NR110K series

Light Load High Efficiency, 31V, Buck Regulator
NR110K series
Sep./15/2015
Package
General Descriptions
The NR110K series is buck regulator ICs integrates
High-side power MOSFET. The feature increasing
efficiency at light loads allows the device to be used in
the energy-saving applications. 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 NR110K series is
available in an 8-pin HSOP8 package with an exposed
thermal pad on the back side.
Features & Benefits
 Up to 94% Efficiency,
Up to 77% Efficiency at IO = 20mA Light Load
 Adjustable “Over Current Protection（OCP）”
 Current mode PWM control
 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
 HSOP8
Thermally enhanced 8-Pin package
BS 1
IN 2
8
SS
7 EN
SW 3
6
ISET
GND 4
5
FB
Electrical Characteristics
 4A output current
 Operating input range VIN = 8V～31V
 Output adjustable VO= 0.8V～24V
 Fixed 350kHz frequency
Applications
 LCD TV / Blu-Ray / Set top box
 Home appliance
 Green Electronic products
 Other power supply
Typical Application Circuit
C1, C2: 10μF / 35V
C4, C5: 22μF / 16V
C7: 0.1μF
C3: 0.1μF
Rev.1.4
R1: 100kΩ
L1: 10μH
R3: 22Ω
D1: SJPW-T4(Sanken)
R4: 18kΩ, R5: 2.7kΩ (Vo=5.0V)
R6: 3.9kΩ
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1
Light Load High Efficiency, 31V, Buck Regulator
NR110K series
Sep./15/2015
Series Lineup
Product No.
fSW
VIN
VO
IO
(1)
NR110K
350kHz
8V to 31V
0.8V to 24V
The minimum input voltage shall be either of 8V or VO+3V, whichever is higher.
(2)
The I/O condition limited by the Minimum on-time (TON(MIN)).
(2)
4A
(1)
Absolute Maximum Ratings
Parameter
Symbol
Ratings
Units
DC input voltage
VIN
35
V
BS Pin voltage
VBS
44
V
BS-SW voltage
VBS-SW
SW Pin voltage
VSW
35
V
FB Pin voltage
VFB
5.5
V
EN Pin voltage
VEN
35
V
SS Pin voltage
VSS
5.5
V
8
DC
V
12
Power dissipation
(3)
PD
(1.69)
W
Junction temperature
(4)
TJ
40 to 150
°C
Pulse width ≦30ns
Glass-epoxy board mounting
in a 30×30mm.
(copper area in a 25×25mm)
Max TJ =150°C
Storage temperature
Thermal resistance
(junction- Pin No. 4)
TS
40 to 150
°C
θJP
(40)
°C /W
Thermal resistance
(junction-ambient air)
θJA
(74)
°C /W
(3)
(4)
Conditions
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
Symbol
(5)
Ratings
Units
MIN
MAX
VIN
Vo+3
31
V
Io
0
4.0
A
Vo
0.8
24
V
Conditions
(6)
DC output current
(7)
Output voltage
(7)
Ambient operating temperature
Top
85
°C
40
The minimum value of input voltage is taken as the larger one of either 8V or VO +3V.
(6)
Recommended circuit refers to Typical Application Circuit.
(7)
To be used within the allowable package power dissipation characteristics.
(5)
Electrical Characteristics
Parameter
Rev.1.4
Ta = 25°C
Symbol
Ratings
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Units
Test conditions
2
Light Load High Efficiency, 31V, Buck Regulator
NR110K series
Reference voltage
Output voltage temperature
coefficient
Switching frequency
Sep./15/2015
MIN
TYP
MAX
VREF
0.784
0.800
0.816
⊿VREF/⊿T
―
±0.05
―
fSW
(245)
350
(455)
V
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～31V, VO =5.0V,
mV
IO=1A
VIN=12V, VO=5.0V,
mV
IO=0.1A～2.0A
VIN =12V, VO =5.0V
ISET=OPEN
A
VIN =12V, VO =5.0V
ISET=SHORT
VIN = 12V
mA
VEN=10kΩ pull up to VIN
VIN =12V, IO =0A,
μA
VEN=0V
Line regulation
(8)
VLine
―
50
―
Load regulation
(8)
VLoad
―
50
―
IS1
―
(1.5)
―
IS2
―
(5.5)
―
IIN
―
1
―
IIN(off)
0
1
―
IEN/SS
6
10
14
μA
VSS=0V, VIN =12V
20
50
μA
VEN= 10V
1.4
2.1
V
VIN =12V
V
VIN =12V
Over current protection
threshold
Supply Current
Shutdown Supply Current
SS Pin
EN Pin
ISET Pin
Source current
at low level
voltage
Sink current
IEN
Threshold voltage
VC/EH
Open voltage
VISET
0.7
1.5
Max on-duty
(8)
DMAX
―
90
―
%
Minimum on-time
(8)
TON(MIN)
―
150
―
nsec
(8)
TSD
151
165
―
°C
(8)
TSD_hys
―
20
―
°C
Thermal shutdown threshold
temperature
Thermal shutdown
restart hysteresis
of temperature
(8)
Guaranteed by design, not tested.
Rev.1.4
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Light Load High Efficiency, 31V, Buck Regulator
NR110K series
Sep./15/2015
Typical Performance Characteristics
NR110K Typical Performance Characteristics
Efficiency
VO=3.3V
100
Efficiency
η [%]
90
80
70
VIN=12V
15V
18V
20V
24V
60
50
40
0.01
0.1
1
10
Output Current IO [A]
VO=5.0V
100
Efficiency
η [%]
90
80
VIN=12V
15V
18V
20V
24V
70
60
50
40
0.01
0.1
1
10
Output Current IO [A]
Rev.1.4
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Light Load High Efficiency, 31V, Buck Regulator
NR110K series
Sep./15/2015
NR110K Typical Performance Characteristics
Output
startup
NR114K UVLO
OCP.
OverNR110K/111K
Current Protection
Vo=5.0V
L=10uH
V =5.0V
7.0
6.5
6.0
5.5
5.0
4.5
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0.0
Output Voltage
Vo [V] VO [V]
VO[V]
Voltage [V]
Output
VO=5.0V,Vo=3.3V
Load =L=47uH
Constant Resistance
O
6.00
5.50
5.00
4.50
4.00
3.50
3.00
2.50
2.00
1.50
1.00
0.50
0.00
VIN=12V
15V
18V
20V
24V
0.0
4.0 4.5 5.0 5.5 6.0 6.5 7.0 7.5 8.0 8.5 9.0 9.5 10.0
1.0
2.0
fosc [kHz]
1.0
1.5
2.0
2.5
3.0
0.0
8.0
9.0
1.0
2.0
3.0
4.0
5.0
Supply Current : IIN
NR114K/115K,NR116K,NR117K IQ
IQ_off
VEN
=0V
VO=5.0V
5.0
0.35
Iin [mA]
Current [mA]
Supply
Current
ShutdownIinSupply
[mA]
[mA]
7.0
Output IoCurrent
IO [A]
[A]
Shutdown
Supply Current : I
NR110K,111K,114K,115K,116K,117KIN(off)
0.30
0.25
0.20
0.15
0.10
0.05
0.00
-0.05
4.5
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
-0.10
0.0
0.0
5.0
10.0
15.0
20.0
25.0
30.0
0.0
5.0
VIN[V]VIN [V]
Input Voltage
Rev.1.4
6.0
500
480
460
440
420
400
380
360
340
320
300
280
260
240
220
200
Output Current
IO [A]
Io [A]
0.40
5.0
Vo=3.3V
VL=10uH
O=5.0V
O
Switching frequency [kHz]
Vo [V]
Voltage [V]
Output
Vo=3.3V L=10uH
Ta=25℃
V =5.0V
0.5
4.0
Switching
Frequency:
fSW
NR110K
focs
NR116KLoadReg.
Load
Regulation: VLoad
0.0
3.0
Io [A] IO [A]
Output Current
VIN[V]
Input Voltage
VIN [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
ISET=GND
ISET=OPEN
10.0
15.0
20.0
25.0
30.0
Output Current
VIN[V] IO [A]
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Light Load High Efficiency, 31V, Buck Regulator
NR110K series
Sep./15/2015
Functional Block Diagram
Pin Assignments & Functions
BS 1
IN 2
8
SS
7 EN
SW 3
6
ISET
GND 4
5
FB
Pin Assignments
Pin Functions
Pin No.
Symbol
1
BS
2
IN
Rev.1.4
3
SW
4
GND
5
FB
6
ISET
7
EN
8
SS
Description
High-side Boost input.
BS supplies the drive for High-side Nch-MOSFET switch.
Connect a capacitor and a resistor between SW to BS.
Power input. IN 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.
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 ,R5and R6.
Adjust Pin of OCP starting current
OCP starting current can be adjusted by connecting a resistor to ISET Pin.
In the case of using at Maximum Io, ISET Pin is required to connect to GND.
Enable input.
Drive EN Pin high to turn on the regulator, low to turn it off.
Soft-Start control input.
To set the soft-start period, connect to a capacitor between GND.
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Light Load High Efficiency, 31V, Buck Regulator
NR110K series
Sep./15/2015
External Components Design Guide
(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), C7
・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.
・C7 is a capacitor for soft start. A soft-start controls the over-shoot of the output voltage rising and rush current.
(4)Resistor R1, R2
・R4, R5, R6 are resistor to the Output Voltage. IADJ is required to set to 0.2mA.
R4, R5, R6 are calculated by the equation (1).
R 4  R5 
VO  VFB  VO  0.8
I ADJ

0.2  10  3
 ， R 6 
VFB
0.8

≒ 4.0k 
I ADJ 0.2  10  3
------- (1)
In order to have optimum operating condition, each component must be connected with the minimum distance.
Rev.1.4
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Light Load High Efficiency, 31V, Buck Regulator
NR110K series
Sep./15/2015
Allowable package power dissipation
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 
V
PD  VO  I O 
 1  VF  I O 1  O
 x

 VIN




VO: Output voltage
VIN: Input voltage
IO: Output current
ηx: Efficiency(%)
VF: Diode forward voltage
SJPB-T4…0.55V(IO=3A)
Rev.1.4
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Light Load High Efficiency, 31V, Buck Regulator
NR110K series
Sep./15/2015
PCB Layout & Recommended Land Pattern
(1)Each ground of all components is connected as close as possible to the Pin No.1 at one point.
(2) To help heat dissipation, connect a large copper plane to exposed pad on the back side of the package.
The copper plane is required for GND
Front Side: Component Side (double sided board)
Back Side: GND Side (double sided board)
NOTES:
Real size of the PCB is 40mm×40mm
(Demo-board circuit-diagram)
Z1
C1, C2: 10μF / 35V
C3:0.1μF
C4, C5: 22μF / 16V
C6:Option
C7: 0.1μF
C9: Open
C10: Mount R9
C11:Option
C12:Option
Rev.1.4
R1:510kΩ
R2:Option
R3:22Ω
R4:18kΩ
R5:2.7kΩ (Vo=5.0V)
R6:3.9kΩ
R7:Open
R8:Option
R9:Adjust
R10:Option
L1: 10μH
D1:SJPW-T4(Sanken)
D2:Option
Z1：NR110K
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9
Light Load High Efficiency, 31V, Buck Regulator
NR110K series
Sep./15/2015
4.30
1.35
3.00
1.27
0.54
Unit: mm
2.80
Recommended land pattern
NOTES:
1) Dimension is in millimeters.
2) Drawing is not to scale.
Rev.1.4
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Light Load High Efficiency, 31V, Buck Regulator
NR110K series
Sep./15/2015
Package Outline
HSOP8 package
8
7
6
5
*1
NR110K
SK *2
*3
1
2
3
4
2.70
*1.Type number
*2.Lot number (three digit)
1st letter
The last digit of year
2nd letter
Month
1 to 9 for Jan. to Sept.,
O for Oct. N for Nov. D for Dec.
3rd letter
week
01～05：Arabic Numerical
*3.Control number (four digit)
PIN Assignment
1.BS
2.IN
3.SW
4.GND
5.FB
6.NC
7.EN
8.SS
Appearance
The body shall be clean and shall not bear any stain, rust or flaw.
Marking
The type number
Rev.1.4
and lot number shall be marked on the body by leaser
which shall not be unreadable easily.
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Light Load High Efficiency, 31V, Buck Regulator
NR110K series
Sep./15/2015
OPERATING PRECAUTIONS
Reliability can be affected adversely by improper storage environments and handling methods. Please observe the
following cautions.
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.1.4
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Light Load High Efficiency, 31V, Buck Regulator
NR110K series
Sep./15/2015
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.1.4
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