RP111x Series
AEC-Q100 Compliant
Good Transient Response Low Voltage 500 mA LDO for Automotive Applications
NO.EC-241-200630
OUTLINE
The RP111x is a CMOS-based LDO regulator featuring 500 mA output current. The input voltage is as low as
1.4 V and the output voltage can be set from 0.7 V. Due to a built-in 0.46 (at VOUT = 2.8 V) on-resistor, RP111x
can provide a low dropout voltage. RP111x also features an excellent line transient response, ripple rejection at
75 dB, and low noise. The output voltage accuracy is as high as ±0.8% and the temperature drift coefficient of
output voltage is low at ±30 ppm/°C. The accuracy of the output voltage of RP111x includes the temperature
characteristics and the load transient response has been improved. The typ. and max value of under/overshoot
for various output current are shown in the typical characteristics, therefore the accuracy of the output voltage
estimation will be easy on the actual operating cases. In addition to a fold-back protection circuit built into
conventional regulators, RP111x contains a thermal shutdown circuit and an inrush current limit circuit.
SOT-23-5, SOT-89-5, and HSOP-6J packages are available.
FEATURES
Input Voltage Range (Maximum Rating)ꞏꞏꞏꞏꞏꞏꞏꞏꞏ 1.4 V to 5.25 V (6.0 V)
Operating Temperature ꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏ −40°C to 105°C
Supply Current ꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏ Typ. 80 A
Standby Current ꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏ Typ. 0.1 A
Dropout Voltage ꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏ Typ. 0.23 V (IOUT = 500 mA、VSET = 2.5 V)
Ripple Rejection ꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏ Typ. 75 dB (f = 1 kHz)
Typ. 70 dB (f = 10 kHz)
Output Voltage Accuracy ꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏ ±0.8% (VSET ≥ 1.8 V)
Output Voltage Temperature Coefficient ꞏꞏꞏꞏꞏꞏꞏꞏꞏ Typ. ±30 ppm/°C (VSET ≥ 1.8 V)
Feedback Voltage Accuracy ꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏ 0.7±18 mV
Feedback Voltage Temperature Coefficient ꞏꞏꞏꞏ Typ. ±100 ppm/°C
Line Regulation ꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏ Typ. 0.02%/V
Input Transient Response ꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏ Typ. ±1.5 mV (VINVSET + 0.5 V⇔VSET + 1.5 V (tr = tf = 5.0 s),
VIN ≥ 1.4 V, IOUT = 30 mA)
Packagesꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏ SOT-23-5, SOT-89-5, HSOP-6J
Output Voltage Range ꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏ 0.7 V, 1.1 V, 1.2 V, 1.5 V, 1.8 V, 2.5 V, 2.8 V, 2.85 V, 2.9 V, 3.0 V,
3.3 V, 3.4 V
Contact Ricoh sales representatives for other voltages.
RP111x001B/D: 0.7 V to 3.6 V (Adjustable with external resistor)
Built-in Fold-back Protection Circuit ꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏ Typ. 50 mA
Thermal Shutdown Temperature ꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏ 165°C
Inrush Current Limitꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏ Typ. 400 mA (for 180 s after start-up)
Ceramic capacitors are recommended to be used with this IC
ꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏ 1.0 F or more (Internally Fixed Output Voltage)
Output Noise ꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏ 20 x VSETVrms (BW = 10 Hz to 100 kHz, VSET ≥ 1.8 V)
APPLICATIONS
Power source for accessories such as car audios, car navigation systems, and ETC systems
Power source for ECUs such as EV inverter and battery charge control unit
1
RP111x
NO.EC-241-200630
BLOCK DIAGRAMS
Internally Fixed Output Voltage (HSOP-6J)
RP111Sxx1B
VDD
RP111Sxx1D
VOUT
VDD
VOUT
Vref
Vref
Current Limit
Thermal Shutdown
CE
Current Limit
Thermal Shutdown
GND
CE
GND
Internally Fixed Output Voltage (SOT-23-5/ SOT-89-5)
RP111Nxx1B / RP111Hxx1B
VDD
RP111Nxx1D / RP111Hxx1D
VOUT
VDD
VOUT
VFB
VFB
Vref
Vref
Current Limit
Thermal Shutdown
CE
Current Limit
Thermal Shutdown
GND
CE
GND
Externally Adjustable Output Voltage (HSOP-6J/ SOT-23-5/ SOT-89-5)
RP111S001B / RP111N001B / RP111H001B
VDD
RP111S001D / RP111N001D / RP111H001D
VOUT
VDD
VOUT
VFB
VFB
Vref
Vref
Current Limit
Thermal Shutdown
CE
2
Current Limit
Thermal Shutdown
GND CE
GND
RP111x
NO.EC-241-200630
SELECTION GUIDE
The set output voltage, auto-discharge function*1, and package type for the IC are user-selectable.
Product Name
RP111Nxx1-TR-#E
RP111N001-TR-#E
RP111Hxx1-T1-#E
RP111H001-T1-#E
RP111Sxx1-E2-#E
RP111S001-E2-#E
Package
Quantity per Reel
Pb Free
Halogen Free
SOT-23-5
3,000 pcs
Yes
Yes
SOT-89-5
1,000 pcs
Yes
Yes
HSOP-6J
1,000 pcs
Yes
Yes
RP111x001B/D: Adjustable with external resistor
xx: Specify the set output voltage (VSET)
0.7 V (07), 1.1 V (11), 1.2 V (12), 1.5 V (15), 1.8 V (18), 2.5 V (25), 2.8 V (28), 2.9 V (29),
3.0 V (30), 3.3 V (33), 3.4 V (34)
2.85 V: RP111x2815
Contact Ricoh sales representatives for other voltages.
: Specify the auto-discharge function at off state
(B) Active-high, without auto discharge function at off state
(D) Active-high, with auto discharge function at off state
#: Specify Automotive Class Code
Operating
Temperature Range
A
−40°C to 105°C
J
−40°C to 105°C
Guaranteed Specs
Temperature Range
25°C
−40°C to 105°C
Screening
High Temperature
High and Low Temperature
*1
Auto-discharge function quickly lowers the output voltage to 0 V by releasing the electrical charge in the external
capacitor when the chip enable signal is switched from the active mode to the standby mode.
3
RP111x
NO.EC-241-200630
PIN DESCRIPTIONS
SOT-23-5
5
4
SOT-89-5
5
HSOP-6J
4
6
5
4
3
1
2
3
(mark side)
1
2
3
1
2
SOT-23-5
Pin No.
1
2
3
4
5
Symbol
VDD
GND
CE
VFB
VOUT
Description
Input Pin
Ground Pin
Chip Enable Pin (Active-high)
Feed Back Pin
Output Pin
The VOUT pin should be connected to the VFB pin when using RP111x as an internal fixed output voltage type. In case of
using this device as an external adjustable type, refer to Adjustable Output Voltage Type Setting for detailed information.
SOT-89-5
Pin No.
1
2
3
4
5
Symbol
VFB
GND
CE
VDD
VOUT
Description
Feed Back Pin
Ground Pin
Chip Enable Pin (Active-high)
Input Pin
Output Pin
The VOUT pin should be connected to the VFB pin when using RP111x as an internal fixed output voltage type. In case of
using this device as an external adjustable type, refer to Adjustable Output Voltage Type Setting for detailed information.
HSOP-6J
Pin No.
1
2
3
4
5
6
Symbol
VOUT
GND
GND
VFB
CE
GND
VDD
Description
Output Pin
Ground Pin
Ground Pin (Internal fixed output voltage type: RP111Sxx1B/D)
Feed Back Pin (Adjustable output voltage type: RP111S001B/D)
Chip Enable Pin
Ground Pin
Input Pin
In case of using this device as an external adjustable type, refer to Adjustable Output Voltage Type Setting for detailed
information.
4
RP111x
NO.EC-241-200630
ABSOLUTE MAXIMUM RATINGS
Symbol
*1
Item
Rating
Unit
VIN
Input Voltage
−0.3 to 6.0
V
VCE
Input Voltage (CE Pin)
−0.3 to 6.0
V
VOUT
Output Voltage
−0.3 to VIN + 0.3
V
IOUT
Output Current
510
mA
PD
Power Dissipation*1
(JEDEC STD. 51)
SOT-23-5
830
SOT-89-5
3200
HSOP-6J
3400
mW
Tj
Junction Temperature
−40 to 150
°C
Tstg
Storage Temperature
−55 to 150
°C
Refer to PACKAGE INFORMATION for detailed information.
ABSOLUTE MAXIMUM RATINGS
Electronic and mechanical stress momentarily exceeded absolute maximum ratings may cause permanent damage
and may degrade the lifetime and safety for both device and system using the device in the field. The functional operation
at or over these absolute maximum ratings are not assured.
RECOMMENDED OPERATING CONDITIONS
Symbol
*2
Item
*2
VIN
Input Voltage
Ta
Operating Temperature
Rating
Unit
1.4 to 5.25
V
−40 to 105
°C
In case of exceeding the maximum Input Voltage of 5.25 V, the device must be operated on condition that the Input
Voltage is up to 5.5 V and the total operating time is within 500 hrs.
RECOMMENDED OPERATING CONDITIONS
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 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.
5
RP111x
NO.EC-241-200630
ELECTRICAL CHARACTERISTICS
VIN = VSET + 1.0 V (VSET > 1.5 V), VIN = 2.5 V (VSET ≤ 1.5 V), IOUT = 1 mA,
CIN = COUT = 1.0 F, unless otherwise noted.
The specifications surrounded by
are guaranteed by design engineering at 40°C ≤ Ta ≤ 105°C.
RP111xxx1D/B (-AE) (Fixed Output Voltage Type)
Symbol
Item
(Ta = 25°C)
Conditions
VSET < 1.8 V
Output voltage
VTRLD
VSET < 1.8 V
Output Current
VOUT/IOUT Load regulation
Load Transient
Response
−18
VSET ≥ 1.8 V x 0.985
−40C ≤ Ta ≤ 105C
IOUT
Typ.
VSET ≥ 1.8 V x 0.992
Ta = 25C
VOUT
Min.
−55
Max.
Unit
x 1.008
V
18
mV
x 1.015
V
50
mV
500
mA
1 mA ≤ IOUT ≤ 500 mA
1
−75
+45
−55
+35
COUT = 1 F
IOUT: 1 mA⇔250 mA
(tr = tf = 0.5 s)
COUT = 2.2 F
IOUT: 1 mA⇔250 mA
(tr = tf = 5 s)
20
mV
mV
−20
+15
COUT = 1 F
VDIF
Dropout Voltage
ISS
Supply Current
IOUT = 0 mA
80
125
A
Standby Current
VCE = 0 V
0.1
7.0
A
VSET + 0.5 V ≤ VIN ≤ 5.25 V,
VIN ≥ 1.4 V
0.02
0.10
%/V
Istandby
VOUT/VIN Line regulation
ISC
Short Current Limit
IPD
CE Pull-down Current
VCEH
CE Input Voltage "H"
VCEL
CE Input Voltage "L"
TTSD
TTSR
RLOW
Refer to the Dropout Voltage
VOUT = 0 V
Thermal Shutdown
Junction Temperature
Detection Temperature
Thermal Shutdown
Junction Temperature
Released Temperature
LOW output Nch Tr. ON
Resistance
VIN = 4.0 V, VCE = 0 V
(RP111xxxD only)
50
0.3
mA
0.6
1.0
A
V
0.4
V
165
°C
100
°C
60
All test items listed under Electrical Characteristics are done under the pulse load condition (Tj ≈ Ta = 25C) except for
Load Transient Response.
6
RP111x
NO.EC-241-200630
The specifications surrounded by
are guaranteed by design engineering at 40°C ≤ Ta ≤ 105°C.
RP111xxx1D/B (-AE) (Fixed Output Voltage Type) Dropout Voltage
Output Voltage
VOUT (V)
(Ta = 25°C)
Dropout Voltage VDIF (V)
Typ.
Max.
0.7 ≤ VSET < 0.8
0.58
0.88
0.8 ≤ VSET < 0.9
0.52
0.80
0.9 ≤ VSET < 1.0
0.45
0.70
1.0 ≤ VSET < 1.2
0.42
0.64
0.35
0.53
0.31
0.48
1.8 ≤ VSET < 2.1
0.27
0.44
2.1 ≤ VSET < 2.5
0.25
0.38
2.5 ≤ VSET < 3.0
0.23
0.34
3.0 ≤ VSET ≤ 3.6
0.22
0.32
1.2 ≤ VSET < 1.4
1.4 ≤ VSET < 1.8
Condition
IOUT = 500 mA
7
RP111x
NO.EC-241-200630
VIN = 2.5 V, IOUT = 1 mA, CIN = COUT = 1.0 F, unless otherwise noted.
The specifications surrounded by
are guaranteed by design engineering at 40°C ≤ Ta ≤ 105°C.
RP111x001D/B (-AE) (Adjustable Output Voltage Type)
Symbol
Item
VFB
Feedback pin
output voltage
VOUT
IOUT
Conditions
Ta = 25C
0.682
0.700
0.718
0.7
3.6
Output Current
500
Load Transient
Response
1 mA ≤ IOUT ≤ 500 mA
IOUT: 1 mA⇔250 mA
(tr = tf = 0.5 s)
IOUT = 500 mA
ISS
Supply Current
IOUT = 0 mA
Standby Current
VOUT/VIN Line regulation
ISC
Short Current Limit
IPD
CE Pull-down Current
VCEH
CE Input Voltage "H"
VCEL
CE Input Voltage "L"
Thermal Shutdown
Detection Temperature
Thermal Shutdown
Released Temperature
COUT = 2.2 F
COUT = 1 F
20
−75
+45
−55
+35
COUT = 1 F
Unit
V
V
mA
1
IOUT: 1 mA⇔250 mA
(tr = tf = 5 s)
VOUT = VFB
TTSR
Max.
Adjustable Output
Voltage Range
Dropout Voltage
TTSD
Typ.
0.750
−40C ≤ Ta ≤ 105C
VDIF
Istandby
VOUT = VFB
Min.
0.645
VOUT/IOUT Load regulation
VTRLD
(Ta = 25°C)
mV
mV
−20
+15
0.88
V
80
125
A
VCE = 0 V
0.1
7.0
A
VOUT = VFB, 1.4 V ≤ VIN ≤ 5.25 V
0.02
0.10
%/V
VOUT = VFB = 0 V
50
0.3
mA
0.6
A
1.0
V
0.4
V
Junction Temperature
165
°C
Junction Temperature
100
°C
All test items listed under Electrical Characteristics are done under the pulse load condition (Tj ≈ Ta = 25C) except for
Load Transient Response.
8
RP111x
NO.EC-241-200630
VIN = VSET + 1.0 V (VSET > 1.5 V), VIN = 2.5 V (VSET ≤ 1.5 V), IOUT = 1 mA,
CIN = COUT = 1.0 F, unless otherwise noted.
RP111xxx1D/B (-JE) (Fixed Output Voltage Type)
Symbol
Item
Conditions
Ta = 25C
VOUT
Output voltage
−40C ≤ Ta ≤ 105C
IOUT
Min.
Load Transient
Response
Typ.
Max.
Unit
VSET ≥ 1.8 V
x 0.992
x 1.008
V
VSET < 1.8 V
−18
18
mV
VSET ≥ 1.8 V
x 0.985
x 1.015
V
VSET < 1.8 V
−55
50
mV
Output Current
VOUT/IOUT Load regulation
VTRLD
(−40C ≤ Ta ≤ 105C)
500
mA
1 mA ≤ IOUT ≤ 500 mA
IOUT: 1 mA⇔250 mA
(tr = tf = 0.5 s)
IOUT: 1 mA⇔250 mA
(tr = tf = 5 s)
1
20
−75
+45
−55
+35
COUT = 1 F
COUT = 2.2 F
mV
mV
−20
+15
COUT = 1 F
VDIF
Dropout Voltage
ISS
Supply Current
IOUT = 0 mA
80
125
A
Standby Current
VCE = 0 V
0.1
7.0
A
VSET + 0.5 V ≤ VIN ≤ 5.25 V,
VIN ≥ 1.4 V
0.02
0.10
%/V
Istandby
VOUT/VIN Line regulation
ISC
Short Current Limit
IPD
CE Pull-down Current
VCEH
CE Input Voltage "H"
VCEL
CE Input Voltage "L"
TTSD
TTSR
RLOW
Refer to the Dropout Voltage
VOUT = 0 V
Thermal Shutdown
Junction Temperature
Detection Temperature
Thermal Shutdown
Junction Temperature
Released Temperature
LOW output Nch Tr. ON
Resistance
VIN = 4.0 V, VCE = 0 V
(RP111xxxD only)
50
0.3
mA
0.6
1.0
A
V
0.4
V
165
°C
100
°C
60
All test items listed under Electrical Characteristics are done under the pulse load condition (Tj ≈ Ta = 25C) except for Load
Transient Response.
9
RP111x
NO.EC-241-200630
RP111xxx1D/B (-JE) (Fixed Output Voltage Type) Dropout Voltage
Output Voltage
VOUT (V)
Dropout Voltage VDIF (V)
Typ.
Max.
0.7 ≤ VSET < 0.8
0.58
0.88
0.8 ≤ VSET < 0.9
0.52
0.80
0.9 ≤ VSET < 1.0
0.45
0.70
1.0 ≤ VSET < 1.2
0.42
0.64
0.35
0.53
0.31
0.48
1.8 ≤ VSET < 2.1
0.27
0.44
2.1 ≤ VSET < 2.5
0.25
0.38
2.5 ≤ VSET < 3.0
0.23
0.34
3.0 ≤ VSET ≤ 3.6
0.22
0.32
1.2 ≤ VSET < 1.4
1.4 ≤ VSET < 1.8
10
(−40C ≤ Ta ≤ 105C)
Condition
IOUT = 500 mA
RP111x
NO.EC-241-200630
VIN = 2.5 V, IOUT = 1 mA, CIN = COUT = 1.0 F, unless otherwise noted.
RP111x001D/B (-JE) (Adjustable Output Voltage Type)
Symbol
Item
VFB
Feedback pin
output voltage
VOUT
IOUT
Conditions
Ta = 25C
0.682
0.700
0.718
0.7
3.6
Output Current
500
Load Transient
Response
1 mA ≤ IOUT ≤ 500 mA
IOUT: 1 mA⇔250 mA
(tr = tf = 0.5 s)
IOUT = 500 mA
ISS
Supply Current
IOUT = 0 mA
Standby Current
VOUT/VIN Line regulation
ISC
Short Current Limit
IPD
CE Pull-down Current
VCEH
CE Input Voltage "H"
VCEL
CE Input Voltage "L"
Thermal Shutdown
Detection Temperature
Thermal Shutdown
Released Temperature
COUT = 2.2 F
COUT = 1 F
20
−75
+45
−55
+35
COUT = 1 F
Unit
V
V
mA
1
IOUT: 1 mA⇔250 mA
(tr = tf = 5 s)
VOUT = VFB
TTSR
Max.
Adjustable Output
Voltage Range
Dropout Voltage
TTSD
Typ.
0.750
−40C ≤ Ta ≤ 105C
VDIF
Istandby
VOUT = VFB
Min.
0.645
VOUT/IOUT Load regulation
VTRLD
(−40C ≤ Ta ≤ 105C)
mV
mV
−20
+15
0.88
V
80
125
A
VCE = 0 V
0.1
7.0
A
VOUT = VFB, 1.4 V ≤ VIN ≤ 5.25 V
0.02
0.10
%/V
VOUT = VFB = 0 V
50
0.3
mA
0.6
A
1.0
V
0.4
V
Junction Temperature
165
°C
Junction Temperature
100
°C
All test items listed under Electrical Characteristics are done under the pulse load condition (Tj ≈ Ta = 25C) except for
Load Transient Response.
11
RP111x
NO.EC-241-200630
TYPICAL APPLICATIONS
Internally Fixed Output Voltage
RP111N/H
VDD
VOUT
VOUT
RP111N/H
C1
C2
VFB
1.0 µF
CE Control
1.0 µF
CE
GND
RP111S
VDD
VOUT
VOUT
RP111S
C1
C2
1.0 µF
CE Control
1.0 µF
CE
GND
Externally Adjustable Output Voltage
RP111x
VDD
RP111x
C1
C2
R2
CE
12
R1
VFB
1.0 µF
CE Control
VOUT
VOUT
GND
4.7 µF
RP111x
NO.EC-241-200630
TECHNICAL NOTES
Phase Compensation
In this device, phase compensation is made for securing stable operation even if the load current is varied. For
this purpose, use a 1.0 μF or more capacitor C2.
In case of using a tantalum capacitor, and its ESR is large, the output may be unstable. Therefore, select C2
carefully considering its frequency characteristics.
When using the Adjustable Output Voltage Type, set 4.7 μF or more of the output capacitor C2 as close as
possible to the device, and make wiring as short as possible.
PCB Layout
Make VDD and GND lines sufficient. If their impedance is high, noise pickup or unstable operation may result.
Connect a capacitor C1 with a capacitance value as much as 1.0 μF or more between VDD and GND pin, and
as close as possible to the pins.
Set external components, especially the output capacitor C2, as close as possible to the device, and make
wiring as short as possible (Refer to TYPICAL APPLICATIONS).
Transient Response
When using the Adjustable Output Voltage Type, the transient response could be affected by the external
resistors. Evaluate the circuit taking the actual conditions of use into account.
13
RP111x
NO.EC-241-200630
TYPICAL APPLICATION FOR IC CHIP BREAKDOWN PREVENTION
Internally Fixed Output Voltage
RP111N/H
VDD
VOUT
VOUT
RP111N/H
C1
C2
VFB
CE
D1
GND
CE Control
RP111S
VDD
VOUT
VOUT
RP111S
C1
C2
CE
D1
GND
CE Control
Externally Adjustable Output Voltage
RP111x
VDD
RP111x
C1
VOUT
VOUT
R1
C2
VFB
D1
R2
CE Control
CE
GND
When a sudden surge of electrical current travels along the VOUT pin and GND due to a short-circuit, electrical
resonance of a circuit involving an output capacitor (C2) and a short circuit inductor generates a negative
voltage and may damage the device or the load devices. Connecting a schottky diode (D1) between the VOUT
pin and GND has the effect of preventing damage to them.
14
RP111x
NO.EC-241-200630
ADJUSTABLE OUTPUT VOLTAGE SETTING
Output Voltage Setting
RP111x is capable of adjusting the output voltage by using the external divider resistors.
If the VFB voltage fixed in the device is described as setVFB, the output voltage can be set by using the following
formulas.
I1 = IIC + I2 ..................................................................................................................... (1)
I2 = setVFB / R2 .............................................................................................................. (2)
Thus,
I1 = IIC + setVFB / R2 ...................................................................................................... (3)
Therefore,
VOUT = setVFB + R1 x I1 .................................................................................................. (4)
Put formula (3) into formula (4), then
VOUT = setVFB + R1 x (IIC + setVFB / R2)
= setVFB x (1 + R1/R2) + R1 x IIC ........................................................................... (5)
In formula (5), R1x IIC is the error-causing factor in VOUT.
As for IIC,
IIC = setVFB / RIC ............................................................................................................. (6)
Therefore, the error-causing factor R1x IIC can be described as follows.
R1 x IIC = R1 x setVFB / RIC
= setVFB x R1 / RIC ............................................................................................ (7)
For better accuracy, choosing R1 (
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