1
LT3021/LT3021-1.2/
LT3021-1.5/LT3021-1.8
3021fa
TEMPERATURE (
C)
50
MINIMUM INPUT VOLTAGE (V)
1.1
1.0
0.9
0.8
0.6
0.7
0.5
0.4
0.3
0.2
0.1
0
3021 TA02
25
0
25
50
75
125
100
I
L
= 500mA
APPLICATIO S
U
FEATURES
TYPICAL APPLICATIO
U
DESCRIPTIO
U
500mA, Low Voltage,
Very Low Dropout
Linear Regulator
V
IN
Range: 0.9V to 10V
Dropout Voltage: 160mV Typical
Output Current: 500mA
Adjustable Output (V
REF
= V
OUT(MIN)
= 200mV)
Fixed Output Voltages: 1.2V, 1.5V, 1.8V
Stable with Low ESR, Ceramic Output Capacitors
(3.3
F Minimum)
0.2% Load Regulation from 0mA to 500mA
Quiescent Current: 120
A (Typ)
3
A Typical Quiescent Current in Shutdown
Current Limit Protection
Reverse-Battery Protection
No Reverse Current
Thermal Limiting with Hysteresis
16-Pin DFN (5mm
5mm) and 8-Lead
SO Packages
1.8V to 1.5V, 500mA VLDO Regulator
Low Current Regulators
Battery-Powered Systems
Cellular Phones
Pagers
Wireless Modems
The LT
3021 is a very low dropout voltage (VLDO
TM
) linear
regulator that operates from input supplies down to 0.9V.
This device supplies 500mA of output current with a
typical dropout voltage of 160mV. The LT3021 is ideal for
low input voltage to low output voltage applications,
providing comparable electrical efficiency to that of a
switching regulator.
The LT3021 regulator optimizes stability and transient
response with low ESR, ceramic output capacitors as
small as 3.3
F. Other LT3021 features include 0.05%
typical line regulation and 0.2% typical load regulation. In
shutdown, quiescent current typically drops to 3
A.
Internal protection circuitry includes reverse-battery pro-
tection, current limiting, thermal limiting with hysteresis,
and reverse-current protection. The LT3021 is available as
an adjustable output device with an output range down to
the 200mV reference. Three fixed output voltages, 1.2V,
1.5V and 1.8V, are also available.
The LT3021 regulator is available in the low profile
(0.75mm) 16-pin (5mm
5mm) DFN package with ex-
posed pad and the 8-lead SO package.
IN
SHDN
SENSE
3.3
F
3021 TA01
OUT
V
IN
1.8V
GND
LT3021-1.5
V
OUT
1.5V
500mA
3.3
F
Minimum Input Voltage
, LTC and LT are registered trademarks of Linear Technology Corporation. VLDO is a
trademark of Linear Technology Corporation. All other trademarks are the property of their
respective owners.
2
LT3021/LT3021-1.2/
LT3021-1.5/LT3021-1.8
3021fa
(Note 1)
IN Pin Voltage ........................................................
10V
OUT Pin Voltage ....................................................
10V
Input-to-Output Differential Voltage .......................
10V
ADJ/SENSE Pin Voltage ........................................
10V
SHDN Pin Voltage .................................................
10V
Output Short-Circut Duration .......................... Indefinite
Operating Junction Temperature Range
(Notes 2, 3) .......................................... 40
C to 125C
Storage Temperature Range
DH .................................................... 65
C to 125C
S8 ..................................................... 65
C to 150C
Lead Temperature (Soldering, 10 sec).................. 300
C
ABSOLUTE AXI U RATI GS
W
W
W
U
PACKAGE/ORDER I FOR ATIO
U
U
W
T
JMAX
= 150
C,
JA
= 125
C/ W*,
JC
= 40
C/ W**
*SEE THE APPLICATIONS INFORMATION SECTION
**MEASURED JUNCTION TO PIN 6
1
2
3
4
8
7
6
5
TOP VIEW
IN
NC
PGND
SHDN
NC
OUT
SENSE
AGND
LT3021-FIXED
S8 PACKAGE
8-LEAD PLASTIC SO
T
JMAX
= 125
C,
JA
= 35
C/ W*,
JC
= 3
C/ W**
EXPOSED PAD IS GND (PIN 17) CONNECT TO PINS 8, 10
*SEE THE APPLICATIONS INFORMATION SECTION
**MEASURED JUNCTION TO PIN 17
16
15
14
13
12
11
10
9
17
1
2
3
4
5
6
7
8
NC
NC
IN
NC
IN
NC
PGND
SHDN
NC
NC
OUT
OUT
NC
NC
SENSE
AGND
TOP VIEW
LT3021-FIXED
DH PACKAGE
16-LEAD (5mm
5mm) PLASTIC DFN
LT3021EDH
ORDER PART
NUMBER
LT3021EDH-1.2
LT3021EDH-1.5
LT3021EDH-1.8
3021
DH PART
MARKING
302112
302115
302118
T
JMAX
= 150
C,
JA
= 125
C/ W*,
JC
= 40
C/ W**
*SEE THE APPLICATIONS INFORMATION SECTION
**MEASURED JUNCTION TO PIN 6
1
2
3
4
8
7
6
5
TOP VIEW
IN
NC
PGND
SHDN
NC
OUT
ADJ
AGND
LT3021-ADJ
S8 PACKAGE
8-LEAD PLASTIC SO
T
JMAX
= 125
C,
JA
= 35
C/ W*,
JC
= 3
C/ W**
EXPOSED PAD IS GND (PIN 17) CONNECT TO PINS 8, 10
*SEE THE APPLICATIONS INFORMATION SECTION
**MEASURED JUNCTION TO PIN 17
16
15
14
13
12
11
10
9
17
1
2
3
4
5
6
7
8
NC
NC
IN
NC
IN
NC
PGND
SHDN
NC
NC
OUT
OUT
NC
NC
ADJ
AGND
TOP VIEW
LT3021-ADJ
DH PACKAGE
16-LEAD (5mm
5mm) PLASTIC DFN
ORDER PART
NUMBER
DH PART
MARKING
LT3021ES8
ORDER PART
NUMBER
LT3021ES8-1.2
LT3021ES8-1.5
LT3021ES8-1.8
3021
S8 PART
MARKING
302112
302115
302118
ORDER PART
NUMBER
S8 PART
MARKING
Consult factory for parts specified with wider operating temperature ranges.
Order Options Tape and Reel: Add #TR
Lead Free: Add #PBF Lead Free Tape and Reel: Add #TRPBF
Lead Free Part Marking:
http://www.linear.com/leadfree/
3
LT3021/LT3021-1.2/
LT3021-1.5/LT3021-1.8
3021fa
Minimum Input Voltage
I
LOAD
= 500mA, T
J
> 0
C
0.9
1.05
V
(Notes 5,14)
I
LOAD
= 500mA, T
J
< 0
C
0.9
1.10
V
ADJ Pin Voltage (Notes 4, 5)
V
IN
= 1.5V, I
LOAD
= 1mA
196
200
204
mV
1.15V < V
IN
< 10V, 1mA < I
LOAD
< 500mA
193
200
206
mV
Regulated Output Voltage
LT3021-1.2
V
IN
= 1.5V, I
LOAD
= 1mA
1.176
1.200
1.224
V
(Note 4)
1.5V < V
IN
< 10V, 1mA < I
LOAD
< 500mA
1.157
1.200
1.236
V
LT3021-1.5
V
IN
= 1.8V, I
LOAD
= 1mA
1.470
1.500
1.530
V
1.8V < V
IN
< 10V, 1mA < I
LOAD
< 500mA
1.447
1.500
1.545
V
LT3021-1.8
V
IN
= 2.1V, I
LOAD
= 1mA
1.764
1.800
1.836
V
2.1V < V
IN
< 10V, 1mA < I
LOAD
< 500mA
1.737
1.800
1.854
V
Line Regulation (Note 6)
LT3021
V
IN
= 1.15V to 10V, I
LOAD
= 1mA
1.75
0
+1.75
mV
LT3021-1.2
V
IN
= 1.5V to 10V, I
LOAD
= 1mA
10.5
0
10.5
mV
LT3021-1.5
V
IN
= 1.8V to 10V, I
LOAD
= 1mA
13
0
13
mV
LT3021-1.8
V
IN
= 2.1V to 10V, I
LOAD
= 1mA
15.8
0
15.8
mV
Load Regulation (Note 6)
LT3021
V
IN
= 1.15V,
I
LOAD
= 1mA to 500mA
2
0.4
2
mV
LT3021-1.2
V
IN
= 1.5V,
I
LOAD
= 1mA to 500mA
6
1
6
mV
LT3021-1.5
V
IN
= 1.8V,
I
LOAD
= 1mA to 500mA
7.5
1.5
7.5
mV
LT3021-1.8
V
IN
= 2.1V,
I
LOAD
= 1mA to 500mA
9
2
9
mV
Dropout Voltage (Notes 7, 12)
I
LOAD
= 10mA
45
75
mV
I
LOAD
= 10mA
110
mV
I
LOAD
= 500mA
155
190
mV
I
LOAD
= 500mA
285
mV
GND Pin Current
I
LOAD
= 0mA
110
250
A
V
IN
= V
OUT(NOMINAL)
+ 0.4V
I
LOAD
= 10mA
920
A
(Notes 8, 12)
I
LOAD
= 100mA
2.25
mA
I
LOAD
= 500mA
6.20
10
mA
Output Voltage Noise
C
OUT
= 4.7
F, I
LOAD
= 500mA, BW = 10Hz to 100kHz, V
OUT
= 1.2V
300
V
RMS
ADJ Pin Bias Current
V
ADJ
= 0.2V, V
IN
= 1.2V (Notes 6, 9)
20
50
nA
Shutdown Threshold
V
OUT
= Off to On
0.61
0.9
V
V
OUT
= On to Off
0.25
0.61
V
SHDN Pin Current (Note 10)
V
SHDN
= 0V, V
IN
= 10V
1
A
V
SHDN
= 10V, V
IN
= 10V
3
9.5
A
Quiescent Current in Shutdown
V
IN
= 6V, V
SHDN
= 0V
3
9
A
Ripple Rejection (Note 6)
LT3021
V
IN
V
OUT
= 1V, V
RIP
= 0.5V
P-P
, f
RIPPLE
= 120Hz,
70
dB
I
LOAD
= 500mA
LT3021-1.2
V
IN
V
OUT
= 1V, V
RIPPLE
= 0.5V
P-P
, f
RIPPLE
= 120Hz,
60
dB
I
LOAD
= 500mA
LT3021-1.5
V
IN
V
OUT
= 1V, V
RIPPLE
= 0.5V
P-P
, f
RIPPLE
= 120Hz,
58
dB
I
LOAD
= 500mA
LT3021-1.8
V
IN
V
OUT
= 1V, V
RIPPLE
= 0.5V
P-P
, f
RIPPLE
= 120Hz,
56
dB
I
LOAD
= 500mA
The
denotes specifications which apply over the full operating temperature range, otherwise specifications are T
J
= 25
C.
ELECTRICAL CHARACTERISTICS
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
4
LT3021/LT3021-1.2/
LT3021-1.5/LT3021-1.8
3021fa
OUTPUT CURRENT (mA)
0
DROPOUT VOLTAGE (mV)
250
225
200
150
175
125
100
75
50
25
0
3021 G01
200
100
300
400
500
T
J
= 125
C
T
J
= 25
C
TEMPERATURE (
C)
50
DROPOUT VOLTAGE (mV)
250
225
200
150
175
125
100
75
50
25
0
3021 G02
25
0
25
50
75
125
100
I
L
= 1mA
I
L
= 100mA
I
L
= 250mA
I
L
= 500mA
I
L
= 50mA
I
L
= 10mA
V
OUT
= 1.2V
The
denotes specifications which apply over the full operating temperature range, otherwise specifications are T
J
= 25
C.
ELECTRICAL CHARACTERISTICS
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
Note 1: Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.
Note 2: The LT3021 regulators are tested and specified under pulse load
conditions such that T
J
T
A
. The LT3021 is 100% production tested at
T
A
= 25
C. Performance at 40C and 125C is assured by design,
characterization and correlation with statistical process controls.
Note 3: This IC includes overtemperature protection that is intended to
protect the device during momentary overload conditions. Junction
temperature will exceed 125
C when overtemperature protection is active.
Continuous operation above the specified maximum operating junction
temperature may impair device reliability.
Note 4: Maximum junction temperature limits operating conditions. The
regulated output voltage specification does not apply for all possible
combinations of input voltage and output current. Limit the output current
range if operating at maximum input voltage. Limit the input voltage range
if operating at maximum output current.
Note 5: Typically the LT3021 supplies 500mA output current with a 1V
input supply. The guranteed minimum input voltage for 500mA output
current is 1.10V.
Note 6: The LT3021 is tested and specified for these conditions with an
external resistor divider (20k and 30.1k) setting V
OUT
to 0.5V. The external
resistor divider adds 10
A of output load current. The line regulation and
load regulation specifications refer to the change in the 0.2V reference
voltage, not the 0.5V output voltage. Specifications for fixed output voltage
devices are referred to the output voltage.
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 equals: (V
IN
V
DROPOUT
).
Note 8: GND pin current is tested with V
IN
= V
OUT(NOMINAL)
+ 0.4V and a
current source load. GND pin current will increase in dropout. See GND
pin current curves in the Typical Performance Characteristics section.
Note 9: Adjust pin bias current flows out of the ADJ pin.
Note 10: Shutdown pin current flows into the SHDN pin.
Note 11: Reverse output current is tested with IN grounded and OUT
forced to the rated output voltage. This current flows into the OUT pin and
out of the GND pin. For fixed voltage devices this includes the current in
the output resistor divider.
Note 12: The LT3021 is tested and specified for these conditions with an
external resistor divider (20k and 100k) setting V
OUT
to 1.2V. The external
resistor divider adds 10
A of load current.
Note 13: Reverse current is higher for the case of (rated_output) < V
OUT
<
V
IN,
because the no-load recovery circuitry is active in this region and is
trying to restore the output voltage to its nominal value.
Note 14: Minimum input voltage is the minimum voltage required by the
control circuit to regulate the output voltage and supply the full 500mA
rated current. This specification is tested at V
OUT
= 0.5V. At higher output
voltages the minimum input voltage required for regulation will be equal to
the regulated output voltage V
OUT
plus the dropout voltage.
TYPICAL PERFOR A CE CHARACTERISTICS
U
W
Dropout Voltage
Dropout Voltage
Current Limit (Note 12)
V
IN
= 10V, V
OUT
= 0V
1.8
A
V
IN
= V
OUT(NOMINAL)
+ 0.5V,
V
OUT
= 5%
550
mA
Input Reverse Leakage Current
V
IN
= 10V, V
OUT
= 0V
1
20
A
Reverse Output Current
LT3021
V
OUT
= 1.2V,
V
IN
= 0V
0.5
5
A
(Notes 11, 13)
LT3021-1.2
V
OUT
= 1.2V,
V
IN
= 0V
10
15
A
LT3021-1.5
V
OUT
= 1.5V,
V
IN
= 0V
10
15
A
LT3021-1.8
V
OUT
= 1.8V,
V
IN
= 0V
10
15
A
TEMPERATURE (
C)
50
MINIMUM INPUT VOLTAGE (V)
1.2
1.1
1.0
0.9
0.8
0.6
0.7
0.5
0.4
0.3
0.2
3021 G16
25
0
25
50
75
125
100
I
L
= 500mA
Minimum Input Voltage
5
LT3021/LT3021-1.2/
LT3021-1.5/LT3021-1.8
3021fa
TEMPERATURE (
C)
50
ADJ PIN VOLTAGE (mV)
206
204
202
198
200
196
194
3021 G04
25
0
25
50
75
125
100
TEMPERATURE (
C)
50
250
225
200
150
175
125
100
75
50
25
0
25
0
25
50
75
125
100
QUIESCENT CURRENT (
A)
3021 G05
V
IN
= 6V
V
OUT
= 1.2V
I
L
= 0
V
SHDN
= V
IN
V
SHDN
= 0V
ADJ Pin Voltage
Quiescent Current
ADJ Pin Bias Current
TYPICAL PERFOR A CE CHARACTERISTICS
U
W
TEMPERATURE (
C)
50
ADJ PIN BIAS CURRENT (nA)
25
20
15
5
10
0
3021 G11
25
0
25
50
75
125
100
Output Voltage
TEMPERATURE (
C)
50
OUTPUT VOLTAGE (V)
1.23
1.22
1.21
1.20
1.19
1.18
1.17
25
75
3021 G28
25
0
50
100
125
I
LOAD
= 1mA
Output Voltage
Output Voltage
TEMPERATURE (
C)
50
OUTPUT VOLTAGE (V)
1.83
1.82
1.81
1.80
1.79
1.78
1.77
25
75
3021 G22
25
0
50
100
125
I
LOAD
= 1mA
TEMPERATURE (
C)
50
OUTPUT VOLTAGE (V)
1.53
1.52
1.51
1.50
1.49
1.48
1.47
25
75
3021 G23
25
0
50
100
125
I
LOAD
= 1mA
INPUT VOLTAGE (V)
0
QUIESCENT CURRENT (mA)
3.0
2.5
2.0
1.0
1.5
0.5
0
3021 G03
3
2
1
5
8
4
7
6
10
9
V
SHDN
= V
IN
V
SHDN
= 0V
V
OUT
= 1.2V
I
L
= 0
T
J
= 25
C
Quiescent Current
Quiescent Current
Quiescent Current
INPUT VOLTAGE (V)
QUIESCENT CURRENT (mA)
3.0
2.5
2.0
1.5
1.0
0.5
0
2
4
6
8
3021 G26
10
1
0
3
5
7
9
V
OUT
= 1.5V
I
L
= 0
T
J
= 25
C
V
SHDN
= 0V
V
SHDN
= V
IN
INPUT VOLTAGE (V)
QUIESCENT CURRENT (mA)
3.0
2.5
2.0
1.5
1.0
0.5
0
2
4
6
8
3021 G27
10
1
0
3
5
7
9
V
OUT
= 1.8V
I
L
= 0
T
J
= 25
C
V
SHDN
= 0V
V
SHDN
= V
IN
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