AMS1117A
1A Bipolar Linear Regulator
Features
Maximum output current is 1.4A
Standby current: 2mA (typ.)
Range of operation input voltage: Max 15V
Load regulation: 0.2%/A (typ.)
Line regulation: 0.03%/V (typ.)
Environment Temperature: -20℃~85℃
Power Management for Computer Mother
Board, Graphic Card
DVD Decode Board
ADSL Modem
LCD Monitor and LCD TV
Post Regulators For Switching Supplies
Applications
General Description
AMS1117A is a series of low dropout three-terminal
two external resistors.
regulators with a dropout of 1.3V at 1A load current.
AMS1117A offers thermal shut down function, to assure the
AMS1117A features a very low standby current 2mA
stability of chip and power system. And it uses trimming
compared to 5mA of competitor.
technique to guarantee output voltage accuracy within
Other than a fixed version, Vout = 1.2V, 1.8V, 2.5V, 2.85V,
2%. Other output voltage accuracy can be customized on
3.3V, and 5V, AMS1117A has an adjustable version,
demand, such as
which can provide an output voltage from 1.25 to 12V
AMS1117A is available in SOT-223, TO-252 power package.
1%.
with only
Typical Application
AMS1117A
fgut
V i n
10uF
V o u t
G n d
10uF
Application circuit of AMS1117A fixed version
Typical Electrical Characteristic
AMS1117A-ADJ
Ver1.5
1
Jul.01,2016
AMS1117A
1A Bipolar Linear Regulator
Selection Table
Marking
Part No.
Output Voltage
XX=12
1.2V
XX=18
1.8V
1117A
XX=28
2.85V
XX YYWW
XX=25
2.5V
XX=33
3.3V
XX=50
5.0V
XX=AD
Adj
Ordering Information
Marking
1117A
XX YYWW
Package
SOT-223
TO-252
Designator
Description
1117A
Product code
XX
Output Voltage(1.2~12.0V)
YYWW
DATE CODE
Note:”XX” stands for output voltages. Other voltages can be specially customized
Parameters
Description
Temperature & Rohs
C:-40~85℃ ,Pb Free Rohs Std.
Package type
L:SOT-223
O:TO-252
Packing type:
TR: Tape & Reel (Standard)
Voltage accuracy
2%(Customized)
Block Diagram
Ver1.5
2
Jul.01,2016
AMS1117A
1A Bipolar Linear Regulator
Pin Configuration
Absolute Maximum Ratings
Max Input Voltage ·········································································································18V
Max Operating Junction Temperature(Tj) ···········································································150℃
Ambient Temperature(Ta) ·······························································································-40℃~ 85℃
Storage Temperature(Ts) ································································································ -40℃~150℃
Lead Temperature & Time·······························································································260℃ 10S
Caution: Exceed these limits to damage to the device. Exposure to absolute maximum rating conditions may affect
device reliability.
Recommended Work Conditions
Recommended maximum input voltage ···················································································
15V
Recommended operating junction temperature(Tj) ····································································
-20~125℃
Thermal Information
Parameter
Package
Package thermal
resistance
Ver1.5
Rating
Unit
SOT-223
20
℃/W
TO-252
12.5
℃/W
3
Jul.01,2016
AMS1117A
1A Bipolar Linear Regulator
Electrical Characteristics
TA=25℃, unless otherwise noted.
Symbol
Parameter
Vref
Reference
voltage
Conditions
AMS1117A-Adj
Min
Typ
Max
Unit
1.225
1.25
1.275
V
1.176
1.2
1.224
V
1.764
1.8
1.836
V
2.45
2.5
2.55
V
2.793
2.85
2.907
V
3.234
3.3
3.366
V
4.9
5
5.1
V
0.03
0.2
%/V
0.03
0.2
%/V
0.03
0.2
%/V
0.03
0.2
%/V
0.03
0.2
%/V
0.03
0.2
%/V
0.03
0.2
%/V
2
8
mV
2
8
mV
3
12
mV
10mA≤Iout≤1A , Vin=3.25V
AMS1117A-1.2V
0≤Iout≤1A , Vin=3.2V
AMS1117A-1.8V
0≤Iout≤1A , Vin=3.8V
AMS1117A-2.5V
Vout
Output voltage
0≤Iout≤1A , Vin=4.5V
AMS1117A-2.85V
0≤Iout≤1A , Vin=4.85V
AMS1117A-3.3V
0≤Iout≤1A , Vin=5.3V
AMS1117A-5.0V
0≤Iout≤1A , Vin=7.0V
AMS1117A-1.2V
Iout=10mA, 2.7V≤Vin≤10V
AMS1117A-ADJ
Iout=10mA, 2.75V≤Vin≤12V
AMS1117A-1.8V
Iout=10mA, 3.3V≤Vin≤12V
△Vout
Line
regulation
AMS1117A-2.5V
Iout=10mA, 4.0V≤Vin≤12V
AMS1117A-2.85V
Iout=10mA, 4.35V≤Vin≤12V
AMS1117A-3.3V
Iout=10mA, 4.8V≤Vin≤12V
AMS1117A-5.0V
Iout=10mA, 6.5V≤Vin≤12V
AMS1117A-1.2V
Vin =2.7V, 10mA≤Iout≤1A
AMS1117A-ADJ
Vin =2.75V, 10mA≤Iout≤1A
AMS1117A-1.8V
Vin =3.3V, 10mA≤Iout≤1A
Ver1.5
4
Jul.01,2016
AMS1117A
1A Bipolar Linear Regulator
△Vout
Load
4
16
mV
5
20
mV
6
24
mV
9
36
mV
Iout =100mA
1.15
1.3
V
Iout=1A
1.3
1.5
V
AMS1117A-ADJ
2
10
mA
AMS1117A-1.2V,Vin=10V
2
5
mA
AMS1117A-1.8V,Vin=12V
2
5
mA
Quiescent
AMS1117A-2.5V,Vin=12V
2
5
mA
Current
AMS1117A-2.85V,Vin=12V
2
5
mA
AMS1117A-3.3V,Vin=12V
2
5
mA
AMS1117A-5.0V,Vin=12V
2
5
mA
AMS1117A-ADJ
55
120
uA
0.2
10
uA
regulation
AMS1117A-2.5V
Vin =4.0V, 10mA≤Iout≤1A
AMS1117A-2.85V
Vin =4.35V, 10mA≤Iout≤1A
AMS1117A-3.3
Vin =4.8V, 10mA≤Iout≤1A
AMS1117A-5.0
Vin =6.5V, 10mA≤Iout≤1A
Vdrop
Imin
Dropout voltage
Minimum load
current
Iq
IAdj
Adjust pin
current
Ichange
Iadj change
Vin=5V,10mA≤Iout≤1A
AMS1117A-ADJ
Vin=5V,10mA≤Iout≤1A
ΔV/ΔT
±100
Temperature
ppm
coefficien
θJC
Thermal
SOT-223
20
resistance
TO-252
10
℃/W
Note1: All test are conducted under ambient temperature 25°C and within a short period of time 20ms
Note2: Load current smaller than minimum load current of AMS1117A-ADJ will lead to unstable or
oscillationoutput.
Ver1.5
5
Jul.01,2016
AMS1117A
1A Bipolar Linear Regulator
Detailed Description
AMS1117A 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, power transistors and its
driver circuit and so on.
The thermal shut down modules can assure chip and its application system working safety when the junction temperature
is larger than 140°C.
The bandgap module provides stable reference voltage, whose temperature coefficient is compensated by careful design
considerations. The temperature coefficient is under 100 ppm/°C. And the accuracy of output voltage is guaranteed by
trimming technique.
Typical Application
AMS1117A has an adjustable version and six fixed versions (1.2V, 1.8V, 2.5V, 2.85V , 3.
3V and 5V)Fixed Output Voltage Version
AMS1117A
Application circuit of AMS1117A fixed version
1)
Recommend using 10uF tan capacitor as bypass capacitor (C1) for all application circuit.
2)
Recommend using 10uF tan capacitor to assure circuit stability.
Adjustable Output Voltage Version
AMS1117A-ADJ
Application Circuit of AMS1117A-ADJ
The output voltage of adjustable version follows the equation: Vout=1.25×(1+R2/R1)+IAdj×R2. We can ignore
IAdj because IAdj (about 50uA) is much less than the current of R1 (about 2~10mA).
1)
Ver1.5
To meet the minimum load current (>10mA) requirement, R1 is recommended to be 125ohm or lower. As
6
Jul.01,2016
AMS1117A
1A Bipolar Linear Regulator
AMS1117A-ADJ can keep itself stable at load current about 2mA, R1 is not allowed to be higher than 625ohm.
2)
Using a bypass capacitor (CADJ) between the ADJ pin and ground can improve ripple rejection.
This bypass
capacitor prevents ripple from being amplified as the output voltage is increased. The impedance of C ADJ should be less
than R1 to prevent ripple from being amplified. As R1 is normally in the range of
100Ω~500Ω, the value of C ADJ should
satisfy this equation: 1/(2π×fripple×CADJ)