1963af.pm6
1
LT1963A Series
1963af
TYPICAL APPLICATIO
N
U
APPLICATIO S
U
FEATURES
DESCRIPTIO
U
1.5A, Low Noise,
Fast Transient Response
LDO Regulators
s
Optimized for Fast Transient Response
s
Output Current: 1.5A
s
Dropout Voltage: 340mV
s
Low Noise: 40
V
RMS
(10Hz to 100kHz)
s
1mA Quiescent Current
s
No Protection Diodes Needed
s
Controlled Quiescent Current in Dropout
s
Fixed Output Voltages: 1.5V, 1.8V, 2.5V, 3.3V
s
Adjustable Output from 1.21V to 20V
s
< 1
A Quiescent Current in Shutdown
s
Stable with 10
F Output Capacitor
s
Stable with Ceramic Capacitors
s
Reverse Battery Protection
s
No Reverse Current
s
Thermal Limiting
The LT
1963A series are low dropout regulators opti-
mized for fast transient response. The devices are capable
of supplying 1.5A of output current with a dropout voltage
of 340mV. Operating quiescent current is 1mA, dropping
to < 1
A in shutdown. Quiescent current is well controlled;
it does not rise in dropout as it does with many other
regulators. In addition to fast transient response, the
LT1963A regulators have very low output noise which
makes them ideal for sensitive RF supply applications.
Output voltage range is from 1.21V to 20V. The LT1963A
regulators are stable with output capacitors as low as
10
F. Small ceramic capacitors can be used without the
necessary addition of ESR as is common with other
regulators. Internal protection circuitry includes reverse
battery protection, current limiting, thermal limiting and
reverse current protection. The devices are available in
fixed output voltages of 1.5V, 1.8V, 2.5V, 3.3V and as an
adjustable device with a 1.21V reference voltage. The
LT1963A regulators are available in 5-lead TO-220, DD,
3-lead SOT-223 and 8-lead SO packages.
3.3V to 2.5V Regulator
s
3.3V to 2.5V Logic Power Supplies
s
Post Regulator for Switching Supplies
, LTC and LT are registered trademarks of Linear Technology Corporation.
IN
SHDN
10
F*
*TANTALUM,
CERAMIC OR
ALUMINUM ELECTROLYTIC
1963 TA01
OUT
V
IN
> 3V
SENSE
GND
LT1963A-2.5
2.5V
1.5A
10
F*
+
+
OUTPUT CURRENT (A)
0
DROPOUT VOLTAGE (mV)
200
300
1.6
1963 TA02
100
0
0.4
0.8
1.2
0.2
0.6
1.0
1.4
400
150
250
50
350
Dropout Voltage
2
LT1963A Series
1963af
(Note 1)
IN Pin Voltage ........................................................
20V
OUT Pin Voltage ....................................................
20V
Input to Output Differential Voltage (Note 2) .........
20V
SENSE Pin Voltage ...............................................
20V
ADJ Pin Voltage ......................................................
7V
SHDN Pin Voltage .................................................
20V
Output Short-Circuit Duration ......................... Indefinite
Operating Junction Temperature Range 45
C to 125
C
Storage Temperature Range ................. 65
C to 150
C
Lead Temperature (Soldering, 10 sec).................. 300
C
ABSOLUTE AXI U RATI GS
W
W
W
U
ORDER PART
NUMBER
LT1963AEQ
LT1963AEQ-1.5
LT1963AEQ-1.8
LT1963AEQ-2.5
LT1963AEQ-3.3
T
JMAX
= 150
C,
JA
= 30
C/ W
*PIN 5 = SENSE FOR LT1963A-1.8/LT1963A-2.5/LT1963A-3.3
= ADJ FOR LT1963A
ORDER PART
NUMBER
LT1963AET
LT1963AET-1.5
LT1963AET-1.8
LT1963AET-2.5
LT1963AET-3.3
*PIN 5 = SENSE FOR LT1963A-1.8/LT1963A-2.5/LT1963A-3.3
= ADJ FOR LT1963A
T
JMAX
= 150
C,
JA
= 50
C/ W
Q PACKAGE
5-LEAD PLASTIC DD
TAB IS
GND
FRONT VIEW
SENSE/ADJ*
OUT
GND
IN
SHDN
5
4
3
2
1
T PACKAGE
5-LEAD PLASTIC TO-220
SENSE/ADJ*
OUT
GND
IN
SHDN
FRONT VIEW
TAB IS
GND
5
4
3
2
1
3
2
1
FRONT VIEW
TAB IS
GND
OUT
GND
IN
ST PACKAGE
3-LEAD PLASTIC SOT-223
T
JMAX
= 150
C,
JA
= 50
C/ W
LT1963AEST-1.5
LT1963AEST-1.8
LT1963AEST-2.5
LT1963AEST-3.3
ORDER PART
NUMBER
LT1963AES8
LT1963AES8-1.5
LT1963AES8-1.8
LT1963AES8-2.5
LT1963AES8-3.3
ORDER PART
NUMBER
1
2
3
4
8
7
6
5
TOP VIEW
IN
GND
GND
SHDN
OUT
SENSE/ADJ*
GND
NC
S8 PACKAGE
8-LEAD PLASTIC SO
*PIN 2 = SENSE FOR LT1963A-1.8/LT1963A-2.5/LT1963A-3.3
= ADJ FOR LT1963A
T
JMAX
= 150
C,
JA
= 70
C/ W
PACKAGE/ORDER I FOR ATIO
U
U
W
ST PART
MARKING
1963A
963A15
963A18
963A25
963A33
S8 PART
MARKING
963A15
963A18
963A25
963A33
Consult LTC Marketing for parts specified with wider operating temperature ranges.
3
LT1963A Series
1963af
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
Minimum Input Voltage (Notes 4,12)
I
LOAD
= 0.5A
1.9
V
I
LOAD
= 1.5A
q
2.1
2.5
V
Regulated Output Voltage (Note 5)
LT1963A-1.5
V
IN
= 2.21V, I
LOAD
= 1mA
1.477
1.500
1.523
V
2.5V < V
IN
< 20V, 1mA < I
LOAD
< 1.5A
q
1.447
1.500
1.545
V
LT1963A-1.8
V
IN
= 2.3V, I
LOAD
= 1mA
1.773
1.800
1.827
V
2.8V < V
IN
< 20V, 1mA < I
LOAD
< 1.5A
q
1.737
1.800
1.854
V
LT1963A-2.5
V
IN
= 3V, I
LOAD
= 1mA
2.462
2.500
2.538
V
3.5V < V
IN
< 20V, 1mA < I
LOAD
< 1.5A
q
2.412
2.500
2.575
V
LT1963A-3.3
V
IN
= 3.8V, I
LOAD
= 1mA
3.250
3.300
3.350
V
4.3V < V
IN
< 20V, 1mA < I
LOAD
< 1.5A
q
3.200
3.300
3.400
V
ADJ Pin Voltage
LT1963A
V
IN
= 2.21V, I
LOAD
= 1mA
1.192
1.210
1.228
V
(Notes 4, 5)
2.5V < V
IN
< 20V, 1mA < I
LOAD
< 1.5A
q
1.174
1.210
1.246
V
Line Regulation
LT1963A-1.5
V
IN
= 2.21V to 20V, I
LOAD
= 1mA
q
2.0
6
mV
LT1963A-1.8
V
IN
= 2.3V to 20V, I
LOAD
= 1mA
q
2.5
7
mV
LT1963A-2.5
V
IN
= 3V to 20V, I
LOAD
= 1mA
q
3.0
10
mV
LT1963A-3.3
V
IN
= 3.8V to 20V, I
LOAD
= 1mA
q
3.5
10
mV
LT1963A (Note 4)
V
IN
= 2.21V to 20V, I
LOAD
= 1mA
q
1.5
5
mV
Load Regulation
LT1963A-1.5
V
IN
= 2.5V,
I
LOAD
= 1mA to 1.5A
2
9
mV
V
IN
= 2.5V,
I
LOAD
= 1mA to 1.5A
q
18
mV
LT1963A-1.8
V
IN
= 2.8V,
I
LOAD
= 1mA to 1.5A
2
10
mV
V
IN
= 2.8V,
I
LOAD
= 1mA to 1.5A
q
20
mV
LT1963A-2.5
V
IN
= 3.5V,
I
LOAD
= 1mA to 1.5A
2.5
15
mV
V
IN
= 3.5V,
I
LOAD
= 1mA to 1.5A
q
30
mV
LT1963A-3.3
V
IN
= 4.3V,
I
LOAD
= 1mA to 1.5A
3
20
mV
V
IN
= 4.3V,
I
LOAD
= 1mA to 1.5A
q
35
mV
LT1963A (Note 4)
V
IN
= 2.5V,
I
LOAD
= 1mA to 1.5A
2
8
mV
V
IN
= 2.5V,
I
LOAD
= 1mA to 1.5A
q
15
mV
Dropout Voltage
I
LOAD
= 1mA
0.02
0.06
V
V
IN
= V
OUT(NOMINAL)
I
LOAD
= 1mA
q
0.10
V
(Notes 6, 7, 12)
I
LOAD
= 100mA
0.10
0.17
V
I
LOAD
= 100mA
q
0.22
V
I
LOAD
= 500mA
0.19
0.27
V
I
LOAD
= 500mA
q
0.35
V
I
LOAD
= 1.5A
0.34
0.45
V
I
LOAD
= 1.5A
q
0.55
V
GND Pin Current
I
LOAD
= 0mA
q
1.0
1.5
mA
V
IN
= V
OUT(NOMINAL)
+ 1V
I
LOAD
= 1mA
q
1.1
1.6
mA
(Notes 6, 8)
I
LOAD
= 100mA
q
3.8
5.5
mA
I
LOAD
= 500mA
q
15
25
mA
I
LOAD
= 1.5A
q
80
120
mA
Output Voltage Noise
C
OUT
= 10
F, I
LOAD
= 1.5A, BW = 10Hz to 100kHz
40
V
RMS
ADJ Pin Bias Current
(Notes 4, 9)
3
10
A
Shutdown Threshold
V
OUT
= Off to On
q
0.90
2
V
V
OUT
= On to Off
q
0.25
0.75
V
SHDN Pin Current
V
SHDN
= 0V
0.01
1
A
(Note 10)
V
SHDN
= 20V
3
30
A
Quiescent Current in Shutdown
V
IN
= 6V, V
SHDN
= 0V
0.01
1
A
Ripple Rejection
V
IN
V
OUT
= 1.5V (Avg), V
RIPPLE
= 0.5V
P-P
,
55
63
dB
f
RIPPLE
= 120Hz, I
LOAD
= 0.75A
Current Limit
V
IN
= 7V, V
OUT
= 0V
2
A
V
IN
= V
OUT(NOMINAL)
+ 1V,
V
OUT
= 0.1V
q
1.6
A
The
q
denotes specifications which apply over the full operating temperature range, otherwise specifications are T
A
= 25
C. (Note 2)
ELECTRICAL CHARACTERISTICS
4
LT1963A Series
1963af
TYPICAL PERFOR A CE CHARACTERISTICS
U
W
OUTPUT CURRENT (A)
0
DROPOUT VOLTAGE (mV)
500
450
400
350
300
250
200
150
100
50
0
0.4
0.8
1.0
1963 G01
0.2
0.6
1.2
1.4
1.6
T
J
= 125
C
T
J
= 25
C
OUTPUT CURRENT (A)
GUARANTEED DROPOUT VOLTAGE (mV)
600
500
400
300
200
100
0
0
0.4
0.8
1.0
1963 G02
0.2
0.6
1.2
1.4
1.6
T
J
125
C
T
J
25
C
TEST POINTS
TEMPERATURE (
C)
50
DROPOUT VOLTAGE (mV)
500
450
400
350
300
250
200
150
100
50
0
0
50
75
1963 G03
25
25
100
125
I
L
= 100mA
I
L
= 1mA
I
L
= 0.5A
I
L
= 1.5A
Typical Dropout Voltage
Guaranteed Dropout Voltage
Dropout Voltage
Note 1: Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.
Note 2: Absolute maximum input to output differential voltage can not be
achieved with all combinations of rated IN pin and OUT pin voltages. With
the IN pin at 20V, the OUT pin may not be pulled below 0V. The total
measured voltage from IN to OUT can not exceed
20V.
Note 3: The LT1963A regulators are tested and specified under pulse load
conditions such that T
J
T
A
. The LT1963A is 100% tested at
T
A
= 25
C. Performance at 40
C and 125
C is assured by design,
characterization and correlation with statistical process controls.
Note 4: The LT1963A (adjustable version) is tested and specified for these
conditions with the ADJ pin connected to the OUT pin.
Note 5: Operating conditions are limited by maximum junction
temperature. The regulated output voltage specification will not apply for
all possible combinations of input voltage and output current. When
operating at maximum input voltage, the output current range must be
limited. When operating at maximum output current, the input voltage
range must be limited.
Note 6: To satisfy requirements for minimum input voltage, the LT1963A
(adjustable version) is tested and specified for these conditions with an
external resistor divider (two 4.12k resistors) for an output voltage of
2.4V. The external resistor divider will add a 300
A DC load on the output.
Note 7: Dropout voltage is the minimum input to output voltage differential
needed to maintain regulation at a specified output current. In dropout, the
output voltage will be equal to: V
IN
V
DROPOUT
.
Note 8: GND pin current is tested with V
IN
= V
OUT(NOMINAL)
+ 1V and a
current source load. The GND pin current will decrease at higher input
voltages.
Note 9: ADJ pin bias current flows into the ADJ pin.
Note 10: SHDN pin current flows into the SHDN pin.
Note 11: Reverse output current is tested with the IN pin grounded and the
OUT pin forced to the rated output voltage. This current flows into the OUT
pin and out the GND pin.
Note 12. For the LT1963A, LT1963A-1.5 and LT1963A-1.8 dropout voltage
will be limited by the minimum input voltage specification under some
output voltage/load conditions.
Note 13. For the ST package, the input reverse leakage current increases
due to the additional reverse leakage current for the SHDN pin, which is
tied internally to the IN pin.
The
q
denotes specifications which apply over the full operating temperature range, otherwise specifications are T
A
= 25
C. (Note 2)
ELECTRICAL CHARACTERISTICS
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
Input Reverse Leakage Current (Note 13)
Q, T, S8 Packages V
IN
= 20V, V
OUT
= 0V
q
1
mA
ST Package
V
IN
= 20V, V
OUT
= 0V
q
2
mA
Reverse Output Current (Note 11)
LT1963A-1.5
V
OUT
= 1.5V, V
IN
< 1.5V
600
1200
A
LT1963A-1.8
V
OUT
= 1.8V, V
IN
< 1.8V
600
1200
A
LT1963A-2.5
V
OUT
= 2.5V, V
IN
< 2.5V
600
1200
A
LT1963A-3.3
V
OUT
= 3.3V, V
IN
< 3.3V
600
1200
A
LT1963A (Note 4)
V
OUT
= 1.21V, V
IN
< 1.21V
300
600
A
5
LT1963A Series
1963af
TEMPERATURE (
C)
50
OUTPUT VOLTAGE (V)
100
1963 G07
0
50
3.38
3.36
3.34
3.32
3.30
3.28
3.26
3.24
3.22
25
25
75
125
I
L
= 1mA
TEMPERATURE (
C)
50
ADJ PIN VOLTAGE (V)
100
1963 G08
0
50
1.230
1.225
1.220
1.215
1.210
1.205
1.200
1.195
1.190
25
25
75
125
I
L
= 1mA
INPUT VOLTAGE (V)
0
QUIESCENT CURRENT (mA)
14
12
10
8
6
4
2
0
1963 G09
2
5
6
7
8
9
10
1
3
4
T
J
= 25
C
R
L
=
V
SHDN
= V
IN
TYPICAL PERFOR A CE CHARACTERISTICS
U
W
LT1963A-3.3 Output Voltage
INPUT VOLTAGE (V)
0
QUIESCENT CURRENT (mA)
14
12
10
8
6
4
2
0
1963 G10
2
10
5
6
7
8
9
1
3
4
T
J
= 25
C
R
L
=
V
SHDN
= V
IN
LT1963A ADJ Pin Voltage
LT1963A-1.8 Quiescent Current
LT1963A-2.5 Quiescent Current
TEMPERATURE (
C)
50
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0
25
75
1963
G04
25
0
50
100
125
QUIESCENT CURRENT (mA)
LT1963A-1.5/1.8/-2.5/-3.3
LT1963A
V
IN
= 6V
R
L
=
, I
L
= 0
V
SHDN
= V
IN
TEMPERATURE (
C)
50
OUTPUT VOLTAGE (V)
100
1963 G05
0
50
1.84
1.83
1.82
1.81
1.80
1.79
1.78
1.77
1.76
25
25
75
125
I
L
= 1mA
Quiescent Current
LT1963A-1.8 Output Voltage
LT1963A-1.5 Output Voltage
TEMPERATURE (
C)
50
OUTPUT VOLTAGE (V)
1.53
25
1963 G40
1.50
1.48
25
0
50
1.47
1.46
1.54
1.52
1.51
1.49
75
100
125
I
L
= 1mA
TEMPERATURE (
C)
50
OUTPUT VOLTAGE (V)
100
1963 G06
0
50
2.58
2.56
2.54
2.52
2.50
2.48
2.46
2.44
2.42
25
25
75
125
I
L
= 1mA
LT1963A-2.5 Output Voltage
LT1963A-1.5 Quiescent Current
INPUT VOLTAGE (V)
0
0
QUIESCENT CURRENT (mA)
2
6
8
10
14
1
5
7
1963 G41
4
12
4
9
10
2
3
6
8
T
J
= 25
C
R
L
=
V
SHDN
= V
IN
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