nr131s ds en

Ultra light load high efficiency,VIN=17V,Current mode Step-down Io=3A Buck Regulator IC
NR131S
Jul./09/2015
General Descriptions
Package
The NR131S is buck regulator ICs integrates High-side
power MOSFETs. With the current mode control, ultra
low ESR capacitors such as ceramic capacitors can be
used. The ICs can realize super-high efficiency by
performing pulse skip operation at light load condition.
The ICs have protection functions such as Over-Current
Protection (OCP), Under-Voltage Lockout (UVLO) and
Thermal Shutdown (TSD). Soft starting time can be set
up by selecting an external capacitor value. The ON/OFF
pin (EN Pin) turns the regulator on or off and helps to
achieve low power consumption requirements. The
NR131S is available in an 8-pin SOIC package.
 SOIC8
Features & Benefits





Current mode PWM control
Up to 94% efficiency at normal load condition
Up to 85% efficiency at light load condition
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/OFF the regulator function
Programable Pulse-Skip operation
Electrical Characteristics




3A Continuous output current
Operating input range VIN = 4.5V~17V
Output adjustable VO = 0.8V~14V
Fixed 350kHz frequency
Applications
 LCD TV / Blue-ray / Set top box
 Green electronic products
 Other power supply
Typical Application Circuit
NR131S
C1, C2: 10μF / 25V, C4, C5: 22μF / 16V, C7: 0.1μF, C9:1800pF, C11: 220pF(Option), R1: 510kΩ , R3: 10Ω, R4: 36 kΩ, R5: 27kΩ
(VO=5.0V), R6: 12kΩ, R7:510kΩ(Option), D1: SJPJ-L4, L1: 10μH
Rev.2.0
SANKEN ELECTRIC CO., LTD.
http://www.sanken-ele.co.jp
1
Ultra light load high efficiency,VIN=17V,Current mode Step-down Io=3A Buck Regulator IC
NR131S
Jul./09/2015
Series Lineup
Product
Name
fSW
VIN
VO
Pin No.1
Function
IO
Pin No.2
Function
Package
4.5V to
0.8V to
(1)
(2)
3A
NC
IN
17V
14V
(1)
The minimum input voltage shall be either of 4.5V or VO+3V, whichever is higher.
(2)
The I/O condition limited by the Minimum on-time (TON(MIN)).
NR131S
350kHz
SOIC8
Absolute Maximum Ratings
Parameter
Symbol
Ratings
Units
DC input voltage
VIN
0.3~19
V
BS terminal voltage
VBS
0.3~25
V
BS-SW Pin voltage
VBS-SW
SW terminal voltage
VSW
FB terminal voltage
VFB
0.3~5.5
V
EN terminal voltage
VEN
0.3~19
V
SS terminal voltage
VSS
0.3~7.4
V
SS terminal allowable input current
Issb
5
mA
-0.3~6.0
V
0.3~7.5
2~19
V
4.5~19
Power dissipation
(3)
PD1
1.42
W
Junction temperature
(4)
TJ
40 ~ 150
°C
TS
40 ~ 150
°C
Storage temperature
Thermal resistance
θJP
60.8
(junction- Pin No. 4)
Thermal resistance
θJA
88.2
(junction-ambient air)
(3)
Limited by thermal shutdown.
(4)
The temperature detection of thermal shutdown is about 165°C
Conditions
DC
Pulse width ≦30ns
DC
Pulse width ≦30ns
Glass-epoxy board mounting
in a 40×40mm.
(copper area in a 25×25mm)
Max TJ =150°C
°C /W
°C /W
Glass-epoxy board mounting
in a 40×40mm.
(copper area in a 25×25mm)
Recommended Operating Conditions
Parameter
DC input voltage
Symbol
(5)
Ratings
Units
MIN
MAX
VIN
Vo+3
17
V
IO
0
3.0
A
VO
0.8
14
V
Conditions
(6)
DC output current
(7)
Output voltage
Ambient operating temperature
TOP
85
°C
40
The minimum value of input voltage is taken as the larger one of either 4.5V or VO +3V.
In the case of VIN=VO +1~VO +3V , it is set to IO = Max. 2A
(6)
Recommended circuit refers to Typical Application Circuit.
(7)
To be used within the allowable package power dissipation characteristics.
(7)
(5)
Rev.2.0
SANKEN ELECTRIC CO., LTD.
http://www.sanken-ele.co.jp
2
Ultra light load high efficiency,VIN=17V,Current mode Step-down Io=3A Buck Regulator IC
NR131S
Jul./09/2015
Electrical Characteristics
Ta = 25°C
Parameter
Symbol
Reference voltage
VREF
Output voltage temperature
coefficient
Ratings
MIN
TYP
MAX
0.780
0.800
0.820
⊿VREF/⊿T
Switching frequency
fSW
±0.05
245
350
Line regulation
(8)
VLine
10
Load regulation
(8)
VLoad
70
Over current protection
threshold
Supply Current(Non-switching)
IS
Shutdown Supply Current
Input Under Voltage Lockout
threshold
SS Pin
EN Pin
Rev.2.0
IIN
100
μA
VIN= 12V, VEN=12V
IIN(off)
1
μA
VIN=12V, VEN=0V
Vuvlo
3.9
4.4
V
VIN Rising
22
31
μA
VSS=0V, VIN=12V
5
10
μA
VEN= 12V
1.3
2.1
V
VIN=12V
IEN
Minimum on-time
Thermal shutdown threshold
temperature
Thermal shutdown restart
hysteresis of temperature
(8)
Guaranteed by design,not tested.
VIN = 12V,Io = 1.0A
V = 12V, Io = 1.0A
mV/°C IN
40°C to +85°C
VIN=12V, Vo=5.0V,
kHz
Io=1A
VIN = 8V~17V,
mV
Vo = 5.0V, Io = 1A
VIN = 12V, Vo = 5.0V,
mV
Io = 0.1A~2.0A
VIN = 12V, Vo = 5.0V
Sink current
Max on-duty
V
A
ISS
Threshold voltage
Test conditions
4.5
Charging current
VEN
3.1
455
Units
13
0.7
(8)
DMAX
90
%
VIN=12V
(8)
TON(MIN)
170
nsec
VIN=12V
(8)
TSD
165
°C
VIN=12V
(8)
TSD_hys
15
°C
VIN=12V
151
SANKEN ELECTRIC CO., LTD.
http://www.sanken-ele.co.jp
3
Ultra light load high efficiency,VIN=17V,Current mode Step-down Io=3A Buck Regulator IC
NR131S
Jul./09/2015
Typical Performance Characteristics
NR131S typical Performance Characteristics
(1)Efficiency
Condition: VO=3.3V
100
90
Ffficiency
η [%]
80
70
60
50
0.001
0.01
Vin=6V
Vin=8V
Vin=10V
Vin=12V
Vin=14V
Vin=16V
0.1
Output Current
1
10
IO [A]
Condition:VO=5.0V
100
Efficiency η [%]
90
80
70
60
50
0.001
0.01
Vin=6V
Vin=8V
Vin=10V
Vin=12V
Vin=14V
Vin=16V
0.1
1
10
Output Current IO [A]
Rev.2.0
SANKEN ELECTRIC CO., LTD.
http://www.sanken-ele.co.jp
4
Ultra light load high efficiency,VIN=17V,Current mode Step-down Io=3A Buck Regulator IC
NR131S
Jul./09/2015
(5)Over Current Protection
Output Voltage
VO [V]
(2) Output startup Io=1A
6
6
5
5
4
4
3
3
2
2
1
1
0
Vin=8[V]
Vin=12[V]
Vin=16[V]
0
3.0
3.5
4.0
4.5
5.0
5.5
6.0
6.5
7.0
1
2
3
(3) Load Regulation : VLoad
8
6
7
6
Input Current
Iin [mA]
Output Voltage
[V]
VVo
O [V]
5.300
5.250
5.200
5.150
5.100
5.050
5.000
4.950
4.900
4.850
4.800
4.750
4.700
5
4
3
2
1
0.0
0.5
1.0
1.5
2.0
2.5
0
3.0
0
3
6
9
12
15
Input Voltage VIN [V]
Io [A] IO [A]
Output Current
(4) Shutdown Supply Current : IIN(off)
NR110K focs
Vo=3.3V L=10uH
0.35
fOSC [kHz]
0.30
frequency
fosc [kHz]
0.25
0.20
0.15
0.10
0.05
0.00
-0.05
-0.10
0.0
5.0
10.0
15.0
20.0
25.0
18
(7) Switching Frequency: fSW
NR110K,111K,114K,115K,116K,117K
VENIQ_off
=0V
0.40
Input Current
Iin [mA]
Iin [mA]
5
(6) Supply Current : IIN
VO=5.0V
Supply Current : IIN
NR116KLoadReg.
Vo=3.3V L=10uH Ta=25℃
30.0
500
480
460
440
420
400
380
360
340
320
300
280
260
240
220
200
0.0
1.0
2.0
3.0
4.0
5.0
Io [A] Current
Output
IO [A]
Input
Voltage
VIN[V]
VIN [V]
Rev.2.0
4
Output Current IO [A]
Input Voltage VIN [V]
SANKEN ELECTRIC CO., LTD.
http://www.sanken-ele.co.jp
5
Ultra light load high efficiency,VIN=17V,Current mode Step-down Io=3A Buck Regulator IC
NR131S
Jul./09/2015
Functional Block Diagram
2
6
EN
ON/
OFF
P.REG
VREF
Current
Sense
Amp
OCP
Σ
OSC
3.5V
IN
8
Drive
REG
BS
BS
DET
0.8V
PWM
LOGIC
3
SW
Compensation
SKIP
1
5
Err Amp
NC
FB
3.5V
Threshold
Select
TSD
UVLO
GND
4
22uA
SS
0.8V
INIT
SS
7
NR131S
Rev.2.0
SANKEN ELECTRIC CO., LTD.
http://www.sanken-ele.co.jp
6
Ultra light load high efficiency,VIN=17V,Current mode Step-down Io=3A Buck Regulator IC
NR131S
Jul./09/2015
Pin Asignments & Functions
Pin Assignments
Pin assignments & functions of NR131S
Pin No.
1
2
Symbol
NC
IN
3
SW
4
GND
5
FB
6
EN
7
SS
8
BS
Rev.2.0
Description
No Connection.(NC)
Power input. VIN supplies the power to the IC.as well as the regulator switches
Power switching output.
SW supplies power to the output.
Connect the LC filter from SW to the output.
Connect a Schottky Barrier Diode between SW and GND.
Note that a capacitor is required from SW to BS to supply the power the High-side
switch
Ground
Connect the exposed pad to Pin No.4
Feedback input Pin to compare Reference Voltage. The feedback threshold is 0.8V.
To set the output voltage, FB Pin is required to connect between resistive voltage
divider R4 and R6.
Enable input.
Drive EN Pin high to turn on the regulator, low to turn it off.
Soft-Start and SKIP operation control input.
To set the soft-start period, connect to a capacitor between GND.
To set the Low Ripple SKIP operation, add the resister 510k ohm between SS terminal
and IN terminal.
High-side Boost input.
BS supplies the drive for High-side Nch-MOSFET switch.
Connect a capacitor and a resistor between SW to BS.
SANKEN ELECTRIC CO., LTD.
http://www.sanken-ele.co.jp
7
Ultra light load high efficiency,VIN=17V,Current mode Step-down Io=3A Buck Regulator IC
NR131S
Jul./09/2015
Example Application Circuit
NR131S
C1, C2: 10μF / 25V, C4, C5: 22μF / 16V, C7: 0.1μF, C9:1800pF, C11: 220pF(Option), R1: 510kΩ , R3: 10Ω, R4: 36 kΩ, R5: 27kΩ
(VO=5.0V), R6: 12kΩ, R7:510kΩ(Option), D1: SJPJ-L4, L1: 10μH
A design guide for add-on parts around of the NR131S.
(1)Diode D1
・The schottky-barrier diode must be used for D1. If other diodes like fast recovery diodes are used, IC may be
damaged because of the reverse voltage applied by the recovery voltage or ON voltage.
(2)Choke coil L1
・If the winding resistance of the choke coil is too high, the efficiency may go down to the extent that it is out of the rating.
・As the start current of the over current protection is approximately 4A, attention must be paid to the heating of the choke
coil by the magnetic saturation due to overload or short-circulated load.
(3)Capacitor C1( C2), C4(C5), C9
・As large ripple current across C1 (C2) and C4 (C5), capacitors with high frequency and low impedance for SMPS must be
used. Especially when the impedance of C4 (C5) is high, the switching waveform may not be normal at low temperature.
・C9 is a capacitor for soft start. In case soft start function is not used, please keep Pin No.2 open.
(4)Resistor R1, R2
・R4, R5, R6 are resistor to the Output Voltage. In case of the I(ADJ) = 66μA, R4, R5, R6 are calculated by the next
equation .
μ
Ω
Ω
Ω
*63kΩ= 27kΩ+36kΩ
In order to have optimum operating condition, each component must be connected with the minimum distance.
Rev.2.0
SANKEN ELECTRIC CO., LTD.
http://www.sanken-ele.co.jp
8
Ultra light load high efficiency,VIN=17V,Current mode Step-down Io=3A Buck Regulator IC
NR131S
Jul./09/2015
Allowable package power dissipation
1.4
許容損失PD[W]
Power Dissipation
1.2
1.0
0.8
0.6
0.4
0.2
0.0
-25
0
25
50
75
100
125
周囲温度 Ta[℃ ]
Ambient Temperature
Allowable package powe disspation of NR131S
NOTES:
1) Glass-epoxy board mounting in a 30×30mm
2) copper area : 25×25mm
3) The power dissipation is calculated at the junction temperature 125 °C
4) Losses can be calculated by the following equation.
As the efficiency is subject to the input voltage and output current, it shall be obtained from the efficiency curve and
substituted in percent
5) Thermal design for D1 shall be made separately.
 100

PD  VO  I O 
 1 ・・・(1)
 x

VO: Output voltage
VIN : Input voltage
IO : Output current
ηx : Efficiency (%)
Vf: SJPB-L4 Io=3A/Vf=0.55V
Diode forward voltage (A to K)
Rev.2.0
SANKEN ELECTRIC CO., LTD.
http://www.sanken-ele.co.jp
9
Ultra light load high efficiency,VIN=17V,Current mode Step-down Io=3A Buck Regulator IC
NR131S
Jul./09/2015
PCB layout recommendation
*The demonstration Printed circuit board. It can mount a part for the experiment ,except for the Example Application Circuit.
*This pattern layout is for NR131A/NR131S.
Front Side: Component Side (double sided board)
PCB レイアウト裏面: GND 面(両面基板)
Back Side: GND Side (double sided board)
Note
1) Size of the PCB is about 40mm × 40mm
2)Dimension is in millimeters, dimension in bracket is in inches.
3) Drawing is not to scale.
Recommended land pattern
Rev.2.0
SANKEN ELECTRIC CO., LTD.
http://www.sanken-ele.co.jp
10
Ultra light load high efficiency,VIN=17V,Current mode Step-down Io=3A Buck Regulator IC
NR131S
Jul./09/2015
Package outline, dimensions
SOIC8 package (Units:mm)
8
1
6
7
2
3
5
4
Bottom view
Top view
Marking
*1. Product number
NR131S
*2. Lot number (three digit)
1st letter : The last digit of the year
2nd letter : Month
January to September : 1 to 9
October : O
November : N
December : D
3rd letter : manufacturing week
First week to 5th week : 1 to 5
*3. Control number (four digit)
Symbol
A1
A2
b
D
E
E1
e
L
*1
Dimension is in millimeters(mm)
MIN
TYP
MAX
0.05
0.15
0.25
1.25
1.40
1.65
0.38
0.51
-
4.80
4.90
5.00
5.80
6.00
6.20
3.80
3.90
4.00
1.27
-
-
0.45
0.6
0.8
NR131S
SK *2
*3
Rev.2.0
SANKEN ELECTRIC CO., LTD.
http://www.sanken-ele.co.jp
11
Ultra light load high efficiency,VIN=17V,Current mode Step-down Io=3A Buck Regulator IC
NR131S
Jul./09/2015
OPERATING PRECAUTIONS
Reliability can be affected adversely by improper storage environments and handling methods. Please observe the
following cautions.
Heat dissipation and reliability
Thermal performance of the surface mo unt package IC depends on the material and area size of PCB and its copper
plane. Design thermal condition with sufficient margin
Parallel operation
The parallel operation to increase the current is not available.
Thermal shut down
The NR131S has a thermal protection circuit.
This circuit protects the IC from the heat generation by the over load.
This circuit cannot guarantee the long-term reliability against the continuously over load status.
Cautions for Storage
 Ensure that storage conditions comply with the standard temperature (5 to 35°C) and the standard relative humidity
(around 40 to 75%); avoid storage locations that experience extreme changes in temperature or humidity.
 Avoid locations where dust or harmful gases are present and avoid direct sunlight.
 Reinspect for rust on leads and solderability of products that have been stored for a long time.
Cautions for Testing and Handling
 When tests are carried out during inspection testing and other standard test periods, protect the products from power
surges from the testing products, shorts between the product pins, and wrong connections. In addition, avoid tests
exceeded ratings
Soldering
When soldering the products, please be sure to minimize the working time, within the following limits.
・Reflow Preheat ; 180°C / 90±30s
Heat ; 250°C / 10±1s (260°C peak ,2times)
・Soldering iron ; 380±10°C / 3.5±0.5s (1time)
Electrostatic Discharge
 When handling the products, the operator must be grounded. Grounded wrist straps worn should have at least 1MΩ of
resistance from the operator to ground to prevent shock hazard, and it should be placed near the operator.
 Workbenches where the products are handled should be grounded and be provided with conductive table and floor mats.
 When using measuring equipment such as a curve tracer, the equipment should be grounded.
 When soldering the products, the head of a soldering irons or the solder bath must be grounded in order to prevent leak
voltages generated by them from being applied to the products.
 The products should always be stored and transported in Sanken shipping containers or conductive containers, or be
wrapped in aluminum foil.
Rev.2.0
SANKEN ELECTRIC CO., LTD.
http://www.sanken-ele.co.jp
12
Ultra light load high efficiency,VIN=17V,Current mode Step-down Io=3A Buck Regulator IC
NR131S
Jul./09/2015
IMPORTANTS NOTES
 The contents in this document are subject to changes, for improvement and other purposes, without notice.
Make sure that this is the latest revision of the document before use.
 Application and operation examples described in this document are quoted for the sole purpose of reference for
the use of the products herein and Sanken can assume no responsibility for any infringement of industrial
property rights, intellectual property rights or any other rights of Sanken or any third party which may result
from its use.
 Although Sanken undertakes to enhance the quality and reliability of its products, the occurrence of failure and
defect of semiconductor products at a certain rate is inevitable. Users of Sanken products are requested to take,
at their own risk, preventative measures including safety design of the equipment or systems against any
possible injury, death, fires or damages to the society due to device failure or malfunction.
 Sanken products listed in this document are designed and intended for the use as components in general purpose
electronic equipment or apparatus (home appliances, office equipment, telecommunication equipment,
measuring equipment, etc.).
When considering the use of Sanken products in the applications where higher reliability is required
(transportation equipment and its control systems, traffic signal control systems or equipment, fire/crime alarm
systems, various safety devices, etc.), please contact your nearest Sanken sales representative to discuss, prior to
the use of the products herein.
The use of Sanken products without the written consent of Sanken in the applications where extremely high
reliability is required (aerospace equipment, nuclear power control systems, life support systems, etc.) is strictly
prohibited.
 In the case that you use Sanken semiconductor products or design your products by using Sanken
semiconductor products, the reliability largely depends on the degree of derating to be made to the rated values.
Derating may be interpreted as a case that an operation range is set by derating the load from each rated value or
surge voltage or noise is considered for derating in order to assure or improve the reliability. In general, derating
factors include electric stresses such as electric voltage, electric current, electric power etc., environmental
stresses such as ambient temperature, humidity etc. and thermal stress caused due to self-heating of
semiconductor products. For these stresses, instantaneous values, maximum values and minimum values must
be taken into consideration.
In addition, it should be noted that since power devices or IC’s including power devices have large self-heating
value, the degree of derating of junction temperature affects the reliability significantly.
 When using the products specified herein by either (i) combining other products or materials therewith or (ii)
physically, chemically or otherwise processing or treating the products, please duly consider all possible risks
that may result from all such uses in advance and proceed therewith at your own responsibility.
 Anti radioactive ray design is not considered for the products listed herein.
 Sanken assumes no responsibility for any troubles, such as dropping products caused during transportation out
of Sanken’s distribution network.
 The contents in this document must not be transcribed or copied without Sanken’s written consent.
Rev.2.0
SANKEN ELECTRIC CO., LTD.
http://www.sanken-ele.co.jp
13