LT3014B
1
3014bfa
TYPICAL APPLICATION
FEATURES
APPLICATIONS
DESCRIPTION
20mA, 3V to 80V
Low Dropout Micropower
Linear Regulator
The LT
®
3014B is a high voltage, micropower low dropout-
linear regulator. The device is capable of supplying 20mA of
output current with a dropout voltage of 350mV. Designed
for use in battery-powered or high voltage systems, the
low quiescent current (7μA operating) makes the LT3014B
an ideal choice. Quiescent current is also well controlled
in dropout.
Other features of the LT3014B include the ability to operate
with very small output capacitors. The regulators are stable
with only 0.47μF on the output while most older devices
require between 10μF and 100μF for stability. Small ceramic
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.
The device is available as an adjustable device with a 1.22V
reference voltage. The LT3014B regulator is available in
the 5-lead ThinSOT and 8-lead DFN packages.
Dropout Voltage
n Wide Input Voltage Range: 3V to 80V
n Low Quiescent Current: 7µA
n Low Dropout Voltage: 350mV
n Output Current: 20mA
n LT3014BHV Survives 100V Transients (2ms)
n No Protection Diodes Needed
n Adjustable Output from 1.22V to 60V
n Stable with 0.47µF Output Capacitor
n Stable with Aluminum, Tantalum or Ceramic
Capacitors
n Reverse-Battery Protection
n No Reverse Current Flow from Output
n Thermal Limiting
n Available in 5-Lead ThinSOT
TM
and
8-Lead DFN Packages
n
Low Current High Voltage Regulators
n
Regulator for Battery-Powered Systems
n Telecom Applications
n Automotive Applications
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.
5V Supply
400
350
300
250
200
150
100
50
0
3014B TA02
OUTPUT CURRENT (mA)
DROPOUT VOLTAGE (mV)
0 4 10 12268 14161820
IN
LT3014B
1μF
VIN
5.4V TO
80V
OUT
ADJ
GND
3014B TA01
VOUT
5V
20mA
0.47μF
3.92M
1.27M
LT3014B
2
3014bfa
ABSOLUTE MAXIMUM RATINGS
IN Pin Voltage, Operating ................................... ±80V
Transient (2ms Survival, LT3014BHV) .............. +100V
OUT Pin Voltage ................................................. ±60V
IN to OUT Differential Voltage ............................±80V
ADJ Pin Voltage ................................................... ±7V
Output Short-Circuit Duration ......................Indefi nite
(Note 1)
5 OUT
4 ADJ
IN 1
TOP VIEW
S5 PACKAGE
5-LEAD PLASTIC SOT-23
GND 2
NC 3
TJMAX = 125°C, θJA = 150°C/ W
θJC = 25°C/W MEASURED AT PIN 2
SEE APPLICATIONS INFORMATION SECTION
TOP VIEW
DD PACKAGE
8-LEAD (3mm s 3mm) PLASTIC DFN
5
6
7
8
4
3
2
1OUT
ADJ
NC
GND
IN
NC
NC
NC
9
TJMAX = 125°C, θJA = 40°C/W
θJC = 10°C/W MEASURED AT PIN 9
EXPOSED PAD (PIN 9) IS GND, MUST BE SOLDERED TO PCB
PIN CONFIGURATION
ORDER INFORMATION
LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE
LT3014BES5#PBF LT3014BES5#TRPBF LTCHK 5-Lead Plastic SOT-23 –40°C to 125°C
LT3014BIS5#PBF LT3014BIS5#TRPBF LTCHK 5-Lead Plastic SOT-23 –40°C to 125°C
LT3014BHVES5#PBF LT3014BHVES5#TRPBF LTCHN 5-Lead Plastic SOT-23 –40°C to 125°C
LT3014BHVIS5#PBF LT3014BHVIS5#TRPBF LTCHN 5-Lead Plastic SOT-23 –40°C to 125°C
LT3014BEDD#PBF LT3014BEDD#TRPBF LCHM 8-Lead (3mm × 3mm) Plastic DFN –40°C to 125°C
LT3014BIDD#PBF LT3014BIDD#TRPBF LCHM 8-Lead (3mm × 3mm) Plastic DFN –40°C to 125°C
LT3014BHVEDD#PBF LT3014BHVEDD#TRPBF LCHP 8-Lead (3mm × 3mm) Plastic DFN –40°C to 125°C
LT3014BHVIDD#PBF LT3014BHVIDD#TRPBF LCHP 8-Lead (3mm × 3mm) Plastic DFN –40°C to 125°C
LEAD BASED FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE
LT3014BES5 LT3014BES5#TR LTCHK 5-Lead Plastic SOT-23 –40°C to 125°C
LT3014BIS5 LT3014BIS5#TR LTCHK 5-Lead Plastic SOT-23 –40°C to 125°C
LT3014BHVES5 LT3014BHVES5#TR LTCHN 5-Lead Plastic SOT-23 –40°C to 125°C
LT3014BHVIS5 LT3014BHVIS5#TR LTCHN 5-Lead Plastic SOT-23 –40°C to 125°C
LT3014BEDD LT3014BEDD#TR LCHM 8-Lead (3mm × 3mm) Plastic DFN –40°C to 125°C
LT3014BIDD LT3014BIDD#TR LCHM 8-Lead (3mm × 3mm) Plastic DFN –40°C to 125°C
LT3014BHVEDD LT3014BHVEDD#TR LCHP 8-Lead (3mm × 3mm) Plastic DFN –40°C to 125°C
LT3014BHVIDD LT3014BHVIDD#TR LCHP 8-Lead (3mm × 3mm) Plastic DFN –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/
This product is only offered in trays. For more information go to: http://www.linear.com/packaging/
Storage Temperature Range
ThinSOT Package .......................... –65°C to 150°C
DFN Package ..................................–65°C to 125°C
Operating Junction Temperature Range
(Notes 3, 9, 10) ..................................–40°C to 125°C
Lead Temperature (Soldering, 10 sec)
SOT-23 Package ............................................300°C
LT3014B
3
3014bfa
ELECTRICAL CHARACTERISTICS
SYMBOL CONDITIONS MIN TYP MAX UNITS
Minimum Input Voltage ILOAD = 20mA l3 3.3 V
ADJ Pin Voltage
(Notes 2, 3)
VIN = 3.3V, ILOAD = 100μA
3.3V < VIN < 80V, 100μA < ILOAD < 20mA l
1.200
1.180
1.220
1.220
1.240
1.260
V
V
Line Regulation ΔVIN = 3.3V to 80V, ILOAD = 100μA (Note 2) l110 mV
Load Regulation VIN = 3.3V, ΔILOAD = 100μA to 20mA (Note 2)
VIN = 3.3V, ΔILOAD = 100μA to 20mA l
13 25
40
mV
mV
Dropout Voltage
VIN = VOUT(NOMINAL) (Notes 4, 5)
ILOAD = 100μA
ILOAD = 100μA l
120 180
250
mV
mV
ILOAD = 1mA
ILOAD = 1mA l
200 270
360
mV
mV
ILOAD = 10mA
ILOAD = 10mA l
300 350
450
mV
mV
ILOAD = 20mA
ILOAD = 20mA l
350 410
570
mV
mV
GND Pin Current
VIN = VOUT(NOMINAL) (Notes 4, 6)
ILOAD = 0mA
ILOAD = 100μA
ILOAD = 1mA
ILOAD = 10mA
ILOAD = 20mA
l
l
l
l
l
7
12
40
250
650
20
30
100
450
1000
μA
μA
μA
μA
μA
Output Voltage Noise COUT = 0.47μF, ILOAD = 20mA, BW = 10Hz to 100kHz 115 μVRMS
ADJ Pin Bias Current (Note 7) 410 nA
Ripple Rejection VIN = 7V (Avg), VRIPPLE = 0.5VP-P , fRIPPLE = 120Hz, ILOAD = 20mA 60 70 dB
Current Limit VIN = 7V, VOUT = 0V
VIN = 3.3V, ΔVOUT = –0.1V (Note 2) l25
70 mA
mA
Input Reverse Leakage Current VIN = –80V, VOUT = 0V l6mA
Reverse Output Current (Note 8) VOUT = 1.22V, VIN < 1.22V (Note 2) 2 4 μA
The l denotes the specifi cations which apply over the full operating
temperature range, otherwise specifi cations are at TJ = 25°C.
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 LT3014B is tested and specifi ed 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 specifi cation 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 LT3014B
is tested and specifi ed 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 specifi ed output current. In dropout, the
output voltage is equal to (VIN – VDROPOUT).
Note 6: GND pin current is tested with VIN = VOUT (nominal) and a current
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 fl ows into the ADJ pin.
Note 8: Reverse output current is tested with the IN pin grounded and the
OUT pin forced to the rated output voltage. This current fl ows into the OUT
pin and out of the GND pin.
Note 9: The LT3014B is tested and specifi ed under pulse load conditions
such that TJ ≅ TA. The LT3014BE is 100% tested at TA = 25°C.
Performance at –40°C to 125°C is assured by design, characterization,
and statistical process controls. The LT3014BI is guaranteed over the full
–40°C to 125°C operating junction temperature range.
Note 10: 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.
LT3014B
4
3014bfa
INPUT VOLTAGE (V)
0
GND PIN CURRENT (μA)
600
800
1000
8
3014B G07
400
200
500
700
900
300
100
02143679510
TJ = 25°C
*FOR VOUT = 1.22V
RL = 61Ω
IL = 20mA*
RL = 122Ω
IL = 10mA*
RL = 1.22k
IL = 1mA*
OUTPUT CURRENT (mA)
0
GND PIN CURRENT (μA)
600
800
1000
16
3014B G08
400
200
500
700
900
300
100
042 86 12 14 18
10 20
VIN = 3.3V
TJ = 25°C
VOUT = 1.22V
GND Pin Current GND Pin Current vs ILOAD
TYPICAL PERFORMANCE CHARACTERISTICS
OUTPUT CURRENT (mA)
DROPOUT VOLTAGE (mV)
3014B G01
01642 6 10 14 18812 20
500
450
400
300
350
250
200
150
100
50
0
TJ = 125°C
TJ = 25°C
OUTPUT CURRENT (mA)
0
DROPOUT VOLTAGE (mV)
200
400
600
100
300
500
4 8 12 16
3014B G02
2020 6 10 14 18
= TEST POINTS
TJ ≤ 125°C
TJ ≤ 25°C
TEMPERATURE (°C)
–50
0
DROPOUT VOLTAGE (mV)
50
150
200
250
500
350
050 75
3014B G03
100
400
450
300
–25 25 100 125
IL = 20mA
IL = 10mA
IL = 1mA
IL = 100μA
TEMPERATURE (°C)
–50
QUIESCENT CURRENT (μA)
14
25
3014B G04
8
4
–25 0 50
2
0
16
12
10
6
75 100 125
VIN = 6V
RL = ∞
IL = 0
TEMPERATURE (°C)
–50
ADJ PIN VOLTAGE (V)
1.235
25
3014B G05
1.220
1.210
–25 0 50
1.205
1.200
1.240
1.230
1.225
1.215
75 100 125
IL = 100μA
08
213579
4610
16
14
12
10
8
6
4
2
0
INPUT VOLTAGE (V)
QUIESCENT CURRENT (μA)
3014B G06
TJ = 25°C
RL = ∞
VOUT = 1.22V
Typical Dropout Voltage Guaranteed Dropout Voltage Dropout Voltage
Quiescent Current ADJ Pin Voltage Quiescent Current
TEMPERATURE (°C)
ADJ PIN BIAS CURRENT (nA)
25
3014B G12
–25 0 50
–50 75 100 125
14
12
10
8
6
4
2
0
ADJ Pin Bias Current
LT3014B
5
3014bfa
TYPICAL PERFORMANCE CHARACTERISTICS
INPUT VOLTAGE (V)
0
CURRENT LIMIT (mA)
16
3014B G13
428612141810 20
70
40
20
10
0
80
60
50
30
VOUT = 0V
TJ = 25°C
TEMPERATURE (°C)
–50
0
CURRENT LIMIT (mA)
10
30
40
50
100
70
050 75
3014B G14
20
80
90
60
–25 25 100 125
VIN = 7V
VOUT = 0V
OUTPUT VOLTAGE (V)
0
REVERSE OUTPUT CURRENT (μA)
30
40
50
8
3014B G15
20
10
25
35
45
15
5
021 43 67 9
510
TJ = 25°C
VIN = 0V
VOUT = VADJ
CURRENT FLOWS
INTO OUTPUT PIN
ADJ PIN
ESD CLAMP
Current Limit Current Limit Reverse Output Current
TEMPERATURE (°C)
–50
REVERSE OUTPUT CURRENT (μA)
7
25
3014B G16
4
2
–25 0 50
1
0
8
6
5
3
75 100 125
VIN = 0V
VOUT = VADJ = 1.22V
TEMPERATURE (°C)
–50
RIPPLE REJECTION (dB)
70
25
3014B G17
64
60
–25 0 50
58
56
72
68
66
62
75 100 125
VIN = 7V + 0.5VP-P
RIPPLE AT f = 120Hz
IL = 20mA
FREQUENCY (Hz)
10
RIPPLE REJECTION (dB)
100 1k 10k 100k 1M
3014B G18
70
40
20
10
0
80
60
50
30
VIN = 7V + 50mVRMS RIPPLE
IL = 20mA
COUT = 4.7μF
COUT = 0.47μF
Reverse Output Current Input Ripple Rejection Input Ripple Rejection
TEMPERATURE (°C)
–50
3.5
3.0
2.5
2.0
1.5
1.0
0.5
025 75
3014B G19
–25 0 50 100 125
MINIMUM INPUT VOLTAGE (V)
ILOAD = 20mA
TEMPERATURE (°C)
–50
LOAD REGULATION (mV)
–5
25
3014B G20
–20
–30
–25 0 50
–35
–40
0
–10
–15
–25
75 100 125
$IL = 100μA TO 20mA
VOUT = 1.22V
FREQUENCY (Hz)
0.1
OUTPUT NOISE SPECTRAL DENSITY (μV/√Hz)
1
10 1k 10k 100k
3014B G21
0.01 100
10 COUT = 0.47μF
IL = 20mA
VOUT = 1.22V
Minimum Input Voltage Load Regulation Output Noise Spectral Density
LT3014B
6
3014bfa
TYPICAL PERFORMANCE CHARACTERISTICS
1ms/DIV
VOUT
200μV/DIV
3014B G22
COUT = 0.47μF
IL = 20mA
VOUT = 1.22V
TIME (μs)
0
OUTPUT VOLTAGE
DEVIATION (V)
LOAD CURRENT (mA)
–0.02
0.02
800
3014B G23
4
–0.04
0
0.04
6
2
0200 400 600 1000
VIN = 7V
VOUT = 5V
CIN = COUT = 0.47μF CERAMIC
$ILOAD = 1mA TO 5mA
10Hz to 100kHz Output Noise Transient Response
PIN FUNCTIONS
IN (Pin 1/Pin 8): Input. Power is supplied to the device
through the IN pin. A bypass capacitor is required on this
pin if the device is more than six inches away from the main
input fi lter 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 suffi cient. The
LT3014B is designed to withstand reverse voltages on
the IN 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 LT3014B will act as if there is
a diode in series with its input. There will be no reverse
current fl ow into the LT3014B and no reverse voltage will
appear at the load. The device will protect both itself and
the load.
GND (Pin 2/Pins 4, 9): Ground.
ADJ (Pin 4/Pin 2): Adjust. This is the input to the error
amplifi er. This pin is internally clamped to ±7V. It has a
bias current of 4nA which fl ows 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
the load. A minimum output capacitor of 0.47μF is required
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.
NC (Pin 3/Pins 3, 5, 6, 7): No Connect. No Connect pins
may be fl oated, tied to IN or tied to GND.
(SOT-23 Package/DD Package)
LT3014B
7
3014bfa
APPLICATIONS INFORMATION
The LT3014B is a 20mA high voltage, low dropout regu-
lator with micropower quiescent current. The device is
capable of supplying 20mA at a dropout voltage of 350mV.
Operating quiescent current is only 7μA. In addition to the
low quiescent current, the LT3014B incorporates several
protection features which make it ideal for use in bat-
tery-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
LT3014B acts like it has a diode in series with its output
and prevents reverse current fl ow.
Adjustable Operation
The LT3014B 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, fl ows 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.
The device is tested and specifi ed with the ADJ pin
tied to the OUT pin and a 5μA DC load (unless otherwise
specifi ed) for an output voltage of 1.22V. Specifi cations
for output voltages greater than 1.22V will be propor-
tional to the ratio of the desired output voltage to 1.22V
(VOUT/1.22V). For example, load regulation for an output
current change of 1mA to 20mA is –13mV typical at VOUT
= 1.22V. At VOUT = 12V, load regulation is:
(12V/1.22V) • (–13mV) = –128mV
Output Capacitance and Transient Response
The LT3014B 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 LT3014B 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 LT3014B, will increase the
effective output capacitor value.
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 specifi ed 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 coeffi cients 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 temperature
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 tempera-
ture, while the
X5R is less expensive and is available in
Figure 1. Adjustable Operation
IN
LT3014B
VIN
OUT
ADJ
GND 3014B F01
VOUT
R2
R1
+
R2
R1
VOUT = 1.22V
VADJ = 1.22V
IADJ = 4nA AT 25°C
OUTPUT RANGE = 1.22V TO 60V
+ (IADJ)(R2)1 +
•
Figure 2. Ceramic Capacitor DC Bias Characteristics
DC BIAS VOLTAGE (V)
CHANGE IN VALUE (%)
3014B F02
20
0
–20
–40
–60
–80
–100 04810
26 12 14
X5R
Y5V
16
BOTH CAPACITORS ARE 16V,
1210 CASE SIZE, 10μF
LT3014B
8
3014bfa
Table 1. SOT-23 Measured Thermal Resistance
COPPER AREA
BOARD AREA
THERMAL RESISTANCE
(JUNCTION-TO-AMBIENT)TOPSIDE BACKSIDE
2500 sq mm 2500 sq mm 2500 sq mm 125°C/W
1000 sq mm 2500 sq mm 2500 sq mm 125°C/W
225 sq mm 2500 sq mm 2500 sq mm 130°C/W
100 sq mm 2500 sq mm 2500 sq mm 135°C/W
50 sq mm 2500 sq mm 2500 sq mm 150°C/W
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 capacitance
change over temperature. Capacitance change due to DC
bias with X5R and X7R capacitors is better than Y5V and
Z5U capacitors, but can still be signifi cant enough to drop
capacitor values below appropriate levels. Capacitor DC
bias characteristics tend to improve as component case
size increases, but expected capacitance at operating
voltage should be verifi ed.
Voltage and temperature coeffi cients are not the only
sources of problems. Some ceramic capacitors have a
piezoelectric response. A piezoelectric device generates
voltage across its terminals due to mechanical stress, simi-
lar to the way a piezoelectric accelerometer or microphone
works. For a ceramic capacitor the stress can be induced
by vibrations in the system or thermal transients.
Thermal Considerations
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:
1. Output current multiplied by the input/output voltage
differential: IOUT • (VIN – VOUT) and,
2. GND pin current multiplied by the input voltage:
IGND • VIN.
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.
The LT3014B 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.
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.
APPLICATIONS INFORMATION
Figure 3. Ceramic Capacitor Temperature Characteristics
Table 2. DFN Measured Thermal Resistance
COPPER AREA
BOARD AREA
THERMAL RESISTANCE
(JUNCTION-TO-AMBIENT)TOPSIDE BACKSIDE
2500 sq mm 2500 sq mm 2500 sq mm 40°C/W
1000 sq mm 2500 sq mm 2500 sq mm 45°C/W
225 sq mm 2500 sq mm 2500 sq mm 50°C/W
100 sq mm 2500 sq mm 2500 sq mm 62°C/W
TEMPERATURE (°C)
–50
40
20
0
–20
–40
–60
–80
–100 25 75
3014B F03
–25 0 50 100 125
Y5V
CHANGE IN VALUE (%)
X5R
BOTH CAPACITORS ARE 16V,
1210 CASE SIZE, 10μF
For the DFN package, the thermal resistance junction-to-
case (θJC), measured at the Exposed Pad on the back of
the die, is 16°C/W.
LT3014B
9
3014bfa
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).
For an application with transient high power peaks, average
power dissipation can be used for junction temperature
calculations as long as the pulse period is signifi cantly less
than the thermal time constant of the device and board.
Calculating Junction Temperature
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?
The power dissipated by the device will be equal to:
I
OUT(MAX) • (VIN(MAX) – VOUT) + (IGND • VIN(MAX))
where:
I
OUT(MAX) = 20mA
V
IN(MAX) = 30V
I
GND at (IOUT = 20mA, VIN = 30V) = 0.55mA
So:
P = 20mA • (30V – 5V) + (0.55mA • 30V) = 0.52W
The thermal resistance for the DFN package will be in the
range of 40°C/W to 62°C/W depending on the copper
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:
TJMAX = 50°C + 26°C = 76°C
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:
P1(48V in, 5mA load) = 5mA • (48V – 5V)
+ (100μA • 48V) = 0.22W
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
P4(72V in, 20mA load) = 20mA • (72V – 5V)
+ (0.55mA • 72V) = 1.38W
Operation at the different power levels is as follows:
76% operation at P1, 19% for P2, 4% for P3, and
1% for P4.
P
EFF = 76%(0.22W) + 19%(0.89W) + 4%(0.34W)
+ 1%(1.38W) = 0.36W
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.
Protection Features
The LT3014B incorporates several protection features
which make it ideal for use in battery-powered circuits. In
addition to the normal protection features associated with
monolithic regulators, such as current limiting and thermal
limiting, the device is protected against reverse-input volt-
ages, and reverse voltages from output to input.
Current limit protection and thermal overload protection
are intended to protect the device against current overload
conditions at the output of the device. For normal operation,
the junction temperature should not exceed 125°C.
The input of the device will withstand reverse voltages
of 80V. Current fl ow 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
LT3014B
10
3014bfa
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.
In situations where the ADJ pin is connected to a resistor
divider that would pull the ADJ pin above its 7V clamp volt-
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.
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 fl ow 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.
When the IN pin of the LT3014B 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 LT3014B is connected to a discharged
(low voltage) battery and the output is held up by either
a backup battery or a second regulator circuit.
APPLICATIONS INFORMATION
Figure 4. Reverse Output Current
OUTPUT VOLTAGE (V)
0
REVERSE OUTPUT CURRENT (μA)
50
45
40
30
35
25
20
15
10
5
08
3014B F04
21357946 10
TJ = 25°C
VIN = 0V
VOUT = VADJ
CURRENT FLOWS
INTO OUTPUT PIN
ADJ PIN
ESD CLAMP
LT3014B Automotive Application
LT3014B Telecom Application
+
ADJ
OUTIN
LT3014B
GND
1μF 1μF
VIN
12V
(LATER 42V) LOAD: CLOCK,
SECURITY SYSTEM
ETC
+
–
ADJ
OUTIN
LT3014B
GND
1μF 1μF
VIN
48V
(72V TRANSIENT)
LOAD:
SYSTEM MONITOR
ETC
NO PROTECTION
DIODE NEEDED!
NO PROTECTION
DIODE NEEDED!
3014B TA05
BACKUP
BATTERY
R1
R2
R1
R2
TYPICAL APPLICATIONS
LT3014B
11
3014bfa
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.
TYPICAL APPLICATIONS
Constant Brightness for Indicator LED over Wide Input Voltage Range
IN
LT3014B
1μF
RETURN
–48V
OUT
ADJ
GND
3014B TA06
1μF
RSET
ILED = 1.22V/RSET
–48V CAN VARY FROM –3.3V TO –80V
PACKAGE DESCRIPTION
S5 Package
5-Lead Plastic TSOT-23
(Reference LTC DWG # 05-08-1635)
1.50 – 1.75
(NOTE 4)
2.80 BSC
0.30 – 0.45 TYP
5 PLCS (NOTE 3)
DATUM ‘A’
0.09 – 0.20
(NOTE 3)
S5 TSOT-23 0302 REV B
PIN ONE
2.90 BSC
(NOTE 4)
0.95 BSC
1.90 BSC
0.80 – 0.90
1.00 MAX
0.01 – 0.10
0.20 BSC
0.30 – 0.50 REF
NOTE:
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
3.85 MAX
0.62
MAX
0.95
REF
RECOMMENDED SOLDER PAD LAYOUT
PER IPC CALCULATOR
1.4 MIN
2.62 REF
1.22 REF
DD Package
8-Lead Plastic DFN (3mm × 3mm)
(Reference LTC DWG # 05-08-1698)
3.00 p0.10
(4 SIDES)
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
0.38 p 0.10
BOTTOM VIEW—EXPOSED PAD
1.65 p 0.10
(2 SIDES)
0.75 p0.05
R = 0.115
TYP
2.38 p0.10
(2 SIDES)
14
85
PIN 1
TOP MARK
(NOTE 6)
0.200 REF
0.00 – 0.05
(DD) DFN 1203
0.25 p 0.05
2.38 p0.05
(2 SIDES)
RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS
1.65 p0.05
(2 SIDES)2.15 p0.05
0.50
BSC
0.675 p0.05
3.5 p0.05
PACKAGE
OUTLINE
0.25 p 0.05
0.50 BSC
LT3014B
12
3014bfa
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com
© LINEAR TECHNOLOGY CORPORATION 2006
LT 0508 REV A • PRINTED IN USA
RELATED PARTS
PART NUMBER DESCRIPTION COMMENTS
LT1129 700mA, Micropower, LDO VIN: 4.2V to 30V, VOUT(MIN) = 3.75V, VDO = 0.4V, IQ = 50μA, ISD = 16μA,
DD, SOT-223, S8, TO220, TSSOP-20 Packages
LT1175 500mA, Micropower Negative LDO VIN: –20V to –4.3V, VOUT(MIN) = –3.8V, VDO = 0.50V, IQ = 45μA, ISD = 10μA,
DD, SOT-223, S8 Packages
LT1185 3A, Negative LDO VIN: –35V to –4.2V, VOUT(MIN) = –2.40V, VDO = 0.80V, IQ = 2.5mA, ISD < 1μA,
TO220-5 Package
LT1761 100mA, Low Noise Micropower, LDO VIN: 1.8V to 20V, VOUT(MIN) = 1.22V, VDO = 0.30V, IQ = 20μA, ISD < 1μA,
ThinSOT Package
LT1762 150mA, Low Noise Micropower, LDO VIN: 1.8V to 20V, VOUT(MIN) = 1.22V, VDO = 0.30V, IQ = 25μA, ISD < 1μA,
MS8 Package
LT1763 500mA, Low Noise Micropower, LDO VIN: 1.8V to 20V, VOUT(MIN) = 1.22V, VDO = 0.30V, IQ = 30μA, ISD < 1μA,
S8 Package
LT1764/LT1764A 3A, Low Noise, Fast Transient Response, LDO VIN: 2.7V to 20V, VOUT(MIN) = 1.21V, VDO = 0.34V, IQ = 1mA, ISD < 1μA,
DD, TO220 Packages
LTC1844 150mA, Very Low Dropout LDO VIN: 1.6V to 6.5V, VOUT(MIN) = 1.25V, VDO = 0.08V, IQ = 40μA, ISD < 1μA,
ThinSOT Package
LT1962 300mA, Low Noise Micropower, LDO VIN: 1.8V to 20V, VOUT(MIN) = 1.22V, VDO = 0.27V, IQ = 30μA, ISD < 1μA,
MS8 Package
LT1963/LT1963A 1.5A, Low Noise, Fast Transient Response, LDO VIN: 2.1V to 20V, VOUT(MIN) = 1.21V, VDO = 0.34V, IQ = 1mA, ISD < 1μA,
DD, TO220, SOT Packages
LT1964 200mA, Low Noise Micropower, Negative LDO VIN: –1.9V to –20V, VOUT(MIN) = –1.21V, VDO = 0.34V, IQ = 30μA, ISD = 3μA,
ThinSOT Package
LT3010 50mA, 80V, Low Noise Micropower, LDO VIN: 3V to 80V, VOUT(MIN) = 1.28V, VDO = 0.3V, IQ = 30μA, ISD < 1μA,
MS8E Package
LT3020 100mA, Low VIN, Low VOUT Micropower, VLDO VIN: 0.9V to 10V, VOUT(MIN) = 0.20V, VDO = 0.15V, IQ = 120μA, ISD < 1μA,
DFN, MS8 Packages
LT3023 Dual 100mA, Low Noise Micropower, LDO VIN: 1.8V to 20V, VOUT(MIN) = 1.22V, VDO = 0.30V, IQ = 40μA, ISD < 1μA,
DFN, MS10 Packages
LT3024 Dual 100mA/500mA, Low Noise Micropower, LDO VIN: 1.8V to 20V, VOUT(MIN) = 1.22V, VDO = 0.30V, IQ = 60μA, ISD < 1μA,
DFN, TSSOP-16E Packages
LT3027 Dual 100mA, Low Noise LDO with Independent
Inputs
VIN: 1.8V to 20V, VOUT(MIN) = 1.22V, VDO = 0.30V, IQ = 40μA, ISD < 1μA,
DFN, MS10E Packages
LT3028 Dual 100mA/500mA, Low Noise LDO with
Independent Inputs
VIN: 1.8V to 20V, VOUT(MIN) = 1.22V, VDO = 0.30V, IQ = 60μA, ISD < 1μA,
DFN, TSSOP-16E Packages
