Advanced AMS1117 Monolithic 1A LOW DROPOUT VOLTAGE REGULATOR
Systems
RoHS compliant
FEATURES
APPLICATIONS
• Three Terminal Adjustable or Fixed Voltages* • High Efficiency Linear Regulators
1.5V, 1.8V,
幸福的根源
2.5V, 2.85V,
3.3V and 5.0V •Post Regulators for Switching Supplies • Output Current of 1A
• 5V to 3.3V Linear Regulator • Operates Down to 1V Dropout • Battery Chargers
• Line Regulation: 0.2% Max. • Active SCSI Terminators
• Load Regulation: 0.4% Max.
• Power Management for Notebook • SOT-223, TO-252 and SO-8 package available • Battery Powered Instrumentation
GENERAL DESCRIPTION
The AMS1117 ries of adjustable and fixed voltage regulators are designed to provide 1A output current and to operate down to 1V input-to-output differential. The dropout voltage of the device is guaranteed maximum 1.3V at maximum output current, decreasing at lower load currents.
On-chip trimming adjusts the reference voltage to 1%. Current limit is also trimmed, minimizing the stress under overload conditions on both the regulator and power source circuitry.
The AMS1117 devices are pin compatible with other three-terminal SCSI regulators and are offered in the low profile surface mount SOT-223 package, in the 8L SOIC package and in the TO-252 (DPAK) plastic package.
ORDERING INFORMATION:
PACKAGE TYPE
OPERATING JUNCTION
TO-252 SOT-223 8L SOIC TEMPERATURE RANGE AMS1117CD AMS1117 AMS1117CS -40 to 125°
C AMS1117CD-1.5 AMS1117-1.5 AMS1117CS-1.5 -40 to 125° C AMS1117CD-1.8 AMS1117-1.8
AMS1117CS-1.8 -40 to 125° C AMS1117CD-2.5 AMS1117-2.5 AMS1117CS-2.5 -40 to 125° C AMS1117CD-2.85 AMS1117-2.85 AMS1117CS-2.85 -40 to 125° C AMS1117CD-3.3 AMS1117-3.3 AMS1117CS-3.3 -40 to 125° C AMS1117CD-5.0 AMS1117-5.0 AMS1117CS-5.0 -40 to 125° C *For additional available fixed voltages contact factory.
PIN CONNECTIONS
SOT-223 Top View
3 PIN FIXED/ADJUSTABLE VERSION
1- Ground/Adjust 2- V OUT 3- V IN
AMS1117
ABSOLUTE MAXIMUM RATINGS (Note 1)
Power Dissipation Internally limited
Soldering information
Input Voltage
15V
Lead Temperature (25 c) 265°C
Operating Junction Temperature
Thermal Resistance
Control Section
0°C to 125°C SO-8 package ϕ JA = 160°C/W Power Transistor 0°C to 150°C TO-252 package ϕ JA = 80°C/W Storage temperature - 65°C to +150°C
SOT-223 package
ϕ JA = 90°C/W*
* With package soldering to copper area over backside
ground plane or internal power plane ϕ JA can vary from 46°C/W to >90°C/W depending on mounting technique and the size of the copper area.
ELECTRICAL CHARACTERISTICS
Electrical Characteristics at I OUT = 0 mA, and T J = +25°C unless otherwi specified. Parameter母亲的伟大
Device Conditions Min Typ Max
Units
Reference Voltage (Note 2) AMS1117 I OUT = 10 mA
10mA ≤ I OUT ≤ 1A, 1.5V ≤ (V IN - V OUT ) ≤ 12V 1.238 1.225 1.250 1.250 1.262 1.270 V V Output Voltage (Note 2) AMS1117-1.5 0 ≤ I OUT ≤ 1A , 3.0V ≤ V IN ≤ 12V 1.485 1.476 1.500 1.500 1.515 1.524 V V AMS1117-1.8 0 ≤ I OUT ≤ 1A , 3.3V ≤ V IN ≤ 12V 1.782 1.773 1.800 1.
800 1.818 1.827 V V AMS1117-2.5 0 ≤ I OUT ≤ 1A , 4.0V ≤ V IN ≤ 12V 2.475 2.460 2.500 2.500 2.525 2.560 V V AMS1117-2.85 0 ≤ I OUT ≤ 1A , 4.35V ≤ V IN ≤ 12V 2.82 2.79 2.850 2.850 2.88 2.91 V V AMS1117-3.3 0 ≤ I OUT ≤ 1A , 4.75V ≤ V IN ≤ 12V 3.267 3.235 3.300 3.300 3.333 3.365 V V
AMS1117-5.0 0 ≤ I OUT ≤ 1A , 6.5V ≤ V IN ≤ 12V 4.950 4.900
5.000 5.000
5.050 5.100
V V Line Regulation
AMS1117
I LOAD = 10 mA , 1.5V ≤ (V IN - V OUT ) ≤ 12V
0.015 0.035 0.2
0.2 % % AMS1117-1.5 3.0V ≤ V IN ≤ 12V 0.3 0.6 5 6 mV mV AMS1117-1.8 3.3V ≤ V IN ≤ 12V 0.
3 0.6 5 6 mV mV AMS1117-2.5 4.0V ≤ V IN ≤ 12V 0.3 0.6 6 6 mV mV AMS1117-2.85 4.35V ≤ V IN ≤ 12V 0.3 0.6 6 6 mV mV AMS1117-3.3 4.75V ≤ V IN ≤ 12V 0.5 1.0 10 10 mV mV AMS1117-5.0 6.5V ≤ V IN ≤ 12V 0.5 1.0 10 10 mV mV Load Regulation (Notes 2, 3)
AMS1117
(V IN - V OUT ) =3V, 10mA ≤ I OUT ≤ 1A
0.1 0.2
0.3 0.4
% % AMS1117-1.5 V IN = 5V, 0 ≤ I OUT ≤ 1A 3 6 10
20 mV mV AMS1117-1.8 V IN = 5V, 0 ≤ I OUT ≤ 1A 3 6 10 20 mV mV AMS1117-2.5 V IN = 5V, 0 ≤ I OUT ≤ 1A
3 6 12 20
mV mV
AMS1117
无所谓的英文
ELECTRICAL CHARACTERISTICS
Electrical Characteristics at I OUT = 0 mA, and T J = +25°C unless otherwi specified. Parameter
Device
Conditions
Min Typ Max
Units
Load Regulation (Notes 2, 3)
AMS1117-2.85
V IN = 5V, 0 ≤ I OUT ≤ 1A
3 6 12
20 mV mV AMS1117-3.3 V IN = 5V, 0 ≤ I OUT ≤ 1A 3 7 15 25 mV mV AMS1117-5.0 V IN = 8V, 0 ≤ I OUT ≤ 1A 5 10 20 35 mV mV Dropout Voltage (V IN - V OUT ) AMS1117-1.5/-1.8/-2.5/-2.85/-3.3/-5.0
∆V OUT , ∆V REF = 1%, I OUT = 1A (Note 4)
1.1
1.3
V Current Limit
AMS1117-1.5/-1.8/-2.5/-2.85/-3.3/-5.0
(V IN - V OUT ) = 5V
900 1,100 1,500 mA Minimum Load Current
AMS1117 (V IN - V OUT ) = 12V (Note 5) 5 10 mA Quiescent Current AMS1117-1.5/-1.8/-2.5/-2.8
5/-3.3/-5.0 V IN ≤ 12V
5 10
mA
Ripple Rejection AMS1117
f =120Hz , C OUT = 22µF Tantalum, I OUT = 1A, (V IN -V OUT ) = 3V, C ADJ =10µF
60 75 dB
AMS1117-1.5/-1.8/-2.5/-2.85
f =120Hz , C OUT = 22µF Tantalum, I OUT = 1A, V IN = 6V
60 72 dB AMS1117-3.3 f =120Hz , C OUT = 22µF Tantalum, I OUT = 1A
V IN = 6.3V 60
72
dB AMS1117-5.0 f =120Hz , C OUT = 22µF Tantalum, I OUT = 1A
V IN = 8V 60 68 dB Thermal Regulation AMS1117 T A = 25°C, 30ms pul
0.008
0.04
%W Adjust Pin Current AMS1117 10mA ≤ I OUT ≤ 1A , 1.5V ≤ (V IN - V OUT ) ≤ 12V 55
120 µA µA Adjust Pin Current Change
AMS1117 10mA ≤ I OUT ≤ 1A , 1.5V ≤ (V IN - V OUT ) ≤ 12V
0.2 5 µA Temperature Stability
0.5
% Long Term Stability T A =125°C, 1000Hrs
0.3 1 % RMS Output Noi (% of V OUT )
T A = 25°C , 10Hz ≤ f ≤ 10kHz
0.003
%
Thermal Resistance Junction-to-Ca
15 °C/W
Parameters identified with boldface type apply over the full operating temperature range.
Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. For guaranteed specifications and test conditions, e the Electrical Characteristics . The guaranteed specifications apply only for the test conditions listed.
Note 2: Line and Load regulation are guaranteed up to the maximum power dissipation of 1.2 W. Power dissipation is determined by the input/output differential and the output current. Guaranteed maximum power dissipation will not be available over the full input/output range.
Note 3: See thermal regulation specifications for changes in output voltage due to heating effects. Line and load regulation are measured at a constant junction temperature by low duty cycle pul testing. Load regulation is measured at the output lead ~1/8” from the package. Note 4: Dropout voltage is specified over the full output current range of the device.
Note 5: Minimum load current is defined as the minimum output current required to maintain regulation. When 1.5V ≤ (V IN - V OUT ) ≤ 12V the device is guaranteed to regulate if the output current is greater than 10mA.
AMS1117 APPLICATION HINTS
The AMS1117 ries of adjustable and fixed regulators are easy to
u and are protected against short circuit and thermal overloads.
Thermal protection circuitry will shut-down the regulator should
the junction temperature exceed 165°C at the n point.
Pin compatible with older three terminal adjustable regulators, the devices offer the advantage of
a lower dropout voltage, more preci reference tolerance and improved reference stability with temperature.
Stability
The circuit design ud in the AMS1117 ries requires the u of an output capacitor as part of the device frequency compensation. The addition of22µF solid tantalum on the output will ensure stability for all operating conditions.
When the adjustment terminal is bypasd with a capacitor to improve the ripple rejection, the requirement for an output capacitor increas. The value of 22µF tantalum covers all cas of bypassing the adjustment terminal. Without bypassing the adjustment terminal smaller capacitors can be ud with equally good results.
To further improve stability and transient respon of the devices larger values of output capacitor can be ud.
Protection Diodes本人工作志愿
Unlike older regulators, the AMS1117 family does not need any protection diodes between the adjust
绿茶减肥效果好吗ment pin and the output and from the output to the input to prevent over-stressing the die. Internal resistors are limiting the internal current paths on the AMS1117 adjustment pin, therefore even with capacitors on the adjustment pin no protection diode is needed to ensure device safety under short-circuit conditions.
Diodes between the input and output are not usually needed. Microcond surge currents of 50A to 100A can be handled by the internal diode between the input and output pins of the device. In normal operations it is difficult to get tho values of surge currents even with the u of large output capacitances. If high value output capacitors are ud, such as 1000µF to 5000µF and the input pin is instantaneously shorted to ground, damage can occur. A diode from output to input is recommended, when a crowbar circuit at the input of the AMS1117 is ud (Figure 1).
F
V
OUT
D1
V
IN
Figure 1.春天的景色画
Output Voltage
The AMS1117 ries develops a 1.25V reference voltage between the output and the adjust terminal. Placing a resistor between the two terminals caus a constant current to flow through R1 and down through R2 to t the overall output voltage. This current is normally the specified minimum load current of 10mA. Becau I ADJ is very small and constant it reprents a small error and it can usually be ignored.
V
OUT V
IN
V OUT = V REF (1+ R2/R1)+I ADJ R2
Figure 2. Basic Adjustable Regulator梦见亲戚结婚
Load Regulation
True remote load nsing it is not possible to provide, becau the AMS1117 is a three terminal device. The resistance of the wire connecting the regulator to the load will limit the load regulation. The data sheet specification for load regulation is measured at the bottom of the package. Negative
side nsing is a true Kelvin connection, with the bottom of the output divider returned to the negative side of the load.
The best load regulation is obtained when the top of the resistor divider R1 is connected directly to the ca not to the load. If R1 were connected to the load, the effective resistance between the regulator and the load would be:
R P x( R2+R1 ) , R P = Parasitic Line Resistance R1
AMS1117
APPLICATION HINTS
Connected as shown , R P is not multiplied by the divider ratio
R L
V IN
R P
PARASITIC
*CONNECT R1 TO CASE
CONNECT R2 TO LOAD
Figure 3. Connections for Best Load Regulation
In the ca of fixed voltage devices the top of R1 is connected
Kelvin internally, and the ground pin can be ud for negative side nsing.
Thermal Considerations
The AMS1117 ries have internal power and thermal limiting circuitry designed to protect the device
under overload conditions. However maximum junction temperature ratings of 125°C should not be exceeded under continuous normal load conditions.
Careful consideration must be given to all sources of thermal resistance from junction to ambient. For the surface mount package SOT-223 additional heat sources mounted near the device must be considered. The heat dissipation capability of the PC board and its copper traces is ud as a heat sink for the device. The thermal resistance from the junction to the tab for the AMS1117 is 15°C/W. Thermal resistance from tab to ambient can be as low as 30°C/W.
The total thermal resistance from junction to ambient can be as low as 45°C/W. This requires a reasonable sized PC board with at least on layer of copper to spread the heat across the board and couple it into the surrounding air.
Experiments have shown that the heat spreading copper layer does not need to be electrically connected to the tab of the device. The PC material can be very effective at transmitting heat between the pad area, attached to the pad of the device, and a ground plane layer either inside or on the opposite side of the board. Although the actual thermal resistance of the PC material is high, the Length/Area ratio of the thermal resistance between layers is small. The data in Table 1, was tak
en using 1/16” FR-4 board with 1 oz. copper foil, and it can be ud as a rough guideline for estimating thermal resistance.
For each application the thermal resistance will be affected by thermal interactions with other components on the board. To determine the actual value some experimentation will be necessary.
The power dissipation of the AMS1117 is equal to: P D = ( V IN - V OUT )( I OUT )
Maximum junction temperature will be equal to:
T J = T A(MAX) + P D (Thermal Resistance (junction-to-ambient)) Maximum junction temperature must not exceed 125°C.
Ripple Rejection
The ripple rejection values are measured with the adjustment pin bypasd. The impedance of the adjust pin capacitor at the ripple frequency should be less than the value of R1 (normally 100Ω to 200Ω) for a proper bypassing and ripple rejection approaching the values shown. The size of the required adjust pin capacitor is a function of the input ripple frequency. If R1=100Ω at 120Hz the adjust pin capacitor should be >13µF. At 10kHz only 0.16µF is needed.
The ripple rejection will be a function of output voltage, in circuits without an adjust pin bypass capacitor. The output ripple will increa directly as a ratio of the output voltage to the reference voltage (V OUT / V REF ).
Table 1.
COPPER AREA
THERMAL RESISTANCE TOP SIDE* BACK SIDE BOARD AREA (JUNCTION-TO-AMBIENT)
2500 Sq. mm 2500 Sq. mm 2500 Sq. mm 45°C/W 1000 Sq. mm 2500 Sq. mm 2500 Sq. mm 45°C/W 225 Sq. mm 2500 Sq. mm 2500 Sq. mm 53°C/W 100 Sq. mm 2500 Sq. mm 2500 Sq. mm 59°C/W 1000 Sq. mm 1000 Sq. mm 1000 Sq. mm 52°C/W 1000 Sq. mm 0 1000 Sq. mm 55°C/W
* Tab of device attached to topside copper.
AMS1117
TYPICAL PERFORMANCE CHARACTERISTICS
Minimum Operating Current (Adjustable Device)
Short-Circuit Current
03
6
9
12M I N I M U M O P E R A T I N G C U R R E N T (m A )
蒜蓉粉丝蒸白菜
-0.20
-0.15
-0.10
-0.05
0.05
0.10
O U T P U T V O L T A G E D E V I A T I O N (%)
-
50
-25
25
50
75
100
125
150
-2.0
-1.0
1.0
2.0
TEMPERATURE (°C)
O U T P U T V O L T A G E C H A N G E (%)
TEMPERATURE (°C)
-50
-250255075100125150
