R1232D SERIES
PWM STEP-DOWN DC/DC CONVERTER WITH SYNCHRONOUS RECTIFIER
NO.EA-129-130510
OUTLINE
The R1232D Series are CMOS-based PWM step-down DC/DC converters with synchronous rectifier, low
supply current. As an output capacitor, a 10μF or more ceramic capacitor can be used with the R1232D.
Each of these ICs consists of an oscillator, a PWM control circuit, a voltage reference unit, an error amplifier, a
soft-start circuit, protection circuits, a protection against miss operation under low voltage (UVLO), a chip enable
circuit, a synchronous rectifier, Nch. driver transistor, and so on. A low ripple, high efficiency step-down DC/DC
converter can be easily composed of this IC with only a few kinds of external components, or an inductor and
capacitors. (As for R1232D001x type, divider resistors are also necessary.) In terms of the output voltage, it is
fixed internally in the R1232Dxx1x types. While in the R1232D001x types, the output voltage is adjustable with
external divider resistors.
As protection circuits, current limit circuit which limits peak current of LX at each clock cycle, and latch type
protection circuit exist. The latch protection works if the term of the over-current condition keeps on a certain time.
Latch-type protection circuit works to latch an internal driver with keeping it disable. To release the condition of
protection, after disable this IC with a chip enable circuit, enable it again, or restart this IC with power-on or make
the supply voltage at UVLO detector threshold level or lower than UVLO.
FEATURES
• Two choices of Oscillator Frequency ............................ 1MHz, 2.25MHz
(Small inductors can be used. 4.7μH for 1MHz/2.2μH for 2.25MHz)
• Built-in Driver ON Resistance ....................................... P-channel 0.2Ω (at VIN=5.0V)
• Built-in Soft-start Function............................................. Typ. 1.0ms (fosc=1MHz type)
• Output Voltage .............................................................. 0.9V to 3.3V (R1232Dxx1x Type)
0.8V to VIN (R1232D001x Type)
• High Accuracy Output Voltage ......................................±2.0%
• Built-in Current Limit Circuit .......................................... Typ. 1.4A
• Package ........................................................................SON-8 (t=0.9mm)
APPLICATIONS
• Power source for portable equipment such as PDA, DSC, Notebook PC.
• Power source for HDD
1
R1232D
BLOCK DIAGRAMS
R1232Dxx1A/B
AGND
VDD
3
VIN
7
2
Slope
Compensation
Current Limit
5
VOUT
4
CE
Phase
Compensation
Q
LX
S
Output
Contorol
8
R
Vref
PWM
Comparator
Error
Amplifer
Oscillator
Soft Start
TEST Circuit
UVLO
“H” Active
Chip Enable
1
6
PGND
TEST
GND Fixed
R1232D001C/D
AGND
VDD
3
VIN
7
2
Slope
Compensation
Current Limit
5
VFB
4
CE
Phase
Compensation
Q
LX
Output
Contorol
8
R
S
PWM
Comparator
Oscillator
Error
Amplifer
Vref
Soft Start
“H” Active
TEST Circuit
UVLO
Chip Enable
2
1
6
PGND
TEST
GND Fixed
R1232D
SELECTION GUIDE
In the R1232D Series, the output voltage, the oscillator frequency and the output voltage adjustment for the
ICs can be selected at the user’s request.
Product Name
R1232Dxx1∗-TR-FE
Package
Quantity per Reel
Pb Free
Halogen Free
SON-8
3,000 pcs
Yes
Yes
xx : The output voltage can be designated in the range from 0.9 V(09) to 3.3V(33) in 0.1V steps.
(For externally adjustable output voltage type, (00).)
∗ : The oscillator frequency and the output voltage adjustment are options as follows.
Code
Oscillator frequency
Output voltage
adjustment
A
1MHz
No
B
2.25MHz
No
C
1MHz
Yes
D
2.25MHz
Yes
3
R1232D
PIN CONFIGURATION
SON-8
Top View
8
7
6
Bottom View
5
5 6
∗
1
2
3
7
8
∗
4
∗
4 3
2
1
PIN DESCRIPTIONS
Pin No
Symbol
Pin Description
1
PGND
2
VIN
Voltage Supply Pin
3
VDD
Voltage Supply Pin
4
CE
Chip Enable Pin (active with "H")
5
VOUT/VFB
6
TEST
Test Pin (Forced to the GND level.)
7
AGND
Ground Pin
8
LX
Ground Pin
Output/Feedback Pin
LX Switching Pin (CMOS Output)
* Tab is GND level. (They are connected to the reverse side of this IC.) The tab is better to be connected to the GND, but
leaving it open is also acceptable.
4
R1232D
ABSOLUTE MAXIMUM RATINGS
Symbol
Item
（AGND=PGND=0V)
Rating
Unit
VIN
VIN Supply Voltage
−0.3 to 6.5
V
VDD
VDD Pin Voltage
−0.3 to 6.5
V
VLX
LX Pin Voltage
−0.3 to VIN + 0.3
V
VCE
CE Pin Input Voltage
−0.3 to VIN + 0.3
V
TEST Pin Input Voltage
−0.3 to VIN + 0.3
V
VOUT/VFB Pin Input Voltage
−0.3 to VIN + 0.3
V
VTEST
VOUT/VFB
ILX
LX Pin Output Current
±1.5
V
PD
Power Dissipation (SON-8)*
480
mW
Ta
Operating Temperature Range
−40 to 85
°C
Storage Temperature Range
−55 to 125
°C
Tstg
∗) For Power Dissipation, please refer to PACKAGE INFORMATION.
ABSOLUTE MAXIMUM RATINGS
Electronic and mechanical stress momentarily exceeded absolute maximum ratings may cause the
permanent damages and may degrade the life time and safety for both device and system using the device
in the field. The functional operation at or over these absolute maximum ratings is not assured.
5
R1232D
ELECTRICAL CHARACTERISTICS
•
R1232DxxxA/C
Ta=25°C
Symbol
VIN
Item
Conditions
Operating Input Voltage
VOUT
Step-down Output Voltage
VIN=VCE=5.0V, IOUT=10mA
VFB
Feedback Voltage
R1232D001C
Step-down Output Voltage
Temperature Coefficient
−40°C
Oscillator Frequency
VIN=VCE =VSET +1.5V
Supply Current
VIN=VCE =5.5V,
VOUT(VFB)=5.5V
Standby Current
VCE=VOUT(VFB)=0V, VIN= 5.5V
ILXleak
LX Leakage Current
VIN=5.5V,VCE=0V
VLX=5.5V or 0V
RONP
RONN
ΔVOUT/ΔTa
fosc
IDD
Istandby
Maxduty
<
=
Ta
<
=
Min.
Max.
Unit
2.6
5.5
V
×0.980
×1.020
V
0.816
V
0.784
Typ.
0.800
ppm/
°C
±150
85°C
0.75
1.00
1.25
MHz
70
140
190
μA
0.0
5.0
μA
0.0
5.0
μA
ON Resistance of Pch Transistor VIN=5.0V, ILX=200mA
0.20
0.35
Ω
ON Resistance of Nch Transistor VIN=5.0V, ILX=200mA
0.20
0.35
Ω
Oscillator Maximum Duty Cycle
−5.0
100
%
tstart
Soft-start Time
VIN=VCE =5.0V, at no load
0.5
1.0
1.4
ms
tprot
Protection Delay Time
VIN=VCE =5.0V
0.1
2.0
10.0
ms
ILXlimit
Lx Current Limit
VIN=VCE =5.0V
1.0
1.4
VUVLO1
UVLO Detector Threshold
VIN=VCE =2.6V-> 1.5V
2.10
2.25
2.40
V
VUVLO2
UVLO Released Voltage
VIN=VCE =1.5V-> 2.6V
2.20
VUVLO1
+0.10
2.50
V
CE Input Current
VIN=5.5V, VCE =5.5V or 0V
−0.1
0.0
0.1
μA
VOUT/IVFB Leakage Current
VIN=5.5V, VCE =0V,
VOUT(IVFB)=5.5V or 0V
−0.1
0.0
0.1
VCEH
CE "H" Input Voltage
VIN=5.5V
1.5
VCEL
CE "L" Input Voltage
VIN=3.0V
ICE
IVOUT
（IVFB）
A
μA
V
0.3
V
RECOMMENDED OPERATING CONDITIONS (ELECTRICAL CHARACTERISTICS)
All of electronic equipment should be designed that the mounted semiconductor devices operate within the
recommended operating conditions. The semiconductor devices cannot operate normally over the
recommended operating conditions, even if when they are used over such conditions by momentary
electronic noise or surge. And the semiconductor devices may receive serious damage when they continue
to operate over the recommended operating conditions.
6
R1232D
•
R1232DxxxB/D
Ta=25°C
Symbol
VIN
Item
Conditions
Operating Input Voltage
VOUT
Step-down Output Voltage
VFB
Feedback Voltage
Min.
Typ.
2.6
VIN=VCE=5.0V,IOUT=10mA
R1232D001D
Max.
Unit
5.5
V
×0.980
×1.020
0.784 0.800 0.816
V
V
ppm/
°C
Step-down Output Voltage
Temperature Coefficient
−40°C
Oscillator Frequency
VIN=VCE=VSET+1.5V
1.91
2.25
2.58
Supply Current
VIN=VCE =5.5V,
VOUT(VFB)=5.5V
170
240
310
Standby Current
VCE=VOUT(VFB)=0V, VIN= 5.5V
0.0
5.0
μA
ILXleak
LX Leakage Current
VIN=5.5V, VCE=0V,
VLX=5.5V or 0V
0.0
5.0
μA
RONP
ON Resistance of Pch Transistor VIN=5.0V, ILX=200mA
0.20
0.35
Ω
RONN
ON Resistance of Nch Transistor VIN=5.0V, ILX=200mA
0.20
0.35
Ω
ΔVOUT/ΔTa
fosc
IDD
Istandby
Maxduty
<
=
Ta
<
=
±150
85°C
Oscillator Maximum Duty Cycle
−5.0
100
MHz
μA
%
tstart
Soft-start Time
VIN=VCE=5.0V, at no load
0.15
0.4
0.7
ms
tprot
Protection Delay Time
VIN=VCE=5.0V
0.1
2.0
10.0
ms
ILXlimit
LX Current Limit
VIN=VCE=5.0V
1.0
1.4
VUVLO1
UVLO Detector Threshold
VIN=VCE=2.6V -> 1.5V
2.10
2.25
2.40
V
VUVLO2
UVLO Released Voltage
VIN=VCE =1.5V -> 2.6V
2.20
VUVLO1
+0.10
2.50
V
CE Input Current
VIN=5.5V, VCE =5.5V/0V
−0.1
0.0
0.1
μA
VOUT/IVFB Leakage Current
VIN=5.5V, VCE =0V,
VOUT(IVFB)=5.5V or 0V
−0.1
0.0
0.1
VCEH
CE "H" Input Voltage
VIN=5.5V
1.5
VCEL
CE "L" Input Voltage
VIN=3.0V
ICE
IVOUT
（IVFB）
A
μA
V
0.3
V
RECOMMENDED OPERATING CONDITIONS (ELECTRICAL CHARACTERISTICS)
All of electronic equipment should be designed that the mounted semiconductor devices operate within the
recommended operating conditions. The semiconductor devices cannot operate normally over the
recommended operating conditions, even if when they are used over such conditions by momentary
electronic noise or surge. And the semiconductor devices may receive serious damage when they continue
to operate over the recommended operating conditions.
7
R1232D
TEST CIRCUIT
V IN
VDD
Lx
V IN
VDD
Lx
CE
OSCILLOSCOPE
CE
V OUT /VFB
AGND
V OUT/VFB
AGND
PGND TEST
A
PGND TEST
Test Circuit for Input Current and Leakage Current
Test Circuit for Input Voltage and UVLO voltage
OSCILLOSCOPE
VIN
VOUT
Lx
V DD
CE
L
VOUT/VFB
AGND
PGND TEST
Test Circuit for Output Voltage, Oscillator Frequency, Soft-Starting Time
OSCILLOSCOPE
A
V IN
V DD
Lx
V IN
VDD
Lx
CE
CE
V OUT/VFB
AGND
PGND TEST
V OUT /VFB
AGND
PGND TEST
Test Circuit for Supply Current and Standby Current
A
Test Circuit for ON resistance of LX, Limit
Current, Delay Time of Protection Circuit
8
R1232D
TYPICAL APPLICATION AND TECHNICAL NOTES
•
Fixed Output Voltage Type
L
PGND
VOUT
LX
CIN
•
VIN
AGND
VDD
TEST
CE
VOUT
LOAD
COUT
Adjustable Output Type
L
PGND
VOUT
LX
CIN
VIN
AGND
VDD
TEST
LOAD
COUT
Cb
CE
R1
VFB
R2
CIN
10μF C2012JB0J106MT (TDK), 10μF CM21B106M06AB (Kyocera)
COUT
10μF C2012JB0J106MT (TDK), 10μF CM21B106M06AB (Kyocera)
4.7μH/2.7μH VLP5610-4R7MR90, VLP5610-2R7M1R0 (TDK)
*2.2μH is also suitable for B/D version.
L
In terms of setting R1, R2, Cb, refer to the technical notes.
9
R1232D
When you use these ICs, consider the following issues;
• Input the same voltage into power supply pins, VIN and VDD. Set the same level as AGND and PGND.
• When you control the CE pin by another power supply, do not make its "H" level more than the voltage level
of VIN / VDD pin.
• Set external components such as an inductor, CIN, COUT as close as possible to the IC, in particular,
minimize the wiring to VIN pin and PGND pin.
• At stand by mode, (CE="L"), the LX output is Hi-Z, or both P-channel transistor and N-channel transistor of
LX pin turn off.
• Set the "Test pin" to the GND. Do not make the test pin voltage as floating or other voltage.
• Reinforce the VIN, PGND, and VOUT lines sufficiently. Large switching current may flow in these lines. If the
impedance of VIN and PGND lines is too large, the internal voltage level in this IC may shift caused by the
switching current, and the operation might be unstable.
• Over current protection circuit supervises the inductor peak current (the current flowing Pch transistor) at all
each switching cycle, and if the current beyond the Lx current limit, Pch transistor is turned off. Further, if the
over current status continues equal or longer than protection delay time, or when the Lx limit current is
exceeded even once when the driver operates by duty 100%, Pch transistor is latched in the OFF state and
the operation of DC/DC converter stops.
The performance of power source circuits using these ICs extremely depends upon the peripheral circuits.
Pay attention in the selection of the peripheral circuits. In particular, design the peripheral circuits in a way that
the values such as voltage, current, and power of each component, PCB patterns and the IC do not exceed their
respected rated values.
10
R1232D
OPERATION of step-down DC/DC converter and Output Current
The step-down DC/DC converter charges energy in the inductor when LX transistor is ON, and discharges the
energy from the inductor when LX transistor is OFF and controls with less energy loss, so that a lower output
voltage than the input voltage is obtained. The operation will be explained with reference to the following
diagrams:
IL
ILmax
i1
Lx Tr
VIN
SD
IOUT
L
ILmin
topen
VOUT
i2
CL
ton
toff
T=1/fosc
Step 1: P-channel Tr. turns on and current IL (=i1) flows, and energy is charged into CL. At this moment,
IL increases from Ilmin (=0) to reach ILmax in proportion to the on-time period (ton) of P-channel Tr.
Step 2: When P-channel Tr. turns off, Synchronous rectifier N-channel Tr. turns on in order that L maintains IL at
ILmax, and current IL (=i2) flows.
Step 3: IL (=i2) decreases gradually and reaches IL=ILmin=0 after a time period of topen, and N-channel Tr.
Turns off. Provided that in the continuous mode, next cycle starts before IL becomes to 0 because toff
time is not enough. In this case, IL value increases from this Ilmin (>0).
In the case of PWM control system, the output voltage is maintained by controlling the on-time period (ton),
with the oscillator frequency (fosc) being maintained constant.
•
Continuous Conduction Mode
The maximum value (ILmax) and the minimum value (ILmin) of the current flowing through the inductor are the
same as those when P-channel Tr. turns on and off.
The difference between ILmax and ILmin, which is represented by ΔI;
ΔI=ILmax−ILmin=VOUT×topen/L=(VIN−VOUT)×ton/L ........................................................ Equation 1
Where, t=1/fosc=ton+toff
duty (%)=ton/t×100=ton×fosc×100
topen <
= toff
In Equation 1, VOUT×topen/L and (VIN−VOUT) ×ton/L are respectively shown the change of the current at ON,
and the change of the current at OFF.
Even if the output current (IOUT) is, topen < toff as illustrated in the above diagram is not realized with this IC. At
least, topen is equal toff (topen=toff), and when IOUT is further increased, ILmin becomes larger than zero
(ILmin>0). The mode is referred to as the continuous mode.
11
R1232D
In the continuous mode, when Equation 1 is solved for ton and assumed that the solution is tonc
tonc=t×VOUT/VIN .............................................................................................................Equation 2
When the ton=tonc, the mode is the continuous mode.
OUTPUT CURRENT AND SELECTION OF EXTERNAL COMPONENTS
When P-channel Tr. of LX is ON:
(Wherein, Ripple Current P-P value is described as IRP, ON resistance of P-channel Tr. and N-channel Tr. of LX
are respectively described as RONP and RONN, and the DC resistor of the inductor is described as RL.)
VIN=VOUT+(RONP+RL)×IOUT+L×IRP/ton...............................................................................Equation 3
When P-channel Tr. of LX is "OFF"(N-channel Tr. is "ON"):
L×IRP/toff=VF+VOUT+RONN×IOUT ........................................................................................Equation 4
Put Equation 4 to Equation 3 and solve for ON duty of P-channel transistor, Don=ton/(toff+ton),
DON=(VOUT−RONN×IOUT+RL×IOUT)/(VIN+RONN×IOUT−RONP×IOUT)............................................Equation 5
Ripple Current is as follows;
IRP=(VIN−VOUT−RONP×IOUT−RL×IOUT)×DON/fosc/L...............................................................Equation 6
wherein, peak current that flows through L, and LX Tr. is as follows;
ILmax=IOUT+IRP/2 ...........................................................................................................Equation 7
Consider ILmax, condition of input and output and select external components.
ÌThe above explanation is directed to the calculation in an ideal case in continuous mode.
12
R1232D
How to Adjust Output Voltage and about Phase Compensation
As for Adjustable Output type, feedback pin (VFB) voltage is controlled to maintain 0.8V.
Output Voltage, VOUT is as following equation;
VOUT R1+R2=VFB:R2
VOUT=VFB×(R1+R2)/R2
Thus, with changing the value of R1 and R2, output voltage can be set in the specified range.
In the DC/DC converter, with the load current and external components such as L and C, phase might be
behind 180 degree. In this case, the phase margin of the system will be less and stability will be worse. To
prevent this, phase margin should be secured with proceeding the phase. A pole is formed with external
components L and COUT.
fpole ~ 1/2π LCOUT
A zero (signal back to zero) is formed with R1 and Cb.
≅fzero ~ 1/(2p×R1×Cb)
First, choose the appropriate value of R1, R2 and Cb.
Set R1+R2 value 100kΩ or less.
For example, if L=4.7μH, COUT =10μF, the cut off frequency of the pole is approximately 23kHz.
To make the cut off frequency of the zero by R1, R2, and Cb be higher than 23kHz,
set R1=33kΩ and Cb=100pF.If VOUT is set at 2.0V, R2=22kΩ is appropriate.
13
R1232D
External Components
1.Inductor
Select an inductor that peak current does not exceed ILmax. If larger current than allowable current flows,
magnetic saturation occurs and makes transform efficiency be worse.
Supposed that the load current is at the same, the smaller value of L is used, the larger the ripple current is.
Provided that the allowable current is large in that case and DC current is small, therefore, for large output
current, efficiency is better than using an inductor with a large value of L and vice versa.
2.Capacitor
As for CIN, use a capacitor with low ESR (Equivalent Series Resistance) Ceramic type of a capacity at least
10μF for stable operation.
COUT can reduce ripple of the output voltage, therefore as much as 10μF ceramic type is recommended.
TIMING CHART
Output
Short
Intemal Opertional Intemal Soft-start
Amplifier Output
Set Voltage
CE pin Voltage
Output Short
Intemal Oscillator Waveform
Lx Pin Output
Latched
Soft-start Time
Stable
Delay Time of Protection
The timing chart as shown above describes the waveforms starting from the IC is enabled with CE and latched
with protection. During the soft-start time, until the level is rising up to the internal soft-start set voltage, the duty
cycle of LX is gradually wider and wider to prevent the over-shoot of the voltage. During the term, the output of
amplifier is "H". After the output voltage reaches the set output voltage, they are balanced well. Herein, if the
output pin would be short circuit, the output of amplifier would become "H" again, and the condition would
continue for 2.0ms (Typ.), or the Lx limit current is exceeded even once when the driver operates by duty 100%,
latch circuit would work and the output of LX would be latched with "OFF". (Output ="High-Z")
If the output short is released before the latch circuit works (within 2ms after output shorted), the output of
amplifier is balanced in the stable state again.
Once the IC is latched, to release the protection, input "L" with CE pin, or make the supply voltage at UVLO
level or less.
14
R1232D
TYPICAL CHARACTERISTICS
1) Output Voltage vs. Output Current (CIN = 10μF, COUT = 10μF)
R1232D121A
R1232D331A
VIN=5.0V
VIN=5.0V
3.400
Output Voltage VOUT(V)
Output Voltage VOUT(V)
1.300
1.250
1.200
1.150
1.100
3.350
3.300
3.250
3.200
1
10
100
Output Current IOUT(mA)
1000
1
R1232D121B
10
100
Output Current IOUT(mA)
R1232D331B
VIN=5.0V
VIN=5.0V
3.400
Output Voltage VOUT(V)
1.300
Output Voltage VOUT(V)
1000
1.250
1.200
1.150
1.100
3.350
3.300
3.250
3.200
1
10
100
Output Current IOUT(mA)
1000
1
10
100
Output Current IOUT(mA)
1000
2) Efficiency vs. Output Current (CIN = 10μF, COUT = 10μF)
R1232D121A
R1232D331A
VIN=5.0V
Efficiency(%)
Efficiency(%)
VIN=3.3V, 5.0V
100
90
80
70
60
50
40
30
20
10
0
(VIN=5.0V)
(VIN=3.3V)
1
10
100
Output Current IOUT(mA)
1000
100
90
80
70
60
50
40
30
20
10
0
1
10
100
Output Current IOUT(mA)
1000
15
R1232D
R1232D121B
R1232D331B
100
90
80
70
60
50
40
30
20
10
0
VIN=5.0V
Efficiency(%)
Efficiency(%)
VIN=3.3V, 5.0V
(VIN=5.0V)
(VIN=3.3V)
1
10
100
Output Current IOUT(mA)
100
90
80
70
60
50
40
30
20
10
0
1000
1
10
100
Output Current IOUT(mA)
1000
3) Output Waveform
R1232D121A
R1232D331A
VIN=5.0V, IOUT=600mA
0.04
0.04
0.03
0.03
Output Ripple Voltage(V)
Output Ripple Voltage(V)
VIN=5.0V, IOUT=600mA
0.02
0.01
0
-0.01
-0.02
-0.03
-0.04
0.02
0.01
0
-0.01
-0.02
-0.03
-0.04
-3
-2
-1
0
1
Time t(ns)
2
3
-3
-2
R1232D121B
3
0.04
Output Ripple Voltage(V)
Output Ripple Voltage(V)
2
VIN=5.0V, IOUT=600mA
0.06
16
0
1
Time t(ns)
R1232D331B
VIN=5.0V, IOUT=600mA
0.04
0.02
0
-0.02
-0.04
-0.06
-1.5
-1
-1.0
-0.5
0
0.5
Time t(ns)
1.0
1.5
0.03
0.02
0.01
0
-0.01
-0.02
-0.03
-0.04
-1.5
-1.0
-0.5
0
0.5
Time t(ns)
1.0
1.5
R1232D
4) Load Transient Response
R1232D121A
R1232D121A
0.8
0.8
0.6
0.4
0.6
0.7
Output Current 10mA→600mA
0.2
0
0.3
0.2
0.1
0
-0.1
Output Voltage
-50
0
50
100
Time t (μs)
-0.2
Output Current 600mA→10mA
0.2
0.3
0.2
Output Voltage
0.1
-50
0
50
100
Time t (μs)
R1232D121B
150
-0.1
200
R1232D121B
VIN=5.0V
VIN=5.0V
0.5
0.8
0.8
0.6
0.4
0.6
0.7
0.4
Output Current 10mA→600mA
0.2
0
0.3
0.2
0.1
0
-0.1
Output Voltage
-50
0
50
100
Time t (μs)
150
-0.2
Output Current IOUT(A)
0.8
Output Voltage VOUT(V)
Output Current IOUT(A)
0.5
0.4
0
0
-0.3
200
150
0.6
0.4
0.6
0.4
Output Current 600mA→10mA
0.2
0.5
0.4
0
0.3
Output Voltage
0.2
0.1
0
-0.3
200
-50
0
50
100
Time t (μs)
150
Output Voltage VOUT(V)
0.4
Output Current IOUT(A)
0.5
Output Voltage VOUT(V)
VIN=5.0V
0.8
Output Voltage VOUT(V)
Output Current IOUT(A)
VIN=5.0V
-0.1
200
5) Output Voltage vs. Input Voltage
R1232D121A
R1232D331A
IOUT=600mA
IOUT=600mA
3.32
Output Voltage VOUT(V)
Output Voltage VOUT(V)
1.22
1.21
1.20
1.19
1.18
2.5
3.0
3.5 4.0 4.5 5.0
Input Voltage VIN(V)
5.5
6.0
3.31
3.30
3.29
3.28
3.0
3.5
4.0
4.5
5.0
5.5
Input Voltage VIN(V)
6.0
17
R1232D
6) Oscillator Frequency vs. Input Voltage
R1232D121A
R1232D121B
IOUT=600mA
IOUT=600mA
2.4
Frequency fosc(MHz)
Frequency fosc(MHz)
1.10
1.05
1.00
0.95
0.90
2.5
3.0
3.5 4.0 4.5 5.0
Input Voltage VIN(V)
5.5
2.3
2.2
2.1
2.0
2.5
6.0
3.0
3.5 4.0 4.5 5.0
Input Voltage VIN(V)
5.5
6.0
7) Lx Transistor On Resistance vs. Input Voltage
Switching Tr. Pch on Resistance
Synchronous Rectifier Tr. Nch on Resistance
IOUT=200mA
0.14
0.14
0.13
0.13
on Resistance(Ω)
on Resistance(Ω)
IOUT=200mA
0.12
0.11
0.10
0.09
2.5
3.0
3.5 4.0 4.5 5.0
Input Voltage VIN(V)
5.5
6.0
0.12
0.11
0.10
0.09
2.5
3.0
3.5 4.0 4.5 5.0
Input Voltage VIN(V)
5.5
6.0
8) Turn-on speed by CE pin
R1232D121A
R1232D121A
VIN=5.0V, L=4.7μH Rload=0Ω
CE
5V/div
CE
5V/div
VOUT
1V/div
VOUT
1V/div
IL
200mA/div
IL
200mA/div
200μs/div
18
VIN=5.0V, L=4.7μH Rload=12Ω
200μs/div
R1232D
R1232D331B
R1232D331B
VIN=5.0V, L=2.7μH Rload=0Ω
VIN=5.0V, L=2.7μH Rload=33Ω
CE
5V/div
CE
5V/div
VOUT
1V/div
VOUT
1V/div
IL
200mA/div
IL
200mA/div
100μs/div
100μs/div
9) Output Voltage vs. Temperature
R1232D121A
R1232D331A
VIN=5.0V
VIN=5.0V
3.40
Output Voltage VOUT(V)
Output Voltage VOUT(V)
1.24
1.22
1.20
1.18
1.16
1.14
-40
-15
10
35
60
Temperature Topt(°C)
3.35
3.30
3.25
3.20
-40
85
-15
10
35
60
Temperature Topt(°C)
85
10) Oscillator Frequency vs. Temperature
R1232D121A
R1232D331B
VIN=5.0V
VIN=5.0V
2.50
1.20
Frequency fOCS(MHz)
Frequency fOCS(MHz)
1.30
1.10
1.00
0.90
0.80
0.70
-40
-15
10
35
60
Temperature Topt(°C)
85
2.40
2.30
2.20
2.10
2.00
-40
-15
10
35
60
Temperature Topt(°C)
85
19
R1232D
11) Supply Current vs. Temperature
R1232D121A
R1232D331B
VIN=5.0V
VIN=5.0V
230
Supply Current IDD1(μA)
Supply Current IDD1(μA)
130
125
120
115
110
-40
-15
10
35
60
Temperature Topt(°C)
225
220
215
210
-40
85
-15
10
35
60
Temperature Topt(°C)
85
12) Soft-start time vs. Temperature
R1232D121A
R1232D331B
VIN=5.0V, Rload=0Ω
VIN=5.0V, Rload=0Ω
0.60
Soft-start Time tstart(ms)
Soft-start Time tstart(ms)
1.3
1.1
0.9
0.7
0.5
-40
-15
10
35
60
Temperature Topt(°C)
0.55
0.50
0.45
0.40
0.35
0.30
-40
85
-15
10
35
60
Temperature Topt(°C)
85
13) UVLO Voltage vs. Temperature
20
R1232D121A
2.40
UVLO Released Voltage UVLO02(V)
UVLO Detector Voltage UVLO01(V)
R1232D121A
2.30
2.20
2.10
-40
-15
10
35
60
Temperature Topt(°C)
85
2.50
2.40
2.30
2.20
-40
-15
10
35
60
Temperature Topt(°C)
85
R1232D
14) CE Input Voltage vs. Temperature
R1232D121A
R1232D121A
VIN=5.0V, CE=H Threshold
VIN=5.0V, CE=L Threshold
1.5
CE Input Voltage "L" VCEL(V)
CE Input Voltage "H" VCEH(V)
1.5
1.3
1.0
0.8
0.5
-40
-15
10
35
60
Temperature Topt(°C)
1.3
1.0
0.8
0.5
-40
85
-15
10
35
60
Temperature Topt(°C)
85
15) TEST Input Voltage vs. Temperature
R1232D121A
VIN=5.0V
TEST Input Voltage VTESTL(V)
1.5
1.3
1.0
0.8
0.5
-40
-15
10
35
60
Temperature Topt(°C)
85
16) Lx Transistor On Resistance vs. Temperature
Rectifier Tr.Nch ON Resistance
VIN=5.0V
0.30
0.20
0.10
0.00
-40
-15
10
35
60
Temperature Topt(°C)
85
Nch. Lx Transistor On Resistance RONN(Ω)
Pch. Lx Transistor On Resistance RONP(Ω)
Driver Tr. Pch ON Resistance
VIN=5.0V
0.30
0.20
0.10
0.00
-40
-15
10
35
60
Temperature Topt(°C)
85
21
R1232D
17) Current Limit vs. Temperature
R1232D121A
R1232D331B
VIN=5.0V
VIN=5.0V
-0.80
Lx Current Limit ILXlimit(A)
Lx Current Limit ILXlimit(A)
-0.80
-1.05
-1.30
-1.55
-1.80
-40
-15
10
35
60
Temperature Topt(°C)
-1.05
-1.30
-1.55
-1.80
-40
85
-15
10
35
60
Temperature Topt(°C)
85
18) Protection Delay Time vs. Temperatures
R1232D121A
R1232D331B
22
10.0
7.5
5.0
2.5
0.0
-40
VIN=5.0V
Protection Delay Time tprot(ms)
Protection Delay Time tprot(ms)
VIN=5.0V
-15
10
35
60
Temperature Topt(°C)
85
6.0
5.0
4.0
3.0
2.0
1.0
0.0
-40
-15
10
35
60
Temperature Topt(°C)
85
1. The products and the product specifications described in this document are subject to change or discontinuation of
production without notice for reasons such as improvement. Therefore, before deciding to use the products, please
refer to Ricoh sales representatives for the latest information thereon.
2. The materials in this document may not be copied or otherwise reproduced in whole or in part without prior written
consent of Ricoh.
3. Please be sure to take any necessary formalities under relevant laws or regulations before exporting or otherwise
taking out of your country the products or the technical information described herein.
4. The technical information described in this document shows typical characteristics of and example application circuits
for the products. The release of such information is not to be construed as a warranty of or a grant of license under
Ricoh's or any third party's intellectual property rights or any other rights.
5. The products listed in this document are intended and designed for use as general electronic components in standard
applications (office equipment, telecommunication equipment, measuring instruments, consumer electronic products,
amusement equipment etc.). Those customers intending to use a product in an application requiring extreme quality
and reliability, for example, in a highly specific application where the failure or misoperation of the product could result
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transportation equipment, combustion equipment, safety devices, life support system etc.) should first contact us.
6. We are making our continuous effort to improve the quality and reliability of our products, but semiconductor products
are likely to fail with certain probability. In order to prevent any injury to persons or damages to property resulting from
such failure, customers should be careful enough to incorporate safety measures in their design, such as redundancy
feature, fire containment feature and fail-safe feature. We do not assume any liability or responsibility for any loss or
damage arising from misuse or inappropriate use of the products.
7. Anti-radiation design is not implemented in the products described in this document.
8. The X-ray exposure can influence functions and characteristics of the products. Confirm the product functions and
characteristics in the evaluation stage.
9. WLCSP products should be used in light shielded environments. The light exposure can influence functions and
characteristics of the products under operation or storage.
10. There can be variation in the marking when different AOI (Automated Optical Inspection) equipment is used. In the
case of recognizing the marking characteristic with AOI, please contact Ricoh sales or our distributor before attempting
to use AOI.
11. Please contact Ricoh sales representatives should you have any questions or comments concerning the products or
the technical information.
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Ricoh is committed to reducing the environmental loading materials in electrical devices
with a view to contributing to the protection of human health and the environment.
Ricoh has been providing RoHS compliant products since April 1, 2006 and Halogen-free products since
April 1, 2012.
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