AIC AIC2951-30CN Low dropout linear regulator Datasheet

AIC2951/2951D
Low Dropout Linear Regulator
n FEATURES
n DESCRIPTION
l
Low Dropout Voltage of 130mV at 100mA Output
Current (AIC2951/2951D-50).
l
Guaranteed 150mA /300mA Output Current.
l
Internal 1.3Ω P-MOSFET Draws no Base Current.
l
Low Ground Current at 55µA.
zero base current loss, very low dropout voltage,
l
1% Accuracy Output of 3V/3.3V/5V.
and 1% accuracy output voltage. Typical ground
l
Error Flag Warns of Output Dropout.
current remains approximately 55µA, from no
l
1µA Supply Current in Shutdown Mode.
load to maximum loading conditions. Dropout
l
Output Programmable from 1.235V~11V.
voltage at 100mA output current is significantly
l
Fast Transient Response.
lower than its bipolar counterpart: 130mV for the
l
Needs only 1µF for Stability.
AIC2951-50/2951D-50, 180mV for the AIC2951-
l
Current and Thermal Limiting.
33/ 2951D-33, and 200mV for the AIC2951-30/
The AIC2951/ 2951D series is the enhanced
CMOS version of the LP2951. The superior characteristics of the AIC2951/ 2951D series include
n APPLICATIONS
2951D-30. Output current limiting and thermal
limiting are built in to provide maximal protection

l
Voltage Regulator for Pentium CPUs.
l
Wireless Communication System.
l
Battery Powered Systems.
to the AIC2951/2951D series from fault conditions.
An error flag output, indicating when output voltage drops out of regulation, often due to the
falling batteries on the input, can be used for a
power-on reset. A logic-controlled shutdown
input enables the regulator to be switched on and
off. The part may be configured for a fixed output
voltage or programmed from 1.235V to 11V with
an external pair of resistors. The part comes in 8pin DIP or SO packages.
n TYPICAL APPLICATION CIRCUIT
VOUT=1.235(1+R1/R2)
+
R3
390
1
2
R4
33
VOUT
VIN
SENSE
FB
3
GND
7
6
SHDN
4
8
TAP
ERROR
AIC2951
C1
470 µF
Q1
D45H2A
VIN
VOUT
R1
5
+
C2
1000µF
R2
Pentium Processor Power Supply
Analog Integrations Corporation
www.analog.com.tw
DS-2951-01 Mar 13, 00
4F, 9, Industry E. 9th Rd, Science Based Industrial Park, Hsinchu Taiwan, ROC
TEL: 886-3-5772500
FAX: 886-3-5772510
1
AIC2951/2951D
Low Dropout Linear Regulator
n ORDERING INFORMATION
AIC2951 X-XXXX
ORDER NUMBER
PACKAGE TYPE
N: PLASTIC DIP
S: SMALL OUTLINE
PIN CONFIGURATION
AIC2951-30CN
AIC2951-33CN
AIC2951-50CN
AIC2951D-30CN
AIC2951D-33CN
AIC2951D-50CN
(PLASTIC DIP)
TEMPERATURE RANGE
C: 0 ° C~+70 °C
OUTPUT VOLTAGE
30 : 3.0V
33 : 3.3V
50 : 5.0V
TOP VIEW
AIC2951-30CS
AIC2951-33CS
AIC2951-50CS
AIC2951D-30CS
AIC2951D-33CS
AIC2951D-50CS
(PLASTIC SO)
MAX. OUTPUT CURRENT
DEFAULT
: 150mA
D : 300mA
VOUT
1
8
VIN
SENSE
2
7
FB
SHDN
3
6
TAP
GND
4
5
ERROR
n 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
n TEST CIRCUIT
VOUT
VOUT
+
C OUT
10µF
SHUTDOWN
VIN
VIN
VREF
FB
SENSE
SHDN
+
C IN
1µ F
TAP
1mA
GND
ERROR
AIC2951
2
AIC2951/2951D
n ELECTRICAL CHARACTERISTICS (Ta=25°C, C
IN=1µF,
COUT=10µF, unless oth-
erwise specified.)
PARAMETER
Output Voltage
TEST CONDITIONS
No Load
AIC2951/2951D-50
AIC2951/2951D-33
AIC2951/2951D-30
MIN.
VIN=5.5~12V
VIN=3.6~12V
VIN=3.3~12V
4.950
3.267
2.970
Output Voltage Tempera- (Note 1)
ture Coefficiency
Line Regulation
Load Regulation
(Note 2)
Current Limit
(Note 3)
Dropout Voltage
(Note 4)
Ground Current
FB Reference Voltage
IL =1mA
AIC2951/2951D-50
AIC2951/2951D-33
AIC2951/2951D-30
AIC2951-50
AIC2951D-50
AIC2951-30/ -33
AIC2951D-30/-33
VIN=5.5~12V
VIN=3.6~12V
VIN=3.3~12V
VIN=7V,
VIN=7V,
VIN=5V,
VIN=5V,
IL =0.1~150mA
IL =0.1~300mA
IL =0.1~150mA
IL =0.1~300mA
VOUT =0V
VOUT =0V
VOUT =0V
VOUT =0V
TYP. MAX.
5.0
3.3
3.0
5.050
3.333
3.030
50
150
3
3
3
10
10
10
7
7
7
7
15
25
15
25
AIC2951-50
AIC2951-30/ -33
AIC2951D-50
AIC2951D-30/ -33
VIN=7V,
VIN=5V,
VIN=7V,
VIN=5V,
AIC2951/2951D
AIC2951-50
AIC2951-33
AIC2951-30
AIC2951D-50
AIC2951D-33
AIC2951D-30
IL =0.1mA
IL =150mA
IL =150mA
IL =150mA
IL =300mA
IL =300mA
IL =300mA
0.2
200
270
300
400
540
600
10
300
370
400
500
640
700
IO=0.1mA~IMAX
AIC2951/2951D-50
AIC2951/2951D-33
AIC2951/2951D-30
VIN=5.5~12V
VIN=4~12V
VIN=4~12V
55
55
55
80
80
80
AIC2951-50
AIC2951-30/ -33
VIN=5.5~12V
VIN=3.6~12V
1.235
1.235
1.248
1.248
50
150
20
60
Reference Voltage Temp.
Coef. (Note 1)
FB Pin Current
AIC2951/2951D
VIN=7V
Error Pin off Leakage
Current
AIC2951/2951D
VIN=7V
Error Pin Pull Low
Voltage
IOL=1mA
AIC2951/2951D-50
AIC2951/2951D-33
VIN=4.5V
VIN=2.9V
220
220
440
440
1.222
1.222
100
100
UNIT
V
PPM/°C
mV
mV
MA
mV
µA
V
PPM/°C
NA
1
µA
300
300
mV
3
AIC2951/2951D
AIC2951/2951D-30
VIN=2.7V
100
300
n ELECTRICAL CHARACTERISTICS (CONTINUED)
PARAMETER
Output Voltage
TEST CONDITIONS
No Load
AIC2951/2951D-50
AIC2951/2951D-33
AIC2951/2951D-30
VIN=5.5~12V
VIN=3.6~12V
VIN=3.3~12V
Error Pin Upper Threshold Voltage
MIN.
4.950
3.267
2.970
5.0
3.3
3.0
40
60
Error Pin Lower Threshold
Voltage
Shutdown Threshold
Voltage
AIC2951/2951D
VIN=7V
Shutdown Input Bias
Current
AIC2951/2951D
VIN=7V, VSHDN=2V
Shutdown Supply
Current
AIC2951/2951D
VIN=7V, VSHDN=2V
Note 1:
Note 2:
Note 3:
Note 4:
TYP. MAX.
0.5
5.050
3.333
3.030
UNIT
V
mV
68
88
0.8
2
10
25
µA
2
µA
MV
V
Guaranteed by design.
Regulation is measured at constant junction temperature, using pulse testing with a low ON time.
Current limit is measured by pulsing a short 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.
4
AIC2951/2951D
n TYPICAL PERFORMANCE CHARACTERISTICS
Ground Current vs. Input Voltage
60
1.26
50
Ground Current (µA)
Reference Voltage (V)
Reference Voltage vs Temperature
1.28
VREF=1.244V
1.24
VREF=1.235V
1.22
VREF=1.225V
1.2
40
30
20
10
1.18
0
-50
-25
0
25
50
75
100
125
0
1
2
3
Temperature(°C)
4
5
6
7
8
Input Voltage (V)
Dropout Voltage vs Load Current
Ground Current vs. Temperature
600
60
500
Dropout Voltage (mV)
Ground Current (µA)
58
IL =300mA
56
IL=150mA
54
IL=0.1mA
52
VOUT=3V
400
VOUT =3.3V
300
VOUT =5V
200
100
0
50
-50
0
-25
25
50
Temperature(° C)
75
100
0
125
250
200
300
Short Circuit Current vs. Temperature
Dropout Voltage vs Temperature
500
VOUT =5V
Short Circuit Current (mA)
Dropout Voltage(mV)
150
Load Current (mA)
600
500
100
50
IL =300mA
400
300
IL =150mA
200
100
AIC2951D
400
300
AIC2951
IL =0.1mA
0
-50
-25
0
25
50
Temperature( °C)
75
100
125
200
-50
-25
0
25
50
Temperature (°C)
75
100
125
5
AIC2951/2951D
TYPICAL PERFORMANCE CHARACTERISTICS (CONTINUED)
Line Transient Response
Load Transient Response
0
C OUT=1µF
IL=1mA
V OUT =5V
6
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
150
0.1
1.0
0
0.5
1.0
1.5
2.0
2.5
3.0
Time (mS)
Time (mS)
Load Transient Response
Enable Transient
COUT =10µF
V OUT=5V
20
0
-200
8
0
COUT=1µF
VOUT=5V
100
-100
Load Current
(mA)
Input Voltage
(V)
-50
Output Voltage
(mV, AC)
Output Voltage
(mV, AC)
50
Output Voltage
(V)
Output Voltage
(mV, AC)
100
0
-20
-40
3.5
4.0
4.5
5.0
COUT=1µF
6
4
IL=10mA
V IN=8V
V OUT=5V
2
C OUT=10 µF
0
150
0.1
0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
Shutdown Voltage
(V)
Load Current
(mA)
-60
2
0
0
0.1
0.2
0.3
Time (mS)
0.4
0.5
0.6
0.7
0.8
0.9
1.0
Time (mS)
FB Pin Bias Current vs. Temperature
Minmum Operating Voltage vs Temperature
40
2.8
Minimum Operating Voltage (V)
FB Pin Current (nA)
n
30
20
10
-50
-25
0
25
50
Temperature (°C)
75
100
125
2.7
2.6
2.5
2.4
2.3
2.2
-50
-25
0
25
50
Temperature (°C)
75
100
125
6
AIC2951/2951D
n BLOCK DIAGRAM
FB
VOUT
VIN
8
7
1
2
SENSE
RF1
+
3
6
ERROR
AMP
TAP
SHDN
RF2
60mV
+
+
-
5
ERROR
ERROR DETECTION
COMPARATOR
+
1.235V REFERENCE
4
GND
n PIN DESCRIPTIONS
ERROR - Open drain output of error flag warns.
PIN 1: VOUT - Output pin.
PIN 5:
PIN 2: SENSE -Remote sense input, connected
to internal resistor divider.
PIN 6: TAP
- Center output of internal resistor divider.
PIN 3: SHDN - Shutdown input.
PIN 7: FB
- Error amplifier positive feedback (see
Block Diagram)
PIN 8: VIN
- Power supply input
PIN 4: GND
- Power GND.
n APPLICATION INFORMATIONS
Output Filter Capacitors
A 1µF (or greater) capacitor is required between the AIC2951/AIC2951D 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.
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 150mA 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 AIC2951/2951D 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 AIC2951/2951D from nearby noise sources can also upset the output. This may especially
be a problem when using high value external resisProgramming the Output Voltage
tors to set the output voltage. Adding a 100pF capacitor between output and feedback and increasThe AIC2951/2951D series can be set to deliver
ing the output capacitor to at least 3.3µF will cure
any output voltage from 1.235V to 11V by using an
this problem.
external voltage divider. In addition, internal voltage
7
AIC2951/2951D
dividers are provided for 3.0V/3.3V/5.0V output versions. To use the internal voltage divider, connect
the SENSE pin to output and the TAP pin to the FB
pin. When using an external divider the SENSE and
TAP pins are left open, and the divider is installed
from the output to ground, with its center connected
to the FB pin (see Fig. 1). When using an external
voltage divider, resistance can be calculated from
the following formula:
R1
VOUT = VREF × (1 +
) + IFB × R1
R2
R2. Using a 1.2MΩ resistor for R2, the bias current
will already cause a 2% shift in output voltage. For
better accuracy, choosing R2=100KΩ reduces this
error to 0.17% at the price of merely increasing the
resistor programming current to 12µA.
Reducing Output Noise
In reference applications it may be advantageous to
reduce the AC noise present at the output. One
method is to reduce the regulator bandwidth by increasing the size of the output capacitor. Another,
noise can be reduced by bypassing the upper resistor in the feedback divider with a small capacitor,
since the capacitor provides a more direct path for
AC feedback. The size of this capacitor can be calculated from the formula:
CBYPASS ≅ 1/(2π × R1× fCORNER )
V OUT
+
VIN
C2
3.3 µF
+
R1
C1
1
VOUT
2
3
SHUTDOWN
VIN
SENSE
FB
SHDN
TAP
8
C3
0.01µF
7
6
Where R1 is the upper resistor of the feedback divider and fCORNOR is the frequency above which the
increased AC feedback is to become active. The
reduction of the output noise at high frequency will
be proportional to the ratio of the two resistors in
the feedback divider, R2/(R1+R2). In order to maintain regulator stability when using a noise-reducing
bypass capacitor, it will also be necessary to increase the size of the output filter capacitor by the
same ratio.
R2
4
GND
ERROR
5
AIC2951
Fig. 1 Adjustable Regulator
Where VREF is the nominal 1.235V reference voltage
and IFB is the feedback pin bias current, nominally 20nA. The minimum recommended load current of
1µA forces an upper limit of 1.2MΩ on the value of
n APPLICATION EXAMPLES
VOUT=1.235(1+R1/1K)
+
1
VOUT
VIN
2
R4
33
SENSE
FB
3
7
6
SHDN
4
8
GND
TAP
ERROR
AIC2951
5
C1
1000µF
6.3V
VIN
5V
Q1
D45H2A
VOUT=3.3V
100
0
-100
VOUT
R1
*
+
C2
R2
1K
1000µFx5
6.3V
Load Current
(A)
R3
390
Output Voltage
(mV, AC)
Load Transient Response
5
0
0

0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
Time (mS)
Fig. 2 Pentium Processor Power Supply
8
AIC2951/2951D
n APPLICATION EXAMPLES (CONTINUED)
IL=1.235/R
LOAD
V IN=2.5V-12V
VOUT ≅VIN
+
1
C1
1 µF
1 VOUT
VIN 8
2 SENSE
FB 7
3
4
SHDN
TAP
ERROR
GND
8
VOUT
V IN=2.5V-12V
2
6
3
5
4
SENSE
SHDN
GND
AIC2951
Fig. 3
VIN
7
FB
6
TAP
+
5
ERROR
R
1µF
C1
AIC2951
Current Limiter
Fig. 4
Precision Sink Current Source
n PHYSICAL DIMENSIONS
l
8 LEAD PLASTIC SO (unit: mm)
D
SYMBOL
MIN
MAX
A
1.35
1.75
A1
0.10
0.25
B
0.33
0.51
C
0.19
0.25
D
4.80
5.00
E
3.80
4.00
H
E
e
e
A
A1
C
B
l
L
1.27(TYP)
H
5.80
6.20
L
0.40
1.27
8 LEAD PLASTIC DIP (unit: mm)
D
E1
E
A2
A1
C
L
eB
b
SYMBOL
MIN
A1
0.381
—
A2
2.92
4.96
b
0.35
0.56
C
0.20
0.36
D
9.01
10.16
E
7.62
8.26
E1
6.09
7.12
e
MAX
2.54 (TYP)
eB
—
10.92
L
2.92
3.81
e
9
AIC2951/2951D
10