LR1117C

LESHAN RADIO COMPANY, LTD.
LR1117C
1A Low Dropout Voltage Regulator
Outline：
：
Features：
：
LR1117C is aseries of low dropout threeterminal regulators with a dropout of 1.2V at
1A load current.
Other than a fixed version（Vout＝
1.8V,2.5V,2.85V,3.3V,5V）, LR1117C has an
adjustable version, which can provide an
output voltage from 1.25 to 13.8V with only
two external resistors。
LR1117C offers thermal shut down and
current limit functions, to assure the stability
of chip and power system. And it uses
trimming technique to guarantee output
voltage accuracy within ±2％.
LR1117C is available in SOT-223,TO-252
and TO-220 power package。
•
Other than a fixed version and an
adjustable version, output value can be
customized on command.
•
•
•
Maximum output current is 1A
Output voltage accuracy is within ±1％
Range of operation input voltage: Max
15V
•
•
•
Line regulation: 0.2％
Load regulation: 0.4％
Environment Temperature: -50℃~140℃
Applications：
：
•
•
•
•
•
Power Management for Computer
Mother Board, Graphic Card
LCD Monitor and LCD TV
DVD Decode Board
ADSL Modem
Post Regulators for Switching Supplies
Block Diagrams：
：
3
VIN
TSD
Current
Limit
VOUT
BandGap
2
Fixed: F1 and F2 connect, disconnect A
F1
F2
A
Adj: A connect, F1 and F2 disconnect
1
ADJ/GND
1/13
LESHAN RADIO COMPANY, LTD.
Pin Description：
：
Fixed Version
Pin No.
1
2
3
Symbol
GND
Vout
Vin
Definition
Ground
Output
Input
Adjustable Version
Pin No.
1
2
3
Symbol Definition
Adj.
Adjustable
Vout
Output
Vin
Input
Ordering Information:
Package Marking
LR1117CS18X
LR1117CS25X
LR1117CS285
LR1117CS33X
LR1117CS5X
LR1117CSX
LR1117CD18X
LR1117CD25X
LR1117CD285
LR1117CD33X
LR1117CD5X
LR1117CDX
LR1117CT18X
LR1117CT25X
LR1117CT285
LR1117CT33X
LR1117CT5X
LR1117CTX
Output Voltage
1.8 V
2.5 V
2.85V
3.3 V
5.0V
Adj.
1.8 V
2.5 V
2.85V
3.3 V
5.0V
Adj.
1.8 V
2.5 V
2.85V
3.3 V
5.0V
Adj.
Package Type
SOT-223
SOT-223
SOT-223
SOT-223
SOT-223
SOT-223
TO-252
TO-252
TO-252
TO-252
TO-252
TO-252
TO-220
TO-220
TO-220
TO-220
TO-220
TO-220
2/13
LESHAN RADIO COMPANY, LTD.
Absolute Maximum Ratings：
：
Maximum Input Voltage --------------------------------------------------------------------------18V
Junction Temperature (TJ) -----------------------------------------------------------------------150°C
Environment Temperature (TA) -----------------------------------------------------------------140°C
Storage Temperature (Ts) ------------------------------------------------------------------------65～150°C
Lead Temperature and Time --------------------------------------------------------------------260°C,10S
Recommended Work Conditions：
：
Item
Input Voltage Range
Environment Temperature
Min
Recommended
-50
Max
15
140
Unit
V
°C
Electrical Characteristics (Table 1)：
：
Tj=25℃
Symbol
Vref
Vout
Parameter
Reference
Voltage
Output
Voltage
Conditions
Min
Typ
Max
Unit
Iout=10mA, Vin-Vout=2V
10mA≤Iout≤1A ,1.5V≤Vin-Vout≤12V
1.238
1.225
1.25
1.25
1.262
1.275
V
LR1117-1.80V
Iout=10mA,Vin=3.8V,Tj=25℃
0≤Iout≤1A ,3.2V≤Vin≤12V
1.782
1.764
1.80
1.80
1.818
1.836
V
LR1117-2.5V
Iout=10mA,Vin=4.5V,Tj=25℃
0≤Iout≤1A ,3.9V≤Vin≤12V
2.475
2.45
2.5
2.5
2.525
2.55
V
LR1117-2.85V
Iout=10mA,Vin=4.85V,Tj=25℃
0≤Iout≤1A ,4.25V≤Vin≤12V
2.822
2.793
2.85
2.85
2.878
2.907
V
LR1117-3.3V
Iout=10mA,Vin=5V,Tj=25℃
0≤Iout≤1A ,4.75V≤Vin≤12V
3.267
3.234
3.3
3.3
3.333
3.366
V
4.95
4.9
5
5
5.05
5.1
V
0.035
0.2
%
LR1117-1.8V
Iout=10mA,3.2V≤Vin≤15V
9
12
mV
LR1117-2.5V
Iout=10mA,3.9V≤Vin≤15V
9
12
mV
LR1117-2.85V
Iout=10mA,4.25V≤Vin≤15V
9
12
mV
LR1117-5V
Iout=10mA,Vin=7V,Tj=25℃
0≤Iout≤1A ,6.5V≤Vin≤12V
∆Vout
Line
Regulation
(note1)
LR1117-ADJ
Iout=10mA,1.5V≤Vin-Vout≤13.775V
3/13
LESHAN RADIO COMPANY, LTD.
LR1117-3.3V
Iout=10mA,4.75V≤Vin≤15V
9
12
mV
LR1117-5V
Iout=10mA,6.5V≤Vin≤15V
9
12
mV
0.2
0.4
%
LR1117-1.8V
Vin=3.2V, 0≤Iout≤1A
3
10
mV
LR1117-2.5V
Vin=3.9V, 0≤Iout≤1A
3
10
mV
LR1117-2.85V
Vin=4.25V, 0≤Iout≤1A
3
10
mV
LR1117-3.3V
Vin=4.75V, 0≤Iout≤1A
3
10
mV
LR1117-5V
Vin=6.5V, 0≤Iout≤1A
3
10
mV
∆Vout, ∆Vref =1%，Iout=100mA
1.11
1.2
V
∆Vout, ∆Vref,=1%，Iout=500mA
1.18
1.25
V
∆Vout, ∆Vref,=1%，Iout=1A
1.26
1.3
V
1.4
1.6
A
LR1117-ADJ
5
10
mA
LR1117-1.8V,Vin-Vout=1.25V
4
8
mA
LR1117-2.5V, Vin-Vout=1.25V
4
8
mA
LR1117-ADJ
Vin-Vout=3V, 10mA≤Iout≤1A
∆Vout
Vin-Vout
Load
Regulation
(note1, 2)
Dropout
Voltage
（note3）
Current Limit
Vin-Vout=2V, Tj=25℃
1.25
Ilimit
Minimum
Load Current
（note4）
Iq
Quiescent
Current
4/13
LESHAN RADIO COMPANY, LTD.
LR1117-2.85V, Vin-Vout=1.25V
4
8
mA
LR1117-3.3V, Vin-Vout=1.25V
4
8
mA
LR1117-5V, Vin-Vout=1.25V
4
8
mA
IAdj
Adjust Pin
Current
(Adjustable
Version)
55
120
uA
Ichange
Adjust Pin
Current
Change
0.2
Temperature
Stability
θJC
Thermal
Resistor
uA
0.5
SOT-223
20
TO-252
10
TO-220
4.5
%
℃/W
Note：
：
Note1：The Parameters of Line Regulation and Load Regulation in Table1 are tested under
constant junction temperature. The Curve of Load Regulation vs. Temperature is
shown in typical parameter curve that follows.
Note2： When Iout varies between 0~1A,Vin-Vout varies between 1.5V~12V under constant
junction temperature，the parameter is satisfied the criterion in table. If temperature
varies between -50℃≤TA≤140℃，it needs output current to be larger than 10mA to
satisfy the criterion.
Note3：Dropout Voltage is specified over the full output current range of the device, and it is
tested under following testing conditions: First step is to find out the Vout value(Vout1)
when Vin1=Vout+1.5V, second step is to decrease Vin(Vin2) until Vout value is equal
to 99%*Vout1(Vout2). Vdropout=Vin2-Vout2.
Note4：Minimum Load Current is defined as the minimum output current required to maintain
regulation. When 1.5V≦Vin-Vout≦12V，the device is guaranteed to regulate if the
output current is greater than 10mA.
Detailed Description:
LR1117C is a series of low dropout voltage, three terminal regulators. Its application circuit is
very simple: the fixed version only needs two capacitors and the adjustable version only needs two
resistors and two capacitors to work. It is composed of some modules including start-up circuit,
bias circuit, bandgap, thermal shutdown, current limit, power transistors and its driver circuit and so
on.
The thermal shut down and current limit modules can assure chip and its application system
working safety when the junction temperature is larger than 140℃ or output current is larger than
1.4A.
5/13
LESHAN RADIO COMPANY, LTD.
The bandgap module provides stable reference voltage, whose temperature coefficient is
compensated by careful design considerations. The temperature coefficient is under 100ppm/℃.
And the accuracy of output voltage is guaranteed by trimming technique,
Typical Application ：
LR1117C has an adjustable version and five fixed versions, Chart1 is its typical application：
LR1117C
Chart 1: Application circuit of LR1117C fixed version
Application Hints：
：
1.
2.
3.
Recommend using 10uF tan capacitor as bypass capacitor(C1) for all application circuit.
Recommend using 22uF tan capacitor to assure circuit stability.
Using a bypass capacitor(CAdj) between the adjust terminal and ground can improve ripple
rejection, This bypass capacitor prevents ripple from being amplified as the output voltage
is increased. The impedance of CAdj should be less than the resistor’s(R1) which is
between output and adjust pins to prevent ripple from being amplified at any ripple
frequency. As R1 is normally in the range of 200Ω~350Ω,the value of CAdj should satisfy
this equation: 1/(2π*Fripple*Cadj)<R1. Recommend using 10uF tan capacitor.
Output Voltage of Adjustable Version：
：
The LR1117C adjustable version provide 1.25V Reference Voltage. Any output voltage
between 1.25V~13.8V can be available by choosing two external resistors (connection method
is shown in chart 2). In chart 2, R1,R2 is the two external resistors
LR1117C
Chart 2. Application Circuit of LR1117C adjustable version
6/13
LESHAN RADIO COMPANY, LTD.
Explanation ：
The output voltage of adjustable version satisfies this followed equation:
VOut=VRef*(1+R2/R1)+IAdj*R2. We can ignore IAdj because IAdj(about 50uA) is much less
than the current of R1(about 4mA).
How to choose R1：The value of R1 should be in the range of 200Ω～350Ω to assure chip
working normally without any load. To assure the electrical performance showed in table 1, the
output current should be larger than 5mA. If R1 is too large, the minimum output current should
be larger than 4mA , The best working condition is to assure that the output current exceeds
10mA.
Thermal Considerations：
：
We have to take heat dissipation into consideration when output current or differential voltage
of input and output voltage is large. Because in such cases, the power dissipation consumed
by LR1117C is very large. LR1117C series uses SOT-223 package type and its thermal
resistance is about 20℃/W. And the copper area of application board can affect the total thermal
resistance. If copper area is 5cm*5cm（two sides）, the resistance is about 30℃/W. So total
thermal resistance is about 20℃/W+30℃/W. We can decrease total thermal resistance by
increasing copper area in application board.
7/13
LESHAN RADIO COMPANY, LTD.
Typical Characteristics：
：
1.LR1117C Dropout Voltage
2.LR1117C Line Regulation
1.4
1.2
1
0.8
0.6
0.4
0.2
0
Line Regulation（Vout=3.3V，Iout=10mA）
T=90℃
0
200
400
600
800 1000
Output Current（mA）
1200
1400
Output Voltage（V）
Dropout Voltage
（V）
Dropout Voltage (TA=25℃,90℃)
3.5
3.4
3.3
3.2
3.1
3
4
6
8
10
12
Input Voltage（V）
14
16
3.LR1117C Load Regulation
Load Regulation (Vout=3.3V)
Output Voltage（V）
∆Vout/Vout*100％
Load Regulation VS. Temp（Iout from10mA to1A）
1
0.5
0
-0.5
-1
-50
-25
0
25
50
75
100
Temperature（℃）
125
3.35
3.3
3.25
3.2
3.15
3.1
0
150
200
400
600 800 1000 1200 1400 1600
Output Current (mA)
4.LR1117C Temperature Stability
Output Voltage VS. Temperature
Output Voltage（Vout＝3.3V）VS.Temperature
Output Voltage
（V）
∆Vout/Vout*100%
3.5
3
2.5
2
1.5
1
0.5
0
-50 -25
0
25 50 75 100 125 150 175 200
Temperature（℃）
5.LR1117C Adj Pin Current VS. Temperature
2
1
0
-1
-2
-50
-25
0
25
50
75
100
125
150
Temperature（℃）
6.LR1117C Load Transient Response
Ch1: Load current change from 2mA to500 mA
Adj Pin Current VS. Temperature
Adj Pin Current（uA)
3
70
60
50
40
30
20
10
0
Ch2: Response of output voltage
-50
-25
0
25
50
75 100
Temperature(℃)
125
150
<50mV
175
Time ：20us/pix
8/13
LESHAN RADIO COMPANY, LTD.
Package outline:
1.SOT-223
Package
SOT-223
Devices per
reel
1000
Unit
mm
Package specification：
9/13
LESHAN RADIO COMPANY, LTD.
Taping dimension：（M1：Standard Type ，M2：Customized）
Taping reel dimension：
10/13
LESHAN RADIO COMPANY, LTD.
2.TO-252
Package
TO-252
Devices per
reel
2500
Unit
mm
Package specification：
Taping dimension：（M1：Standard Type ，M2：Customized）
11/13
LESHAN RADIO COMPANY, LTD.
Taping reel dimension
3.TO-220
Package
TO-220
Devices per
tube
50
Unit
mm
Package specification：
12/13