum Duty Cycle, VFB Voltage Test *Consumption Current Test
3.3V
6V
A
V
EXT
CE
V
IN
IN
OSCILLOSCOPE
CE
FB
FB
V
V
GND
GND
DELAY
DELAY
*EXT “H” ON Resistance
*EXT “L” ON Resistance
3.3V
3.3V
EXT
CE
EXT
CE
V
V
IN
IN
150Ω
OSCILLOSCOPE
150Ω
V
FB
V
V
FB
GND
GND
DELAY
DELAY
*DELAY Pin Charge Current
*DELAY PIn Discharge Current
2.5V
3.3V
V
IN
V
IN
CE
FB
CE
FB
V
V
GND
DELAY
GND
DELAY
A
A
0.1V
Rev. 1.10
- 16 -
*DELAY Pin Detector Threshold Voltage Test
*Standby Current Test
3.3V
6V
IN
V
EXT
CE
A
V
IN
CE
OSCILLOSCOPE
V
FB
FB
V
GND
DELAY
GND
DELAY
*UVLO Detector Threshold/Hysteresis Range Test
* CE “L” Input Current/”H” Input Current Test
EXT
V
IN
V
IN
CE
OSCILLOSCOPE
CE
FB
A
V
FB
0V/6V
V
GND
DELAY
DELAY
GND
*CE “L” Input Voltage/”H” Input Voltage Test
IN
V
EXT
CE
OSCILLOSCOPE
FB
V
DELAY
GND
*Soft-start Time Test
VOUT
Coil
C2
C5
NMOS
OSCILLOSCOPE
Rout
V
IN
EXT
CE
C1
C3
0V/3.3V
R1
R2
FB
V
R3
GNDDELAY
Rev. 1.10
- 17 -
<Components>
Inductor (L)
Diode (SD)
Capacitors
: 22µH (TDK LDR655312T-220)
: CRS02 (Toshiba)
C1: 680pF(Ceramic), C2: 22µF (Tantalum)+2.2µF (Ceramic),
C3: 68µF (Tantalum)+2.2µF (Ceramic), C5: 22µF (Tantalum)
NMOS Transistor : IRF7601 (International Rectifier)
Resistors : R1: 90kΩ, R2: 10kΩ, R3: 30kΩ
ꢀ TYPICAL CHARACTERISTICS
1) Output Voltage vs. Output Current
R1211X002A
L=10uH
R1211X002A
L=10uH
OUT
V
=5V
VOUT=10V
5.1
10.2
10
5
IN
V =2.5V
VIN=2.5V
VIN=3.3V
IN
V =3.3V
IN
V =5.0V
4.9
9.8
5.1
1
10
100
[mA]
1000
1
10
100
1000
Output Current IOUT [mA]
OUT
Output Current I
R1211X002A
L=10uH
R1211X002B
L=10uH
OUT
OUT
V
V
=15V
=5V
15.3
15
5
VIN=2.5V
VIN=3.3V
VIN=5.0V
VIN=2.5V
VIN=3.3V
14.7
4.9
1
10
100
[mA]
1000
1
10
100
OUT
[mA]
1000
OUT
Output Current I
Output Current I
R1211X002B
L=10uH
R1211X002B
L=10uH
VOUT=10V
V
OUT=15V
10.2
15.3
15
10
VIN=2.5V
VIN=3.3V
VIN=5.0V
VIN=2.5V
V
V
IN=3.3V
IN=5.0V
9.8
1
10
100
1000
14.7
OUT [
Output Current I
mA]
1
10
100
1000
Output Current IOUT [mA]
Rev. 1.10
- 18 -
R1211X002C
L=22uH
VOUT=5V
R1211X002C
L=22uH
VOUT=10V
5.1
10.2
10
5
VIN=2.5V
VIN=3.3V
VIN=5.0V
VIN=2.5V
VIN=3.3V
9.8
4.9
1
10
100
1000
1
10
100
1000
Output Current IOUT [mA]
Output Current IOUT [mA]
R1211X002C
L=22uH
VOUT=15V
R1211X002D
L=22uH
VOUT=5V
15.3
5.1
15
5
VIN=2.5V
VIN=3.3V
VIN=5.0V
VIN=2.5V
VIN=3.3V
14.7
10.2
4.9
1
10
100
1000
1
10
100
1000
Output Current IOUT [mA]
Output Current IOUT [mA]
R1211X002D
L=22uH
VOUT=10V
R1211X002D
L=22uH
VOUT=15V
15.3
10
15
VIN=2.5V
VIN=3.3V
VIN=5.0V
VIN=2.5V
VIN=3.3V
VIN=5.0V
9.8
14.7
1
10
100
1000
1
10
100
1000
Output Current IOUT [mA]
Output Current IOUT [mA]
Rev. 1.10
- 19 -
2) Efficiency vs. Output Current
R1211X002A
L=10uH
VOUT=5V
R1211X002A
R1211X002B
R1211X002B
L=10uH
VOUT=10V
100
80
60
40
20
0
100
80
60
40
20
0
VIN=2.5V
VIN=3.3V
VIN=5.0V
VIN=2.5V
VIN=3.3V
1
1
1
10
100
1000
1
10
100
1000
1000
1000
Output Current IOUT [mA]
Output Current IOUT [mA]
R1211X002A
L=10uH
VOUT=15V
L=10uH
VOUT=5V
100
80
60
40
20
0
100
80
60
40
20
0
VIN=2.5V
VIN=3.3V
VIN=5.0V
VIN=2.5V
VIN=3.3V
10
100
1000
1
10
100
Output Current IOUT [mA]
Output Current IOUT [mA]
R1211X002B
L=10uH
VOUT=10V
L=10uH
VOUT=15V
100
80
60
40
20
0
100
80
60
40
20
0
VIN=2.5V
VIN=3.3V
VIN=5.0V
VIN=2.5V
VIN=3.3V
VIN=5.0V
1
10
100
10
100
1000
Output Current IOUT [mA]
Output Current IOUT [mA]
Rev. 1.10
- 20 -
R1211X002C
L=22uH
VOUT=5V
R1211X002C
L=22uH
OUT=10V
V
100
80
60
40
20
0
100
80
60
40
20
0
VIN=2.5V
VIN=2.5V
VIN=3.3V
VIN=3.3V
VIN=5.0V
1
10
100
1000
1
10
100
1000
1000
1000
Output Current IOUT [mA]
Output Current IOUT [mA]
R1211X002C
L=22uH
OUT=15V
R1211X002D
L=22uH
VOUT=5V
V
100
80
60
40
20
0
100
80
60
40
20
0
VIN=2.5V
VIN=3.3V
VIN=5.0V
VIN=2.5V
VIN=3.3V
1
10
100
1
10
100
1000
Output Current IOUT [mA]
Output Current IOUT [mA]
R1211X002D
L=22uH
VOUT=10V
R1211X002D
L=22uH
VOUT=15V
100
80
60
40
20
0
100
80
60
40
20
0
VIN=2.5V
VIN=3.3V
VIN=5.0V
VIN=2.5V
VIN=3.3V
VIN=5.0V
1
10
100
1
10
100
1000
Output Current IOUT [mA]
Output Current IOUT [mA]
Rev. 1.10
- 21 -
3) VFB Voltage vs. Input Voltage (Topt =25°C)
R1211X002X
1015
1010
1005
1000
995
990
985
2
3
4
5
6
Input Voltage VIN [V]
4) Oscillator Frequency vs. Input Voltage (Topt=25°C)
R1211X002A/B
900
R1211X002C/D
400
350
300
250
200
800
700
600
500
2
3
4
5
6
2
3
4
5
6
Input Voltage VIN [V]
Input Voltage VIN [V]
5) Supply Current vs. Input Voltage (Topt=25°C)
R1211X002A
600
R1211X002B
600
500
400
300
200
100
0
500
400
300
200
100
0
2
3
4
5
6
2
3
4
5
6
Input Voltage VIN [V]
Input Voltage V [V]
IN
Rev. 1.10
- 22 -
R1211X002C
R1211X002D
400
300
200
100
0
400
300
200
100
0
2
3
4
5
6
2
3
4
5
6
Input Voltage VIN [V]
Input Voltage VIN [V]
6) Maximum Duty Cycle vs. Input Voltage (Topt=25°C)
R1211X002A/B
96
R1211X002C/D
96
94
92
90
88
86
84
82
80
94
92
90
88
86
84
82
80
2
3
4
5
6
2
3
4
5
6
Input Voltage VIN [V]
Input Voltage VIN [V]
7) VFB Voltage vs. Temperature
R1211X002X
1015
VIN=3.3V
1010
1005
1000
995
990
985
-50
-25
0
25
50
75
100
(°C)
Temperature Topt
Rev. 1.10
- 23 -
8) Oscillator Frequency vs. Temperature
R1211X002A/B VIN=3.3V
900
R1211X002C/D VIN=3.3V
400
350
300
250
200
800
700
600
500
-50
-25
0
25
50
75
100
-50
-25
0
25
50
75
100
Temperature Topt (°C)
Temperature Topt (°C)
9) Supply Current vs. Temperature
R1211X002A
VIN=3.3V
R1211X002B
VIN=3.3V
600
500
400
300
200
100
0
600
500
400
300
200
100
0
-50
-25
0
25
50
75
100
-50
-25
0
25
50
75
100
(°C)
Temperature Topt
Temperature Topt(°C)
R1211X002C
VIN=3.3V
R1211X002D
VIN=3.3V
400
300
200
100
0
400
300
200
100
0
-50
-25
0
25
50
(°C)
75
100
-50
-25
0
25
50
75
100
(°C)
Temperature Topt
Temperature Topt
Rev. 1.10
- 24 -
10) Maximum Duty Cycle vs. Temperature
R1211X002A/B
VIN=3.3V
R1211X002C/D VIN=3.3V
96
94
92
90
88
86
84
82
80
96
94
92
90
88
86
84
82
80
-50
-25
0
25
50
(°C)
75
100
-50
-25
0
25
50
(°C)
75
100
Temperature Topt
Temperature Topt
11) EXT”H” Output Current vs. Temperature
R1211X002X
VIN=3.3V
8
7
6
5
4
3
2
-50
-25
0
25
50
(°C)
75
100
Temperature Topt
12) EXT”L” Output Current vs. Temperature
R1211X002X
VIN=3.3V
5
4
3
2
1
-50
-25
0
25
50
(°C)
75
100
Temperature Topt
Rev. 1.10
- 25 -
13) Soft-start Time vs. Temperature
R1211X002A/B
VIN=3.3V
R1211X002C/D VIN=3.3V
16
14
12
10
8
16
14
12
10
8
6
6
-50
-25
0
25
50
(°C)
75
100
-50
-25
0
25
50
(°C)
75
100
Temperature Topt
Temperature Topt
14) UVLO Detector Threshold vs. Temperature
R1211X002X
VIN=3.3V
2300
2250
2200
2150
2100
-50
-25
0
25
50
75
100
(°C)
Temperature Topt
15) AMP “H” Output Current vs. Temperature
R1211X002A/C VIN=3.3V
1600
1400
1200
1000
800
600
400
-50
-25
0
25
50
75
100
Temperature Topt
(°C)
Rev. 1.10
- 26 -
16) AMP “L” Output Current vs. Temperature
R1211X002A
VIN=3.3V
R1211X002C
VIN=3.3V
80
70
60
50
40
30
20
80
70
60
50
40
30
20
-50
-25
0
25
50
75
100
-50
-25
0
25
50
(°C)
75
100
Temperature Topt
(°C)
Temperature Topt
17) DELAY Pin Charge Current vs. Temperature
R1211X002A/B
VIN=3.3V
R1211X002C/D VIN=3.3V
7
6
5
4
3
2
7
6
5
4
3
2
-50
-25
0
25
50
(°C)
75
100
-50
-25
0
25
50
(°C)
75
100
Temperature Topt
Temperature Topt
18) DELAY Pin Detector Threshold vs. Temperature
R1211X002X
VIN=3.3V
1040
1020
1000
980
960
-50
-25
0
25
50
75
100
(°C)
Temperature Topt
Rev. 1.10
- 27 -
19) DELAY Pin Discharge Current vs. Temperature
R1211X002X
VIN=2.5V
10
8
6
4
2
0
-50
-25
0
25
50
(°C)
75
100
Temperature Topt
20) CE “L” Input Voltage vs. Temperature
R1211X002B/D
VIN=2.5V
1200
1100
1000
900
800
700
600
-50
-25
0
25
50
75
100
(°C)
Temperature Topt
21) CE “H” Input Voltage vs. Temperature
R1211X002B/D
VIN=6.0V
1200
1100
1000
900
800
700
600
-50
-25
0
25
50
75
100
(°C)
Temperature Topt
Rev. 1.10
- 28 -
22) Standby Current vs. Temperature
R1211X002B/D
VIN=6.0V
1
0.8
0.6
0.4
0.2
0
-0.2
-50
-25
0
25
50
75
100
Temperature Topt(°C)
23) Load Transient Response
R1211X002A
L=10uH
VIN=3.3V , C3=22uF
VOUT=5V , IOUT=1-100mA
5.6
300
200
100
0
VOUT
5.0
4.4
IOUT
Time [5ms/div]
R1211X002A
L=10uH
VIN=3.3V , C3=22uF
VOUT=10V , IOUT=1-100mA
11.2
10.0
8.8
300
VOUT
200
100
0
IOUT
Time [5ms/div]
R1211X002A
L=10uH
VIN=3.3V , C3=22uF
VOUT=15V , IOUT=1-50mA
16.8
15.0
13.2
300
200
100
0
VOUT
IOUT
Time [5ms/div]
Rev. 1.10
- 29 -
R1211X002B
L=10uH
VIN=3.3V , C3=22uF
VOUT=5V , IOUT=1-100mA
5.6
5.0
4.4
300
200
100
0
VOUT
IOUT
Time [5ms/div]
R1211X002B
L=10uH
VIN=3.3V , C3=22uF
VOUT=10V , IOUT=1-100mA
11.2
10.0
8.8
300
200
100
0
VOUT
IOUT
Time [5ms/div]
R1211X002B
L=10uH
VIN=3.3V , C3=22uF
VOUT=15V , IOUT=1-50mA
16.8
15.0
13.2
300
200
100
0
VOUT
IOUT
Time [5ms/div]
R1211X002C
L=22uH
VIN=3.3V , C3=22uF
VOUT=5V , IOUT=1-100mA
5.6
5.0
4.4
300
200
100
0
VOUT
IOUT
Time [5ms/div]
Rev. 1.10
- 30 -
R1211X002C
L=22uH
VIN=3.3V , C3=22uF
VOUT=10V , IOUT=1-100mA
11.2
10.0
8.8
300
200
100
0
VOUT
IOUT
Time [5ms/div]
R1211X002C
L=22uH
VIN=3.3V , C3=22uF
VOUT=15V , IOUT=1-50mA
16.8
15.0
13.2
300
200
100
0
VOUT
IOUT
Time [5ms/div]
R1211X002D
L=22uH
VIN=3.3V , C3=22uF
VOUT=5V , IOUT=1-100mA
5.6
5.0
4.4
300
200
100
0
VOUT
IOUT
Time [5ms/div]
R1211X002D
L=22uH
VIN=3.3V , C3=22uF
VOUT=10V , IOUT=1-100mA
11.2
10.0
8.8
300
200
100
0
VOUT
IOUT
Time [5ms/div]
Rev. 1.10
- 31 -
R1211X002D
L=22uH
VIN=3.3V , C3=22uF
VOUT=15V , IOUT=1-50mA
16.8
15.0
13.2
300
200
100
0
VOUT
IOUT
Time [5ms/div]
24) Power-on Response
R1211X002A
16
L=10uH
VIN=3.3V , IOUT=10mA
R1211X002B
L=10uH
VIN=3.3V , IOUT=10mA
16
14
12
10
8
14
12
10
8
(c)VOUT=15V
(c)VOUT=15V
(b)VOUT=10V
(a)VOUT=5V
(b)VOUT=10V
(a)VOUT=5V
6
6
4
4
2
2
VIN
VIN
0
0
0
5
10
15
20
25
0
5
10
15
20
25
Time [5ms/div]
Time [5ms/div]
R1211X002C
L=22uH
R1211X002D
L=22uH
VIN=3.3V , IOUT=10mA
(c)VOUT=15V
VIN=3.3V , IOUT=10mA
(c)VOUT=15V
16
14
12
10
8
16
14
12
10
8
(b)VOUT=10V
(a)VOUT=5V
(b)VOUT=10V
(a)VOUT=5V
6
6
4
4
2
2
VIN
VIN
20
0
0
0
5
10
15
25
0
5
10
15
20
25
Time [5ms/div]
Time [5ms/div]
Rev. 1.10
- 32 -
25) Turn-on speed with CE pin
R1211X002B
16
L=10uH
VIN=3.3V , IOUT=10mA
R1211X002D
L=22uH
VIN=3.3V , IOUT=10mA
16
14
12
10
8
14
12
10
8
(c)VOUT=15V
(c)VOUT=15V
(b)VOUT=10V
(a)VOUT=5V
(b)VOUT=10V
(a)VOUT=5V
CE
6
6
4
4
2
2
CE
20
0
0
0
5
10
15
20
25
0
5
10
15
25
Time [5ms/div]
Time [5ms/div]
Rev. 1.10
- 33 -
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