Application Notes for Voltage Regulator
Introduction
Ricoh has a superior voltage regulator lineup from a maximum input voltage 36V to a maximum output current 3A.
R1524x R1517x
R1518x
Maximum input voltage (V)
R1511x/R1513S
R1514x/R1516x
R1154x/R1155x
RP171x R1191x
RP170x
RP173x
RP132x
10
RP108J
R1171S
RP130x
RP190x
3000
Output current (mA)
¡) R1513S is available for automotive applications only.
See "Electronic Device Product Catalog for Automotive" and Datasheet for detailed information.
High Input Voltage Regulator
The CMOS type voltage regulator is now released in the maximum input voltage 36V. There are optional wide operating
temperature range products available for industrial equipment, and automotive applications such as car navigation and car audio
systems. Ricoh's high input voltage regulators have a built-in thermal shutdown circuit to prevent a heat generation and an ignition.
Maximum Input Voltage : 16V
R1190x
R1191x
Maximum Input Voltage : 24V
R1150H
R1154x
R1155x
R1500x
R1501x
R1514x
R1515x
Maximum Input Voltage : 36V
R1510S
R1511x
R1513S¡
R1516x
R1517x
R1518x
R1524x
¡) Products available for automotive applications only.
See "Electronic Device Product Catalog for Automotive" and Datasheet for detailed information.
Large Output Current Voltage Regulator
The CMOS type voltage regulator is now released in the maximum output current 3A. Ricoh's large output current voltage
regulators have a built-in thermal shutdown circuit to ensure safety for the circuit design.
Maximum Output Current : 1A
R1172x
R1173x
R1190x
Maximum Output Current : 1.5A
R1171S
1 Voltage Regulator
R1501x
R1518x
RP115x
Maximum Output Current : 2A
R1171J
RP131x
RP132x
Maximum Output Current : 3A
RP108J
Voltage Regulator
Low Supply Current Type and High-performance Type
Ricoh voltage regulators can be classified in three types by performance; a Low Supply Current Type, a High-performance Type,
and the Standard Type of average specifications. The Low Supply Current Type is used for the performance by the reduction of the
supply current during operation. The High-performance Type is used for the superior performance during operation (low noise and
fast transient response). A Standard Type is an average product of performance and supply current. Ricoh is preparing many
variations, in order to respond to a user's request.
Supply Current
Transient Response
Ripple Rejection
Low Supply Current Type
Ultra low
Slow
Low
High-performance Type
High
Fast
High
Low Supply Current Type Voltage Regulator
The Low Supply Current Type Voltage Regulator is used for applications which are always operating on for a long time, such as a
standby mode of mobile phone. Its supply current is from 1μA to several μA. The C version has a minimum supply current since the
CE pin and belonging internal CE circuit are not present.
RP110xxxxC
VDD
RP110xxxxB
VOUT
VDD
Vref
VOUT
Vref
Current Limit
Current Limit
GND
NC
CE
GND
C Version : Reducing the pull-down constant current to the CE pin.
Low Supply Current Type
Rx5RL
Rx5RW
R1100D
R1150H
R1524x
RP104x
RP110x
RP173x
R1154x
R1180x
R1514x
R1515x
R1517x
R1518x
High-performance Type Voltage Regulator
The High-performance Type Voltage Regulator is a product with high ripple rejection ratio (low noise), low output noise, sufficient
load regulation and high load transient response.
High-performance Type
R1172x
R1173x
RP102x
RP111x
RP112x
RP115x
RP130x
RP150K
Standard Type Voltage Regulator
The Standard Type Voltage Regulator has specifications which can be used for many applications. There are many variations of
this type between Low Supply Current Type and High-performance Type Voltage Regulator.
Voltage Regulator
2
ECO Function
An ECO Function is a function which implements a High-performance
Type Voltage Regulator and a Low Supply Current Type Voltage
Regulator integrated in a single chip. Having this ECO function enables
a performance of three operating modes instead of only two; On mode,
Off mode, and Sleep mode.
The voltage regulator with ECO function is able to switch between a
fast response mode (high-performance) and a low power mode (low
supply current), additionally it can be switched to the Off mode by the
CE pin.
The voltage regulator with ECO function is able to reduce the supply
current and number of parts on the board space since it switches
between those modes depending on the device status.
Fast transient response
High ripple rejection ratio
High-performance
Type Regulator
Fast Response
Mode
Standard Type
Regulator
ng
hi
Low supply current
itc
Sw
Low Supply Current
e
od
Type Regulator
M
Low Power
Mode
Comparison of Supply Current
The examples of the supply current of a Low Supply Current Type Voltage Regulator, a Voltage Regulator with ECO Function, and
a High-performance Type Voltage Regulator are shown in below table.
Low Supply Current Type
RP110x
ECO Function Included
RP201x
High-performance Type
RP112x
Typ. 1μA
Low Power Mode : Typ. 1.5μA
Fast Response Mode : Typ. 55μA
Typ. 75μA
Comparison of Ripple Rejection Ratio
The ripple rejection ratio graph of a Low Supply Current Type Voltage Regulator, a Voltage Regulator with ECO Function and
High-performance Type Voltage Regulator. (Since the measurement conditions may be slightly different, please consider below
graphs as a reference)
Low Supply Current Type
RP110x25xx
100
80
60
40
20
VIN=3.8V+0.2Vp-p
120
Ripple Rejection RR (dB)
IOUT=1mA
IOUT=30mA
IOUT=150mA
IOUT=50mA
IOUT=30mA
100
80
60
40
20
IOUT=1mA (Fast Response Mode)
IOUT=1mA (Low Power Mode)
0
0
0
1
10
100
Frequency f (kHz)
High-performance Type
RP112x28xx
0
1000
1
10
100
Frequency f (kHz)
VIN=3.8V
120
Ripple Rejection RR (dB)
VIN=3.5V
120
Ripple Rejection RR (dB)
ECO Function Included
RP201x28xx
100
80
60
IOUT=1mA
IOUT=30mA
IOUT=50mA
IOUT=100mA
IOUT=150mA
40
20
0
1000
0
1
10
100
Frequency f (kHz)
1000
Comparison of Load Transient Response
The load transient response graph of a Low Supply Current Type Voltage Regulator, a Voltage Regulator with ECO Function and High-performance
Type Voltage Regulator. (Since the measurement conditions may be slightly different, please consider below graphs as a reference)
Please note that the scale of the horizontal-axis for Low Supply Current Type and a Low Power Mode are in "ms", while those of a
High-performance Type and a Fast Response Mode are in "μs", the load transient response is more than 100 times faster and
output voltage variations are suppressed to 1/10.
ECO Function Included
Low Power Mode
Fast Response Mode
R1162x28x (ECO=L)
R1162x28x (ECO=H)
2.2
Output Voltage
1.9
-0.1 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9
Time t(ms)
3 Voltage Regulator
3.5
3.0
2.5
Output Voltage
2.0
-0.4 -0.2 0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6
Time t(ms)
0
Output Voltage VOUT(V)
2.5
Output Current
1mA
10mA
VIN=3.8V, CIN=1µF, COUT=1µF
150
150
Output Current IOUT(mA)
2.8
Output Voltage VOUT(V)
0
20
10
RP112x28xx
VIN=3.8V, CIN=1µF, COUT=0.47µF
100
Output Current
50mA
100mA
50
0
2.9
2.8
Output Voltage
2.7
2.6
-4 -2
0
2
4 6 8 10 12 14 16
Time t(µs)
100
Output Current
50mA
100mA
2.80
2.78
50
0
2.82
Output Voltage
2.76
-20 -10 0 10 20 30 40 50 60 70 80
Time t(µs)
Output Current IOUT(mA)
20
10
Output Current
1mA
10mA
VIN=3.8V, CIN=1µF, COUT=0.47µF
Output Current IOUT (mA)
Output Voltage VOUT (V)
VIN=3.5V, COUT=0.1µF
Output Voltage VOUT(V)
RP110x25xx
High-performance Type
Output Current IOUT(mA)
Low Supply Current Type
Voltage Regulator
How to Switch the ECO Function
There are four methods of switching the ECO Function, and Ricoh offers four types of products utilizing each method.
1. Manual Mode Shift Type····················The mode is switched by H/L input to an ECO pin.
2. Automatic Mode Shift Type················The voltage regulator automatically switches between modes depending on system load.
The switching point is fixed in the IC.
3. Seamless Type··································Instead of switching between two modes, a transition is made between modes
depending on the output current.
4. Manual/Automatic Mode Shift Type······The mode is switched by H/L input to an AE pin.
When AE="H", the mode is set to the fast response mode, and when AE="L", the voltage
regulator operates like the Automatic Mode Shift Type.
This type has both advantage of the Manual Mode Shift Type and the Automatic Mode Shift
Type.
Manual Mode Shift Type (with ECO pin)
Automatic Mode Shift Type
Seamless Type
R1162xxx1B
(Imaginary graph)
ECO
Vref
Supply Current
VOUT
Fast Response Mode
Supply Current
VDD
(Imaginary graph)
Low Power Mode
Current Limit
Output Current
CE
Output Current
GND
The mode is switched by controlling H/L to
the ECO pin.
Switching occurs between low power mode The supply current smoothly decreases as
and fast response mode depending on
the system load (output current) decreases.
system load (output current).
Manual/Automatic Mode Shift Type
AE
Automatic Mode Shift
(Imaginary graph)
Supply Current
VDD
VOUT
Fast Response
Mode
Vref
Current Limit
CE
Fast Response Mode
Low Power Mode
Output Current
GND
Fast response mode and Automatic mode shift can be switched by controlling H/L to the AE pin.
ECO Function Included
∗) Under development
Manual Mode Shift Type
R1160N
R1161N
R1163x
R1191x
Automatic Mode Shift Type
R1155x
R1510S
R5326K
RP202x
Seamless Type
R1116N
Manual/Automatic Mode Shift Type
RP200x
R5328K
RP201x
Voltage Regulator
4
Various protection circuits are built into Ricoh voltage regulators.
Fold-back Protection Circuit
The Fold-back Protection Circuit shown in the blue ellipse as "Current Limit" protects the voltage regulator from damage by
overcurrent if the output pin (VOUT) and the ground pin (GND) are shorted.
It consists of the overcurrent protection circuit and the short current protection circuit.
In the typical characteristics, the overcurrent protection activities are shown by the blue line on the "Output Voltage vs. Output
Current" graph, and the short current protection activities are shown by the blue circle on the same graph.
The limiting current value of the overcurrent protection is not defined in the datasheet. Please refer to the graph of the typical
characteristics.
The limiting current value of the short current protection is defined in the datasheet as short current limit (lSC). In Ricoh voltage
regulators, this is usually set within a range of about 30mA to 250mA.
R1131x26xx
VOUT
VDD
+
Vref
Current Limit
GND
CE
Output Voltage VOUT (V)
3.5
3.0
3.6V 4.6V
2.5
2.0
1.5
3.1V
VIN =2.9V
1.0
0.5
0.0
0
100
200
300
400
500
600
Output Current lOUT (mA)
Fold-back Protection Circuit Included
The Fold-back Protection Circuit is built in all voltage regulators except for Rx5RL Series.
Inrush Current Preventing Circuit
At the start-up of a voltage regulator, an inrush current equivalent to a peak current flows until the output capacitor is charged up to
the set output voltage if the voltage regulator does not have an inrush current protection circuit or soft-start circuit. When the inrush
current is large, the input voltage of a voltage regulator may be unstable. If there is a large input voltage drop, the operation of
another connected circuit may be affected.
Ricoh provides two kinds of Inrush Current Protection Circuits, and both have different features.
Control Method
Inrush Current Limit Circuit
Constant Slope Circuit
Start up Time
Limiting with constant current.
When COUT is small, it is possible to start up quickly
compared with a constant slope circuit.
Limiting with constant time, so-called
Soft Start Function.
Start-up time is fixed in the IC and start-up time
does not change by the capacitance of COUT.
RP115x has both of the inrush current protection circuit and the constant slope circuit built in, and it switches the circuits according
to the capacitance of COUT. Please refer to a datasheet for details.
5 Voltage Regulator
Voltage Regulator
Inrush Current Limit Circuit
Inrush Current Limit Circuit has a function
that limits the output current for a fixed
period of time to reduce the inrush current
at the start-up and prevents the
fluctuation of the input voltage.
Imaginary graph
The volume of inrush current is affected
by the capacitance of the output
capacitor.
The time of the inrush current becomes
longer when the output capacitor is large.
A sufficient effect of inrush current
limitation might not be achieved when the
output capacitor is large.
If it is necessary to limit the inrush current
completely in case of using the large
output capacitor, Ricoh recommends the
product equipped with an Adjustable
Inrush Current Limit Time Function.
The inrush current limit circuit of the
R1190x Series and RP132x Series has a
DELAY pin, and it is possible to adjust the
time of the inrush current limitation by
connecting a capacitor to the DELAY pin.
Imaginary graph
CE Input Voltage
Imaginary graph
CE Input Voltage
CE Input Voltage
Output Voltage
Output Voltage
Limiting lnrush current
Limiting not enough because of the
limiting time is too short
Limiting the inrush current
Inrush Current
Inrush Current
Inrush Current
Output Voltage
Extended the
inrush current
limiting time
Time t
Time t
Time t
Inrush Current Limit Circuit Included
R1172x
∗1
∗2
R1173x
R1190x∗1
RP111x
RP115x∗2
RP131x
RP132x∗1
Inrush Current Limit Time can be adjusted by external capacitor.
The RP115x prevents the inrush current by the constant current limit circuit during the starting up operation.
Voltage Regulator
6
Constant Slope Circuit
CIN=none, IOUT=0mA, Topt=25°C
VIN=3.5V
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0
CE Input Voltage
Output Voltage
COUT=0.1µF
COUT=1.0µF
COUT=2.2µF
COUT=4.7µF
COUT=10µF
Inrush Current
0
350
300
250
200
150
100
50
0
Inrush Current IVDD (mA)
See "Inrush Current Characteristics Example of RP110x25xB/D" on
the right, if the output capacitor is less than 4.7μF, the Constant
Slope Circuit operates during start-up, likewise, if the output
capacitor is over 10μF, the output current limit circuit operates
during the start-up. The boundary point of using these two circuits
is inversely proportional to the output voltage. If the output voltage
is higher, the output current limit circuit operates even if the output
capacitor capacitance is small. The boundary points vary with each
products.
RP110x25xB/D Inrush Current Characteristics
CE Input Voltage VCE / Output Voltage VOUT (V)
Some products have a Constant Slope Circuit which prevents the
overshoot of the output voltage.
The constant slope is a kind of soft-start circuit which allows the
output voltage to start up gradually. The capacitor to create the
start-up slope is built in the IC that does not require any external
components. The start-up time and start-up slope angle are fixed
inside the IC.
If the capacitance of the external output capacitor exceeds a
certain capacitance, the output current limit circuit minimizes the
incoming current of the output capacitor at the start-up. As a result,
the start-up time becomes longer and the start-up slope angle
becomes less steep.
50 100 150 200 250 300 350 400
Time t (µs)
Constant Slope Circuit Included
RP106x
RP107x
RP108J
RP110x
RP115x
RP116Z
RP170x
RP171x
RP202x
R1517x
R1518x
Reverse Current Protection Circuit
The Reverse Current Protection Circuit stops the reverse current
from VOUT pin to VDD pin when VOUT becomes higher than VIN.
Usually, the voltage regulator using Pch output transistor
contains a parasitic diode between VDD pin and VOUT pin.
Therefore, if VOUT is higher than VIN, the parasitic diode conducts
in forward direction. As a result, the current flows from VOUT pin
to VDD pin.
RP173x Series switches to the reverse current protection mode
before VIN becomes lower than VOUT by connecting the parasitic
diode of Pch output transistor to the backward direction, and
connecting the gate to VOUT pin.
As a result, the Pch output transistor is turned off and the current
path from VOUT pin to GND pin is disconnected. (Except RP115x)
ECO
VDD
VOUT
Vref
Current Limit
Reverse Detector
CE
∗
GND
indicates a parasitic diode.
When using a backup circuit, a protection schottky diode is required with the voltage regulator in case of using the voltage regulator
that does not have a Reverse Current Protection Circuit as shown in the next page left figure. Please note that a schottky diode
causes a dropout of about 0.3V and leakage current of a few μA to 50μA.
When using a voltage regulator including the Reverse Current Protection Circuit such as RP173x, the protection diode is not
needed as shown in the next page right figure. Therefore, it can prevent the voltage drop and the leakage current.
7 Voltage Regulator
Voltage Regulator
Parasitic diode
Protection diode
Vf
VOUT
VDD
RTC
Memory
etc.
Main
Power
Supply
Regulator
GND
Leakage
Back-up
current
Power
Supply
GND
VOUT
VDD
RP173x
Main
Power
Supply
Vf
RTC
Memory
Leakage
current Back-up
Power
Supply
GND
etc.
GND
Reverse Current Protection Circuit Included
R1155x
R1163x
R1191x
RP108J
RP115x
RP173x
Thermal Shutdown Circuit
The Thermal Shutdown Circuit detects overheating of the voltage regulator if the output pin (VOUT) is shorted to the ground pin
(GND) and stops the voltage regulator operation to protect it from damage.
For example, the Thermal Shutdown Circuit stops voltage regulator operation if the junction temperature of the R1150H Series
becomes higher than 150°C. Additionally, if the junction temperature after the voltage regulator being stopped decreases to a level
below 125°C, it restarts voltage regulator operation. (The temperature is different according to the product).
As a result the operation of the Thermal Shutdown Circuit causes the voltage regulator repeatedly to turn OFF and ON till the
causes of overheating are removed. As a consequence a pulse shaped output voltage occurs. Please prevent this situation.
In the datasheet it is shown as a thermal shutdown detection temperature (TTSD) and a thermal shutdown release temperature
(TTSR).
Output Voltage VOUT(V)
VOUT
VIN
+
Vref
Short
Peak Current
Protection Protection
GND
CE
VIN=10V, IOUT=1mA
8
7
6
5
4
3
2
1
0
0
Temperature (°C)
Thermal
Shutdown
150
Regulator
R1150H (VOUT=5V)
ON
125
0
Time
OFF
20 40 60 80 100 120 140 160 180
Junction Temperature Tjct(°C)
Thermal Shutdown Circuit Included
R1150H
R1154x
R1155x
R1170x
R1501x
R1510S
R1511x
R1513S
RP108J
RP111x
RP115x
RP131x
¡
R1171x
R1172x
R1173x
R1190x
R1191x
R1500x
R1517x
R1518x
R1524x
R1514x
R1515x
R1516x
RP132x
RP170x
RP171x
¡) Products available for automotive applications only. See "Electronic Device Product Catalog for Automotive" and Datasheet for detailed information.
Voltage Regulator
8
Auto-discharge Function
When using a capacitor with large capacity value in VOUT side, the VOUT pin voltage might not immediately fall to the ground level
when the CE pin is switched from the active mode to the standby mode. By adding N-channel transistor to the output circuit (shown
in blue circles in the diagram below), the auto-discharge function quickly lowers the VOUT to the ground level by releasing the
electrical charge accumulated in the external capacitor.
This auto-discharge function can be combined with the system shutdown sequence.
During Operation
During Standby
VOUT
VDD
VOUT
VDD
-
-
+
+
Vref
Vref
Current Limit
Current Limit
GND
CE
GND
CE
When the CE pin is in the active mode, the voltage regulator
is operating. The P-channel transistor circled in light blue is
ON. The N-channel transistor circled in blue that provides
the Auto-discharge function is OFF.
When the CE pin is in the disable mode, the voltage
regulator is in the standby mode. When in standby mode
the P-channel transistor circled in light blue turns OFF and
stops the voltage regulator output from the VOUT pin. The
N-channel transistor circled in blue that provides the
auto-discharge function turns ON and the charge in the
output capacitor connected to the VOUT pin is rapidly
discharged to the ground pin. It is called the
"Auto-discharge function".
Illustrations of Typical Output with /
without the Auto-discharge functions
Without the Auto-discharge function
With the Auto-discharge function
VOUT
Voltage (V)
Voltage (V)
VDD
CE
2.73s
VOUT
-
CE
+
126μs
Vref
Current Limit
VOUT
0 0.4 0.8 1.2 1.6 2.0 2.4 2.8 3.2 3.6
Time (s)
0 40 80 120 160 200 240 280 320 360
Time (μs)
GND
CE
⋅ As shown in the figure on the left, the capacitor which is connected to the VOUT pin is discharged in 2.73s without the
Auto-discharge function, whereas it is discharged in 126μs with the function.
⋅ This Auto-discharge function ensures that output rapidly drops when the voltage regulator enters standby mode, but it also
effectively prevents system malfunctions that might occur by the capacitance of the output capacitor connected to the VOUT pin.
Auto-discharge Function Included
R1114x
R1116N
R1131N
R1141Q
R1161N
R1163x
R1172x
R1173x
R1190x
R1191x
R5326K
R5328K
RP100x
RP101x
RP102x
RP103x
RP104x
RP105x
RP106x
RP107x
RP108J
RP109x
RP110x
RP111x
RP112x
RP114x
RP115x
RP116Z
RP130x
RP131x
RP132x
RP150K
RP151K
RP152x
RP153L
RP154x
RP170x
RP171x
RP173x
RP200x
RP201x
RP202x
R1513S¡
R1517x
R1518x
¡) Products available for automotive applications only. See "Electronic Device Product Catalog for Automotive" and Datasheet for detailed information.
How to define which products have an Auto-discharge function from the Product Name
⋅ Single voltage regulator (Low Drop Out) regulator products include an Auto-discharge function if the 10th character of product name is a "D".
(Example : R1114N281D-TR-F, RP103K281D-TR)
⋅ Multi voltage regulator (Low Drop Out) regulator products include an Auto-discharge function if the 10th character of product name is a "B".
(Example : RP152N010B-TR-FE, RP150K001B-TR)
9 Voltage Regulator
Voltage Regulator
Dual Voltage Regulator
There are single input type and dual input type in dual voltage regulators.
The single input type has one shared input pin for both voltage regulators. The single input type provides a small package due to
the reduction of the number of pins. However, if the difference between the input voltage and the output voltage is large, since the
input voltage of both voltage regulators is same voltage, the energy loss and the power dissipation becomes large.
(Imaginary chart)
Single input type
Dual input type
3.6V
3.6V
2.5V
2.5V
1.8V
1.2V
Energy loss & power dissipation
large
1.2V
Energy loss & power dissipation
small
Dual Voltage Regulator Input Types
Single input type
R5326K
R5328K
Dual input type
RP153L
RP154L
RP150K
RP152x
RP154N
Sequence Control
RP152xxxxC has a sequence control function. When CE1 and CE2 are enabled, VR2 has 100μs delay for start up compared with
VR1. As for the shutdown sequence, the discharge period for VR2 is approximately 5 times shorter compared to VR1.
(Imaginary chart)
CE1
CE2
VOUT1
RP152x
VOUT2
100μs
Discharges 5 times
earlier
Enhanced Load Transient Response Speed Version
The RP153LxxxD/E versions have enhanced load transient response characteristics. In case of an increase in output current, the
voltage drop and recovery period at the load change is significantly lower compared with the RP153LxxxA/B versions although its
supply current is increased.
Output Voltage VOUT (V) Output Current IOUT (mA)
Load Transient Response of RP153L
200
Output Current 1mA ⇔ 150mA
100
0
A/B Versions
2.5
2.4
D/E Versions
2.5
2.4
0 10 20 30 40 50 60 70 80 90
Time t (μs)
Voltage Regulator
10
Technical Notes
TYPICAL APPLICATIONS
IN
VDD
C1
R1116x
Series
CE
CE2
VOUT
C2
IN
V DD
C1
GND
CE1
VOUT2
R5326x
Series
GND
OUT2
C3
OUT1
VOUT1
C2
PCB Layout
Ensure the VDD and GND lines are sufficiently robust. If their impedance is too high, noise pickup or unstable operation may result.
Connect a capacitor with a suitable value between the VDD and GND pins, and as close as possible to the pins.
Phase Compensation
In voltage regulators, phase compensation is provided to secure stable operation even when the load current is varied. For this
purpose, use a capacitor COUT with good frequency characteristics and proper ESR (Equivalent Series Resistance), value in the
hatched area.
If a capacitor with large ESR value, especially a tantalum type capacitor, is used, the output might be unstable. Evaluate a circuit
including consideration of frequency characteristics.
Depending on the capacitor size, manufacturer, and part number, the bias characteristics and temperature characteristics are
different. Evaluate the circuit taking actual characteristics into account.
R1116x281x
R1116x Series Example
The relations between IOUT (Output Current) and ESR of an
output capacitor are shown right.
The conditions when the white noise level is under 40mV (Avg.)
are shown by the hatched area in the graph.
Measurement conditions
x C21GRM155B30J105KE18B (Murata)
x Noise Frequency Band
: 10Hz to 1MHz
x Measurement Temperature : 25°C
x Hatched Area
: Noise level below 40mV
(average value)
11 Voltage Regulator
Equivalent Series Resistance ESR(Ω)
Equivalent Series Resistance vs. Output Current
VIN=2.82V to 6.5V
100
Topt=85°C
10
Topt=-40°C
1
0.1
0.01
0
30
60
90
120
Output Current IOUT(mA)
150
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