3A, 18V, Buck Regulator
NR120E series
eneral Descriptions
The NR120E series is buck regulator ICs integrates
High-side power MOSFET. With the current mode
control, ultra low ESR capacitors such as ceramic
capacitors can be used. The ICs have protection functions
such as Over-Current Protection (OCP), Under-Voltage
Lockout (UVLO) and Thermal Shutdown (TSD). An
adjustable Soft-Start by an external capacitor prevents the
excessive inrush current at turn-on. The ICs integrate
phase compensation circuit which reduces the number of
external components and simplifies the design of
customer application. The ON/OFF pin (EN Pin) turns
the regulator on or off and helps to achieve low power
consumption requirements. The NR120E series is
available in an 8-pin SOIC package with an exposed
thermal pad on the back side.
Nov./10/2015
Package
Exposed SOIC 8
Thermally enhanced 8-Pin package
Features & Benefits
Current mode PWM control
Up to 94% efficiency
Stable with low ESR ceramic output capacitors
Built-in protection function
Over Current Protection (OCP)
Thermal Shutdown (TSD)
Under Voltage Lockout (UVLO)
Built-in phase compensation
Adjustable Soft-Start with an external capacitor
Turn ON/OF the regulator function
Electrical Characteristics
3A output current
Operating input range V
IN
= 4.5V½18V
Output adjustable V
O
= 0.8V½14V
Fixed 350kHz frequency
Applications
LCD TV / Blu-Ray / Set top box
Green Electronic products
Other power supply
Typical Application Circuit
C1, C2: 10μF / 25V
C4, C5: 22μF / 16V
C7: 0.1μF
C3: 0.1μF
R1: 100kΩ
R3: 22Ω
R4: 8.2 kΩ, R5: 4.3kΩ (V
O
=3.3V)
R6: 3.9kΩ
D1: SJPB-L4(Sanken)
L1: 10μH
Rev.1.1
SANKEN ELECTRIC CO., LTD.
http://www.sanken-ele.co.jp
1
3A, 18V, Buck Regulator
NR120E series
Series Lineup
Product No.
f
SW
V
IN
V
O
(2)
Nov./10/2015
I
O
3A
(1)
NR121E
350kHz
4.5V to 18V
0.8V to 14V
(1)
The minimum input voltage shall be either of 4.5V or V
O
+3V, whichever is higher.
(2)
The I/O condition limited by the Minimum on-time (T
ON(MIN)
).
Absolute Maximum Ratings
Parameter
DC input voltage
Power dissipation
Junction temperature
Storage temperature
Thermal resistance
(junction- Pin No. 4)
Thermal resistance
(junction-ambient air)
(3)
(4)
(3)
Symbol
V
IN
P
D
T
J
T
S
θ
JP
θ
JA
Ratings
20
1.76
40
to 150
40
to 150
26
71
Units
V
W
°C
°C
°C /W
°C /W
Conditions
Glass-epoxy board mounting
in a 30×30mm.
(copper area in a 25×25mm)
Max T
J
=150°C
(4)
Glass-epoxy board mounting
in a 30×30mm.
(copper area in a 25×25mm)
Limited by thermal shutdown.
The temperature detection of thermal shutdown is about 160°C
Recommended Operating Conditions
Parameter
DC input voltage
DC output current
Output voltage
(5)
(6)
(7)
Symbol
V
IN
Io
Vo
Ratings
MIN
Vo+3
0
0.8
MAX
18
3.0
14
Units
V
A
V
Conditions
(7)
Ambient operating temperature
Top
85
°C
40
(5)
The minimum value of input voltage is taken as the larger one of either 4.5V or V
O
+ 3V.
In the case of V
IN
=V
O
+1½V
O
+3V , it is set to I
O
= Max. 2A
(6)
Recommended circuit refers to Typical Application Circuit.
(7)
To be used within the allowable package power dissipation characteristics
Rev.1.1
SANKEN ELECTRIC CO., LTD.
http://www.sanken-ele.co.jp
2
3A, 18V, Buck Regulator
NR120E series
Electrical Characteristics
Parameter
Reference voltage
Output voltage temperature
coefficient
Switching
NR121E
frequency
Line regulation
Load regulation
Over current protection
threshold
Supply Current
Shutdown Supply Current
Source current
at low level
voltage
High level
voltage
Sink current
Threshold voltage
(8)
(8)
(8)
Nov./10/2015
Ta = 25°C
Symbol
V
REF
⊿V
REF
/⊿T
f
SW
V
Line
V
Load
I
S
I
IN
I
IN(off)
I
EN/SS
V
SSH
I
EN
V
C/EH
D
MAX
T
ON(MIN)
0.7
―
―
151
―
Ratings
MIN
0.784
―
280
―
―
3.1
―
0
6
―
TYP
0.800
±0.05
350
50
50
―
6
―
10
3.0
50
1.4
90
150
165
20
MAX
0.816
―
420
―
―
6.0
―
10
14
―
100
2.1
―
―
―
―
Units
V
Test conditions
(8)
V
IN
= 12V，I
O
= 1.0A
V = 12V, I
O
= 1.0A
mV/°C
IN
40°C
to +85°C
V
IN
=12V, V
O
=3.3V,
kHz
I
O
=1A
V
IN
= 6.3V½18V,
mV
V
O
= 3.3V, I
O
= 1A
V
IN
= 12V, V
O
= 3.3V,
mV
I
O
= 0.1A½3.0A
A
mA
μA
μA
V
μA
V
%
nsec
°C
°C
V
IN
= 12V, V
o
= 3.3V
V
IN
= 12V
V
EN
=10kΩ pull up to V
IN
V
IN
=12V, I
O
=0A,
V
EN
=0V
V
SS
=0V, V
IN
=12V
V
IN
=12V
V
EN
= 10V
V
IN
=12V
SS Pin
EN Pin
Max on-duty
Minimum on-time
NR121E
(9)
Thermal shutdown threshold
(8)
TSD
temperature
Thermal shutdown
(8)
restart hysteresis
TSD_hys
of temperature
(8)
Guaranteed by design, not tested.
(9)
The I/O characteristic are limited by the T
ON(MIN)
.
Rev.1.1
SANKEN ELECTRIC CO., LTD.
http://www.sanken-ele.co.jp
3
3A, 18V, Buck Regulator
NR120E series
Typical Performance Characteristics
NR121E Typical Performance Characteristics
Efficiency
Nov./10/2015
V
O
= 3.3V, L=10uH
100
95
Efficiency [%]
90
85
80
75
70
VIN=8V
VIN=12V
VIN=18V
65
60
0
0.5
1
1.5
2
Output Current : Io [A]
2.5
3
V
O
= 5V, L=10uH
100
95
Efficiency [%]
90
85
80
75
70
VIN=8V
VIN=12V
VIN=18V
65
60
0
0.5
1
1.5
2
Output Current : Io [A]
2.5
3
Rev.1.1
SANKEN ELECTRIC CO., LTD.
http://www.sanken-ele.co.jp
4
3A, 18V, Buck Regulator
NR120E series
NR121E Typical Performance Characteristics
Output startup
V
O
=3.3V, Load = Constant Resistance, I
O
=0.5A
4
Nov./10/2015
Over Current Protection
V
O
=3.3V
4
Output Voltage Vo [V]
3.5
3
2.5
Output Voltage Vo [V]
3
2
2
1.5
1
1
0
0.5
0
3
3.5
4
4.5
5
5.5
6
VIN=8V
VIN=12V
VIN=16V
0
1
2
3
4
5
Input Voltage : V
IN
[V]
Output Current : Io [A]
Load Regulation
V
O
=3.3V
Switching Frequency [kHz]
3.35
400
390
380
370
360
350
340
Switching Frequency
V
O
=3.3V
VIN=8V
Output Voltage Vo [V]
3.33
3.31
3.29
3.27
3.25
0
1
2
VIN=12V
VIN=18V
VIN=8V
VIN=12V
VIN=18V
330
320
310
300
0
1
2
3
3
Output Current : Io [A]
Output Current : Io [A]
Shutdown Supply Current
10.0
Supply Current
7.0
V
EN
=0V
Supply Current [mA]
V
O
=3.3V
Shutdown Supply Current
[μA]
9.0
8.0
7.0
6.0
5.0
4.0
6.0
5.0
4.0
3.0
2.0
3.0
2.0
1.0
0.0
0
2
4
6
8
10
12
14
16
18
1.0
0.0
0
2
4
6
8
10
12
14
16
18
Input Voltage : V
IN
[V]
Input Voltage : V
IN
[V]
Rev.1.1
SANKEN ELECTRIC CO., LTD.
http://www.sanken-ele.co.jp
5
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