A1085S3VR-33 [AITSEMI]
3A LOW-DROPOUT POSITIVE VOLTAGE REGULATOR;型号: | A1085S3VR-33 |
厂家: | AiT Semiconductor |
描述: | 3A LOW-DROPOUT POSITIVE VOLTAGE REGULATOR |
文件: | 总12页 (文件大小:616K) |
中文: | 中文翻译 | 下载: | 下载PDF数据表文档文件 |
A1085
AiT Semiconductor Inc.
www.ait-ic.com
3A LOW-DROPOUT POSITIVE VOLTAGE REGULATOR
THERMAL SHUTDOWN AND CURRENT LIMIT FUNCTIONS
DESCRIPTION
FEATURES
ꢀ
Provide Fixed Version and an Adjustable
Version, Output Value can be customized on
command.
The A1085 is a series of low dropout three terminal
regulators with a dropout of 1.3V at 3A load current.
Other than a fixed version (VOUT=1.8V, 2.5V, 3.3V,
5V), The A1085 has an adjustable version, which
can set the output voltage with only two external
resistors.
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
Maximum Output Current: 3A
Output Voltage Accuracy within ±2%
Range of Operation Input Voltage: Max 15V
Line Regulation: 0.2% (Typ.)
Load Regulation: 0.4% (Typ.)
Environment Temperature: -50oC~+140oC
The A1085 offers thermal shut down and current
limit functions, to assure the stability of chip and
power system. And the A1085 uses trimming
technique to guarantee output voltage accuracy
within ±2%
Available in TO-252, TO-263-2 and TO-263-3
Package
APPLICATION
ꢀ
Power Management for Computer Mother
Board, Graphic Card
The A1085 is available in TO-252, TO-263-2 and
TO-263-3 package.
ꢀ
ꢀ
ꢀ
Battery Charger
Microprocessor Supply
Post Regulators for Switching Supplies
ORDERING INFORMATION
TYPICAL APPLICATION (Schematics 1)
Package Type
TO-252
Part Number
A1085DR-XX
D
A1085DVR-XX
A1085S2R-XX
A1085S2VR-XX
A1085S3R-XX
A1085S3VR-XX
TO-263-2
TO-263-3
S2
S3
Adjustable Version
XX: Output Voltage,
33 = 3.3V, 50 = 5V
ADJ: Adjustable
VOUT = VREF x (1 + R2 / R1) + IADJ x R2
Note
R : Tape & Reel
V: Green Package
AiT provides all Pb free products
Suffix “V” means Green Package
Fixed Output Version
REV1.2
-AUG 2006 RELEASED – SEP 2008 REVISED -
- 1 -
A1085
AiT Semiconductor Inc.
www.ait-ic.com
3A LOW-DROPOUT POSITIVE VOLTAGE REGULATOR
THERMAL SHUTDOWN AND CURRENT LIMIT FUNCTIONS
PIN DESCIPTION
Top View
Top View
Top View
Pin
#
TO-252
TO-263-2
TO-263-3
A1085DR-XX
GND
A1085DR-ADJ
A1085S2R-XX
A1085S2R-ADJ A1085S3R--XX A1085S3R-ADJ
1
ADJ
VOUT
VIN
GND
VOUT
VIN
ADJ
VOUT
VIN
GND
VOUT
VIN
ADJ
VOUT
VIN
2
VOUT
3
VIN
ABSOLUTE MAXIMUM RATINGS
Maximum Input Voltage
15V
Junction Temperature (TJ)
Environment Temperature (TA)
Storage Temperature (Ts)
Lead Temperature and Time
150oC
80oC
-65oC to 150oC
260oC, 10S
Stresses above may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at
these or any other conditions beyond those indicated in the Electrical Characteristics is not implied. Exposure to absolute maximum
rating conditions for extended periods may affect device reliability.
REV1.2
-AUG 2006 RELEASED – SEP 2008 REVISED -
- 2 -
A1085
AiT Semiconductor Inc.
www.ait-ic.com
3A LOW-DROPOUT POSITIVE VOLTAGE REGULATOR
THERMAL SHUTDOWN AND CURRENT LIMIT FUNCTIONS
ELECTRICAL CHARACTERISTICS
Test Condition: CIN=10uF, COUT=22uF, TA = 25oC, unless otherwise noted.
Symbol
VREF
Parameter
Conditions
Min.
Typ.
Max.
1.262
1.275
Unit
V
I
OUT=10mA, VIN-VOUT=3V
1.238 1.25
1.225 1.25
Reference Voltage
10mA≦IOUT≦3A, 5V≦VIN-VOUT≦5V
A1085-1.8V
I
OUT=0mA, VIN=4.8V, TJ=25oC
1.782 1.80
1.764 1.80
1.818
1.836
V
V
V
V
10mA≦IOUT≦3A, 3.4V≦VIN≦7V
A1085-2.5V
IOUT=0mA, VIN=4.8V, TJ=25oC
10mA≦IOUT≦3A, 4.1V≦VIN≦7V
A1085-3.3V
IOUT=0mA, VIN=6.3V, TJ=25oC
10mA≦IOUT≦3A, 4.9V≦VIN≦8V
A1085-5.0V
IOUT=0mA, VIN=8.0V, TJ=25oC
10mA≦IOUT≦3A, 6.6V≦VIN≦10V
A1085-ADJ
2.475 2.50
2.450 2.50
2.525
2.550
VOUT
Output Voltage
3.267
3.234
3.3
3.3
3.333
3.366
4.95
4.90
5.0
5.0
5.05
5.10
I
OUT=10mA, 2.85V≦VIN≦10V
0.035
0.2
5
%
A1085-1.8V
IOUT=10mA, 3.4V≦VIN≦10V
A1085-2.5V
1
1
mV
mV
mV
%
Line Regulation
(Note1)
ΔVOUT
IOUT=10mA, 4.9V≦VIN≦10V
A1085-5.0V
5
IOUT=10mA, 6.6V≦VIN≦10V
A1085-ADJ
1
5
VIN-VOUT=3V, 10mA≦IOUT≦3A
A1085-1.8V
0.2
3
0.4
15
15
15
VIN-VOUT=3V, 0≦IOUT≦3A
A1085-2.5V
mV
mV
mV
Load Regulation
(Note1, 2)
ΔVOOT
VIN-VOUT=3V, 0≦IOUT≦3A
A1085-3.3V
3
VIN-VOUT=3V, 0≦IOUT≦3A
A1085-5.0V
3
VIN-VOUT=3V, 0≦IOUT≦3A
3
15
mV
V
Dropout Voltage (Note3)
Current Limit
VIN-VOUT
ILIMIT
ΔVOUT, ΔVREF=1%, IOUT=3A
VIN-VOUT=3V, TJ=25oC
1.3
1.5
3.2
4.5
A
REV1.2
-AUG 2006 RELEASED – SEP 2008 REVISED -
- 3 -
A1085
AiT Semiconductor Inc.
www.ait-ic.com
3A LOW-DROPOUT POSITIVE VOLTAGE REGULATOR
THERMAL SHUTDOWN AND CURRENT LIMIT FUNCTIONS
Symbol
Parameter
Conditions
Min.
Typ.
3
Max.
10
Unit
mA
mA
uA
Minimum Load Current (Note 4)
A1085-ADJ
VIN=10V
Iq
Quiescent Current
Adjust Pin Current
4
10
IADJ
VIN=4.25V, IOUT=10mA
45
110
F=120Hz, COUT=25uF (Tan)
IOUT=3A, VIN-VOUT=3V
60
Ripple Rejection
dB
Adjust Pin Current
Change
Temperature Stability
Thermal Resistance
Junction to Case
10mA≦IOUT≦3A, 1.5V≦VIN≦6V
0.2
5
ICHANGE
uA
%
IOUT=10mA, VIN-VOUT=1.5V
TO-252
0.5
12.5
3
θJC
oC/W
TO-263-2 and TO-263-3
Note 1: The parameters of Line Regulation and Load Regulation are tested under constant junction temperature.
Note 2: When IOUT varies between 0~3A, VIN-VOUT varies between 1.5V~6V under constant junction temperature, the parameter is
satisfied the criteria in above mentioned. If temperature varies between -50oC≦TA≦140oC, needs output current to be larger
than 10mA to satisfy the criteria.
Note 3: Dropout Voltage is specified over IOUT=3A and the 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% x VOUT1 (VOUT2). VDROPOUT= VIN2 - VOUT2
Note 4: Minimum Load Current is defined as the minimum output current required to maintain regulation.
When 1.5V≦VIN-VOUT≦6V, the device is guaranteed to regulate if the output current is greater than 10mA.
.
REV1.2
-AUG 2006 RELEASED – SEP 2008 REVISED -
- 4 -
A1085
AiT Semiconductor Inc.
www.ait-ic.com
3A LOW-DROPOUT POSITIVE VOLTAGE REGULATOR
THERMAL SHUTDOWN AND CURRENT LIMIT FUNCTIONS
TYPICAL PERFORMANCE CHARACTERISTICS
1.Dropout Voltage vs. Output Current
3.Reference Voltage vs. Thermal Protection
5.Load Transient Response
2.Reference Voltage vs. Temperature
4.Output Voltage vs. Output Current
6. Line Transient Response
REV1.2
-AUG 2006 RELEASED – SEP 2008 REVISED -
- 5 -
A1085
AiT Semiconductor Inc.
www.ait-ic.com
3A LOW-DROPOUT POSITIVE VOLTAGE REGULATOR
THERMAL SHUTDOWN AND CURRENT LIMIT FUNCTIONS
BLOCK DIAGRAM
REV1.2
-AUG 2006 RELEASED – SEP 2008 REVISED -
- 6 -
A1085
AiT Semiconductor Inc.
www.ait-ic.com
3A LOW-DROPOUT POSITIVE VOLTAGE REGULATOR
THERMAL SHUTDOWN AND CURRENT LIMIT FUNCTIONS
DETAILED INFORMATION
The A1085 is a series of low dropout voltage, three terminal regulators which application circuit of 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, band-gap, thermal shutdown,
current limit, power transistors and its driver circuit and so on.
Thermal Shutdown and Current Limit
The A1085 thermal shutdown and current limit modules can assure chip and its application system working
safety when the environment temperature is larger than 140oC or output current is larger than 3.2A.
Stable Reference Output Voltage
The band-gap module provides stable reference voltage, whose temperature coefficient is compensated by
careful design considerations. The temperature coefficient is under 100ppm/oC. And the accuracy of
output voltage is guaranteed by trimming technique.
Application Hints
See Schematic 1
1. Recommend 10uF Tan capacitor (CIN) as bypass capacitor for all application circuit.
2. Recommend 22uF Tan capacitor (COUT) to assure circuit stability.
3. 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 increase. The impedance
of CADJ should be less than the resistor’s (R1) which is normally in the range of 120Ω ~ 200Ω, the value of
CADJ should satisfy this equation: 2 x FRIPPLE x <R1. Recommend using 10uF Tan capacitor.
Output Voltage of Adjustable Version
The A1085-ADJ adjustable version provides 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 Schematic 1), R1
and R2 are the two external resistors.
REV1.2
-AUG 2006 RELEASED – SEP 2008 REVISED -
- 7 -
A1085
AiT Semiconductor Inc.
www.ait-ic.com
3A LOW-DROPOUT POSITIVE VOLTAGE REGULATOR
THERMAL SHUTDOWN AND CURRENT LIMIT FUNCTIONS
Example
The output voltage of A1085-ADJ adjustable version satisfies this followed equation:
OUT=VREF x (1+R2/R1) + IADJ x R2
V
We can ignore IADJ because IADJ (about 50uA) is much less than the current of R1 (about 4mA).
The value of R1 should be in the range 120Ω ~ 200Ω to assure chip working normally without any load. To
assure the electrical performance showed in Table 1, the output than 4mA, the best working condition is to
assure that the output current exceeds 10mA.
(Schematic 1)
Adjustable Version
VOUT=VREF x (1+R2/R1) + IADJ x R2
Fixed Output Version
REV1.2
-AUG 2006 RELEASED – SEP 2008 REVISED -
- 8 -
A1085
AiT Semiconductor Inc.
www.ait-ic.com
3A LOW-DROPOUT POSITIVE VOLTAGE REGULATOR
THERMAL SHUTDOWN AND CURRENT LIMIT FUNCTIONS
PACKAGE INFORMATION
Dimension in TO-252 (Unit: mm)
Tape Dimension
Reel Dimension
REV1.2
-AUG 2006 RELEASED – SEP 2008 REVISED -
- 9 -
A1085
AiT Semiconductor Inc.
www.ait-ic.com
3A LOW-DROPOUT POSITIVE VOLTAGE REGULATOR
THERMAL SHUTDOWN AND CURRENT LIMIT FUNCTIONS
Dimension in TO-263-2 (Unit: mm)
Tape Dimension
Reel Dimension
REV1.2
-AUG 2006 RELEASED – SEP 2008 REVISED -
- 10 -
A1085
AiT Semiconductor Inc.
www.ait-ic.com
3A LOW-DROPOUT POSITIVE VOLTAGE REGULATOR
THERMAL SHUTDOWN AND CURRENT LIMIT FUNCTIONS
Dimension in TO-263-3 (Unit: mm)
Tape Dimension
Reel Dimension
REV1.2
-AUG 2006 RELEASED – SEP 2008 REVISED -
- 11 -
A1085
AiT Semiconductor Inc.
www.ait-ic.com
3A LOW-DROPOUT POSITIVE VOLTAGE REGULATOR
THERMAL SHUTDOWN AND CURRENT LIMIT FUNCTIONS
IMPORTANT NOTICE
AiT Semiconductor Inc. (AiT) reserves the right to make changes to any its product, specifications, to
discountinue any integrated circuit product or service without notice, and advises its customers to obtain the
latest version of relevant information to verify, before placing orders, that the information being relied on is
current.
AiT Semiconductor Inc.'s integrated circuit products are not designed, intended, authorized, or warranted to
be suitable for use in life support applications, devices or systems or other critical applications. Use of AiT
products in such applications is understood to be fully at the risk of the customer.
As used herein may
In order to
involve potential risks of death, personal injury, or servere property, or environmental damage.
minimize risks associated with the customer's applications, the customer should provide adequate design and
operating safeguards.
AiT Semiconductor Inc. assumes to no liability to customer product design or application support. AiT
warrants the performance of its products of the specifications applicable at the time of sale.
REV1.2
-AUG 2006 RELEASED – SEP 2008 REVISED -
- 12 -
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