Page No. : 1/7
AX1117 Series
1.2A Low Dropout Positive Voltage Regulator
AX1117 Series Pin Assignment
3-Lead Plastic
SOT-89
Package Code: M
Pin 1: ADJ/GND
Pin 2: V
OUT
Pin 3: V
IN
3-Lead Plastic
SOT-223
Package Code: SJ
Pin 1: ADJ/GND
Pin 2 & Tab: V
OUT
Pin 3: V
IN
3-Lead Plastic
TO-252
Package Code: J
Pin 1: ADJ/GND
Pin 2 & Tab: V
OUT
Pin 3: V
IN
3-Lead Plastic
TO-220AB
Package Code: E
Pin 1: ADJ/GND
Pin 2 & Tab: V
OUT
Pin 3: V
IN
1
2
3
1
2
3
Features
•
Low Dropout Voltage 1.2V at 1.2A
•
Adjustable or Fixed Voltage (1.8V, 2.5V, 3.3V, 5V)
•
Over Current Protection
•
Thermal Overload Protection
•
Maximum Line Regulation 0.45%
•
Maximum Load Regulation 0.4%
•
Adjust Pin Current Less Than 90 uA
Tab
3
1 2
Tab
Applications
•
SCSI-2 Active Termination
•
High Efficiency Linear Regulators
•
5V to 3.3V Voltage Converter
•
Battery Charger
•
Battery Management Circuits For Notebook And Palmtop PCs
•
Core Voltage Supply: FPGA, PLD, DSP, CPU
1
Tab
2
3
General Description
The AX1117 Series are available in fixed and adjustable output voltage versions. Over current and thermal overload protection
are integrated onto the chip. Output current will decrease while it reaches the preset current or temperature limit. The dropout
voltage is specified at 1.2V Maximum at full rated output current. AX1117 Series provide excellent regulation over variations due
to changes in line, load and temperature. AX1117 Series are three terminal regulators and available in popular packages.
Device Selection Guide
Device
AX1117M-Adj
AX1117M-Fix
AX1117SJ-Adj
AX1117SJ-Fix
Output Voltage
1.3V to 4V
1.8V, 2.5V, 3.3V, 5V
1.3V to 4V
1.8V, 2.5V, 3.3V, 5V
Package
SOT-89
SOT-223
Device
AX1117J-Adj
AX1117J-Fix
AX1117E-Adj
AX1117E-Fix
Output Voltage
1.3V to 4V
1.8V, 2.5V, 3.3V, 5V
1.3V to 4V
1.8V, 2.5V, 3.3V, 5V
Package
TO-252
TO-220AB
Absolute Maximum Ratings
Parameter
Input Voltage
Power Dissipation
Operating Junction Temperature Range
Storage Temperature Range
Lead Temperature (Soldering) 5 Sec
Electrostatic Discharge Sensitivity
*: SOT-223: 0.9W(Max.), SOT-89: 0.6W(Max.), TO-252: 0.9W(Max.), TO-220: 2.1W(Max.)
Symbol
V
IN
P
D
T
OPR
T
STG
T
LEAD
Maximum
20
Internally Limited *
0 To +125
-65 To +150
260
2
Units
V
W
°C
°C
°C
KV/Min
AVANTICS - AX1117 Series
Specification No.: 050309-FE0005
Page No. : 4/7
Applications Description
•
Output Voltage Adjustment
Like most regulators, AX1117 series regulate the output by
comparing the output voltage to an internally generated reference
voltage. On the adjustable version, the V
REF
is available externally as
1.25V between V
OUT
and ADJ. The voltage ratio formed by R
1
and R
2
should be set to conduct 10mA (minimum output load). The output
voltage is given by the following equation: V
OUT
=V
REF
(1+R
2
/R
1
) + I
ADJ
R
2
On fixed versions of AX1117 series, the voltage divider is provided
internally.
•
Thermal Protection
AX1117 series have thermal protection which limits junction
temperature to 150°C. However, device functionality is only
guaranteed to a maximum junction temperature of +125°C.
The power dissipation and junction temperature for AX1117 in all
packages given by
P
D
=(V
IN
- V
OUT
) I
OUT
, T
JUNCTION
=T
AMBIENT
+(P
D
xθ
JA
), Note: T
JUNCTION
must
not exceed 125°C
•
Current Limit Protection
AX1117 series are protected against overload conditions. Current protection is triggered at typically 1.5A.
•
Stability And Load Regulation
AX1117 series require a capacitor from V
OUT
to GND to provide
compensation feedback to the internal gain stage. This is to ensure
stability at the output terminal. Typically, a 10uF tantalum or 50uF
aluminum electrolytic is sufficient.
Note : It is important that the ESR for this capacitor does not exceed
0.5Ω.
The output capacitor does not have a theoretical upper limit and
increasing its value will increase stability. C
OUT
= 100 uF or more is
typical for high current regulator design.
AX1117 series load regulation are limited by the resistance of the
wire connecting it to the load(R
P
). For the adjustable version, the best
load regulation is accomplished when the top of the resistor divider(R
1
)
is connected directly to the output pin of the AX1117 series. When so
connected, R
P
is not multiplied by the divider ratio. For fixed output
versions, the top of R
1
is internally connected to the output and
ground pin can be connected to low side of the load as a negative
side sense if, so desired.
•
Thermal Consideration
The AX1117 series contain thermal limiting circuitry designed to protect itself for over-temperature conditions. Even for normal load
conditions, maximum junction temperature ratings must not be exceeded. As mention in thermal protection section, we need to
consider all sources of thermal resistance between junction and ambient. It contains junction-to-case, case-to-heat-sink interface and
heat sink resistance itself. An additional heat sink is applied externally sometimes. It can increase the maximum power dissipation. For
example, the equivalent junction temperature of 300mA output current is 115°C without external heat sink. Under the same junction
temperature IC can operates 500mA with an adequate heat sink. Therefore, to attach an extra heat sink is recommended.
Junction-to-case thermal resistance is specified from the IC junction to the bottom of the case directly below the die. The bonding
wires are appending paths. The former is the lowest resistance path. Proper mounting is required to ensure the best possible thermal
flow this area of the package to the heat sink. Thermal compound at the case-to-heat-sink interface is strongly recommended. The
case of all devices in this series is electrically connected to the output. Therefore, if the case of the device must be electrically isolated,
a thermally conductive spacer can be used, as long its thermal resistance is considered.
•
Protection Diode
(The figure is shown as Regulator with Reverse Diode Protection in advanced applications)
In general operation, AX1117 series don’t need any protection diodes. From the cross-section structure of AX1117 sries, the output
pin is connected to P+ substrate, and the input pin is connected to N- well. There is a parasitic reverse diode between them. It can
handle microsecond surge currents of 5A to 10A. Even with large output capacitance, it is very difficult to get those values of surge
currents in normal operation. Only with high value output capacitors, such as 1000uF. And with the input pin instantaneously shorted to
ground. can damage occur. A crowbar circuit at the input of the AX1117 series can generate those kinds of currents, and a diode from
output to input is recommended. Normal power supply cycling or even plugging and unplugging in the system will not generate
currents large enough to do any damage.
R
P
Parasitic
Line Resistance
In
V
IN
Adj
R1
Connect
R1 to Case
Out
V
IN
In
ADJ
Out
V
REF
I
ADJ
10uA
R2
R1
V
OUT
V
OUT
=V
REF
(1+R
2
/R
1
) + I
ADJ
R
2
RL
R2
Connect
R2 to Load
AVANTICS - AX1117 Series
Specification No.: 050309-FE0005
Page No. : 5/7
SOT-223 Dimension
Marking:
A
Pb Free Mark
Pb-Free: "
.
"
(Note)
A X
Normal: None
S J
Product Series
Control Code
(ADJ,1.8,2.5,3.3,5)
1 1 1 7 -
B
1
2
3
C
Date Code
Note: Green label is used for pb-free packing
Pin Style: 1.ADJ/GND 2.VOUT 3.VIN
D
E
F
G
H
a1
I
a2
3-Lead SOT-223 Plastic
Surface Mounted Package
AVANTICS Package Code: SJ
Material:
•
Lead solder plating: Sn60/Pb40 (Normal),
Sn/3.0Ag/0.5Cu or Pure-Tin (Pb-free)
•
Mold Compound: Epoxy resin family,
flammability solid burning class: UL94V-0
DIM
A
B
C
D
E
F
G
H
I
a1
a2
Min.
2.90
6.70
3.30
0.60
*2.30
6.30
1.40
0.25
0.02
*13
o
0
o
Max.
3.10
7.30
3.70
0.80
-
6.70
1.80
0.35
0.10
-
10
o
*: Typical, Unit: mm
SOT-89 Dimension
C
H
Marking:
Date Code
AX1 1 1 7
Control Code
Pb Free Mark
Pb-Free: "
.
"
(Note)
Normal: None
B
1
E
G
A
2
3
D
Product Series
ADJ(A),1.8(B),2.5(C)
3.3(D),5(E)
I
Note: Green label is used for pb-free packing
Pin Style: 1.ADJ/GND 2.VOUT 3.VIN
Material:
•
Lead solder plating: Sn60/Pb40 (Normal),
Sn/3.0Ag/0.5Cu or Pure-Tin (Pb-free)
•
Mold Compound: Epoxy resin family,
flammability solid burning class: UL94V-0
F
DIM
A
B
C
D
E
F
G
H
I
Min.
4.40
4.05
1.50
2.40
0.36
*1.50
*3.00
1.40
0.35
Max.
4.60
4.25
1.70
2.60
0.51
-
-
1.60
0.41
*: Typical, Unit: mm
3-Lead SOT-89 Plastic
Surface Mounted Package
AVANTICS Package Code: M
AVANTICS - AX1117 Series
Specification No.: 050309-FE0005
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