LT3021/LT3021-1.2/
LT3021-1.5/LT3021-1.8
500mA, Low Voltage,
Very Low Dropout
Linear Regulator
FEATURES
n
VIN Range: 0.9V to 10V
n
Dropout Voltage: 160mV Typical
n
Output Current: 500mA
n
Adjustable Output (V
n
Fixed Output Voltages: 1.2V, 1.5V, 1.8V
n
Stable with Low ESR, Ceramic Output Capacitors
REF
= V
OUT(MIN)
= 200mV)
(3.3μF Minimum)
n
0.2% Load Regulation from 0mA to 500mA
n
Quiescent Current: 120μA (Typ)
n
3μA Typical Quiescent Current in Shutdown
n
Current Limit Protection
n
Reverse-Battery Protection
n
No Reverse Current
n
Thermal Limiting with Hysteresis
n
16-Pin DFN (5mm × 5mm) and 8-Lead
SO Packages
APPLICATIONS
n
Low Current Regulators
n
Battery-Powered Systems
n
Cellular Phones
n
Pagers
n
Wireless Modems
DESCRIPTION
The LT®3021 is a very low dropout voltage (VLDO™) 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 effi ciency to that of a
switching regulator.
The LT3021 regulator optimizes stability and transient
response with low ESR, ceramic output capacitors as small
as 3.3μF. Other LT3021 features include 0.05% typical line
regulation and 0.2% typical load regulation. In shutdown,
quiescent current typically drops to 3μA.
Internal protection circuitry includes reverse-battery protection, 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 fi xed output voltages, 1.2V,
1.5V and 1.8V, are also available.
The LT3021 regulator is available in the low profi le
(0.75mm) 16-pin (5mm × 5mm) DFN package with exposed pad and the 8-lead SO package.
L, LT, LTC and LTM 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.
TYPICAL APPLICATION
1.8V to 1.5V, 500mA VLDO Regulator
V
1.8V
IN
3.3μF
IN
LT3021-1.5
SHDN
OUT
SENSE
GND
3021 TA01
3.3μF
V
OUT
1.5V
500mA
Minimum Input Voltage
1.1
IL = 500mA
1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
MINIMUM INPUT VOLTAGE (V)
0.2
0.1
0
–50
250–25 50 75
TEMPERATURE (°C)
125100
3021 TA02
3021fc
1
LT3021/LT3021-1.2/
(
(
LT3021-1.5/LT3021-1.8
ABSOLUTE MAXIMUM RATINGS
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 ......................... Indefi nite
PIN CONFIGURATION
TOP VIEW
NC
1
NC
2
OUT
3
OUT
4
NC
5
NC
6
ADJ
7
AGND
8
16-LEAD
T
= 125°C, θJA = 35°C/ W*, θJC = 3°C/W**
JMAX
EXPOSED PAD IS GND (PIN 17) CONNECT TO PINS 8, 10
EXPOSED PAD MUST BE SOLDERED TO THE PCB
*SEE THE APPLICATIONS INFORMATION SECTION
**MEASURED JUNCTION TO PIN 17
17
LT3021-ADJ
DH PACKAGE
5mm × 5mm) PLASTIC DFN
NC
16
NC
15
IN
14
NC
13
IN
12
NC
11
PGND
10
SHDN
9
(Note 1)
Operating Junction Temperature Range (E, I Grade)
(Notes 2, 3) ............................................– 40°C to 125°C
Storage Temperature Range
DH .....................................................– 65°C to 125°C
S8 ......................................................–65°C to 150°C
Lead Temperature (Soldering, 10 sec, S8) ............ 300°C
TOP VIEW
NC
1
NC
2
OUT
3
OUT
4
NC
5
NC
6
SENSE
7
AGND
8
16-LEAD
T
= 125°C, θJA = 35°C/ W*, θJC = 3°C/W**
JMAX
EXPOSED PAD IS GND (PIN 17) CONNECT TO PINS 8, 10
EXPOSED PAD MUST BE SOLDERED TO THE PCB
*SEE THE APPLICATIONS INFORMATION SECTION
**MEASURED JUNCTION TO PIN 17
17
LT3021-FIXED
DH PACKAGE
5mm × 5mm) PLASTIC DFN
NC
16
NC
15
IN
14
NC
13
IN
12
NC
11
PGND
10
SHDN
9
TOP VIEW
NC
1
OUT
2
ADJ
3
AGND
4
LT3021-ADJ
S8 PACKAGE
T
JMAX
*SEE THE APPLICATIONS INFORMATION SECTION
8-LEAD PLASTIC SO
= 150°C, θJA = 125°C/ W*, θJC = 40°C/W**
**MEASURED JUNCTION TO PIN 6
IN
8
NC
7
PGND
6
SHDN
5
TOP VIEW
NC
1
OUT
2
SENSE
3
AGND
4
LT3021-FIXED
S8 PACKAGE
T
JMAX
*SEE THE APPLICATIONS INFORMATION SECTION
8-LEAD PLASTIC SO
= 150°C, θJA = 125°C/ W*, θJC = 40°C/W**
**MEASURED JUNCTION TO PIN 6
IN
8
NC
7
PGND
6
SHDN
5
3021fc
2
LT3021/LT3021-1.2/
LT3021-1.5/LT3021-1.8
ORDER INFORMAITON
LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE
LT3021EDH#PBF LT3021EDH#TRPBF 3021
LT3021EDH-1.2#PBF LT3021EDH-1.2#TRPBF 302112
LT3021EDH-1.5#PBF LT3021EDH-1.5#TRPBF 302115
LT3021EDH-1.8#PBF LT3021EDH-1.8#TRPBF 302118
LT3021ES8#PBF LT3021ES8#TRPBF 3021 8-Lead Plastic SO –40°C to 125°C
LT3021ES8-1.2#PBF LT3021ES8-1.2#TRPBF 302112 8-Lead Plastic SO –40°C to 125°C
LT3021ES8-1.5#PBF LT3021ES8-1.5#TRPBF 302115 8-Lead Plastic SO –40°C to 125°C
LT3021ES8-1.8#PBF LT3021ES8-1.8#TRPBF 302118 8-Lead Plastic SO –40°C to 125°C
LT3021IS8-1.8#PBF LT3021IS8-1.8#TRPBF 302118 8-Lead Plastic SO –40°C to 125°C
LEAD BASED FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE
LT3021EDH LT3021EDH#TR 3021
LT3021EDH-1.2 LT3021EDH-1.2#TR 302112
LT3021EDH-1.5 LT3021EDH-1.5#TR 302115
LT3021EDH-1.8 LT3021EDH-1.8#TR 302118
LT3021ES8 LT3021ES8#TR 3021 8-Lead Plastic SO –40°C to 125°C
LT3021ES8-1.2 LT3021ES8-1.2#TR 302112 8-Lead Plastic SO –40°C to 125°C
LT3021ES8-1.5 LT3021ES8-1.5#TR 302115 8-Lead Plastic SO –40°C to 125°C
LT3021ES8-1.8 LT3021ES8-1.8#TR 302118 8-Lead Plastic SO –40°C to 125°C
LT3021IS8-1.8 LT3021IS8-1.8#TR 302118 8-Lead Plastic SO –40°C to 125°C
Consult LTC Marketing for parts specifi ed with wider operating temperature ranges. *The temperature grade is identifi ed by a label on the shipping container.
For more information on lead free part marking, go to: http://www.linear.com/leadfree/
For more information on tape and reel specifi
cations, go to: http://www.linear.com/tapeandreel/
16-Lead (5mm × 5mm) Plastic DFN
16-Lead (5mm × 5mm) Plastic DFN
16-Lead (5mm × 5mm) Plastic DFN
16-Lead (5mm × 5mm) Plastic DFN
16-Lead (5mm × 5mm) Plastic DFN
16-Lead (5mm × 5mm) Plastic DFN
16-Lead (5mm × 5mm) Plastic DFN
16-Lead (5mm × 5mm) Plastic DFN
–40°C to 125°C
–40°C to 125°C
–40°C to 125°C
–40°C to 125°C
–40°C to 125°C
–40°C to 125°C
–40°C to 125°C
–40°C to 125°C
3021fc
3
LT3021/LT3021-1.2/
LT3021-1.5/LT3021-1.8
ELECTRICAL CHARACTERISTICS
The l denotes the specifi cations which apply over the full operating
temperature range, otherwise specifi cations are at T
SYMBOL CONDITIONS MIN TYP MAX UNITS
Minimum Input Voltage
(Notes 5,14)
ADJ Pin Voltage (Notes 4, 5) V
Regulated Output Voltage
(Note 4)
Line Regulation (Note 6) LT3021 ΔV
Load Regulation (Note 6) LT3021 V
Dropout Voltage (Notes 7, 12) I
GND Pin Current
V
IN
= V
OUT(NOMINAL)
+ 0.4V
(Notes 8, 12)
Output Voltage Noise C
ADJ Pin Bias Current V
Shutdown Threshold V
SHDN Pin Current (Note 10) V
Quiescent Current in Shutdown V
Ripple Rejection (Note 6) LT3021 V
Current Limit (Note 12) V
Input Reverse Leakage Current V
Reverse Output Current
(Notes 11, 13)
= 500mA, TJ > 0°C
I
LOAD
I
= 500mA, TJ < 0°C
LOAD
= 1.5V, I
IN
1.15V < V
LOAD
< 10V, 1mA < I
IN
LT3021-1.2 V
1.5V < V
LT3021-1.5 V
1.8V < V
LT3021-1.8 V
2.1V < V
LT3021-1.2 ΔV
LT3021-1.5 ΔV
LT3021-1.8 ΔV
LT3021-1.2 V
LT3021-1.5 V
LT3021-1.8 V
= 10mA
LOAD
I
= 10mA
LOAD
I
= 500mA
LOAD
I
= 500mA l
LOAD
= 0mA
I
LOAD
I
= 10mA
LOAD
I
= 100mA
LOAD
I
= 500mA
LOAD
= 4.7μF, I
OUT
ADJ
OUT
V
OUT
SHDN
V
SHDN
IN
= 0.2V, V
= 6V, V
LOAD
IN
= Off to On
= On to Off
= 0V, V
IN
= 10V, V
SHDN
I
LT3021-1.2 V
I
LT3021-1.5 V
I
LT3021-1.8 V
I
= 10V, V
IN
V
IN
IN
OUT
= V
OUT(NOMINAL)
= –10V, V
OUT
LT3021 V
LT3021-1.2 V
LT3021-1.5 V
LT3021-1.8 V
= 25°C.
J
= 1mA
= 1.5V, I
IN
IN
IN
IN
IN
IN
IN
IN
IN
IN
IN
LOAD
< 10V, 1mA < I
IN
= 1.8V, I
LOAD
< 10V, 1mA < I
IN
= 2.1V, I
LOAD
< 10V, 1mA < I
IN
= 1.15V to 10V, I
= 1.5V to 10V, I
= 1.8V to 10V, I
= 2.1V to 10V, I
= 1.15V, ΔI
= 1.5V, ΔI
= 1.8V, ΔI
= 2.1V, ΔI
< 500mA l
LOAD
= 1mA
< 500mA
LOAD
= 1mA
< 500mA
LOAD
= 1mA
< 500mA
LOAD
= 1mA
LOAD
= 1mA
LOAD
= 1mA
LOAD
= 1mA
LOAD
= 1mA to 500mA
LOAD
= 1mA to 500mA
LOAD
= 1mA to 500mA
LOAD
= 1mA to 500mA
LOAD
0.9
0.9
196
193
1.176
l
1.157
1.470
l
1.447
1.764
l
1.737
l
–1.75
l
–10.5
l
–13
l
–15.8
–2
–6
–7.5
–9
200
200
1.200
1.200
1.500
1.500
1.800
1.800
0
0
0
0
0.4
1
1.5
2
1.05
1.10
204
206
1.224
1.236
1.530
1.545
1.836
1.854
+1.75
10.5
13
15.8
2
6
7.5
9
45 75
l
110
155 190
285
l
110
250
920
2.25
= 500mA, BW = 10Hz to 100kHz, V
l
= 1.2V 300 μV
OUT
6.20
10
RMS
= 1.2V (Notes 6, 9) 20 50 nA
= 10V
= 10V
IN
l
l
0.25
l
l
0.61
0.61
3
0.9 V
±1
9.5
= 0V 3 9 μA
– V
IN
LOAD
– V
IN
LOAD
– V
IN
LOAD
– V
IN
LOAD
= 0V
= 1V, V
OUT
= 500mA
= 1V, V
OUT
= 500mA
= 1V, V
OUT
= 500mA
= 1V, V
OUT
= 500mA
+ 0.5V, ΔV
OUT
= 0.5V
RIP
RIPPLE
RIPPLE
RIPPLE
= –5%
P-P
= 0.5V
= 0.5V
= 0.5V
, f
RIPPLE
P-P
P-P
P-P
, f
RIPPLE
, f
RIPPLE
, f
RIPPLE
= 120Hz,
= 120Hz,
= 120Hz,
= 120Hz,
70 dB
60 dB
58 dB
56 dB
1.8 A
l
550
= 0V 1 20 μA
OUT
OUT
OUT
OUT
= 1.2V, V
= 1.2V, V
= 1.5V, V
= 1.8V, V
= 0V
IN
= 0V
IN
= 0V
IN
= 0V
IN
0.5
10
10
10
5
15
15
15
mV
mV
mV
mV
mV
mV
mV
mV
mV
mV
mV
mV
mV
mV
μA
μA
mA
mA
μA
μA
mA
μA
μA
μA
μA
V
V
V
V
V
V
V
V
V
4
3021fc
LT3021/LT3021-1.2/
LT3021-1.5/LT3021-1.8
ELECTRICAL CHARACTERISTICS
The l denotes the specifi cations which apply over the full operating
temperature range, otherwise specifi cations are at T
Note 1: Stresses beyond those listed under Absolute Maximum Ratings
may cause permanent damage to the device. Exposure to any Absolute
Maximum Rating condition for extended periods may affect device
reliability and lifetime.
Note 2: The LT3021 regulators are tested and specifi ed under pulse load
conditions such that T
at T
= 25°C. Performance at –40°C and 125°C is assured by design,
A
characterization and correlation with statistical process controls. The
LT3021I regulators are guaranteed over the full – 40ºC to 125ºC operating
junction temperature range.
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 specifi ed maximum operating junction
temperature may impair device reliability.
Note 4: Maximum junction temperature limits operating conditions. The
regulated output voltage specifi cation 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 specifi ed for these conditions with an
external resistor divider (20k and 30.1k) setting V
resistor divider adds 10μA of output load current. The line regulation and
load regulation specifi cations refer to the change in the 0.2V reference
≈ TA. The LT3021E regulators are 100% tested
J
OUT
= 25°C.
J
to 0.5V. The external
voltage, not the 0.5V output voltage. Specifi cations for fi xed 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 specifi ed output current. In dropout the
output voltage equals: (V
Note 8: GND pin current is tested with V
IN
– V
DROPOUT
).
= V
IN
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 fl ows out of the ADJ pin.
Note 10: Shutdown pin current fl ows into the SHDN pin.
Note 11: Reverse output current is tested with IN grounded and OUT
forced to the rated output voltage. This current fl ows into the OUT pin and
out of the GND pin. For fi xed voltage devices this includes the current in
the output resistor divider.
Note 12: The LT3021 is tested and specifi ed for these conditions with an
external resistor divider (20k and 100k) setting V
to 1.2V. The external
OUT
resistor divider adds 10μA of load current.
Note 13: Reverse current is higher for the case of (rated_output) < V
< V
because the no-load recovery circuitry is active in this region and is
IN,
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 specifi cation is tested at V
= 0.5V. At higher output
OUT
voltages the minimum input voltage required for regulation will be equal to
the regulated output voltage V
plus the dropout voltage.
OUT
OUT
TYPICAL PERFORMANCE CHARACTERISTICS
Dropout Voltage Dropout Voltage Minimum Input Voltage
250
225
200
175
150
125
100
75
DROPOUT VOLTAGE (mV)
50
25
0
250
V
= 1.2V
OUT
TJ = 125°C
TJ = 25°C
0
200100 300
OUTPUT CURRENT (mA)
400
500
3021 G01
225
200
175
150
125
100
75
DROPOUT VOLTAGE (mV)
50
25
0
–50
250–25 50 75
TEMPERATURE (°C)
IL = 500mA
IL = 250mA
IL = 100mA
IL = 50mA
IL = 10mA
IL = 1mA
125100
3021 G02
1.2
1.1
1.0
0.9
0.8
0.7
0.6
0.5
0.4
MINIMUM INPUT VOLTAGE (V)
0.3
0.2
IL = 500mA
–50
250–25 50 75
TEMPERATURE (°C)
125100
3021 G16
3021fc
5
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