LT3014IS5 [Linear]
IC VREG 1.22 V-60 V ADJUSTABLE POSITIVE LDO REGULATOR, 0.57 V DROPOUT, PDSO5, PLASTIC, MO-193, TSOT-23, 5 PIN, Adjustable Positive Single Output LDO Regulator;
| 型号： | LT3014IS5 |
| 厂家： | 
Linear |
| 描述： | IC VREG 1.22 V-60 V ADJUSTABLE POSITIVE LDO REGULATOR, 0.57 V DROPOUT, PDSO5, PLASTIC, MO-193, TSOT-23, 5 PIN, Adjustable Positive Single Output LDO Regulator 光电二极管 输出元件 调节器 |
| 文件： | 总16页 (文件大小：181K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
LT3014
20mA, 3V to 80V
Low Dropout Micropower
Linear Regulator
FEATURES
DESCRIPTION
The LT®3014 is a high voltage, micropower low dropout
linearregulator.Thedeviceiscapableofsupplying20mAof
output current with a dropout voltage of 350mV. Designed
foruseinbattery-poweredorhighvoltagesystems,thelow
quiescent current (7μA operating and 1μA in shutdown)
makes the LT3014 an ideal choice. Quiescent current is
also well controlled in dropout.
n
Wide Input Voltage Range: 3V to 80V
n
Low Quiescent Current: 7µA
n
Low Dropout Voltage: 350mV
Output Current: 20mA
n
n
LT3014HV Survives 100V Transients (2ms)
n
No Protection Diodes Needed
n
Adjustable Output from 1.22V to 60V
n
1µA Quiescent Current in Shutdown
Other features of the LT3014 include the ability to operate
withverysmalloutputcapacitors.Theregulatorsarestable
with only 0.47μF on the output while most older devices
requirebetween10μFand100μFforstability.Smallceramic
capacitors can be used without the necessary addition of
ESR as is common with other regulators. Internal protec-
tion circuitry includes reverse-battery protection, current
limiting, thermal limiting and reverse current protection.
n
Stable with 0.47µF Output Capacitor
n
Stable with Aluminum, Tantalum or Ceramic
Capacitors
Reverse-Battery Protection
n
n
No Reverse Current Flow from Output
n
Thermal Limiting
Available in 5-Lead ThinSOTTM and
■
8-Lead DFN Packages
Thedeviceisavailableasanadjustabledevicewitha1.22V
reference voltage. The LT3014 regulator is available in the
5-lead ThinSOT and 8-lead DFN packages.
APPLICATIONS
n
Low Current High Voltage Regulators
L, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
ThinSOT is a trademark of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
Protected by U.S. Patents including 6118263, 6144250.
n
Regulator for Battery-Powered Systems
n
Telecom Applications
Automotive Applications
n
TYPICAL APPLICATION
5V Supply with Shutdown
Dropout Voltage
400
V
OUT
350
300
250
200
150
100
50
IN
OUT
ADJ
5V
20mA
V
IN
LT3014
3.92M
1.27M
5.4V TO
80V
0.47μF
1μF
SHDN
GND
3014 TA01
V
OUTPUT
SHDN
<0.3V
>2.0V
OFF
ON
0
0
2
4
6
8
10 12 14 16 18 20
OUTPUT CURRENT (mA)
3014 TA02
3014fd
1
LT3014
ABSOLUTE MAXIMUM RATINGS
(Note 1)
IN Pin Voltage, Operating................................... 80V
Transient (2ms Survival, LT3014HV)................ +100V
OUT Pin Voltage................................................. 60V
IN to OUT Differential Voltage ............................ 80V
ADJ Pin Voltage ................................................... 7V
SHDN Pin Input Voltage..................................... 80V
Output Short-Circuit Duration ......................Indefinite
Storage Temperature Range
ThinSOT Package.......................... –65°C to 150°C
DFN Package..................................–65°C to 125°C
Operating Junction Temperature Range
(Notes 3, 10, 11)............................–40°C to 125°C
Lead Temperature
(Soldering, 10 sec, SOT-23 Package)............300°C
PIN CONFIGURATION
TOP VIEW
TOP VIEW
OUT
ADJ
NC
1
2
3
4
8
7
6
5
IN
IN 1
GND 2
5 OUT
4 ADJ
NC
9
NC
SHDN 3
GND
SHDN
S5 PACKAGE
5-LEAD PLASTIC SOT-23
DD PACKAGE
T
= 125°C, θ = 150°C/ W
8-LEAD (3mm s 3mm) PLASTIC DFN
JMAX
JA
EXPOSED PAD IS GND (PIN 9) MUST BE SOLDERED TO PCB
θ
= 25°C/W MEASURED AT PIN 2
SEE APPLICATIONS INFORMATION SECTION
JC
T
= 125°C, θ = 40°C/ W
JA
= 10°C/W MEASURED AT PIN 9
JMAX
θ
JC
ORDER INFORMATION
LEAD FREE FINISH
LT3014ES5#PBF
LT3014IS5#PBF
LT3014HVES5#PBF
LT3014HVIS5#PBF
LT3014EDD#PBF
LT3014IDD#PBF
LT3014HVEDD#PBF
LT3014HVIDD#PBF
LEAD BASED FINISH
LT3014ES5
TAPE AND REEL
PART MARKING*
LTBMF
PACKAGE DESCRIPTION
TEMPERATURE RANGE
–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
TEMPERATURE RANGE
–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
LT3014ES5#TRPBF
LT3014IS5#TRPBF
LT3014HVES5#TRPBF
LT3014HVIS5#TRPBF
LT3014EDD#TRPBF
LT3014IDD#TRPBF
LT3014HVEDD#TRPBF
LT3014HVIDD#TRPBF
TAPE AND REEL
5-Lead Plastic SOT-23
LTBMF
5-Lead Plastic SOT-23
LTBRS
5-Lead Plastic SOT-23
LTBRS
5-Lead Plastic SOT-23
LBMG
8-Lead (3mm × 3mm) Plastic DFN
8-Lead (3mm × 3mm) Plastic DFN
8-Lead (3mm × 3mm) Plastic DFN
8-Lead (3mm × 3mm) Plastic DFN
PACKAGE DESCRIPTION
LBMG
LBRT
LBRT
PART MARKING*
LTBMF
LT3014ES5#TR
5-Lead Plastic SOT-23
LT3014IS5
LT3014IS5#TR
LTBMF
5-Lead Plastic SOT-23
LT3014HVES5
LT3014HVES5#TR
LT3014HVIS5#TR
LT3014EDD#TR
LTBRS
5-Lead Plastic SOT-23
LT3014HVIS5
LTBRS
5-Lead Plastic SOT-23
LT3014EDD
LBMG
8-Lead (3mm × 3mm) Plastic DFN
8-Lead (3mm × 3mm) Plastic DFN
8-Lead (3mm × 3mm) Plastic DFN
8-Lead (3mm × 3mm) Plastic DFN
LT3014IDD
LT3014IDD#TR
LBMG
LT3014HVEDD
LT3014HVIDD
LT3014HVEDD#TR
LT3014HVIDD#TR
LBRT
LBRT
Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified 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 specifications, go to: http://www.linear.com/tapeandreel/
3014fd
2
LT3014
ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at TJ = 25°C.
SYMBOL
CONDITIONS
= 20mA
MIN
TYP
MAX
UNITS
l
Minimum Input Voltage
I
3
3.3
V
LOAD
ADJ Pin Voltage
(Notes 2, 3)
V
= 3.3V, I
= 100μA
1.200
1.180
1.220
1.220
1.240
1.260
V
V
IN
LOAD
l
l
3.3V < V < 80V, 100μA < I
< 20mA
LOAD
IN
Line Regulation
1
10
mV
ΔV = 3.3V to 80V, I
= 100μA (Note 2)
IN
LOAD
Load Regulation (Note 2)
13
25
40
mV
mV
V
V
= 3.3V, ΔI
= 3.3V, ΔI
= 100μA to 20mA
= 100μA to 20mA
IN
IN
LOAD
LOAD
l
l
l
l
l
Dropout Voltage
I
I
= 100μA
= 100μA
120
200
300
350
180
250
mV
mV
LOAD
LOAD
V
IN
= V
(Notes 4, 5)
OUT(NOMINAL)
I
I
= 1mA
= 1mA
270
360
mV
mV
LOAD
LOAD
I
I
= 10mA
= 10mA
350
450
mV
mV
LOAD
LOAD
I
I
= 20mA
= 20mA
410
570
mV
mV
LOAD
LOAD
l
l
l
l
l
GND Pin Current
= V
I
I
I
I
I
= 0mA
7
20
30
100
450
1000
μA
μA
μA
μA
μA
LOAD
LOAD
LOAD
LOAD
LOAD
V
(Notes 4, 6)
OUT(NOMINAL)
= 100μA
= 1mA
12
IN
40
250
650
= 10mA
= 20mA
Output Voltage Noise
ADJ Pin Bias Current
Shutdown Threshold
C
= 0.47μF, I
= 20mA, BW = 10Hz to 100kHz
115
4
μV
RMS
OUT
LOAD
(Note 7)
10
2
nA
l
l
V
OUT
V
OUT
= Off to On
= On to Off
1.3
1.3
V
V
0.25
l
l
SHDN Pin Current (Note 8)
V
SHDN
V
SHDN
= 0V
= 6V
1
0
4
1
μA
μA
l
Quiescent Current in Shutdown
Ripple Rejection
V
= 6V, V
= 0V
SHDN
1
4
μA
dB
IN
V
LOAD
= 7V (Avg), V
= 20mA
= 0.5V , f = 120Hz,
P-P RIPPLE
60
25
70
IN
RIPPLE
I
Current Limit
V
IN
V
IN
= 7V, V
= 3.3V, ΔV
= 0V
70
mA
mA
OUT
l
l
= –0.1V (Note 2)
OUT
Input Reverse Leakage Current
Reverse Output Current (Note 9)
V
IN
= –80V, V
= 0V
OUT
6
4
mA
μA
V
OUT
= 1.22V, V < 1.22V (Note 2)
2
IN
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 LT3014 is tested and specified for these conditions with the
ADJ pin connected to the OUT pin.
Note 3: 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 4: To satisfy requirements for minimum input voltage, the LT3014 is
tested and specified for these conditions with an external resistor divider
(249k bottom, 392k top) for an output voltage of 3.3V. The external
resistor divider adds a 5µA DC load on the output.
Note 5: Dropout voltage is the minimum input to output voltage differential
needed to maintain regulation at a specified output current. In dropout, the
output voltage is equal to (V – V
).
IN
DROPOUT
Note 6: GND pin current is tested with V = V
(nominal) and a current
IN
OUT
source load. This means the device is tested while operating in its dropout
region. This is the worst-case GND pin current. The GND pin current
decreases slightly at higher input voltages.
Note 7: ADJ pin bias current flows into the ADJ pin.
Note 8: SHDN pin current flows out of the SHDN pin.
Note 9: 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 of the GND pin.
Note 10: The LT3014 is tested and specified under pulse load conditions
such that T ≅ T . The LT3014E is 100% tested at T = 25°C. Performance
J
A
A
at –40°C to 125°C is assured by design, characterization, and statistical
3014fd
3
LT3014
ELECTRICAL CHARACTERISTICS
process controls. The LT3014I is guaranteed over the full –40°C to 125°C
operating junction temperature.
temperature will exceed 125°C when overtemperature protection is active.
Continuous operation above the specified maximum operating junction
temperature may impair device reliability.
Note 11: This IC includes overtemperature protection that is intended
to protect the device during momentary overload conditions. Junction
TYPICAL PERFORMANCE CHARACTERISTICS
Typical Dropout Voltage
Guaranteed Dropout Voltage
Dropout Voltage
500
450
400
350
300
250
200
150
100
50
500
450
400
350
300
250
200
150
100
50
600
500
= TEST POINTS
T
b 125oC
J
T
= 125oC
J
I
L
= 20mA
400
300
I
= 10mA
T
b 25oC
L
J
T
= 25oC
J
I
= 1mA
L
200
100
0
I
= 100MA
L
0
0
0
2
4
6
8
10 12 14 16 18 20
–50
0
25
50
75 100 125
0
2
4
6
8
10 12 14 16 18 20
–25
OUTPUT CURRENT (mA)
TEMPERATURE (oC)
OUTPUT CURRENT (mA)
3014 G01
3014 G02
3014 G03
Quiescent Current
ADJ Pin Voltage
Quiescent Current
16
1.240
16
14
12
10
8
I
= 100μA
T
R
V
= 25oC
= d
OUT
V
= 6V
L
J
L
IN
L
R
I
= d
14
12
1.235
1.230
= 1.22V
= 0
L
10
8
1.225
1.220
1.215
1.210
1.205
V
= V
IN
SHDN
V
= V
IN
SHDN
6
6
4
4
2
2
V
= 0V
SHDN
V
= 0V
5
SHDN
4
0
0
1.200
0
1
2
3
6
7
8
9
10
–25
0
50
75 100 125
–25
0
50
75 100 125
–50
25
–50
25
INPUT VOLTAGE (V)
TEMPERATURE (oC)
TEMPERATURE (oC)
3014 G06
3014 G04
3014 G05
3014fd
4
LT3014
TYPICAL PERFORMANCE CHARACTERISTICS
GND Pin Current
GND Pin Current vs ILOAD
SHDN Pin Threshold
2.0
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0
1000
900
800
700
600
500
400
300
200
100
0
1000
900
800
700
600
500
400
300
200
100
0
T
= 25oC
V
J
= 3.3V
J
IN
*FOR V
= 1.22V
T = 25oC
OUT
V
= 1.22V
OUT
R
L
= 617
L
I
= 20mA*
R
I
= 1227
L
L
= 10mA*
R
L
= 1.22k
= 1mA*
L
I
–50 –25
0
25
50
75 100 125
0
1
2
3
4
5
6
7
8
9
10
0
2
4
6
8
10 12 14 16 18 20
TEMPERATURE (oC)
INPUT VOLTAGE (V)
OUTPUT CURRENT (mA)
3014 G09
3014 G07
3014 G08
SHDN Pin Current
SHDN Pin Current
ADJ Pin Bias Current
1.6
14
12
10
8
1.2
1.0
T
= 25oC
V
= 0V
J
SHDN
CURRENT FLOWS
OUT OF SHDN PIN
CURRENT FLOWS
OUT OF SHDN PIN
1.4
1.2
0.8
0.6
1.0
0.8
0.6
0.4
0.2
6
0.4
0.2
0
4
2
0
0
2.5
3
–50 –25
0
25
50
75 100 125
–50 –25
0
25
50
75 100 125
0
0.5
1
1.5
2
3.5
4
SHDN PIN VOLTAGE (V)
TEMPERATURE (oC)
TEMPERATURE (oC)
3014 G11
3014 G12
3014 G10
Current Limit
Current Limit
Reverse Output Current
100
90
80
70
60
50
40
30
20
10
0
80
50
45
40
35
30
25
20
15
10
5
V
V
= 7V
V
T
= 0V
IN
OUT
T
V
V
= 25oC
OUT
J
J
= 0V
= 25oC
= 0V
IN
OUT
70
60
ADJ PIN
ESD CLAMP
= V
ADJ
50
40
30
20
10
CURRENT FLOWS
INTO OUTPUT PIN
0
0
–50
0
25
50
75 100 125
0
2
4
6
8
10 12 14 16 18 20
–25
0
1
2
3
4
5
6
7
8
9
10
TEMPERATURE (oC)
INPUT VOLTAGE (V)
OUTPUT VOLTAGE (V)
3014 G14
3014 G13
3014 G15
3014fd
5
LT3014
TYPICAL PERFORMANCE CHARACTERISTICS
Reverse Output Current
Input Ripple Rejection
Input Ripple Rejection
72
80
8
V
V
= 0V
= V
V
I
= 7V + 50mV
RIPPLE
V
= 7V + 0.5V
P-P
IN
OUT
IN
RMS
IN
= 1.22V
ADJ
= 20mA
RIPPLE AT f = 120Hz
L
70
68
70
60
7
6
I
= 20mA
L
66
64
62
60
58
50
40
30
20
10
5
4
3
2
1
C
= 4.7μF
OUT
C
= 0.47μF
OUT
56
0
0
–25
0
50
75 100 125
–50
25
10
100
1k
10k
100k
1M
–25
0
50
75 100 125
–50
25
TEMPERATURE (oC)
FREQUENCY (Hz)
TEMPERATURE (oC)
3014 G18
3014 G17
3014 G16
Minimum Input Voltage
Load Regulation
Output Noise Spectral Density
10
1
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0
0
C
I
= 0.47μF
$I = 100μA TO 20mA
I
= 20mA
OUT
L
OUT
L
OUT
LOAD
= 20mA
V
= 1.22V
–5
V
= 1.22V
–10
–15
–20
–25
–30
–35
0.1
–40
0.01
–50 –25
0
25
50
75
100 125
–50 –25
0
25
50
75 100 125
10
100
1k
10k
100k
TEMPERATURE (oC)
TEMPERATURE (oC)
FREQUENCY (Hz)
3014 G21
3014 G19
3014 G20
10Hz to 100kHz Output Noise
Transient Response
0.04
0.02
0
V
= 7V
= 5V
IN
V
OUT
–0.02
–0.04
V
OUT
200μV/DIV
C
= C
= 0.47μF CERAMIC
IN
OUT
$I
= 1mA TO 5mA
LOAD
6
4
C
L
V
= 0.47μF
1ms/DIV
OUT
OUT
3014 G22
2
0
I
= 200mA
= 1.22V
0
200
400
600
800
1000
TIME (μs)
3014 G23
3014fd
6
LT3014
PIN FUNCTIONS (SOT-23 Package/DD Package)
IN (Pin 1/Pin 8): Input. Power is supplied to the device
through the IN pin. A bypass capacitor is required on this
pinifthedeviceismorethansixinchesawayfromthemain
input filter capacitor. In general, the output impedance of
a battery rises with frequency, so it is advisable to include
a bypass capacitor in battery-powered circuits. A bypass
capacitor in the range of 0.1μF to 10μF is sufficient. The
LT3014isdesignedtowithstandreversevoltagesontheIN
pin with respect to ground and the OUT pin. In the case of
a reversed input, which can happen if a battery is plugged
in backwards, the LT3014 will act as if there is a diode in
series with its input. There will be no reverse current flow
into the LT3014 and no reverse voltage will appear at the
load. The device will protect both itself and the load.
logic with a pull-up resistor. The pull-up resistor is only
required to supply the pull-up current of the open-collec-
tor gate, normally several microamperes. If unused, the
SHDN pin must be tied to IN or to a logic high.
ADJ (Pin 4/Pin 2): Adjust. This is the input to the error
amplifier. This pin is internally clamped to 7V. It has a
bias current of 4nA which flows into the pin (see curve
of ADJ Pin Bias Current vs Temperature in the Typical
Performance Characteristics). The ADJ pin voltage is
1.22V referenced to ground, and the output voltage range
is 1.22V to 60V.
OUT (Pin 5/Pin 1): Output. The output supplies power to
theload.Aminimumoutputcapacitorof0.47μFisrequired
to prevent oscillations. Larger output capacitors will be
required for applications with large transient loads to limit
peak voltage transients. See the Applications Information
section for more information on output capacitance and
reverse output characteristics.
GND (Pin 2/Pins 4, 9): Ground.
SHDN (Pin 3/Pin 5): Shutdown. The SHDN pin is used
to put the LT3014 into a low power shutdown state. The
output will be off when the SHDN pin is pulled low. The
SHDNpincanbedriveneitherby5Vlogicoropen-collector
3014fd
7
LT3014
APPLICATIONS INFORMATION
The LT3014 is a 20mA high voltage low dropout regulator
with micropower quiescent current and shutdown. The
device is capable of supplying 20mA at a dropout voltage
of350mV.Thelowoperatingquiescentcurrent(7μA)drops
to 1μA in shutdown. In addition to the low quiescent cur-
rent, the LT3014 incorporates several protection features
which make it ideal for use in battery-powered systems.
The device is protected against both reverse input and
reverse output voltages. In battery backup applications
where the output can be held up by a backup battery
when the input is pulled to ground, the LT3014 acts like it
has a diode in series with its output and prevents reverse
current flow.
is –13mV typical at V
regulation is:
= 1.22V. At V
= 12V, load
OUT
OUT
(12V/1.22V) • (–13mV) = –128mV
Output Capacitance and Transient Response
The LT3014 is designed to be stable with a wide range of
output capacitors. The ESR of the output capacitor affects
stability, most notably with small capacitors. A minimum
output capacitor of 0.47μF with an ESR of 3Ω or less is
recommended to prevent oscillations. The LT3014 is a
micropower device and output transient response will be
a function of output capacitance. Larger values of output
capacitance decrease the peak deviations and provide
improved transient response for larger load current
changes. Bypass capacitors, used to decouple individual
components powered by the LT3014, will increase the
effective output capacitor value.
Adjustable Operation
The LT3014 has an output voltage range of 1.22V to 60V.
The output voltage is set by the ratio of two external
resistors as shown in Figure 1. The device servos the
output to maintain the voltage at the adjust pin at 1.22V
referenced to ground. The current in R1 is then equal to
1.22V/R1 and the current in R2 is the current in R1 plus
the ADJ pin bias current. The ADJ pin bias current, 4nA
at 25°C, flows through R2 into the ADJ pin. The output
voltage can be calculated using the formula in Figure 1.
The value of R1 should be less than 1.62M to minimize
errors in the output voltage caused by the ADJ pin bias
current. Note that in shutdown the output is turned off
and the divider current will be zero. The device is tested
and specified with the ADJ pin tied to the OUT pin and a
5μA DC load (unless otherwise specified) for an output
voltageof1.22V.Specificationsforoutputvoltagesgreater
than 1.22V will be proportional to the ratio of the desired
Extra consideration must be given to the use of ceramic
capacitors. Ceramic capacitors are manufactured with a
variety of dielectrics, each with different behavior across
temperature and applied voltage. The most common
dielectrics used are specified with EIA temperature char-
acteristic codes of Z5U, Y5V, X5R and X7R. The Z5U and
Y5V dielectrics are good for providing high capacitances
in a small package, but they tend to have strong voltage
and temperature coefficients as shown in Figures 2 and 3.
When used with a 5V regulator, a 16V 10μF Y5V capacitor
can exhibit an effective value as low as 1μF to 2μF for the
DC bias voltage applied and over the operating tempera-
ture range. The X5R and X7R dielectrics result in more
stable characteristics and are more suitable for use as the
output capacitor. The X7R type has better stability across
temperature, while the X5R is less expensive and is avail-
able in higher values. Care still must be exercised when
using X5R and X7R capacitors; the X5R and X7R codes
only specify operating temperature range and maximum
capacitancechangeovertemperature.Capacitancechange
due to DC bias with X5R and X7R capacitors is better than
Y5VandZ5Ucapacitors,butcanstillbesignificantenough
to drop capacitor values below appropriate levels. Capaci-
tor DC bias characteristics tend to improve as component
casesizeincreases, butexpectedcapacitanceatoperating
voltage should be verified.
output voltage to 1.22V (V /1.22V). For example, load
OUT
regulation for an output current change of 1mA to 20mA
V
IN
OUT
LT3014
ADJ
OUT
+
R2
R1
V
IN
GND
3014 F01
R2
R1
V
V
= 1.22V 1 +
•
+ (I )(R2)
ADJ
OUT
ADJ
ꢀ
ꢁ
= 1.22V
= 4nA AT 25oC
I
ADJ
OUTPUT RANGE = 1.22V TO 60V
Figure 1. Adjustable Operation
3014fd
8
LT3014
APPLICATIONS INFORMATION
Voltage and temperature coefficients are not the only
sources of problems. Some ceramic capacitors have a
piezoelectric response. A piezoelectric device generates
voltageacrossitsterminalsduetomechanicalstress,simi-
lartothewayapiezoelectricaccelerometerormicrophone
works. For a ceramic capacitor the stress can be induced
by vibrations in the system or thermal transients.
For surface mount devices, heat sinking is accomplished
by using the heat spreading capabilities of the PC board
and its copper traces. Copper board stiffeners and plated
through-holes can also be used to spread the heat gener-
ated by power devices.
The following table lists thermal resistance for several
different board sizes and copper areas. All measurements
were taken in still air on 3/32” FR-4 board with one ounce
copper.
20
BOTH CAPACITORS ARE 16V,
1210 CASE SIZE, 10μF
0
X5R
Table 1. SOT-23 Measured Thermal Resistance
–20
COPPER AREA
THERMAL RESISTANCE
(JUNCTION-TO-AMBIENT)
–40
TOPSIDE BACKSIDE BOARD AREA
2500 sq mm 2500 sq mm
1000 sq mm 2500 sq mm
225 sq mm 2500 sq mm
100 sq mm 2500 sq mm
2500 sq mm
2500 sq mm
2500 sq mm
2500 sq mm
2500 sq mm
125°C/W
125°C/W
130°C/W
135°C/W
150°C/W
–60
Y5V
–80
–100
0
8
12 14
2
4
6
10
16
50 sq mm
2500 sq mm
DC BIAS VOLTAGE (V)
3014 F02
Table 2. DFN Measured Thermal Resistance
COPPER AREA
Figure 2. Ceramic Capacitor DC Bias Characteristics
THERMAL RESISTANCE
TOPSIDE BACKSIDE BOARD AREA
(JUNCTION-TO-AMBIENT)
Thermal Considerations
2500 sq mm 2500 sq mm
1000 sq mm 2500 sq mm
225 sq mm 2500 sq mm
100 sq mm 2500 sq mm
2500 sq mm
2500 sq mm
2500 sq mm
2500 sq mm
40°C/W
45°C/W
50°C/W
62°C/W
The power handling capability of the device will be limited
by the maximum rated junction temperature (125°C). The
power dissipated by the device will be made up of two
components:
For the DFN package, the thermal resistance junction-to-
1. Output current multiplied by the input/output voltage
case (θ ), measured at the Exposed Pad on the back of
differential: I
• (V – V ) and,
JC
OUT
IN OUT
the die, is 16°C/W.
2. GND pin current multiplied by the input voltage:
• V .
40
I
GND
IN
20
The GND pin current can be found by examining the GND
Pin Current curves in the Typical Performance Character-
istics. Power dissipation will be equal to the sum of the
two components listed above.
0
X5R
–20
–40
Y5V
The LT3014 regulator has internal thermal limiting de-
signed to protect the device during overload conditions.
For continuous normal conditions the maximum junction
temperature rating of 125°C must not be exceeded. It is
important to give careful consideration to all sources of
thermal resistance from junction to ambient. Additional
heat sources mounted nearby must also be considered.
–60
–80
BOTH CAPACITORS ARE 16V,
1210 CASE SIZE, 10μF
–100
50
TEMPERATURE (oC)
100 125
–50 –25
0
25
75
3014 F03
Figure 3. Ceramic Capacitor Temperature Characteristics
3014fd
9
LT3014
APPLICATIONS INFORMATION
Continuous operation at large input/output voltage dif-
ferentials and maximum load current is not practical
due to thermal limitations. Transient operation at high
input/output differentials is possible. The approximate
thermal time constant for a 2500sq mm 3/32" FR-4 board
with maximum topside and backside area for one ounce
copper is 3 seconds. This time constant will increase as
more thermal mass is added (i.e. vias, larger board, and
other components).
area. So the junction temperature rise above ambient will
be approximately equal to:
0.52W • 50°C/W = 26°C
The maximum junction temperature will then be equal to
the maximum junction temperature rise above ambient
plus the maximum ambient temperature or:
T
= 50°C + 26°C = 76°C
JMAX
Example 2: Given an output voltage of 5V, an input voltage
of 48V that rises to 72V for 5ms(max) out of every 100ms,
and a 5mA load that steps to 20mA for 50ms out of every
250ms, what is the junction temperature rise above ambi-
ent? Using a 500ms period (well under the time constant
of the board), power dissipation is as follows:
Foranapplicationwithtransienthighpowerpeaks,average
power dissipation can be used for junction temperature
calculationsaslongasthepulseperiodissignificantlyless
than the thermal time constant of the device and board.
Calculating Junction Temperature
P1(48V in, 5mA load) = 5mA • (48V – 5V)
+ (100μA • 48V) = 0.22W
Example 1: Given an output voltage of 5V, an input volt-
age range of 24V to 30V, an output current range of 0mA
to 20mA, and a maximum ambient temperature of 50°C,
what will the maximum junction temperature be?
P2(48V in, 20mA load) = 20mA • (48V – 5V)
+ (0.55mA • 48V) = 0.89W
P3(72V in, 5mA load) = 5mA • (72V – 5V)
+ (100μA • 72V) = 0.34W
The power dissipated by the device will be equal to:
I
• (V
– V ) + (I
• V
)
OUT(MAX)
IN(MAX)
OUT
GND
IN(MAX)
P4(72V in, 20mA load) = 20mA • (72V – 5V)
+ (0.55mA • 72V) = 1.38W
where:
I
= 20mA
= 30V
OUT(MAX)
Operation at the different power levels is as follows:
V
IN(MAX)
76% operation at P1, 19% for P2, 4% for P3, and
1% for P4.
I
at (I = 20mA, V = 30V) = 0.55mA
OUT IN
GND
So:
PEFF = 76%(0.22W) + 19%(0.89W) + 4%(0.34W)
+ 1%(1.38W) = 0.36W
P = 20mA • (30V – 5V) + (0.55mA • 30V) = 0.52W
With a thermal resistance in the range of 40°C/W to
62°C/W, this translates to a junction temperature rise
above ambient of 20°C.
The thermal resistance for the DFN package will be in the
range of 40°C/W to 62°C/W depending on the copper
3014fd
10
LT3014
APPLICATIONS INFORMATION
Protection Features
In situations where the ADJ pin is connected to a resistor
dividerthatwouldpulltheADJpinaboveits7Vclampvolt-
age if the output is pulled high, the ADJ pin input current
must be limited to less than 5mA. For example, a resistor
divider is used to provide a regulated 1.5V output from the
1.22V reference when the output is forced to 60V. The top
resistor of the resistor divider must be chosen to limit the
current into the ADJ pin to less than 5mA when the ADJ
pin is at 7V. The 53V difference between the OUT and ADJ
pins divided by the 5mA maximum current into the ADJ
pin yields a minimum top resistor value of 10.6k.
TheLT3014incorporatesseveralprotectionfeatureswhich
make it ideal for use in battery-powered circuits. In ad-
dition to the normal protection features associated with
monolithicregulators,suchascurrentlimitingandthermal
limiting, thedeviceisprotectedagainstreverse-inputvolt-
ages, and reverse voltages from output to input.
Current limit protection and thermal overload protection
areintendedtoprotectthedeviceagainstcurrentoverload
conditionsattheoutputofthedevice.Fornormaloperation,
the junction temperature should not exceed 125°C.
In circuits where a backup battery is required, several
different input/output conditions can occur. The output
voltage may be held up while the input is either pulled
to ground, pulled to some intermediate voltage, or is left
open circuit. Current flow back into the output will follow
the curve shown in Figure 4. The rise in reverse output
current above 7V occurs from the breakdown of the 7V
clamp on the ADJ pin. With a resistor divider on the
regulator output, this current will be reduced depending
on the size of the resistor divider.
The input of the device will withstand reverse voltages
of 80V. Current flow into the device will be limited to less
than 6mA (typically less than 100μA) and no negative
voltage will appear at the output. The device will protect
both itself and the load. This provides protection against
batteries which can be plugged in backward.
The ADJ pin can be pulled above or below ground by as
much as 7V without damaging the device. If the input is
left open circuit or grounded, the ADJ pin will act like an
open circuit when pulled below ground, and like a large
resistor (typically 100k) in series with a diode when pulled
above ground. If the input is powered by a voltage source,
pulling the ADJ pin below the reference voltage will cause
the device to current limit. This will cause the output to go
to an unregulated high voltage. Pulling the ADJ pin above
the reference voltage will turn off all output current.
When the IN pin of the LT3014 is forced below the OUT
pin or the OUT pin is pulled above the IN pin, input cur-
rent will typically drop to less than 2μA. This can happen
if the input of the LT3014 is connected to a discharged
(low voltage) battery and the output is held up by either
a backup battery or a second regulator circuit. The state
of the SHDN pin will have no effect on the reverse output
current when the output is pulled above the input.
50
T
V
V
= 25oC
J
45
40
35
30
25
20
15
10
5
= 0V
IN
OUT
ADJ PIN
ESD CLAMP
= V
ADJ
CURRENT FLOWS
INTO OUTPUT PIN
0
0
1
2
3
4
5
6
7
8
9
10
OUTPUT VOLTAGE (V)
3014 F04
Figure 4. Reverse Output Current
3014fd
11
LT3014
TYPICAL APPLICATIONS
5V Buck Converter with Low Current Keep Alive Backup
D2
D1N914
6
C2
L1†
15μH
0.33μF
BOOST
V
V
IN
OUT
4
2
5.5V*
V
SW
5V
IN
C3
4.7μF
100V
D1
TO 60V
1A/20mA
10MQ060N
LT1766
CERAMIC
15
14
10
12
SHDN
BIAS
FB
R1
C1
+
15.4k
100μF 10V
SOLID
SYNC
GND
R2
4.99k
TANTALUM
V
C
1, 8, 9, 16 11
C
C
1nF
3014 TA03
IN
OUT
*FOR INPUT VOLTAGES BELOW 7.5V,
SOME RESTRICTIONS MAY APPLY
† INCREASE L1 TO 30μH FOR LOAD
CURRENTS ABOVE 0.6A AND TO
60μH ABOVE 1A
LT3014
3.92M
1.27M
OPERATING
CURRENT
SHDN
ADJ
HIGH
LOW
GND
Buck Converter
Efficiency vs Load Current
100
V
= 5V
OUT
L = 68μH
V
V
= 10V
= 42V
IN
IN
90
80
70
60
50
0
0.25
0.50
0.75
1.00
1.25
LOAD CURRENT (A)
3014 TA04
3014fd
12
LT3014
TYPICAL APPLICATIONS
LT3014 Automotive Application
IN
OUT
ADJ
NO PROTECTION
DIODE NEEDED!
+
V
IN
LT3014
SHDN
R1
R2
1μF
12V
1μF
LOAD: CLOCK,
SECURITY SYSTEM
ETC
(LATER 42V)
GND
OFF
ON
LT3014 Telecom Application
V
IN
IN
OUT
48V
(72V TRANSIENT)
+
–
LT3014
BACKUP
BATTERY
R1
R2
NO PROTECTION
DIODE NEEDED!
1μF
1μF
LOAD:
SYSTEM MONITOR
ETC
SHDN
ADJ
GND
3014 TA05
OFF
ON
Constant Brightness for Indicator LED over Wide Input Voltage Range
RETURN
IN
OUT
LT3014
1μF
1μF
OFF ON
–48V
SHDN ADJ
GND
R
SET
3014 TA06
I
= 1.22V/R
SET
LED
–48V CAN VARY FROM –3.3V TO –80V
3014fd
13
LT3014
PACKAGE DESCRIPTION
S5 Package
5-Lead Plastic TSOT-23
(Reference LTC DWG # 05-08-1635)
0.62
MAX
0.95
REF
2.90 BSC
(NOTE 4)
1.22 REF
1.50 – 1.75
(NOTE 4)
2.80 BSC
1.4 MIN
3.85 MAX 2.62 REF
PIN ONE
RECOMMENDED SOLDER PAD LAYOUT
PER IPC CALCULATOR
0.30 – 0.45 TYP
5 PLCS (NOTE 3)
0.95 BSC
0.80 – 0.90
0.20 BSC
DATUM ‘A’
0.01 – 0.10
1.00 MAX
0.30 – 0.50 REF
1.90 BSC
0.09 – 0.20
(NOTE 3)
NOTE:
S5 TSOT-23 0302 REV B
1. DIMENSIONS ARE IN MILLIMETERS
2. DRAWING NOT TO SCALE
3. DIMENSIONS ARE INCLUSIVE OF PLATING
4. DIMENSIONS ARE EXCLUSIVE OF MOLD FLASH AND METAL BURR
5. MOLD FLASH SHALL NOT EXCEED 0.254mm
6. JEDEC PACKAGE REFERENCE IS MO-193
3014fd
14
LT3014
PACKAGE DESCRIPTION
DD Package
8-Lead Plastic DFN (3mm × 3mm)
(Reference LTC DWG # 05-08-1698)
0.675 p0.05
3.5 p0.05
2.15 p0.05 (2 SIDES)
1.65 p0.05
PACKAGE
OUTLINE
0.25 p 0.05
0.50
BSC
2.38 p0.05
(2 SIDES)
RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS
R = 0.115
0.38 p 0.10
TYP
5
8
3.00 p0.10
(4 SIDES)
1.65 p 0.10
(2 SIDES)
PIN 1
TOP MARK
(NOTE 6)
(DD) DFN 1203
4
1
0.25 p 0.05
0.75 p0.05
0.200 REF
0.50 BSC
2.38 p0.10
(2 SIDES)
0.00 – 0.05
BOTTOM VIEW—EXPOSED PAD
NOTE:
1. DRAWING TO BE MADE A JEDEC PACKAGE OUTLINE M0-229 VARIATION OF (WEED-1)
2. DRAWING NOT TO SCALE
3. ALL DIMENSIONS ARE IN MILLIMETERS
4. DIMENSIONS OF EXPOSED PAD ON BOTTOM OF PACKAGE DO NOT INCLUDE
MOLD FLASH. MOLD FLASH, IF PRESENT, SHALL NOT EXCEED 0.15mm ON ANY SIDE
5. EXPOSED PAD SHALL BE SOLDER PLATED
6. SHADED AREA IS ONLY A REFERENCE FOR PIN 1 LOCATION
ON TOP AND BOTTOM OF PACKAGE
3014fd
Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no representa-
tion that the interconnection of its circuits as described herein will not infringe on existing patent rights.
15
LT3014
RELATED PARTS
PART NUMBER
DESCRIPTION
COMMENTS
V : 4.2V to 30V, V
LT1129
700mA, Micropower, LDO
= 3.75V, V = 0.4V, I = 50μA, I = 16μA,
OUT(MIN) DO Q SD
IN
DD, SOT-223, S8, TO220, TSSOP-20 Packages
LT1175
500mA, Micropower Negative LDO
3A, Negative LDO
V : –20V to –4.3V, V = –3.8V, V = 0.50V, I = 45μA, I = 10μA,
IN
OUT(MIN)
DO
Q
SD
DD, SOT-223, S8 Packages
LT1185
V : –35V to –4.2V, V = –2.40V, V = 0.80V, I = 2.5mA, I <1μA,
OUT(MIN) DO Q SD
IN
TO220-5 Package
LT1761
100mA, Low Noise Micropower, LDO
150mA, Low Noise Micropower, LDO
500mA, Low Noise Micropower, LDO
3A, Low Noise, Fast Transient Response, LDO
150mA, Very Low Dropout LDO
V : 1.8V to 20V, V
= 1.22V, V = 0.30V, I = 20μA, I <1μA,
DO Q SD
IN
OUT(MIN)
OUT(MIN)
OUT(MIN)
OUT(MIN)
ThinSOT Package
LT1762
V : 1.8V to 20V, V
= 1.22V, V = 0.30V, I = 25μA, I <1μA,
DO Q SD
IN
MS8 Package
LT1763
V : 1.8V to 20V, V
= 1.22V, V = 0.30V, I = 30μA, I <1μA,
DO Q SD
IN
S8 Package
LT1764/LT1764A
LTC1844
LT1962
V : 2.7V to 20V, V
= 1.21V, V = 0.34V, I = 1mA, I <1μA,
DO Q SD
IN
DD, TO220 Packages
V : 1.6V to 6.5V, V
= 1.25V, V = 0.08V, I = 40μA, I <1μA,
DO Q SD
IN
OUT(MIN)
OUT(MIN)
OUT(MIN)
ThinSOT Package
300mA, Low Noise Micropower, LDO
1.5A, Low Noise, Fast Transient Response, LDO
200mA, Low Noise Micropower, Negative LDO
50mA, 80V, Low Noise Micropower, LDO
V : 1.8V to 20V, V
= 1.22V, V = 0.27V, I = 30μA, I <1μA,
DO Q SD
IN
MS8 Package
LT1963/LT1963A
LT1964
V : 2.1V to 20V, V
= 1.21V, V = 0.34V, I = 1mA, I <1μA,
DO Q SD
IN
DD, TO220, SOT Packages
V : –1.9V to –20V, V
= –1.21V, V = 0.34V, I = 30μA, I = 3μA,
DO Q SD
IN
OUT(MIN)
ThinSOT Package
LT3010
V : 3V to 80V, V
= 1.28V, V = 0.3V, I = 30μA, I <1μA,
IN
OUT(MIN) DO Q SD
MS8E Package
LT3020
100mA, Low V , Low V
Micropower, VLDO
V : 0.9V to 10V, V
= 0.20V, V = 0.15V, I = 120μA, I <1μA,
OUT(MIN) DO Q SD
IN
OUT
IN
DFN, MS8 Packages
LT3023
Dual 100mA, Low Noise Micropower, LDO
V : 1.8V to 20V, V
= 1.22V, V = 0.30V, I = 40μA, I <1μA,
OUT(MIN) DO Q SD
IN
DFN, MS10 Packages
LT3024
Dual 100mA/500mA, Low Noise Micropower, LDO
V : 1.8V to 20V, V
= 1.22V, V = 0.30V, I = 60μA, I <1μA,
OUT(MIN) DO Q SD
IN
DFN, TSSOP-16E Packages
V : 1.8V to 20V, V = 1.22V, V = 0.30V, I = 40μA, I <1μA,
OUT(MIN) DO Q SD
LT3027
Dual 100mA, Low Noise LDO with Independent
Inputs
IN
DFN, MS10E Packages
LT3028
Dual 100mA/500mA, Low Noise LDO with
Independent Inputs
V : 1.8V to 20V, V
= 1.22V, V = 0.30V, I = 60μA, I <1μA,
OUT(MIN) DO Q SD
IN
DFN, TSSOP-16E Packages
3014fd
LT 0808 REV D • PRINTED IN USA
LinearTechnology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
16
●
●
© LINEAR TECHNOLOGY CORPORATION 2005
(408) 432-1900 FAX: (408) 434-0507 www.linear.com
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