RICOH R1232D151B

R1232D SERIES
PWM STEP-DOWN DC/DC CONVERTER WITH SYNCHRONOUS RECTIFIER
NO.EA-129-0606
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 (xx1x Type)
0.8V to VIN (001x 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
VDD
3
VIN
7
AGND
2
Slope
Compensation
Current Limit
5
VOUT
4
CE
Phase
Compensation
Q
LX
S
Output
Contorol
8
R
PWM
Comparator
Error
Amplifer
Oscillator
Soft Start
TEST Circuit
UVLO
Vref
“H” Active
Chip Enable
1
6
PGND
TEST
“L” or GND Fixed
R1232D001C/D
VDD
3
VIN
7
AGND
2
Slope
Compensation
Current Limit
5
VFB
4
CE
Phase
Compensation
Q
LX
Output
Contorol
8
R
S
PWM
Comparator
Error
Amplifer
Oscillator
Soft Start
TEST Circuit
UVLO
Vref
“H” Active
Chip Enable
2
1
6
PGND
TEST
“L” or GND Fixed
R1232D
SELECTION GUIDE
In the R1232D Series, the output voltage, the oscillator frequency, and the taping 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;
R1232Dxx1x-xx-x ←Part Number
↑ ↑↑ ↑ ↑
a bc d e
Code
Contents
a
Setting Output Voltage(VOUT):
Stepwise setting with a step of 0.1V in the range of 0.9V to 3.3V is possible for fixed
output version."00" is for Output Voltage Adjustable version
(0.8V as the feedback voltage.)
b
1: fixed
c
d
e
Designation of Optional Function
A: 1MHz, Fixed Output Voltage
B: 2.25MHz, Fixed Output Voltage
C: 1MHz, Adjustable Output Voltage
D: 2.25MHz, Adjustable Output Voltage
Designation of Taping Type;
(Refer to Taping Specification)"TR" is prescribed as a standard.
Designation of Composition of pin plating
-F : Lead free plating
3
R1232D
PIN CONFIGURATION
SON-8
Top View
8
7
Bottom View
6 5
5 6
∗
1
2
7
8
∗
3 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 "L" or GND level.)
7
AGND
Ground Pin
8
LX
Ground Pin
Output/Feedback Pin
LX Switching Pin (CMOS Output)
∗ 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
Item
Unit
VIN
VIN Supply Voltage
6.5
V
VDD
VDD Pin Voltage
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
VFB
VFB Pin Input Voltage
−0.3 to VIN + 0.3
V
ILX
LX Pin Output Current
±1.5
V
480
mW
VTEST
PD
1
Power Dissipation (SON-8)*
Topt
Operating Temperature Range
−40 to 85
°C
Tstg
Storage Temperature Range
−55 to 125
°C
∗1) For the power dissipation, refer to the package information on the website.
4
Rating
R1232D
ELECTRICAL CHARACTERISTICS
•
R1232DxxxA/C
Topt=25°C
Symbol
VIN
Item
Conditions
Operating Input Voltage
Min.
Max.
Unit
2.6
5.5
V
×1.020
V
0.816
V
VOUT
Step-down Output Voltage
VIN=VCE=5.0V, IOUT=10mA
×0.980
VFB
Feedback Voltage
VIN=VCE=5.0V, IOUT=10mA
0.784
Step-down Output Voltage
Temperature Coefficient
−40°C
Oscillator Frequency
VIN=VCE =VSET +1.5V
Supply Current
VIN=VCE =5.5V, VOUT=5.5V
Standby Current
VCE=VOUT=0V, VIN= 5.5V
ILXleak
LX Leakage Current
VIN=5.5V,VCE=0V
VLX=0V/5.5V
RONP
RONN
∆VOUT/∆Topt
fosc
IDD
Istandby
Maxduty
<
=
Topt
<
=
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/0V
−0.1
0.0
0.1
µA
IVOUT
VOUT Leakage Current
VIN=5.5V, VCE =0V,
VOUT=5.5V/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
0.3
V
TEST pin "L" Input Voltage
VIN=3.0V
0.3
V
ICE
VTESTL
A
µA
V
5
R1232D
•
R1232DxxxB/D
Topt=25°C
Symbol
VIN
Conditions
Operating Input Voltage
Min.
Typ.
Max.
Unit
2.6
5.5
V
×1.020
V
0.816
V
VOUT
Step-down Output Voltage
VIN=VCE=5.0V,IOUT=10mA
×0.980
VFB
Feedback Voltage
VIN=VCE=5.0V,IOUT=10mA
0.784
Step-down Output Voltage
Temperature Coefficient
−40°C
Oscillator Frequency
VIN=VCE=VSET+1.5V
1.91
2.25
2.58
MHz
Supply Current
VIN=VCE=5.5V, VOUT=5.5V
170
240
310
µA
Standby Current
VCE=VOUT=0V, VIN=5.5V
0.0
5.0
µA
ILXleak
LX Leakage Current
VIN=5.5V, VCE=0V,
VLX=0V/5.5V
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
∆VOUT/∆Topt
fosc
IDD
Istandby
Maxduty
<
=
Topt
<
=
ppm/
°C
±150
85°C
Oscillator Maximum Duty Cycle
0.800
−5.0
100
%
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
IVOUT
VOUT Leakage Current
VIN=5.5V, VCE=0V,
VOUT=5.5V/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
0.3
V
TEST "L" Input Voltage
VIN=3.0V
0.3
V
ICE
VTESTL
6
Item
A
µA
V
R1232D
TEST CIRCUIT
LX
PGND
VIN
AGND
VDD
TEST
CE
VFB
A
Test Circuit for Input Current and Leakage Current
PGND
A
LX
PGND
LX
VIN
AGND
VIN
AGND
VDD
TEST
VDD
TEST
CE
VFB
CE
VFB
Test Circuit for Supply Current and Standby Current
PGND
V
Test Circuit for ON resistance of LX
LX
VIN
AGND
VDD
TEST
CE
VFB
OSCILLOSCOPE
Input Voltage, Output Voltage, Frequency, Lx Current Limit,
Protection Delay Time, UVLO Voltage Test Circuit
PGND
LX
VIN
AGND
VDD
TEST
CE
VFB
OSCILLOSCOPE
Soft Start Time Test Circuit
The bypass capacitor between power supply and GND is a ceramic capacitor 10µF.
7
R1232D
TYPICAL APPLICATION AND TECHNICAL NOTES
•
Fixed Output Voltage Type
L
PGND
VOUT
LX
CIN
•
VIN
AGND
VDD
TEST
CE
VFB
LOAD
COUT
Adjustable Output Type
L
PGND
VOUT
LX
CIN
VIN
AGND
VDD
TEST
CE
VFB
LOAD
COUT
Cb
R1
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 version.
L
In terms of setting R1, R2, Cb, refer to the technical notes.
8
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.
• In terms of the protection circuits, current limit for the peak current of each cycle of Lx, and the latch
protection circuit, which works if the over-limit current flows continuously for a certain time exist. To release
the protection, once make this IC into be standby mode with chip enable pin, or make the supply voltage be
down to UVLO threshold level or less.
• 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.
• Connect the TEST Pin to the "L" or GND level.
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.
9
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:
<Basic Circuits>
<Current through L>
i1
Lx Tr
VIN
SD
IOUT
L
i2
VOUT
CL
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 ∆I;
∆I=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.
10
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.
11
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.
12
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
Set Voltage
Amplifier Output
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.), 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.
13
R1232D
TYPICAL CHARACTERISTICS
1) Output Voltage vs. Output Current (CIN = 10µF, COUT = 10µF)
R1232D121A
VIN=5.0V
1.250
1.200
1.150
VIN=5.0V
3.400
Output Voltage VOUT(V)
1.300
Output Voltage VOUT(V)
R1232D331A
1.100
3.350
3.300
3.250
3.200
1
10
100
Output Current IOUT(mA)
1000
1
R1232D121B
1.250
1.200
1.150
1.100
VIN=5.0V
3.400
Output Voltage VOUT(V)
Output Voltage VOUT(V)
1000
R1232D331B
VIN=5.0V
1.300
10
100
Output Current IOUT(mA)
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)
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)
R1232D121B
14
R1232D331A
Efficiency(%)
Efficiency(%)
R1232D121A
1000
VIN=5.0V
100
90
80
70
60
50
40
30
20
10
0
1
10
100
Output Current IOUT(mA)
R1232D331B
1000
VIN=3.3V, 5.0V
100
90
80
70
60
50
40
30
20
10
0
Efficiency(%)
Efficiency(%)
R1232D
(VIN=5.0V)
(VIN=3.3V)
1
10
100
Output Current IOUT(mA)
VIN=5.0V
100
90
80
70
60
50
40
30
20
10
0
1000
1
10
100
Output Current IOUT(mA)
1000
3) Output Waveform
R1232D121A
0.04
0.03
0.02
0.01
0
-0.01
-0.02
-0.03
-0.04
-3
-2
-1
0
1
Time t(ns)
2
VIN=5.0V, IOUT=600mA
0.04
Output Ripple Voltage(V)
Output Ripple Voltage(V)
R1232D331A
VIN=5.0V, IOUT=600mA
0.03
0.02
0.01
0
-0.01
-0.02
-0.03
-0.04
3
-3
-2
R1232D121B
0.02
0
-0.02
-0.04
-1.0
-0.5
0
0.5
Time t(ns)
2
3
1.0
1.5
VIN=5.0V, IOUT=600mA
0.04
Output Ripple Voltage(V)
Output Ripple Voltage(V)
0.04
-0.06
-1.5
0
1
Time t(ns)
R1232D331B
VIN=5.0V, IOUT=600mA
0.06
-1
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
15
R1232D
4) Load Transient Response
Output Current 10mA→600mA
0.2
0.4
0.6
0.3
0.2
0.1
0
0
-0.1
Output Voltage
-50
0
50
100
Time t (µs)
-0.2
-0.3
200
150
VIN=5.0V
0.7
0.6
0.4
Output Current 600mA→10mA
0.2
0.3
0.1
0
-50
0.8
0.4
0.6
0.3
0.2
0.1
0
0
-0.1
Output Voltage
-50
0
50
100
Time t (µs)
150
-0.2
Output Current IOUT(A)
Output Current 10mA→600mA
0.5
Output Voltage VOUT(V)
Output Current IOUT(A)
0.6
0.2
0.2
Output Voltage
0
50
100
Time t (µs)
150
-0.1
200
R1232D121B
VIN=5.0V
0.4
0.5
0.4
0
R1232D121B
0.8
0.8
-0.3
200
VIN=5.0V
0.8
0.7
0.6
0.4
Output Current 600mA→10mA
0.2
0.5
0.4
0
0.3
Output Voltage
0.2
0.1
0
-50
0
50
100
Time t (µs)
150
-0.1
200
5) Output Voltage vs. Input Voltage
R1232D121A
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
IOUT=600mA
3.32
Output Voltage VOUT(V)
1.22
Output Voltage VOUT(V)
R1232D331A
IOUT=600mA
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) Oscillator Frequency vs. Input Voltage
R1232D121A
16
R1232D121B
6.0
Output Voltage VOUT(V)
0.4
0.8
Output Current IOUT(A)
0.6
0.5
Output Voltage VOUT(V)
0.8
Output Current IOUT(A)
R1232D121A
VIN=5.0V
Output Voltage VOUT(V)
R1232D121A
R1232D
IOUT=600mA
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
IOUT=600mA
2.4
Frequency fosc(MHz)
Frequency fosc(MHz)
1.10
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
0.14
0.13
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
IOUT=200mA
0.14
on Resistance(Ω)
on Resistance(Ω)
Synchronous Rectifier Tr. Nch on Resistance
IOUT=200mA
0.13
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
VIN=5.0V, L=4.7µH Rload=12Ω
CE
5V/div
CE
5V/div
VOUT
1V/div
VOUT
1V/div
IL
200mA/div
IL
200mA/div
200µs/div
R1232D331B
200µs/div
R1232D331B
17
R1232D
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
1.22
1.20
1.18
1.16
1.14
-40
-15
10
35
60
Temperature Topt(°C)
VIN=5.0V
3.40
Output Voltage VOUT(V)
1.24
Output Voltage VOUT(V)
R1232D331A
VIN=5.0V
3.35
3.30
3.25
3.20
-40
85
-15
10
35
60
Temperature Topt(°C)
85
10) Oscillator Frequency vs. Temperature
R1232D121A
1.20
1.10
1.00
0.90
0.80
0.70
-40
18
2.50
Frequency fOCS(MHz)
Frequency fOCS(MHz)
1.30
R1232D331B
VIN=5.0V
-15
10
35
60
Temperature Topt(°C)
85
VIN=5.0V
2.40
2.30
2.20
2.10
2.00
-40
-15
10
35
60
Temperature Topt(°C)
85
R1232D
11) Supply Current vs. Temperature
R1232D121A
125
120
115
110
-40
-15
10
35
60
Temperature Topt(°C)
VIN=5.0V
230
Supply Current IDD1(µA)
130
Supply Current IDD1(µA)
R1232D331B
VIN=5.0V
225
220
215
210
-40
85
-15
10
35
60
Temperature Topt(°C)
85
12) Soft-start time vs. Temperature
R1232D121A
1100
900
700
500
-40
600
Soft-start Time tstart(ms)
Soft-start Time tstart(ms)
1300
R1232D331B
VIN=5.0V, Rload=0Ω
-15
10
35
60
Temperature Topt(°C)
550
500
450
400
350
300
-40
85
VIN=5.0V, Rload=0Ω
-15
10
35
60
Temperature Topt(°C)
85
13) UVLO Voltage vs. Temperature
R1232D121A
UVLO Released Voltage UVLO02(V)
UVLO Detector Voltage UVLO01(V)
R1232D121A
2.40
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
19
R1232D
14) CE Input Voltage vs. Temperature
R1232D121A
1.5
CE Input Voltage "L" VCEL(V)
1.5
CE Input Voltage "H" VCEH(V)
R1232D121A
VIN=5.0V, CE=H Threshold
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
VIN=5.0V, CE=L Threshold
-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
20
0.30
Rectifier Tr.Nch ON Resistance
VIN=5.0V
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
0.30
VIN=5.0V
0.20
0.10
0.00
-40
-15
10
35
60
Temperature Topt(°C)
85
R1232D
17) Current Limit vs. Temperature
R1232D121A
-1.05
-1.30
-1.55
-1.80
-40
-15
10
35
60
Temperature Topt(°C)
VIN=5.0V
-0.80
Lx Current Limit ILXlimit(A)
-0.80
Lx Current Limit ILXlimit(A)
R1232D331B
VIN=5.0V
-1.05
-1.30
-1.55
-1.80
-40
85
-15
10
35
60
Temperature Topt(°C)
85
18) Protection Delay Time vs. Temperatures
10.0
R1232D331B
VIN=5.0V
Protection Delay Time tprot(ms)
Protection Delay Time tprot(ms)
R1232D121A
7.5
5.0
2.5
0.0
-40
-15
10
35
60
Temperature Topt(°C)
85
6.0
VIN=5.0V
5.0
4.0
3.0
2.0
1.0
0.0
-40
-15
10
35
60
Temperature Topt(°C)
85
21
PACKAGE INFORMATION
•
PE-SON-8-0510
SON-8
Unit: mm
PACKAGE DIMENSIONS
2.9±0.2
0.15 +0.1
−0.15
0.13±0.05
0.475TYP
1
0.23±0.1
0.2±0.1
5
0.2±0.1
2.8±0.2
3.0±0.2
8
0.15 +0.1
−0.15
4
Attention : Tab suspension leads in the
parts have VDD or GND level. (They are
connected to the reverse side of this IC.)
Refer to PIN DISCRIPTION.
Do not connect to other wires or land patterns.
0.9MAX.
0.13±0.05
Bottom View
0.1
0.65
0.3±0.1
0.1 M
TAPING SPECIFICATION
4.0±0.1
+0.1
φ1.5 0
2.0±0.05
3.3
4.0±0.1
2.0MAX.
∅1.1±0.1
TR
User Direction of Feed
TAPING REEL DIMENSIONS
(1reel=3000pcs)
2±0.5
0
∅ 180 −1.5
∅ 60 +1
0
21±0.8
∅13±0.2
11.4±1.0
9.0±0.3
8.0±0.3
3.2
3.5±0.05
1.75±0.1
0.2±0.1
PACKAGE INFORMATION
PE-SON-8-0510
POWER DISSIPATION (SON-8)
This specification is at mounted on board. Power Dissipation (PD) depends on conditions of mounting on board.
This specification is based on the measurement at the condition below:
Measurement Conditions
Standard Land Pattern
Environment
Mounting on Board (Wind velocity=0m/s)
Board Material
Glass cloth epoxy plactic (Double sided)
Board Dimensions
40mm × 40mm × 1.6mm
Copper Ratio
Top side : Approx. 50% , Back side : Approx. 50%
Through-hole
φ0.5mm × 44pcs
Measurement Result
(Topt=25°C,Tjmax=125°C)
Standard Land Pattern
Free Air
Power Dissipation
480mW
300mW
Thermal Resistance
θja=(125−25°C)/0.48W=208°C/W
333°C/W
On Board
480
500
400
40
Free Air
300
200
40
Power Dissipation PD(mW)
600
100
0
0
25
50
75 85 100
Ambient Temperature (°C)
125
150
Power Dissipation
Measurement Board Pattern
IC Mount Area (Unit : mm)
RECOMMENDED LAND PATTERN
0.65
0.65
1.15
0.35
(Unit: mm)
MARK INFORMATION
ME-R1232D-0510
R1232D SERIES MARK SPECIFICATION
• SON-8
to
1
1
R
•
2
3
4
5
6
5
,
4
6
: Product Code (refer to Part Number vs. Product Code)
: Lot Number
Part Number vs. Product Code
Part Number
Product Code
Part Number
Product Code
Part Number
Product Code
1
2
3
4
1
2
3
4
1
2
3
4
R1232D091A
K
0
9
A
R1232D091B
K
0
9
B
R1232D001C
K
0
1
C
R1232D101A
K
1
0
A
R1232D101B
K
1
0
B
R1232D001D
K
0
1
D
R1232D111A
K
1
1
A
R1232D111B
K
1
1
B
R1232D121A
K
1
2
A
R1232D121B
K
1
2
B
R1232D131A
K
1
3
A
R1232D131B
K
1
3
B
R1232D141A
K
1
4
A
R1232D141B
K
1
4
B
R1232D151A
K
1
5
A
R1232D151B
K
1
5
B
R1232D161A
K
1
6
A
R1232D161B
K
1
6
B
R1232D171A
K
1
7
A
R1232D171B
K
1
7
B
R1232D181A
K
1
8
A
R1232D181B
K
1
8
B
R1232D191A
K
1
9
A
R1232D191B
K
1
9
B
R1232D201A
K
2
0
A
R1232D201B
K
2
0
B
R1232D211A
K
2
1
A
R1232D211B
K
2
1
B
R1232D221A
K
2
2
A
R1232D221B
K
2
2
B
R1232D231A
K
2
3
A
R1232D231B
K
2
3
B
R1232D241A
K
2
4
A
R1232D241B
K
2
4
B
R1232D251A
K
2
5
A
R1232D251B
K
2
5
B
R1232D261A
K
2
6
A
R1232D261B
K
2
6
B
R1232D271A
K
2
7
A
R1232D271B
K
2
7
B
R1232D281A
K
2
8
A
R1232D281B
K
2
8
B
R1232D291A
K
2
9
A
R1232D291B
K
2
9
B
R1232D301A
K
3
0
A
R1232D301B
K
3
0
B
R1232D311A
K
3
1
A
R1232D311B
K
3
1
B
R1232D321A
K
3
2
A
R1232D321B
K
3
2
B
R1232D331A
K
3
3
A
R1232D331B
K
3
3
B