AIC1741CN [AIC]
LOW DROPOUT ADJUSTABLE REGULATOR; 低压差可调稳压
| 型号： | AIC1741CN |
| 厂家： | 
ANALOG INTERGRATIONS CORPORATION |
| 描述： | LOW DROPOUT ADJUSTABLE REGULATOR |
| 文件： | 总6页 (文件大小：80K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
AIC1741
LOW DROPOUT ADJUSTABLE REGULATOR
SPEC NO: DS-1741-00
ꢀ FEATURES
ꢀ DESCRIPTION
ꢀ 1% Accuracy 1.235V Voltage Reference.
The AIC1741 is a low power precision adjustable
regulator with 80mA output capability. The device
can be used as a secondary regular to provide
feedback in a switching power supply.
ꢀ Fast Transient Response.
ꢀ Low Ground Current at 55µA.
ꢀ Wide Output Current Range, 10µA~80mA.
ꢀ Output Programmable from 1.235V~11V.
ꢀ Low Temperature Coefficiency.
ꢀ Error Flag Warns of Output Dropout.
The AIC1741 circuitry includes an internal wide
band amplifier, a precision bandgap reference,
and a PMOS output transistor. The feedback
input can be connected to an external resistor
divider to program the sensed output voltage.
The VOUT pin provides loop frequency
compensation when used as a part of a larger
servo system.
ꢀ APPLICATIONS
ꢀ Voltage Regulator for Pentium® CPUs.
ꢀ Wireless Communication System.
ꢀ 5V to 3.3V Regulator for VGA Cards.
ꢀ Battery Powered Systems.
Although the device works as a stand-alone
regulator, it can also drive an NPN power
transistor to construct a high current low dropout
regulator, with only very minor current loss to
ground.
ꢀ TYPICAL APPLICATION CIRCUIT
VIN
5V
8
1
Q1
TIP31C
VOUT
NC
VIN
FB
C1
10 F
+
7
2
µ
VOUT
3.3V/3 A
+
3
4
6
5
GND
NC
FLAG
NC
R1
390
C2
33 F
µ
R3
2K
+
C3
AIC1741
10 F
µ
R2
1.2K
5V to 3.3V Regulator for VGA Cards.
ꢀ ORDERING INFORMATION
AIC1741 XX
PIN CONFIGURATION
ORDER NUMBER
PACKAGE TYPE
N: PLASTIC DIP
S: SMALL OUTLINE
TOP VIEW
AIC1741CN
(PLASTIC DIP)
VOUT
VIN
FB
1
2
3
4
8
7
6
5
TEMPERATURE RANGE
C: 0°C~+70°C
NC
GND
NC
AIC1741CS
(PLASTIC SO)
FLAG
NC
®
Pentium is a registered trademark of Intel Corporation
ANALOG INTEGRATIONS CORPORATION
www.analog.com.tw
4F,9IndustryE.9thRoad,Science-basedIndustrialPark,Hsinchu,Taiwan, R.O.C.
TEL: (8863)577-2500 FAX:(8863)577-2510
1
AIC1741
LOW DROPOUT ADJUSTABLE REGULATOR
SPEC NO: DS-1741-00
ꢀ ABSOLUTE MAXIMUM RATINGS
Input Supply Voltage
................……………...................................................... -0.3~12V
Feedback Input Voltage .............……………...................................................... -0.3~12V
Shutdown Input Voltage ...........……………....................................................... -0.3~12V
Error Comparator Output ..........………….......................................................... -0.3~12V
Operating Junction Temperature Range ……….......................................... -40°C~125°C
Storage Temperature Range ...............…………......................................... -65°C~150°C
ꢀ TEST CIRCUIT
1
2
8
7
VOUT
NC
VIN
VOUT
3.3V
V
IN
+
CIN
1 F
FB
COUT
10 F
1mA
µ
R1
2K
µ
6
5
3
4
FLAG
NC
GND
NC
R2
1.2K
AIC1741
ꢀ ELECTRICAL CHARACTERISTICS (Ta=25°C, CIN=1µF, COUT=10µF, unless otherwise
specified. Test conditions are referred to TEST CIRCUIT.)
PARAMETER
TEST CONDITIONS
MIN.
TYP.
MAX. UNIT
Output Voltage
VIN=3.6~12V, No Load, VOUT=3.3V
(Note 1)
3.267
3.3
3.333
150
V
Output Voltage Temperature
Coefficiency
50
PPM/°C
Line Regulation
VIN=3.6~12V, IL=1mA, VOUT=3.3V
VIN=7V, IL=0.1~80mA, VOUT=3.3V
3
4
10
10
mV
mV
Load Regulation
(Note 2)
Dropout Voltage
(Note 3)
IL=0.1mA
0.2
10
mV
IL=80mA, VOUT=3.3V
200
300
Ground Current
VIN=4~12V, IO=0.1mA~IMAX
55
80
1
µA
µA
Flag Pin Off Leakage Current VIN=7V
Flag Pin Pull Low Voltage
IOL=1mA, VIN=2.9V
100
60
300
mV
Flag Pin Upper Threshold
Voltage
40
mV
mV
Flag Pin Lower Threshold
Voltage
68
88
Note 1:
Note 2:
Note 3:
Guaranteed by design.
Regulation is measured at constant junction temperature, using pulse testing with a low ON time.
Dropout voltage is defined as the input to output differential at which the output voltage drops 100mV
below the value measured with a 1V differential.
ANALOG INTEGRATIONS CORPORATION
www.analog.com.tw
4F,9IndustryE.9thRoad,Science-basedIndustrialPark,Hsinchu,Taiwan, R.O.C.
TEL: (8863)577-2500 FAX:(8863)577-2510
2
AIC1741
LOW DROPOUT ADJUSTABLE REGULATOR
SPEC NO: DS-1741-00
ꢀ TYPICAL PERFORMANCE CHARACTERISTICS
Reference Voltage vs. Temperature
Ground Current vs. Input Voltage
1.28
1.26
1.24
1.22
1.2
60
50
VREF=1.244V
40
30
20
VREF=1.225V
VREF=1.225V
10
0
1.18
-50
-25
0
25
50
75
100
125
0
2
8
4Input Vol6tage (V)
10
12
Temperature ( C)
°
Dropout Voltage vs. Load Current
VOUT=3.3V
Ground Current vs. Temperature
60
58
56
54
52
50
200
150
100
IL=80mA
IL=0.1mA
50
0
0
20
40
60
80
100
-50
-25
0
25
50
75
100
125
Temperature( C)
°
Load Current (mA)
Dropout Voltage vs Temperature
Bias Current vs. Temperature
40
300
250
200
150
100
50
VOUT=3.3V
IL=80mA
30
20
10
IL=0.1mA
0
125
-50
-25
0
25
50
75
100
-50
-25
0
25
50
75
100
125
Temperature( C)
°
Temperature ( C)
°
ANALOG INTEGRATIONS CORPORATION
4F,9IndustryE.9thRoad,Science-basedIndustrialPark,Hsinchu,Taiwan, R.O.C.
www.analog.com.tw
TEL: (8863)577-2500 FAX:(8863)577-2510
3
AIC1741
LOW DROPOUT ADJUSTABLE REGULATOR
SPEC NO: DS-1741-00
ꢀ TYPICAL PERFORMANCE CHARACTERISTICS (CONTINUED)
Minimum Operating Voltage vs Temperature
2.8
2.7
2.6
2.5
2.4
2.3
2.2
-50
-25
0
25
50
75
100
125
Temperature ( C)
°
ꢀ BLOCK DIAGRAM
8
VIN
7
+
FB
-
1
6
VOUT
FLAG
66mV
+
-
1.235V, Reference
3
GND
ꢀ PIN DESCRIPTIONS
PIN 1: VOUT - Output pin.
PIN 6: FLAG - Open drain output of error flag
warns.
PIN 2: NC
-
PIN 7: FB
- Error amplifier positive feedback
(see Block Diagram)
PIN 3: GND - Power GND.
PIN 4: NC
PIN 5: NC
-
-
PIN 8: VIN
- Power supply input.
ANALOG INTEGRATIONS CORPORATION
4F,9IndustryE.9thRoad,Science-basedIndustrialPark,Hsinchu,Taiwan, R.O.C.
www.analog.com.tw
TEL: (8863)577-2500 FAX:(8863)577-2510
4
AIC1741
LOW DROPOUT ADJUSTABLE REGULATOR
SPEC NO: DS-1741-00
ꢀ APPLICATION INFORMATIONS
nearby noise sources can also upset the output. This
may especially be a problem when using high value
external resistors to set the output voltage. Adding a
100pF capacitor between output and feedback and
increasing the output capacitor to at least 3.3µF will
cure this problem.
The AIC1741 has two major applications, one as a
low dropout linear regulator and another an error
amplifier for a switching power supply to provide
precision feedback control.
Use as a Linear Regulator
When AIC1741 is connected as a low dropout linear
regulator, two external divider resistors are needed to
set the output voltage (see Test Circuit). The output
voltage can be calculated from the following formula:
The AIC1741 can drive low cost NPN bipolar
transistor to deliver more output current. Typical
application circuit is an example of 5V to 3.3V linear
regulator for VGA cards power supply. A 390Ω
resistor and 1µF capacitor are needed between
VOUT pin and ground for stability. The minimum
dropout voltage between input to output is VBEQ1+VDS
of AIC1741 output PMOSFET, typical 1V @ 3A
output current.
VOUT=VREF(1+R1/R2)+IFBR1
where VREF is the nominal 1.235V reference voltage
and IFB is the feedback pin bias current, nominally
-20nA. For better accuracy, the recommended
maximum value of R2 is 100KΩ.
A 1µF (or greater) capacitor is required between the
AIC1741 output and ground for stability. Without this
capacitor the part will oscillate. Even though most
types of capacitor may work, if Aluminum electrolytic
type is used, the equivalent series resistance (ESR)
should be held to 5Ω. or less. Many Aluminum
electrolytics have electrolytes that freeze at about
-30°C, so solid tantalums are recommended for
operation below -25°C. The value of this capacitor
may be increased without limit.
Use as an Error Amplifier
Fig. 1 shows a popular application for the AIC1741 in
switching power supply. The output voltage is sensed
between FB pin and GND pin of the AIC1741 through
the divider resistor. The VIN pin servos to control the
duty cycle of the pulse width modulator to stabilize
the output voltage at the set voltage. The FB pin and
VIN pin are in same phase while the FB pin and
VOUT pin are in opposite phases. Connecting a
capacitor from VOUT pin to FB pin provides
frequency compensation for the control loop. The
AIC1741 provides output voltage remote sensing to
improve precision and regulation specifications of the
output of the switching power supply.
The output capacitance required for stability varies
with output voltage (smaller for higher output voltage)
and output current (smaller for lower output currents).
At the worst-case situation of a 80mA load at 1.235V
output (output shorted to FB pin) a 3.3 µF or greater
capacitor should be used.
A 0.1µF capacitor should be placed from the
AIC1741 input to ground if the lead inductance
between the input and power source exceeds 500nH
(approximately 10 inches of trace). Noise injection
into the feedback terminal of the AIC1741 from
ANALOG INTEGRATIONS CORPORATION
www.analog.com.tw
4F,9IndustryE.9thRoad,Science-basedIndustrialPark,Hsinchu,Taiwan, R.O.C.
TEL: (8863)577-2500 FAX:(8863)577-2510
5
AIC1741
LOW DROPOUT ADJUSTABLE REGULATOR
SPEC NO: DS-1741-00
ꢀ APPLICATION EXAMPLES
C3
VIN
5V
1N4148
D3
0.1µF
+
D2
1N4148
1000µF/6.3Vx2
C6
Q2
SC
VOUT : 2.5V~3.5V/10A
L1
R1
1K
SE
BST
7.5µF
+
AIC1562
12V
0.022µF
C4
TC
VCC
FB
C11
C10
C4
P5
MICROPROCESSOR
CPU
R2
24K
+
D1
GND
0.1µF
x2
0.1µF
1000µF/6.3V
C1
x2
x5
ZD1
5.1V
47µF
+
C2
220pF
C13
R8
10K
VIN
FB
VOUT
R2*
GND
C11, C12: Ceramic Capacitor
L1: Iron Powder Core
VOUT= (1+R10/1K)x1.235V
R10
1K
C5
R7
470
R3
1K
AIC1741
0.1µF
Fig. 1 CPU Power Supply for P5 Mother Board
ꢀ PHYSICAL DIMENSIONS
ꢀ 8 LEAD PLASTIC DIP
ꢀ
8 LEAD PLASTIC SO
4.80±0.20
9.3±0.3
±
6.2 0.2
8.0±0.5
±
1.27±0.10
3.3 0.1
0.015X45°
±
0.6 0.3
1.5±0.2
±
2.5 0.1
3.2±0.3
10°max
8.5±1.0
0.5±0.1
±
2.54 0.10
0.45±0.10
8° max.
UNIT: mm
ANALOG INTEGRATIONS CORPORATION
www.analog.com.tw
4F,9IndustryE.9thRoad,Science-basedIndustrialPark,Hsinchu,Taiwan, R.O.C.
TEL: (8863)577-2500 FAX:(8863)577-2510
6
相关型号：
©2020 ICPDF网 联系我们和版权申明