LT3010EMS8E-5 [Linear]
50mA, 3V to 80V Low Dropout Micropower Linear Regulator; 50mA时3V至80V低压差微功耗线性稳压器![LT3010EMS8E-5](http://pdffile.icpdf.com/pdf1/p00050/img/icpdf/LT3010_260810_icpdf.jpg)
型号: | LT3010EMS8E-5 |
厂家: | ![]() |
描述: | 50mA, 3V to 80V Low Dropout Micropower Linear Regulator |
文件: | 总16页 (文件大小:245K) |
中文: | 中文翻译 | 下载: | 下载PDF数据表文档文件 |
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LT3010/LT3010-5
50mA, 3V to 80V
Low Dropout
Micropower Linear Regulator
U
FEATURES
DESCRIPTIO
The LT®3010 is a high voltage, micropower low dropout
linear regulator. The device is capable of supplying 50mA
outputcurrentwithadropoutvoltageof300mV. Designed
for use in battery-powered or high voltage systems, the
low quiescent current (30µA operating and 1µA in shut-
down) makes the LT3010 an ideal choice. Quiescent
current is also well controlled in dropout.
■
Wide Input Voltage Range: 3V to 80V
■
Low Quiescent Current: 30µA
■
Low Dropout Voltage: 300mV
Output Current: 50mA
Thermally Enhanced 8-Lead MSOP Package
■
■
■
No Protection Diodes Needed
Fixed Output Voltage: 5V (LT3010-5)
■
■
Adjustable Output from 1.275V to 60V (LT3010)
Other features of the LT3010 include the ability to operate
with very small output capacitors. The regulators are
stable with only 1µF on the output while most older
devices require between 10µF and 100µF for stability.
Small ceramic capacitors can be used without the neces-
sary addition of ESR as is common with other regulators.
Internal protection circuitry includes reverse-battery pro-
tection, current limiting, thermal limiting and reverse
current protection.
■
1µA Quiescent Current in Shutdown
■
Stable with 1µF Output Capacitor
■
Stable with Aluminum, Tantalum or Ceramic
Capacitors
Reverse-Battery Protection
No Reverse Current Flow from Output
Thermal Limiting
■
■
■
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APPLICATIO S
The device is available in a fixed output voltage of 5V and
as an adjustable device with a 1.275V reference voltage.
The LT3010 regulator is available in the 8-lead MSOP
package with an exposed pad for enhanced thermal han-
dling capability.
■
Low Current High Voltage Regulators
■
Regulator for Battery-Powered Systems
■
Telecom Applications
Automotive Applications
■
, LTC and LT are registered trademarks of Linear Technology Corporation.
U
TYPICAL APPLICATIO
Dropout Voltage
350
5V Supply with Shutdown
300
V
OUT
250
200
150
100
50
IN
OUT
LT3010-5
5V
50mA
V
IN
5.4V TO
80V
1µF
1µF
SHDN SENSE
GND
3010 TA01
V
(PIN 5) OUTPUT
SHDN
<0.3V
>2.0V
NC
OFF
ON
ON
0
10
20
30
50
0
40
OUTPUT CURRENT (mA)
3010 TA02
3010f
1
LT3010/LT3010-5
W W
U W
U W
U
ABSOLUTE AXI U RATI GS
PACKAGE/ORDER I FOR ATIO
(Note 1)
IN Pin Voltage................................................... ±80V
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 ............ –65°C to 150°C
Operating Junction Temperature Range
ORDER PART
TOP VIEW
NUMBER
OUT
SENSE/ADJ*
NC
1
2
3
4
8 IN
7 NC
6 NC
5 SHDN
LT3010EMS8E
LT3010EMS8E-5
GND
MS8E PACKAGE
8-LEAD PLASTIC MSOP
*SENSE FOR LT3010-5, ADJ FOR LT3010
TJMAX = 125°C, θJA = 40°C/ W, θJC = 16°C/ W†
SEE APPLICATIONS INFORMATION SECTION.
EXPOSED PAD IS GND
MS8 PART MARKING
LTZF
LTAEF
(MUST BE SOLDERED TO PCB)
†MEASURED AT BOTTOM PAD
(Notes 3, 10, 11) ......................... –40°C to 125°C
Lead Temperature (Soldering, 10 sec)............ 300°C
Consult LTC Marketing for parts specified with wider operating temperature ranges.
ELECTRICAL CHARACTERISTICS
The ● denotes specifications which apply over the full operating temperature range, otherwise specifications are at TJ = 25°C.
PARAMETER
CONDITIONS
LT3010
MIN
TYP
MAX
UNITS
Minimum Input Voltage
Regulated Output Voltage (Note 3)
I
= 50mA
●
●
●
3
4
V
LOAD
LT3010-5
V
= 5.5V, I
= 1mA
LOAD
4.925
4.850
5.000
5.000
5.075
5.150
V
V
IN
6V < V < 80V, 1mA < I
< 50mA
< 50mA
IN
LOAD
ADJ Pin Voltage
(Notes 2,3)
LT3010
V
= 3V, I
= 1mA
1.258
1.237
1.275
1.275
1.292
1.313
V
V
IN
LOAD
4V < V < 80V, 1mA < I
IN
LOAD
Line Regulation
LT3010-5
LT3010 (Note 2)
∆V = 5.5V to 80V, I
= 1mA
LOAD
●
●
3
3
15
13
mV
mV
IN
∆V = 3V to 80V, I
= 1mA
IN
LOAD
Load Regulation
LT3010-5
V
V
= 6V, ∆I
= 6V, ∆I
= 1mA to 50mA
= 1mA to 50mA
25
50
90
mV
mV
IN
IN
LOAD
LOAD
●
●
●
●
●
LT3010 (Note 2)
V
V
= 4V, ∆I
= 4V, ∆I
= 1mA to 50mA
= 1mA to 50mA
10
20
32
mV
mV
IN
IN
LOAD
LOAD
Dropout Voltage
I
I
= 1mA
= 1mA
100
200
300
150
190
mV
mV
LOAD
LOAD
V
IN
= V
OUT(NOMINAL)
(Notes 4, 5)
I
I
= 10mA
= 10mA
260
350
mV
mV
LOAD
LOAD
I
I
= 50mA
= 50mA
370
550
mV
mV
LOAD
LOAD
GND Pin Current
I
I
I
I
= 0mA
= 1mA
= 10mA
= 50mA
●
●
●
●
30
100
400
1.8
60
180
700
3.3
µA
µA
µA
LOAD
LOAD
LOAD
LOAD
V
IN
= V
OUT(NOMINAL)
(Notes 4, 6)
mA
Output Voltage Noise
ADJ Pin Bias Current
Shutdown Threshold
C
= 10µF, I
= 50mA, BW = 10Hz to 100kHz
100
50
µV
RMS
OUT
LOAD
(Note 7)
100
2
nA
V
OUT
V
OUT
= Off to On
= On to Off
1.3
0.8
V
V
0.3
SHDN Pin Current
(Note 8)
V
SHDN
V
SHDN
= 0V
= 6V
0.5
0.1
2
0.5
µA
µA
Quiescent Current in Shutdown
V
IN
= 6V, V
= 0V
1
5
µA
SHDN
3010f
2
LT3010/LT3010-5
ELECTRICAL CHARACTERISTICS
The ● denotes specifications which apply over the full operating temperature range, otherwise specifications are at TJ = 25°C.
PARAMETER
CONDITIONS
MIN TYP
MAX
UNITS
Ripple Rejection
LT3010
LT3010-5
V
IN
V
IN
= 7V(Avg), V
= 7V(Avg), V
= 0.5V , f
= 120Hz, I
= 120Hz, I
= 50mA
= 50mA
65
60
75
68
dB
dB
RIPPLE
RIPPLE
P-P RIPPLE
LOAD
LOAD
= 0.5V , f
P-P RIPPLE
Current Limit
V
= 7V, V
= 0V
140
mA
mA
mA
IN
OUT
LT3010-5
LT3010 (Note 2) V = 4V, ∆V
V
IN
IN
= 6V, ∆V
= –0.1V
= –0.1V
●
●
60
60
OUT
OUT
Input Reverse
V
IN
= –80V, V
= 0V
●
6
mA
OUT
Leakage Current
Reverse Output Current
(Note 9)
LT3010-5
LT3010 (Note 2) V
V
= 5V, V < 5V
10
8
20
15
µA
µA
OUT
OUT
IN
= 1.275V, V < 1.275V
IN
Note 6: GND pin current is tested with V = V
(nominal) and a current
OUT
Note 1: Absolute Maximum Ratings are those values beyond which the life
IN
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 will
decrease slightly at higher input voltages.
of a device may be impaired.
Note 2: The LT3010 (adjustable version) is tested and specified for these
conditions with the ADJ pin connected to the OUT pin.
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 the GND pin.
Note 10: The LT3010E is guaranteed to meet performance specifications
from 0°C to 125°C operating junction temperature. Specifications over
the –40°C to 125°C operating junction temperature range are assured by
design, characterization and correlation with statistical process controls.
Note 11: 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 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 LT3010
(adjustable version) 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 will add 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 will be equal to (V – V
).
IN
DROPOUT
U W
TYPICAL PERFOR A CE CHARACTERISTICS
Typical Dropout Voltage
Guaranteed Dropout Voltage
Dropout Voltage
500
450
400
350
300
250
200
150
100
50
600
500
500
450
400
350
300
250
200
150
100
50
= TEST POINTS
I
L
= 50mA
400
300
T
= 125°C
J
T
≤ 125°C
≤ 25°C
J
I
= 10mA
= 1mA
L
T
J
T
= 25°C
200
100
0
J
I
L
0
0
0
5
10 15 20 25 30 35 40 45 50
OUTPUT CURRENT (mA)
–50
0
25
50
75 100 125
–25
0
5
10 15 20 25 30 35 40 45 50
OUTPUT CURRENT (mA)
3010 G01
TEMPERATURE (°C)
3010 G02
3010 G03
3010f
3
LT3010/LT3010-5
TYPICAL PERFOR A CE CHARACTERISTICS
U W
Quiescent Current
LT3010 ADJ Pin Voltage
LT3010-5 Output Voltage
40
1.295
5.08
I
L
= 1mA
I
L
= 1mA
35
30
1.290
1.285
5.06
5.04
V
SHDN
= V
IN
25
20
15
10
5
1.280
1.275
1.270
1.265
1.260
5.02
5.00
4.98
4.96
4.94
V
R
R
> 6V
IN
L
L
= ∞, I = 0 (LT3010-5)
L
= 250k, I = 5µA (LT3010)
L
V
= 0V
50
SHDN
0
1.255
4.92
–25
0
75 100 125
–25
0
50
75 100 125
–25
0
50
75 100 125
–50
25
–50
25
–50
25
TEMPERATURE (°C)
TEMPERATURE (°C)
TEMPERATURE (°C)
3010 G04
3010 G06
3010 G05
LT3010 Quiescent Current
LT3010-5 Quiescent Current
LT3010 GND Pin Current
50
45
40
35
30
25
20
15
10
5
200
180
160
140
120
100
80
2.0
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0
T
= 25°C
T
= 25°C
R = ∞
L
T
= 25°C
J
L
J
J
R
=
∞
*FOR V
= 1.275V
OUT
V
= V
IN
R
= 25.5Ω
= 50mA*
SHDN
L
L
I
R
L
= 51Ω
L
I
= 25mA*
R
L
= 127Ω
= 10mA*
L
60
I
V
= V
IN
SHDN
40
R
= 1.27k I = 1mA*
L
20
L
V
= 0V
6
SHDN
5
V
6
= 0V
8
SHDN
7
0
0
0
1
2
3
4
7
8
9
10
0
1
2
3
4
5
9
10
0
1
2
3
4
5
6
7
8
9
10
INPUT VOLTAGE (V)
INPUT VOLTAGE (V)
INPUT VOLTAGE (V)
3010 G08
3010 G07
3010 G10
LT3010-5 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
2.0
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0
1.6
T
= 25°C
V
= V
+ 1V
OUT(NOMINAL)
J
IN
*FOR V
= 5V
T = 25°C
J
OUT
1.4
1.2
OFF-TO-ON
R
I
= 100Ω
= 50mA*
L
L
1.0
0.8
0.6
0.4
0.2
R
L
= 200Ω
= 25mA*
L
I
ON-TO-OFF
R
I
= 500Ω
= 10mA*
L
L
R
= 5k, I = 1mA*
L
L
0
0
1
2
3
4
5
6
7
8
9
10
0
5
10 15 20 25 30 35 40 45 50
OUTPUT CURRENT (mA)
3010 G11
–50 –25
0
25
50
75 100 125
TEMPERATURE (°C)
INPUT VOLTAGE (V)
3010 G09
3010 G12
3010f
4
LT3010/LT3010-5
U W
TYPICAL PERFOR A CE CHARACTERISTICS
SHDN Pin Current
SHDN Pin Current
ADJ Pin Bias Current
0.6
0.5
0.8
80
T = 25°C
J
V
SHDN
= 0V
CURRENT FLOWS
OUT OF SHDN PIN
CURRENT FLOWS
OUT OF SHDN PIN
0.7
0.6
70
60
0.4
0.3
0.5
0.4
0.3
0.2
0.1
50
40
30
20
10
0.2
0.1
0
0
0
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
5
–25
0
50
75 100 125
–25
0
50
75 100 125
–50
25
–50
25
SHDN PIN VOLTAGE (V)
TEMPERATURE (°C)
TEMPERATURE (°C)
3010 G13
3010 G14
3010 G15
Current Limit
Current Limit
Reverse Output Current
200
180
160
140
120
100
80
200
180
160
140
120
100
80
100
90
80
70
60
50
40
30
20
10
0
V
V
= 7V
IN
OUT
V
T
= 0V
T
= 25°C
IN
OUT
J
J
= 0V
= 25°C
V
= 0V
CURRENT FLOWS
INTO OUTPUT PIN
V
V
= V
= V
(LT3010)
ADJ
SENSE
OUT
OUT
ADJ
(LT3010-5)
PIN CLAMP
(SEE APPLICATIONS
INFORMATION)
LT3010
60
60
40
40
LT3010-5
20
20
0
0
–50
0
25
50
75 100 125
–25
0
1
2
3
4
5
6
7
8
9
10
0
1
2
3
4
5
6
7
8
9
10
TEMPERATURE (°C)
INPUT VOLTAGE (V)
OUTPUT VOLTAGE (V)
3010 G17
3010 G16
3010 G18
Reverse Output Current
Input Ripple Rejection
Input Ripple Rejection
100
90
24
80
78
76
74
72
70
68
66
64
62
60
V
I
= 7V + 50mV
RIPPLE
V
V
V
= 0V
= V
IN
L
RMS
IN
OUT
OUT
= 50mA
= 1.275V (LT3010)
ADJ
21
18
= V
= 5V (LT3010-5)
SENSE
80
70
15
12
9
C
OUT
= 10µF
60
50
LT3010-5
LT3010
40
30
20
10
0
C
OUT
= 1µF
6
V
L
= 7V + 0.5V RIPPLE AT f = 120Hz
P-P
IN
3
I
= 50mA
V
OUT
= 1.275V
0
–25
0
50
75 100 125
10
100
1k
10k
100k
1M
–50
25
–50
0
25
50
75 100 125
–25
TEMPERATURE (°C)
FREQUENCY (Hz)
TEMPERATURE (°C)
3010 G21
3010 G19
3010 G20
3010f
5
LT3010/LT3010-5
TYPICAL PERFOR A CE CHARACTERISTICS
U W
LT3010 Minimum Input Voltage
Load Regulation
Output Noise Spectral Density
10
1
4.0
0
∆I = 1mA TO 50mA
L
C
= 1µF
OUT
= 50mA
I
= 50mA
LOAD
I
L
3.5
3.0
–5
LT3010
–10
2.5
2.0
1.5
1.0
0.5
–15
–20
–25
–30
–35
LT3010-5
0.1
0.01
0
–40
–25
0
50
75 100 125
–25
0
50
75 100 125
–50
25
–50
25
10
100
1k
10k
100k
FREQUENCY (Hz)
TEMPERATURE (°C)
TEMPERATURE (°C)
3010 G24
3010 G22
3010 G23
LT3010-5 10Hz to 100kHz
Output Noise
LT3010-5 Transient Response
0.2
0.1
0
VOUT
100µV/DIV
–0.1
–0.2
V
C
C
= 6V
IN
IN
= 1µF CERAMIC
= 1µF CERAMIC
= 1mA TO 50mA
OUT
∆I
LOAD
50
25
0
COUT = 1µF
IL = 50mA
1ms/DIV
3010 G25
0
200
400
600
800
1000
TIME (µs)
3010 G26
3010f
6
LT3010/LT3010-5
U
U
U
PI FU CTIO S
OUT (Pin 1): Output. The output supplies power to the
load. A minimum output capacitor of 1µF is required to
prevent oscillations. Larger output capacitors will be re-
quired 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.
the Typical Performance Characteristics). The ADJ pin
voltage is 1.275V referenced to ground, and the output
voltage range is 1.275V to 60V.
GND (Pin 4, Tab): Ground. The exposed backside of the
package is an electrical connection for GND. As such, to
ensure optimum device operation, the exposed pad must
be connected directly to pin 4 on the PC board.
SENSE (Pin 2): Sense. For the LT3010-5, the SENSE pin
is the input to the error amplifier. Optimum regulation will
be obtained at the point where the SENSE pin is connected
to the OUT pin of the regulator. In critical applications,
small voltage drops are caused by the resistance (RP) of
PC traces between the regulator and the load. These may
be eliminated by connecting the SENSE pin to the output
at the load as shown in Figure 1 (Kelvin Sense Connec-
tion). Note that the voltage drop across the external PC
traces will add to the dropout voltage of the regulator. The
SENSEpinbiascurrentis10µAatthenominalratedoutput
voltage.
SHDN (Pin 5): Shutdown. The SHDN pin is used to put the
LT3010 into a low power shutdown state. The output will
be off when the SHDN pin is pulled low. The SHDN pin can
be driven either by 5V logic or open-collector logic with a
pull-up resistor. The pull-up resistor is only required to
supply the pull-up current of the open-collector gate,
normally several microamperes. If unused, the SHDN pin
can be left open circuit. The device will be active, output
on, if the SHDN pin is not connected.
IN (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
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 1µF to 10µF is sufficient. The
LT3010 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 LT3010 will act as if there is a
diode in series with its input. There will be no reverse
current flow into the LT3010 and no reverse voltage will
appear at the load. The device will protect both itself and
the load.
ADJ (Pin 2): Adjust. For the adjustable LT3010, this is the
input to the error amplifier. This pin is internally clamped
to ±7V. It has a bias current of 50nA which flows into the
pin (see curve of ADJ Pin Bias Current vs Temperature in
R
P
8
5
1
2
IN
OUT
LT3010
+
+
SHDN SENSE
GND
LOAD
V
IN
4, TAB
3010 F01
Figure 1. Kelvin Sense Connection
3010f
7
LT3010/LT3010-5
W U U
U
APPLICATIO S I FOR ATIO
The LT3010 is a 50mA high voltage low dropout regulator
with micropower quiescent current and shutdown. The
device is capable of supplying 50mA at a dropout voltage
of 300mV. The low operating quiescent current (30µA)
drops to 1µA in shutdown. In addition to the low quiescent
current, the LT3010 incorporates several protection fea-
tures 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
batterywhentheinputispulledtoground,theLT3010acts
like it has a diode in series with its output and prevents
reverse current flow.
A small capacitor (C1) placed in parallel with the top
resistor(R2)oftheoutputdividerisnecessaryforstability
and transient performance of the adjustable LT3010. The
impedance of C1 at 10kHz should be less than the value of
R1.
The adjustable device is tested and specified with the ADJ
pintiedtotheOUTpinanda5µADCload(unlessotherwise
specified) for an output voltage of 1.275V. Specifications
for output voltages greater than 1.275V will be propor-
tional to the ratio of the desired output voltage to 1.275V;
(VOUT/1.275V). For example, load regulation for an
output current change of 1mA to 50mA is –10mV typical
at VOUT = 1.275V. At VOUT = 12V, load regulation is:
Adjustable Operation
(12V/1.275V) • (–10mV) = –94mV
The adjustable version of the LT3010 has an output
voltage range of 1.275V to 60V. The output voltage is set
bytheratiooftwoexternalresistorsasshowninFigure 2.
The device servos the output to maintain the voltage at
the adjust pin at 1.275V referenced to ground. The
current in R1 is then equal to 1.275V/R1 and the current
in R2 is the current in R1 plus the ADJ pin bias current.
TheADJpinbiascurrent,50nAat25°C,flowsthroughR2
into the ADJ pin. The output voltage can be calculated
using the formula in Figure 2. The value of R1 should be
less than 250k to minimize errors in the output voltage
caused by the ADJ pin bias current. Note that in shut-
down the output is turned off and the divider current will
be zero.
Output Capacitance and Transient Response
The LT3010 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 1µF with an ESR of 3Ω or less is
recommended to prevent oscillations. The LT3010 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 LT3010, will increase the
effective output capacitor value.
V
IN
OUT
LT3010
ADJ
OUT
+
R2
R1
C1
V
IN
GND
3010 F02
R2
R1
V
V
= 1.275V 1 +
+ (I )(R2)
ADJ
OUT
ADJ
(
)
= 1.275V
I
= 50nA AT 25°C
OUTPUT RANGE = 1.275V TO 60V
ADJ
Figure 2. Adjustable Operation
3010f
8
LT3010/LT3010-5
W U U
APPLICATIO S I FOR ATIO
U
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 di-
electrics used are Z5U, Y5V, X5R and X7R. The Z5U and
Y5V dielectrics are good for providing high capacitances
in a small package, but exhibit strong voltage and tem-
perature coefficients as shown in Figures 3 and 4. When
used with a 5V regulator, a 10µF Y5V capacitor can exhibit
an effective value as low as 1µF to 2µF 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 temperature, while the X5R is less expensive and
is available in higher values.
similar to the way a piezoelectric accelerometer or micro-
phone 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.Powerdissipationwillbeequaltothesumofthetwo
components listed above.
Voltage and temperature coefficients 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,
40
20
20
BOTH CAPACITORS ARE 16V,
1210 CASE SIZE, 10µF
0
0
X5R
X5R
–20
–20
–40
–40
Y5V
–60
–60
Y5V
–80
–80
BOTH CAPACITORS ARE 16V,
1210 CASE SIZE, 10µF
–100
–100
50
TEMPERATURE (°C)
100 125
–50 –25
0
25
75
0
8
12 14
2
4
6
10
16
DC BIAS VOLTAGE (V)
3010 F04
3010 F03
Figure 4. Ceramic Capacitor Temperature Characterics
Figure 3. Ceramic Capacitor DC Bias Characterics
3010f
9
LT3010/LT3010-5
W U U
U
APPLICATIO S I FOR ATIO
maximumtopsideandbacksideareaforoneouncecopper
is 3 seconds. This time constant will increase as more
thermal mass is added (i.e. vias, larger board, and other
components).
The LT3010 series regulators have internal thermal limit-
ing designed to protect the device during overload condi-
tions. For continuous normal conditions the maximum
junction temperature rating of 125°C must not be ex-
ceeded. 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 an application with transient high power peaks, aver-
age power dissipation can be used for junction tempera-
turecalculationsaslongasthepulseperiodissignificantly
less than the thermal time constant of the device and
board.
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.
Calculating Junction Temperature
Example 1: Given an output voltage of 5V, an input voltage
range of 24V to 30V, an output current range of 0mA to
50mA, and a maximum ambient temperature of 50°C,
what will the maximum junction temperature be?
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.
The power dissipated by the device will be equal to:
I
OUT(MAX) • (VIN(MAX) – VOUT) + (IGND • VIN(MAX)
where:
IOUT(MAX) = 50mA
)
Table 1. Measured Thermal Resistance
COPPER AREA
THERMAL RESISTANCE
TOPSIDE
2500 sq mm
1000 sq mm
225 sq mm
100 sq mm
BACKSIDE
2500 sq mm
2500 sq mm
2500 sq mm
2500 sq mm
BOARD AREA
2500 sq mm
2500 sq mm
2500 sq mm
2500 sq mm
(JUNCTION-TO-AMBIENT)
40°C/W
VIN(MAX) = 30V
45°C/W
IGND at (IOUT = 50mA, VIN = 30V) = 1mA
50°C/W
62°C/W
So:
P = 50mA • (30V – 5V) + (1mA • 30V) = 1.28W
The thermal resistance junction-to-case (θJC), measured
at the exposed pad on the back of the die, is 16°C/W.
The thermal resistance 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:
Continuous operation at large input/output voltage differ-
entials 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
1.31W • 50°C/W = 65.5°C
3010f
10
LT3010/LT3010-5
W U U
APPLICATIO S I FOR ATIO
U
The maximum junction temperature will then be equal to
the maximum junction temperature rise above ambient
plus the maximum ambient temperature or:
Protection Features
TheLT3010incorporatesseveralprotectionfeatureswhich
make it ideal for use in battery-powered circuits. In addi-
tion to the normal protection features associated with
monolithic regulators, such as current limiting and ther-
mal limiting, the device is protected against reverse-input
voltages, and reverse voltages from output to input.
T
JMAX = 50°C + 65.5°C = 115.5°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 50mA 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:
Current limit protection and thermal overload protection
areintendedtoprotectthedeviceagainstcurrentoverload
conditions at the output of the device. For normal opera-
tion, the junction temperature should not exceed 125°C.
P1(48V in, 5mA load) = 5mA • (48V – 5V)
+ (200µA • 48V) = 0.23W
The input of the device will withstand reverse voltages of
80V.Currentflowintothedevicewillbelimitedtolessthan
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.
P2(48V in, 50mA load) = 50mA • (48V – 5V)
+ (1mA • 48V) = 2.20W
P3(72V in, 5mA load) = 5mA • (72V – 5V)
+ (200µA • 72V) = 0.35W
P4(72V in, 50mA load) = 50mA • (72V – 5V)
+ (1mA • 72V) = 3.42W
The ADJ pin of the adjustable device can be pulled above
or below ground by as much as 7V without damaging the
device. Iftheinputisleftopencircuitorgrounded, theADJ
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 refer-
ence voltage will cause the device to try and force the
current limit current out of the output. This will cause the
output to go to a unregulated high voltage. Pulling the ADJ
pin above the reference voltage will turn off all output
current.
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%(0.23W) + 19%(2.20W) + 4%(0.35W)
+ 1%(3.42W) = 0.64W
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 26°C to 38°C.
3010f
11
LT3010/LT3010-5
W U U
U
APPLICATIO S I FOR ATIO
In situations where the ADJ pin is connected to a resistor
divider that would pull the ADJ pin above its 7V clamp
voltage 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
fromthe1.22Vreferencewhentheoutputisforcedto60V.
The top resistor of the resistor divider must be chosen to
limitthecurrentintotheADJpintolessthan5mAwhenthe
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.
open circuit. Current flow back into the output will follow
the curve shown in Figure 5. 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 LT3010 is forced below the OUT pin
or the OUT pin is pulled above the IN pin, input current will
typicallydroptolessthan2µA. Thiscanhappeniftheinput
of the LT3010 is connected to a discharged (low voltage)
battery and the output is held up by either a backup battery
orasecondregulatorcircuit.ThestateoftheSHDNpinwill
have no effect on the reverse output current when the
output is pulled above the input.
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
100
T
= 25°C
IN
A
V
90
80
70
60
50
40
30
20
10
0
= 0V
CURRENT FLOWS
INTO OUTPUT PIN
ADJ
PIN CLAMP
(SEE ABOVE)
V
V
= V
ADJ
= V
SENSE
(LT3010)
OUT
OUT
(LT3010-5)
LT3010
LT3010-5
4
0
1
2
3
5
6
7
8
9
10
OUTPUT VOLTAGE (V)
3010 F05
Figure 5. Reverse Output Current
3010f
12
LT3010/LT3010-5
U
TYPICAL APPLICATIO S
5V Buck Converter with Low Current Keep Alive Backup
D2
D1N914
6
C2
L1†
0.33µF
BOOST
15µH
V
V
IN
OUT
4
2
5.5V*
V
SW
5V
IN
C3
4.7µF
100V
D1
TO 60V
1A/50mA
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
8
5
1
2
3010 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
LT3010-5
OPERATING
CURRENT
SHDN
SENSE
HIGH
LOW
GND
4
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)
3010 TA04
3010f
13
LT3010/LT3010-5
U
TYPICAL APPLICATIO
LT3010 Automotive Application
IN
OUT
NO PROTECTION
DIODE NEEDED!
+
V
IN
LT3010-5
1µF
12V
1µF
LOAD: CLOCK,
SECURITY SYSTEM
ETC
(LATER 42V)
SHDN
SENSE
GND
OFF
ON
LT3010 Telecom Application
V
IN
IN
OUT
48V
(72V TRANSIENT)
+
–
LT3010-5
BACKUP
BATTERY
NO PROTECTION
DIODE NEEDED!
1µF
1µF
LOAD:
SYSTEM MONITOR
ETC
SHDN
SENSE
GND
3010 TA05
OFF
ON
Constant Brightness for Indicator LED over Wide Input Voltage Range
RETURN
IN
OUT
LT3010
1µF
1µF
OFF ON
–48V
SHDN ADJ
GND
R
SET
3010 TA06
I
= 1.275V/R
LED
SET
–48V CAN VARY FROM –4V TO –80V
3010f
14
LT3010/LT3010-5
U
PACKAGE DESCRIPTIO
MS8E Package
8-Lead Plastic MSOP
(Reference LTC DWG # 05-08-1662)
BOTTOM VIEW OF
EXPOSED PAD OPTION
2.06 ± 0.102
(.080 ± .004)
1
1.83 ± 0.102
(.072 ± .004)
0.889 ± 0.127
(.035 ± .005)
2.794 ± 0.102
(.110 ± .004)
5.23
(.206)
MIN
3.2 – 3.45
(.126 – .136)
2.083 ± 0.102
(.082 ± .004)
8
3.00 ± 0.102
(.118 ± .004)
(NOTE 3)
0.52
(.206)
REF
0.65
(.0256)
BSC
0.42 ± 0.04
(.0165 ± .0015)
8
7 6
5
TYP
RECOMMENDED SOLDER PAD LAYOUT
3.00 ± 0.102
(.118 ± .004)
NOTE 4
4.90 ± 0.15
(1.93 ± .006)
DETAIL “A”
0.254
(.010)
0° – 6° TYP
GAUGE PLANE
1
2
3
4
0.53 ± 0.015
(.021 ± .006)
1.10
(.043)
MAX
0.86
(.034)
REF
DETAIL “A”
0.18
(.077)
SEATING
PLANE
0.22 – 0.38
(.009 – .015)
TYP
0.13 ± 0.076
(.005 ± .003)
0.65
(.0256)
BSC
MSOP (MS8E) 0802
NOTE:
1. DIMENSIONS IN MILLIMETER/(INCH)
2. DRAWING NOT TO SCALE
3. DIMENSION DOES NOT INCLUDE MOLD FLASH, PROTRUSIONS OR GATE BURRS.
MOLD FLASH, PROTRUSIONS OR GATE BURRS SHALL NOT EXCEED 0.152mm (.006") PER SIDE
4. DIMENSION DOES NOT INCLUDE INTERLEAD FLASH OR PROTRUSIONS.
INTERLEAD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.152mm (.006") PER SIDE
5. LEAD COPLANARITY (BOTTOM OF LEADS AFTER FORMING) SHALL BE 0.102mm (.004") MAX
3010f
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 represen-
tationthattheinterconnectionofitscircuitsasdescribedhereinwillnotinfringeonexistingpatentrights.
15
LT3010/LT3010-5
RELATED PARTS
PART NUMBER
DESCRIPTION
COMMENTS
V : 4.5V to 36V, V
LT1020
125mA, Micropower Regulator and Comparator
= 2.5V, V = 0.4V, I = 40µA, I = 40µA,
OUT DO Q SD
IN
Comparator and Reference, Class B Outputs, S16, PDIP14 Packages
LT1120/LT1120A 125mA, Micropower Regulator and Comparator
V : 4.5V to 36V, V = 2.5V, V = 0.4V, I = 40µA, I = 10µA,
Comparator and Reference,Logic Shutdown, Ref Sources and Sinks 2/4mA,
S8, N8 Packages
IN
OUT
DO
Q
SD
LT1121/
LT1121HV
150mA, Micropower, LDO
700mA, Micropower, LDO
V : 4.2V to 30/36V, V
Reverse Battery Protection, SOT-223, S8, Z Packages
= 3.75V, V = 0.42V, I = 30µA, I = 16µA,
OUT DO Q SD
IN
LT1129
LT1616
LT1676
LT1761
LT1762
LT1763
V : 4.2V to 30V, V = 3.75V, V = 0.4V, I = 50µA, I = 16µA,
IN
OUT
DO
Q
SD
DD, S0T-223, S8,TO220-5, TSSOP20 Packages
25V, 500mA (I ), 1.4MHz, High Efficiency
V : 3.6V to 25V, V
= 1.25V, I = 1.9mA, I = <1µA, ThinSOT Package
Q SD
OUT
IN
OUT
OUT
Step-Down DC/DC Converter
60V, 440mA (I ), 100kHz, High Efficiency
V : 7.4V to 60V, V
IN
= 1.24V, I = 3.2mA, I = 2.5µA, S8 Package
Q SD
OUT
Step-Down DC/DC Converter
100mA, Low Noise Micropower, LDO
V : 1.8V to 20V, V
IN
= 1.22V, V = 0.3V, I = 20µA, I = <1µA,
OUT DO Q SD
Low Noise < 20µV
, Stable with 1µF Ceramic Capacitors, ThinSOT Package
RMS P-P
150mA, Low Noise Micropower, LDO
500mA, Low Noise Micropower, LDO
V : 1.8V to 20V, V
IN
= 1.22V, V = 0.3V, I = 25µA, I = <1µA,
OUT
DO
Q
SD
Low Noise < 20µV
, MS8 Package
RMS P-P
V : 1.8V to 20V, V
IN
= 1.22V, V = 0.3V, I = 30µA, I = <1µA,
OUT
DO
Q
SD
Low Noise < 20µV
, S8 Package
RMS P-P
LT1764/LT1764A 3A, Low Noise, Fast Transient Response, LDO
V : 2.7V to 20V, V
= 1.21V, V = 0.34V, I = 1mA, I = <1µA,
OUT DO Q SD
IN
Low Noise < 40µV
, “A” Version Stable with Ceramic Capacitors,
RMS P-P
DD, TO220-5 Packages
LT1766
LT1776
60V, 1.2A (I ), 200kHz, High Efficiency
Step-Down DC/DC Converter
V : 5.5V to 60V, V
= 1.20V, I = 2.5mA, I = 25µA, TSSOP16/E Package
Q SD
OUT
IN
OUT
OUT
40V, 550mA (I ), 200kHz, High Efficiency
V : 7.4V to 40V, V
IN
= 1.24V, I = 3.2mA, I = 30µA, N8, S8 Packages
Q SD
OUT
Step-Down DC/DC Converter
LT1934/
LT1934-1
300mA/60mA, (I ), Constant Off-Time, High
Efficiency Step-Down DC/DC Converter
90% Efficiency, V : 3.2V to 34V, V
ThinSOT Package
= 1.25V, I = 14µA, I = <1µA,
OUT Q SD
OUT
IN
LT1956
60V, 1.2A (I ), 500kHz, High Efficiency
Step-Down DC/DC Converter
V : 5.5V to 60V, V
IN
= 1.20V, I = 2.5mA, I = 25µA, TSSOP16/E Package
OUT Q SD
OUT
LT1962
300mA, Low Noise Micropower, LDO
V : 1.8V to 20V, V
= 1.22V, V = 0.27V, I = 30µA, I = <1µA,
, MS8 Package
IN
OUT
DO
Q
SD
Low Noise < 20µV
RMS P-P
LT1963/LT1963A 1.5A, Low Noise, Fast Transient Response, LDO
V : 2.1V to 20V, V
= 1.21V, V = 0.34V, I = 1mA, I = <1µA,
OUT DO Q SD
IN
Low Noise < 40µV
, “A” Version Stable with Ceramic Capacitors,
RMS P-P
DD, TO220-5, S0T-223, S8 Packages
LT1964
200mA, Low Noise Micropower, Negative LDO
V : –0.9V to –20V, V
= –1.21V, V = 0.34V, I = 30µA, I = 3µA,
OUT DO Q SD
IN
Low Noise < 30µV
, Stable with Ceramic Capacitors, ThinSOT Package
RMS P-P
3010f
LT/TP 0403 2K • PRINTED IN USA
16 LinearTechnology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
●
●
(408) 432-1900 FAX: (408) 434-0507 www.linear.com
LINEAR TECHNOLOGY CORPORATION 2003
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![](http://pdffile.icpdf.com/pdf2/p00299/img/page/LT3010MPMS8E_1808603_files/LT3010MPMS8E_1808603_2.jpg)
LT3010HMS8E-5#TRPBF
LT3010/LT3010-5 - 50mA, 3V to 80V Low Dropout Micropower Linear Regulator; Package: MSOP; Pins: 8; Temperature Range: -40°C to 125°C
Linear
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LT3010MPMS8E#PBF
LT3010/LT3010-5 - 50mA, 3V to 80V Low Dropout Micropower Linear Regulator; Package: MSOP; Pins: 8; Temperature Range: -55°C to 125°C
Linear
![](http://pdffile.icpdf.com/pdf1/p00178/img/page/LT301_999421_files/LT301_999421_1.jpg)
![](http://pdffile.icpdf.com/pdf1/p00178/img/page/LT301_999421_files/LT301_999421_2.jpg)
LT3010MPMS8E#TR
LT3010/LT3010-5 - 50mA, 3V to 80V Low Dropout Micropower Linear Regulator; Package: MSOP; Pins: 8; Temperature Range: -55°C to 125°C
Linear
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