R1230D1.91A-TR [ETC]
Analog IC ; 模拟IC\n2002. Jan. 30
PWM/VFM step-down DC/DC converter with Synchronous
Rectifier
R1230D Series
ꢀ OUTLINE
The R1230D Series are PWM step-down DC/DC Converters with synchronous rectifier, low supply current by CMOS
process.
Each of these ICs consists of an oscillator, a PWM control circuit, a reference voltage unit, an error amplifier, a
soft-start circuit, protection circuits, a protection against miss operation under low voltage (UVLO), PWM/VFM
alternative circuit, a chip enable circuit, and a driver transistor. 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 R1230D001C/D types, divider resistors are also necessary.) In terms of Output Voltage, it is fixed
internally in the R1230DXX1A/B types. While in the R1230D001C/D types, Output Voltage is adjustable with external
divider resistors.
PWM/VFM alternative circuit is active with Mode Pin of the R1230D Series. Thus, when the load current is small,
the operation can be switching into the VFM operation from PWM operation by the logic of MODE pin and the
efficiency at small load current can be improved. As protection circuits, Current Limit circuit which limits peak current
of Lx at each clock cycle, and Latch type protection circuit which works if the term of Over-current condition keeps on
a certain time in PWM mode exist. 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
ꢀ Built-in Driver ON Resistance • • • • • • • • • • • • • P-channel 0.35Ω, N-channel 0.45Ω (at VIN=5V)
ꢀ Built-in Soft-start Function (TYP. 1.5ms), and Latch-type Protection Function (Delay Time; TYP. 1.5ms)
ꢀ Two choices of Oscillator Frequency • • • • • • 500kHz, 800kHz
ꢀ PWM/VFM alternative with MODE pin • • • • • • PWM operation; MODE pin at “L”,
VFM operation; MODE pin at “H”
ꢀ High Efficiency • • • • • • • • • • • • • • • • • • TYP. 90%
ꢀ Output Voltage • • • • • • • • •Stepwise Setting with a step of 0.1V in the range of 1.2V 3.3V(XX1A/B Type)
or adjustable in the range of 0.8V to VIN(001C/D Type)
ꢀ High Accuracy Output Voltage • • • • • • • • • •±2.0%(XX1A/B Type)
ꢀ Package • • • • • SON8 (Max height 0.9mm, thin type)
ꢀ APPLICATIONS
ꢀ Power source for portable equipment.
Rev. 1.15
- 1 -
ꢀ BLOCK DIAGRAM
ꢀR1230DXX1A/B
VDD
MODE“L”= PWM
“H”= VFM
VIN
VOUT
OSC
PWM/VFM
CONTROL
Phase Compensation
Lx
OUTPUT
CONTROL
Vref
CE
Current Protection
UVLO
“H” Active
Soft Start
CE
Chip Enable
PGND
AGND
ꢀR1230D001C/D
VDD
MODE
“L”= PWM
“H”= VFM
VIN
VFB
OSC
PWM/VFM
CONTROL
Phase Compensation
Lx
OUTPUT
CONTROL
“H” Active
Vref
CE
Chip Enable
Current Protection
UVLO
Soft Start
PGND
AGND
Rev. 1.15
- 2 -
ꢀ SELECTION GUIDE
In the R1230D 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 by designating the part number as shown below;
R1230DXXXX-XX
↑
↑ ↑
↑
a
b c d
Code
a
Contents
Setting Output Voltage(VOUT):
Stepwise setting with a step of 0.1V in the range of 1.2V to 3.3V is possible for A/B version.
“00” is for Output Voltage Adjustable C/D version
1 : fixed
b
c
Designation of Optional Function
A : 500kHz, Fixed Output Voltage
B : 800 kHz, Fixed Output Voltage
C : 500kHz, Adjustable Output Voltage
D : 800kHz, Adjustable Output Voltage
d
Designation of Taping Type; Ex. :TR,TL(refer to Taping Specification)
”TR” is prescribed as a standard.
ꢀ PIN CONFIGURATION
ꢀ SON-8
2.9 0.2
±
0.48TYP
8
5
*
*
1
4
*Attention : Tab suspension leads 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.
0.1
0.65
0.3 0.1
±
Unit : mm
0.1 M
Rev. 1.15
- 3 -
ꢀ PIN DESCRIPTION
Symbol
Description
Pin No.
1
2
3
4
5
6
7
8
V
Voltage Supply Pin
Ground Pin
Voltage Supply Pin
Chip Enable Pin (active with “H”)
Output/Feedback Pin
Mode changer Pin (PWM mode at “L”, VFM mode at “H”.)
Ground Pin
Lx Pin
IN
PGND
V
DD
CE
V
/V
OUT FB
MODE
AGND
Lx
ꢀ ABSOLUTE MAXIMUM RATINGS
(AGND=PGND=0V)
Symbol
Item
Supply Voltage
Rating
6.5
6.5
Unit
V
V
V
IN
V
V
IN
V
DD
Pin Voltage
DD
V
LX
Lx Pin Voltage
V
-0.3 V +0.3
IN
V
CE Pin Input Voltage
MODE Pin Input Voltage
V
V
CE
-0.3 V +0.3
IN
V
MODE
-0.3 V +0.3
IN
V
I
P
Topt
Tstg
V
Pin Input Voltage
V
A
mW
°C
°C
FB
LX
FB
-0.3 V +0.3
IN
L Pin Output Current
-0.8
250
-40 +85
-55 +125
X
Power Dissipation
Operating Temperature Range
Storage Temperature Range
D
Rev. 1.15
- 4 -
ꢀ ELECTRICAL CHARACTERISTICS
ꢀR1230D**1A/B
(Topt=25°C)
Symbol
Item
Conditions
+1.5V, V
MIN.
2.4
TYP.×
0.980
TYP.
MAX. Unit
V
IN
Operating Input Voltage
Step-down Output Voltage
5.5
V
V
V
OUT
V =V =V
=0V,
V
SET
IN
CE
SET
MODE
TYP.×
1.020
I
=10mA
OUT
Step-down Output Voltage
Temperature Coefficient
ppm
/°C
∆V
/
-40°C ≤ Topt ≤ 85°C
±150
OUT
∆T
fosc
fosc
Oscillator Frequency(xx1A) V =V =V
+1.5V
+1.5V
+1.5V,
425
680
500
800
230
575 kHz
920 kHz
IN
CE
SET
SET
SET
Oscillator Frequency(xx1B) V =V =V
IN
CE
I
Supply Current(xx1A)
V =V =V
300
DD
IN
CE
µA
V
OUT
=V
=0V
MODE
I
Supply Current(xx1B)
V =V =V
+1.5V,
250
350
DD
IN
CE
SET
µA
V
OUT
=V
=0V
MODE
I
Standby Current
ON Resistance of
Pch Transistor
ON Resistance of
Nch Transistor
V =5.5V, V =V =0V
OUT
V =5.0V
IN
0
0.35
5
0.60
stb
IN
CE
µA
Ω
R
0.20
0.20
ONP
R
V =5.0V
IN
0.45
0.70
ONN
Ω
I leak Lx Leakage Current
V =5.5V, V =0V, V =0V/5.5V
-0.1
-0.1
-0.1
1.5
0.0
0.0
0.0
0.1
0.1
0.1
LX
IN
CE
LX
µA
µA
µA
V
V
%
V
I
V
OUT
Leakage Current
V =5.5V, V =0V, V =0V/5.5V
VOUT
IN
CE
LX
I
CE Input Current
V =5.5V, V
=0V, V =5.5V/0V
CE
IN
MODE
CE
V
V
CE "H" Input Voltage
CE "L" Input Voltage
V =5.5V, V =0V
OUT
CEH
IN
V =2.4V, V =0V
OUT
0.3
CEL
IN
Oscillator Maximum Duty Cycle
Maxdty
V
V
=0V
100
MODE
V
LX
Lx Limit Voltage
= V
=0V, V =V =3.0V
V -0.15 V -0.35 V -
IN
MODE
OUT
IN
CE
IN
IN
0.55
2.5
2.5
2.2
2.3
0.1
Delay Time by Soft-Start function
Delay Time for protection circuit
UVLO Threshold Voltage
UVLO Released Voltage
MODE Pin Input Current
MODE ”H” Input Voltage
MODE ”L” Input Voltage
T
T
at no load, V =V =V
+1.5V
0.5
1.5
ms
ms
V
V
µA
V
start
IN
CE
SET
V =V =V
+1.5V, V =0V
MODE
0.5
1.8
1.9
-0.1
1.5
1.5
2.1
2.2
prot
IN
CE
SET
V
V
I
V =V =2.5V->1.5V, V
=0V
UVLO1
UVLO2
MODE
IN
CE
OUT
V =V =1.5V->2.5V, V
=0V
IN
CE
OUT
V =5.5V, V =0V, V
=5.5V/0V
IN
CE
MODE
V
V =V =5.5V, V
=0V
=0V
MODEH
IN
CE
OUT
V
V =V =2.4V, V
0.3
85
V
%
MODEL
IN
CE
OUT
VFMdty VFM Duty Cycle
V =V = V
=2.4V, V =0V
OUT
55
65
IN
CE
MODE
Rev. 1.15
- 5 -
ꢀR1230D001C/D
(Topt=25°C)
Symbol
Item
Conditions
+1.5V, V =0V,
MODE
MIN.
2.4
0.776
TYP. MAX. Unit
V
IN
Operating Input Voltage
Feedback Voltage
5.5
V
V
V
FB
V =V =V
0.800 0.824
IN
CE
SET
I
=10mA
OUT
Feedback Voltage
ppm
∆V
/
-40°C ≤ Topt ≤ 85°C
±150
FB
Temperature Coefficient
/°C
∆T
fosc
fosc
Oscillator Frequency(xx1C)
Oscillator Frequency(xx1D)
Supply Current(xx1C)
Supply Current(xx1D)
Standby Current
V =V =V
+1.5V
+1.5V
425
680
500
800
230
250
0
575 kHz
920 kHz
IN
CE
SET
V =V =V
IN
CE
SET
I
I
V =V =5.5V, V =V
=0V
=0V
300
DD
IN
CE
FB
MODE
µA
V =V =5.5V, V =V
350
DD
IN
CE
FB
MODE
µA
I
stb
V =5.5V, V =V =0V
IN
5
CE
FB
µA
R
ON Resistance of
Pch Transistor
ON Resistance of
V =5.0V
0.20
0.20
0.35
0.60
ONP
IN
Ω
R
V =5.0V
IN
0.45
0.70
ONN
Ω
Nch Transistor
I leak Lx Leakage Current
V =5.5V, V =0V, V =0V/5.5V
-0.1
-0.1
-0.1
1.5
0.0
0.0
0.0
0.1
0.1
0.1
LX
IN
CE
LX
µA
µA
µA
V
V
%
V
I
V
FB
Leakage Current
V =5.5V, V =0V, V =0V/5.5V
VFB
IN
CE
FB
I
CE Input Current
V =5.5V, V
=0V, V =5.5V/0V
CE
IN
MODE
CE
V
V
CE "H" Input Voltage
CE "L" Input Voltage
V =5.5V, V =0V
CEH
IN
FB
V =2.4V, V =0V
0.3
CEL
IN
FB
Maxdty Oscillator Maximum Duty Cycle V
=0V
100
MODE
V
LX
Lx Limit Voltage
V =V =3.0V, V
=0V, V =0V
V -0.15 V -
IN
V -
IN
CE
MODE
FB
IN
0.35
1.5
1.5
2.1
2.2
IN
0.55
2.5
Delay Time by Soft-Start function
Delay Time for protection circuit
UVLO Threshold Voltage
UVLO Released Voltage
MODE Pin Input Current
MODE ”H” Input Voltage
MODE ”L” Input Voltage
T
T
at no load, V =V =V +1.5V
SET
0.5
ms
ms
V
V
µA
V
start
IN
CE
V =V =3.6V, V
=0V
prot
IN
CE
MODE
V
V
I
V =V =2.5V->1.5V, V =0V
1.8
1.9
-0.1
1.5
2.2
2.3
0.1
UVLO1
UVLO2
MODE
IN
CE
FB
V =V =1.5V->2.5V, V =0V
IN
CE
FB
V =5.5V, V
=5.5V/0V, V =0V
MODE CE
IN
V
MODE
V =V =5.5V, V =0V
IN CE FB
V
V =V =2.4V, V =0V
0.3
85
V
%
MODEL
IN
CE
FB
VFMdty VFM Duty Cycle
V =V =V
=2.4V, V =0V
55
65
IN
CE
MODE
FB
Rev. 1.15
- 6 -
ꢀ TEST CIRCUITS
IN
V
IN
Lx
CE
V
Lx
VDD
VDD
CE
OSCILLOSCOPE
OUT
AGND VOUT
PGND MODE
V
AGND
PGND
A
MODE
Test Circuit for Input Current and Leakage Current
Test Circuit for Input Voltage and UVLO voltage
OSCILLOSCOPE
OUT
V
IN
V
Lx
VDD
CE
L
10uF
V
OUT
AGND
PGND MODE
Test Circuit for Output Voltage, Oscillator Frequency, Soft-Starting Time
IN
V
Lx
OSCILLOSCOPE
A
VDD
CE
VIN
Lx
CE
VDD
OUT
V
AGND
A
PGND MODE
OUT
V
AGND
PGND MODE
Test Circuit for Supply Current and Standby Current
Test Circuit for ON resistance of Lx, Limit Voltage, Delay
Time of Protection Circuit
The bypass capacitor between Power Supply and GND is Ceramic capacitor 10µF.
Rev. 1.15
- 7 -
ꢀ TYPICAL APPLICATION AND TECHNICAL NOTES
1) Fixed Output Voltage Type
VOUT
VIN
Lx
AGND
MODE
VOUT
L
CIN
PGND
VDD
CE
LOAD
COUT
L
: 10µH LQH3C100K54 (Murata)
COUT: 10µF ECSTOJX106R (Panasonic)
CIN : 10µF C3216JB0J106M (TDK)
2) Adjustable Output Voltage Type
L
VOUT
VIN
LX
AGND
MODE
VFB
CIN
PGND
R1
LOAD
Cb
VDD
CE
COUT
R
2
Rb
L
: 10µH LQH3C100K54 (Murata)
COUT: 10µF ECSTOJX106R (Panasonic)
CIN : 10µF C3216JB0J106M (TDK)
As for how to choose Cb, Rb, R1, and R2 values, refer to the technical notes.
When you use these ICs, consider the following issues;
ꢀ Input same voltage into Power Supply pins, VIN and VDD. Set the same level as AGND and PGND.
ꢀ
ꢀ
ꢀ
ꢀ
When you control the CE pin and MODE 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.
Use an external capacitor COUT with a capacity of 10µF or more, and with good high frequency characteristics
such as tantalum capacitors.
ꢀ
ꢀ
At VFM mode, (MODE=”H”), Latch protection circuit does not operate.
If the mode is switched over into PWM mode from VFM mode during the operation, change the mode at light load
current. If the load current us large, output voltage may decline.
Rev. 1.15
- 8 -
ꢀ
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.
ꢀ 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.
ꢀ 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
ILmax
IOUT
ILmin
ton
topen
L
Pch Tr
Nch Tr
VIN
VOUT
i2
CL
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.
ꢀ Discontinuous Conduction Mode and 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
Wherein 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 respectively show the change of the current at “ON”, and the
change of the current at “OFF”.
When the output current (IOUT) is relatively small, topen<toff as illustrated in the above diagram. In this case, the
energy is charged in the inductor during the time period of ton and is discharged in its entirely during the time period of
toff, therefore ILmin becomes to zero (ILmin=0). When Iout is gradually increased, eventually, topen becomes to toff
(topen=toff), and when IOUT is further increased, ILmin becomes larger than zero (ILmin>0). The former mode is
referred to as the discontinuous mode and the latter mode is referred to as continuous mode.
In the continuous mode, when Equation 1 is solved for ton and assumed that the solution is tonc,
Rev. 1.15
- 9 -
tonc =T×VIN/VOUT Equation 2
When ton<tonc, the mode is the discontinuous mode, and when 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
Equation 4
When P-channel Tr. of Lx is “OFF”(N-channel Tr. is “ON”):
L×IRP/toff = RL×IOUT + VOUT + Ronn×IOUT
Put Equation 4 to Equation 3 and solve for ON duty of P-channel transistor, ton/(toff+ton)=DON,
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.
ꢀThe above explanation is directed to the calculation in an ideal case in continuous mode.
ꢀ 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/(2π×R1×Cb)
First, choose the appropriate value of R1, R2 and Cb.
Set R1+R2 value 100kΩ or less.
For example, if L=10µH, COUT=10µF, the cut off frequency of the pole is approximately 16kHz.
To make the cut off frequency of the zero as much as 16kHz, set R1=42kΩ and Cb=100pF.
If VOUT is set at 1.5V, R2=48kΩ is appropriate.
If a ceramic capacitor is desirable as COUT in your application, nonetheless of the usage of both the fixed output
voltage type and adjustable output type, add 0.2Ω or more resistance to compensate the ESR.
Further, if a ceramic capacitor is desirable to use as COUT without adding another resister to compensate the ESR,
phase should be back drastically. To make it, R2 value should be smaller compared to R1. As a result, the set output
voltage may be large. For example, to make VOUT=1.5V, constants are R1=42kΩ, R2=48kΩ, and Cb=100pF. If the
ceramic capacitor is used, under the heavy load condition, oscillation may be result. On the other hand, if R2=12kΩ
and VOUT=3.6V, phase back becomes also large, and even if the device is used with a heavy load, the operation will
be stable.
Rb is effective for reducing the noise on VFB, however, it is not always necessary. If it is necessary, use as much as
30kΩ as Rb.
Rev. 1.15
- 10 -
ꢀ 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 make transform efficiency 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 Output Voltage, therefore as much as 10µF tantalum type is recommended.
ꢀ TIMING CHART
CE pin Voltage
Output
Short
Output Short
Internal Soft-start
Set Voltage
Internal Operational
Amplifier Output
Internal Oscillator Waveform
Lx Pin Output
Latched
Delay Time of Protection
Stable
Soft-start Time
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”,
then after the output voltage reaches the set output voltage, they are balanced with the stable state. Herein, if the
output pin would be short circuit, the output of amplifier would become “H” again, and the condition would continue for
1.5ms (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 1.5ms 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.
Rev. 1.15
- 11 -
ꢀ TYPICAL CHARACTERISTICS
1) Output Voltage vs. Output Current
1.9
1.88
1.86
1.84
1.82
1.8
1.78
1.76
1.74
1.72
1.7
R1230D181A
Vin=3.3V PWM
Vin=3.3V VFM
Vin=5.0V PWM
Vin=5.0V VFM
1
10
10
10
100
1000
Output Current IOUT[mA]
1.9
1.88
1.86
1.84
1.82
1.8
1.78
1.76
1.74
1.72
1.7
R1230D181B
Vin=3.3V PWM
Vin=3.3V VFM
Vin=5.0V PWM
Vin=5.0V VFM
1
100
1000
Output Current IOUT[mA]
2.6
2.55
2.5
R1230D251B
Vin=3.3V PWM
Vin=3.3V VFM
Vin=5.0V PWM
Vin=5.0V VFM
2.45
2.4
1
100
1000
OUT
Output Current I
[mA]
2) Efficiency vs. Output Current
100
90
80
70
60
50
40
30
20
10
0
R1230D181A
Vin=3.3V PWM
Vin=3.3V VFM
Vin=5.0V PWM
Vin=5.0V VFM
1
10
100
1000
OUT
Output Current I
[mA]
Rev. 1.15
- 12 -
100
90
80
70
60
50
40
30
20
10
0
R1230D181B
Vin=3.3V PWM
Vin=3.3V VFM
Vin=5.0V PWM
Vin=5.0V VFM
1
10
100
1000
OUT
Output Current I
[mA]
100
90
80
70
60
50
40
30
20
10
0
R1230D251B
Vin=3.3V PWM
Vin=3.3V VFM
Vin=5.0V PWM
Vin=5.0V VFM
1
10
100
1000
Output Current IOUT[mA]
3) Ripple Voltage vs. Output Current
COUT=10uF Tantalum Capacitor ESR=400mohm
R1230D181A
0.06
0.04
0.02
0
-0.02
-0.04
-0.06
-0.08
-1.00E-06 0.00E+00 1.00E-06 2.00E-06 3.00E-06 4.00E-06 5.00E-06 6.00E-06 7.00E-06 8.00E-06
Time [sec]
PWM Mode
VIN=5.0V IOUT=200mA
80
70
60
50
40
30
20
10
0
VIN=5.0V
IN
V =3.3V
0
50
100
150
200
250
300
350
400
450
500
R1230D181B
Output Current IOUT[mA]
COUT=10µF Tantalum Capacitor ESR=400mΩ
Rev. 1.15
- 13 -
COUT=10uF Ceramic Capacitor ESR=220mohm
R1230D181B
0.04
0.03
0.02
0.01
0
-0.01
-0.02
-0.03
-0.04
-1.00E-06 0.00E+00 1.00E-06 2.00E-06 3.00E-06 4.00E-06 5.00E-06 6.00E-06 7.00E-06 8.00E-06
Time [sec]
PWM Mode
VIN=5.0V IOUT=200mA
4) Output Waveform
COUT=10uF Tantalum Capacitor ESR=400mohm
R1230D181B
0.05
0.04
0.03
0.02
0.01
0
-0.01
-0.02
-0.03
-0.04
-4.00E-06
-3.00E-06
-2.00E-06
-1.00E-06
0.00E+00
Time[sec]
1.00E-06
2.00E-06
3.00E-06
OUT
=10mA
4.00E-06
IN
PWM Mode
V =5.0V I
COUT=10uF Tantalum Capacitor ESR=400mohm
R1230D181B
0.04
0.03
0.02
0.01
0
-0.01
-0.02
-0.03
-0.04
-0.05
-0.06
-4.00E-06
-3.00E-06
-2.00E-06
-1.00E-06
0.00E+00
Time[sec]
1.00E-06
2.00E-06
3.00E-06
OUT
=100mA
4.00E-06
IN
PWM Mode
V =5.0V I
5) Output Voltage vs. Input Voltage
R1230D181B IOUT=20mA
1.9
1.85
1.8
VFM
PWM
1.75
1.7
2
2.5
3
3.5
4
4.5
5
5.5
6
Input Voltage VIN[V]
Rev. 1.15
- 14 -
6) Output Voltage vs. Temperature
R1230D181B IOUT=100mA
1.9
1.88
1.86
1.84
1.82
1.8
1.78
1.76
1.74
1.72
1.7
-60
-40
-20
0
20
40
60
80
100
(°C)
Temperature Topt
R1230D001C/D IOUT=100mA
0.9
0.85
0.8
0.75
0.7
-60
-40
-20
0
20
40
60
80
100
(°C)
Temperature Topt
7) Oscillator Frequency vs. Temperature
1000
900
800
700
600
500
400
300
-60
-40
-20
0
20
40
60
80
100
Temperature Topt (°C)
VIN=VOUT+1.5V
8) Supply Current vs. Temperature
450
380
310
240
170
100
800kHz
500kHz
-60
-40
-20
0
20
Temperature Topt
40
60
VIN=5.5V
80
100
(°C)
Rev. 1.15
- 15 -
9) Soft-start time vs. Temperature
R1230D181B VIN=3.3V
3
2.4
1.8
1.2
0.6
0
800kHz
500kHz
-60
-40
-20
0
20
40
60
80
100
(°C)
(°C)
(°C)
Temperature Topt
10) Delay Time for protection vs. Temperature
3
2.4
1.8
1.2
0.6
0
-60
-40
-20
0
20
40
60
80
100
Temperature Topt
11) UVLO Threshold/Released Voltage vs. Temperature
2.3
2.25
2.2
UVLO Released Voltage
2.15
2.1
UVLO Detector Threshold
2.05
2
1.95
1.9
1.85
1.8
-60
-40
-20
0
20
Temperature Topt
40
60
80
100
12) CE Pin Input Voltage vs. Temperature
1.6
1.4
1.2
1
CEH
0.8
CEL
0.6
0.4
0.2
0
-60
-40
-20
0
20
40
60
80
100
(°C)
Temperature Topt
Rev. 1.15
- 16 -
13) Mode Pin Input Voltage vs. Temperature
1.6
1.4
1.2
1
MODEH
0.8
0.6
0.4
0.2
0
MODEL
-60
-40
-20
0
20
40
60
80
100
(°C)
Temperature Topt
14) Duty Cycle at VFM Mode vs. Temperature
80
75
70
65
60
55
50
-60
-40
-20
0
20
40
60
80
100
(°C)
Temperature Topt
15) Lx Transistor on Resistance vs. Temperature
VIN=3.0V
1
0.75
0.5
Nch Tr. On Resistance
Pch Tr. On Resistance
0.25
0
-60
-40
-20
0
20
40
60
80
100
(°C)
Temperature Topt
16) Limit Voltage vs. Temperature
0.5
0.45
0.4
0.35
0.3
0.25
0.2
0.15
0.1
-60
-40
-20
0
20
40
60
80
100
Temperature Topt (°C)
Rev. 1.15
- 17 -
17) Load Transient Response
0.6
0.5
0.4
0.3
0.2
0.1
0
OUT
I
=100mA
IOUT=0A
-0.1
-0.2
-0.3
-4.00E-05 -2.00E-05 0.00E+00
2.00E-05
4.00E-05
6.00E-05
Time[sec]
8.00E-05
1.00E-04
1.20E-04
1.40E-04
R1230D181B VIN=5.0V PWM
IOUT=200mA
0.6
0.5
0.4
0.3
0.2
0.1
0
IOUT=0A
-0.1
-0.2
-0.3
-4.00E-05 -2.00E-05 0.00E+00
2.00E-05
4.00E-05
6.00E-05
Time[sec]
8.00E-05
1.00E-04
1.20E-04
1.40E-04
R1230D181B VIN=5.0V PWM
0.6
0.5
0.4
0.3
0.2
0.1
0
IOUT=0A
IOUT=100mA
-0.1
-0.2
-0.3
-4.00E-06
1.00E-06
6.00E-06
1.10E-05
1.60E-05
2.10E-05
2.60E-05
3.10E-05
3.60E-05
R1230D181B VIN=5.0V PWM
Time [sec]
0.6
0.5
0.4
0.3
0.2
0.1
0
IOUT=100mA
IOUT=2mA
-0.1
-0.2
-0.3
-0.0002
-0.0001
0
0.0001
0.0002
0.0003
0.0004
0.0005
0.0006
0.0007
0.0008
Time [sec]
R1230D181B VIN=5.0V PWM
Rev. 1.15
- 18 -
IOUT=200mA
0.6
0.5
0.4
0.3
0.2
0.1
0
IOUT=0A
-0.1
-0.2
-0.3
-4.00E-06
1.00E-06
6.00E-06
1.10E-05
1.60E-05
2.10E-05
2.60E-05
3.10E-05
3.60E-05
R1230D181B VIN=5.0V PWM
Time[sec]
IOUT=200mA
0.6
0.5
0.4
0.3
0.2
0.1
0
IOUT=2mA
-0.1
-0.2
-0.3
-0.0002
-0.0001
0
0.0001
0.0002
0.0003
0.0004
0.0005
0.0006
0.0007
0.0008
Time [sec]
R1230D181B VIN=5.0V PWM
18) Turn-on Waveform
PWM Mode IOUT=0A
5
4
4
2
CE
0
3
2
1
VOUT
0
-1
-0.0004
0
0.0004
0.0008
0.0012
0.0016
0.002
0.0024
0.0028
R1230D181B VIN=5.0V
Time [sec]
PWM ModeꢀIOUT=50mA
5
4
3
2
1
0
4
2
CE
0
0
VOUT
-1
-0.0004
0
0.0004
0.0008
0.0012
0.0016
0.002
0.0024
0.0028
R1230D181B VIN=5.0V
Time [sec]
Rev. 1.15
- 19 -
PWM ModeꢀIOUT=200mA
5
4
3
2
1
0
4
2
0
CE
0
VOUT
-1
-0.0004
0
0.0004
0.0008
0.0012
0.0016
0.002
0.0024
0.0028
Time [sec]
R1230D181B VIN=5.0V
VFM Mode IOUT=0A
5
4
3
2
1
0
4
2
0
CE
VOUT
-1
-0.0004
0
0.0004
0.0008
0.0012
0.0016
0.002
0.0024
0.0028
R1230D181B VIN=5.0V
Time [sec]
VFM Mode IOUT=50mA
5
4
3
2
1
0
4
2
0
CE
0
VOUT
-1
-0.0004
0
0.0004
0.0008
0.0012
0.0016
0.002
0.0024
0.0028
Time [sec]
R1230D181B VIN=5.0V
Rev. 1.15
- 20 -
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