LTM8057MPY#PBF [Linear]
LTM8057 - 3.1Vin to 31Vin Isolated µModule (Power Module) DC/DC Converter; Package: BGA; Pins: 38; Temperature Range: -55°C to 125°C;
| 型号： | LTM8057MPY#PBF |
| 厂家： | 
Linear |
| 描述： | LTM8057 - 3.1Vin to 31Vin Isolated µModule (Power Module) DC/DC Converter; Package: BGA; Pins: 38; Temperature Range: -55°C to 125°C 开关 输出元件 |
| 文件： | 总20页 (文件大小：256K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
LTM8057
3.1V to 31V Isolated
IN
IN
µModule DC/DC Converter
FEATURES
DESCRIPTION
The LTM®8057 is a 2kV AC isolated flyback µModule®
(micromodule) DC/DC converter. Included in the package
are the switching controller, power switches, transformer,
and all support components. Operating over an input volt-
age range of 3.1V to 31V, the LTM8057 supports an output
voltage range of 2.5V to 12V, set by a single resistor. Only
outputandinputcapacitorsareneededtofinishthedesign.
Other components may be used to control the soft-start
control and biasing.
n
2kV AC Isolated µModule Converter (Tested at 3kVDC)
n
UL60950 Recognized File 464570
n
Wide Input Voltage Range: 3.1V to 31V
n
Up to 440mA Output Current (V = 24V V
= 2.5V)
IN
,
OUT1
Output Adjustable from 2.5V to 12V
n
n
n
n
Current Mode Control
Programmable Soft-Start
User Configurable Undervoltage Lockout
Low Profile (9mm × 11.25mm × 4.92mm)
BGA Package
The LTM8057 is packaged in a thermally enhanced, com-
pact (9mm × 11.25mm × 4.92mm) overmolded ball grid
array (BGA) package suitable for automated assembly
by standard surface mount equipment. The LTM8057 is
available with SnPb or RoHS compliant terminal finish.
APPLICATIONS
n
Industrial Sensors
n
Industrial Switches
L, LT, LTC, LTM, Linear Technology, the Linear logo and µModule are registered trademarks of
Linear Technology Corporation. All other trademarks are the property of their respective owners.
n
Test and Measurement Equipment
TYPICAL APPLICATION
2kV AC Isolated µModule Regulator
Maximum Output Current vs VIN
400
V
IN
V
OUT
V
V
IN
OUT
4.3V TO 29V
5V
•
300
200
100
RUN
22µF
•
2.2µF
–
V
GND
BIAS
OUT
4.7µF
6.98k
SS
ADJ
LTM8057
8057 TA01a
0
0
5
10
15
(V)
20
25
30
2kV AC ISOLATION
V
IN
8057 TA01b
8057f
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For more information www.linear.com/LTM8057
LTM8057
ABSOLUTE MAXIMUM RATINGS
PIN CONFIGURATION
(Note 1)
TOP VIEW
V , RUN, BIAS ........................................................32V
IN
ADJ, SS.......................................................................5V
A
–
V
Relative to V
OUT
............................................16V
B
OUT1
V + V
IN
OUT
(Note 2)...................................................36V
BANK 2
BANK 1
V
OUT
C
D
E
–
V
OUT
BIAS Above V ........................................................ 0.1V
IN
–
GND to V
Isolation (Note 3) ......................... 2kV AC
OUT
BANK 4
GND
Maximum Internal Temperature (Note 4).............. 125°C
Peak Solder Reflow Body Temperature................. 245°C
Storage Temperature.............................. –55°C to 125°C
BANK 5
IN
F
V
RUN
3
G
H
ADJ
BIAS SS
1
2
4
5
6
7
BGA PACKAGE
38-LEAD (11.25mm × 9mm × 4.92mm)
= 125°C, θ = 16°C/W, θ = 4.1°C/W, θ = 15°C/W, θ = 4°C/W
T
JMAX
JA
JCbottom
JCtop
JB
WEIGHT = 1.1g, θ VALUES DETERMINED PER JEDEC 51-9, 51-12
ORDER INFORMATION
PART MARKING*
PACKAGE
TYPE
MSL
PART NUMBER
LTM8057EY#PBF
LTM8057IY#PBF
LTM8057IY
PAD OR BALL FINISH
SAC305 (RoHS)
SAC305 (RoHS)
SnPb (63/37)
DEVICE
CODE
e1
RATING
TEMPERATURE RANGE (SEE NOTE 4)
–40°C to 125°C
LTM8057Y
LTM8057Y
LTM8057Y
LTM8057Y
LTM8057Y
BGA
BGA
BGA
BGA
BGA
3
3
3
3
3
e1
–40°C to 125°C
e0
–40°C to 125°C
LTM8057MPY#PBF
LTM8057MPY
SAC305 (RoHS)
SnPb (63/37)
e1
–55°C to 125°C
e0
–55°C to 125°C
Consult Marketing for parts specified with wider operating temperature
ranges. *Device temperature grade is indicated by a label on the shipping
container. Pad or ball finish code is per IPC/JEDEC J-STD-609.
• Recommended LGA and BGA PCB Assembly and Manufacturing
Procedures:
www.linear.com/umodule/pcbassembly
• LGA and BGA Package and Tray Drawings:
www.linear.com/packaging
• Terminal Finish Part Marking:
www.linear.com/leadfree
8057f
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For more information www.linear.com/LTM8057
LTM8057
ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the full internal
operating temperature range, otherwise specifications are at TA = 25°C, RUN = 12V (Note 4).
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
l
l
Minimum Input DC Voltage
BIAS = V , RUN = 2V
3.1
4.3
V
V
IN
BIAS Open, RUN = 2V
V
DC Voltage
R
R
R
= 12.4k
= 6.98k
= 3.16k
2.5
5
V
V
V
OUT
ADJ
ADJ
ADJ
l
4.75
5.25
1
12
V
Quiescent Current
V
= 0V
µA
µA
IN
RUN
Not Switching
850
1.7
1.5
20
V
V
V
Line Regulation
Load Regulation
Ripple (RMS)
6V ≤ V ≤ 31V, I = 0.15A, RUN = 2V
OUT
%
%
OUT
OUT
OUT
IN
0.05A ≤ I
≤ 0.2A, RUN = 2V
OUT
I
= 0.1A, 1MHz BW
mV
V DC
mA
V
OUT
Isolation Test Voltage
Input Short-Circuit Current
RUN Pin Input Threshold
RUN Pin Current
(Note 3)
Shorted
3000
1.18
V
30
OUT
RUN Pin Rising
1.24
1.30
3.1
V
RUN
V
RUN
= 1V
= 1.3V
2.5
0.1
µA
µA
SS Threshold
0.7
–10
9
V
µA
mA
V
SS Sourcing Current
BIAS Current
SS = 0V
V
= 12V, BIAS = 5V, I
= 100mA
LOAD
IN
Minimum BIAS Voltage (Note 5)
I
= 100mA
LOAD
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.
specifications over the full –40°C to 125°C internal operating temperature
range. The LTM8057MP is guaranteed to meet specifications over the
full –55°C to 125°C internal operating temperature range. Note that
the maximum internal temperature is determined by specific operating
conditions in conjunction with board layout, the rated package thermal
resistance and other environmental factors.
Test flowcharts are posted for viewing at:
www.linear.com/quality
Note 5: This is the BIAS pin voltage at which the internal circuitry is
powered through the BIAS pin and not the integrated regulator. See BIAS
Pin Considerations for details.
–
Note 2: V + V
is defined as the sum of (V – GND) + (V
– V
).
OUT
IN
OUT
IN
OUT
Note 3: The LTM8057 isolation is tested at 3kV DC for one second.
Note 4: The LTM8057E is guaranteed to meet performance specifications
from 0°C to 125°C. Specifications over the –40°C to 125°C internal
temperature range are assured by design, characterization and correlation
with statistical process controls. LTM8057I is guaranteed to meet
8057f
3
For more information www.linear.com/LTM8057
LTM8057
Unless otherwise noted, operating conditions are
TYPICAL PERFORMANCE CHARACTERISTICS
as in Table 1 (TA = 25°C).
Efficiency vs Output Current
Efficiency vs Output Current
Efficiency vs Output Current
75
70
65
60
55
50
80
75
80
V
= 2.5V
OUT
V
= 3.3V
V
= 5V
OUT
OUT
12V
IN
BIAS = 5V
BIAS = 5V
BIAS = 5V
75
12V
IN
12V
IN
24V
24V
IN
IN
70
65
70
65
24V
IN
60
55
50
60
55
50
100
200
300
0
400
0
100
200
300
400
0
100
200
300
400
OUTPUT CURRENT (mA)
OUTPUT CURRENT (mA)
OUTPUT CURRENT (mA)
8057 G01
8057 G02
8057 G03
Efficiency vs Output Current
Efficiency vs Output Current
Input Current vs Output Current
85
80
75
70
65
60
55
50
85
80
75
90
80
70
60
50
40
30
20
10
0
V
= 8V
V
= 12V
V
= 2.5V
OUT
OUT
OUT
12V
BIAS = 5V
IN
BIAS = 5V
BIAS = 5V
12V
IN
24V
IN
12V
IN
24V
IN
70
65
60
55
50
24V
IN
200
OUTPUT CURRENT (mA)
300
0
50
100
150
250
50
100
200
200
OUTPUT CURRENT (mA)
0
150
1
400
100
300
OUTPUT CURRENT (mA)
8057 G04
8057 G05
8057 G06
Input Current vs Output Current
Input Current vs Output Current
100
90
80
70
60
50
40
30
20
10
0
140
V
= 5V
V
= 3.3V
OUT
OUT
BIAS = 5V
BIAS = 5V
120
100
12V
IN
12V
IN
80
60
40
20
0
24V
IN
24V
IN
0
100
200
300
400
0
100
200
300
400
OUTPUT CURRENT (mA)
OUTPUT CURRENT (mA)
8057 G07
8057 G08
8057f
4
For more information www.linear.com/LTM8057
LTM8057
Unless otherwise noted, operating conditions are
TYPICAL PERFORMANCE CHARACTERISTICS
as in Table 1 (TA = 25°C).
Input Current vs Output Current
Input Current vs Output Current
Bias Current vs Output Current
200
180
160
140
120
100
80
180
160
140
120
100
80
9
V
= 2.5V
V
= 8V
V
= 12V
OUT
OUT
OUT
BIAS = 5V
BIAS = 5V
BIAS = 5V
8
7
6
5
4
3
2
1
0
12V
IN
24V
12V
IN
IN
12V
IN
24V
IN
24V
IN
60
60
40
40
20
20
0
0
0
50
OUTPUT CURRENT (mA)
100
150
200
1
100
200
OUTPUT CURRENT (mA)
300
400
0
50
100
150
300
200
250
OUTPUT CURRENT (mA)
8057 G10
8057 G11
8057 G09
Bias Current vs Output Current
Bias Current vs Output Current
Bias Current vs Output Current
10
9
8
7
6
5
4
3
2
1
0
12
10
8
12
10
8
V
= 5V
V
= 8V
V
= 3.3V
OUT
OUT
OUT
BIAS = 5V
BIAS = 5V
BIAS = 5V
12V
IN
12V
IN
12V
IN
24V
IN
24V
IN
24V
IN
6
6
4
4
2
2
0
0
0
100
200
300
400
0
100
200
300
400
0
100
150
200
250
300
50
OUTPUT CURRENT (mA)
OUTPUT CURRENT (mA)
OUTPUT CURRENT (mA)
8057 G12
8057 G13
8057 G14
Bias Current vs Output Current
Maximum Output Current vs VIN
14
12
10
500
400
300
200
V
= 12V
OUT
BIAS = 5V FOR V ≥ 5V
IN
BIAS = 5V
BIAS = V FOR V < 5V
IN
IN
12V
IN
24V
IN
8
6
4
2
0
100
0
V
V
V
= 2.5V
= 3.3V
= 5V
OUT
OUT
OUT
50
100
200
0
150
0
10
15
(V)
20
25
30
5
V
OUTPUT CURRENT (mA)
IN
8057 G15
8057 G16
8057f
5
For more information www.linear.com/LTM8057
LTM8057
Unless otherwise noted, operating conditions are
TYPICAL PERFORMANCE CHARACTERISTICS
as in Table 1 (TA = 25°C).
Minimum Required Load
Minimum Required Load
vs Input Voltage
Maximum Output Current vs VIN
vs Input Voltage
25
45
40
35
30
25
20
15
10
5
400
300
200
100
BIAS = 5V FOR V ≥ 5V
IN
BIAS = 5V FOR V ≥ 5V
IN
BIAS = 5V FOR V ≥ 5V
IN
BIAS = V FOR V < 5V
BIAS = V FOR V < 5V
BIAS = V FOR V < 5V
IN
IN
IN
IN
IN
IN
20
15
10
5
0
V
V
V
= 2.5V
= 3.3V
= 5V
OUT
OUT
OUT
V
V
= 8V
V
V
= 8V
= 12V
OUT1
OUT1
OUT
OUT
= 12V*
0
0
0
10
INPUT VOLTAGE (V)
*SEE APPLICATIONS INFORMATION SECTION
FOR DISCUSSION OF 12V MINIMUM LOAD
15
20
25
30
5
20
INPUT VOLTAGE (V)
0
10
30
40
0
5
10
15
(V)
20
25
30
8057 G19
V
IN
8057 G18
8057 G17
OUT
Typical Output Ripple
100mA Output Current, VIN = 12V
DC1988 VOUT1 Start-Up Behavior
for Different CSS Values
Typical Switching Frequency vs
Output Current Stock DC1988A
900
800
700
600
500
400
300
200
100
NO C
SS
C
= 0.01µF
SS
C
= 0.1µF
12V
IN
SS
5mV/DIV
1V/DIV
5V
IN
8057 G20
8057 G21
500ns/DIV
200µs/DIV
100mA RESISTIVE LOAD
MEASURED ON DC1987 WITH ADDIONAL 1µF
AND BNC ATTACHED TO OUTPUT TERMINALS.
C7 = 0.1µF. USED HP461A 150MHz AMPLIFIER,
SET TO 40dB GAIN.
0
0
200
250
50
100
150
OUTPUT CURRENT (mA)
8057 G22
Input Current
vs VIN, VOUT Shorted
80
Junction Temperature Rise
vs Load Current
8
7
6
5
4
3
2
1
0
V
= 2.5V
OUT
70
60
50
40
30
20
10
3.3V
IN
IN
5V
12V
24V
IN
IN
0
4
8
12 16 20 24 28 32
(V)
0
50 100 150 200 250 300 350 400
LOAD CURRENT (mA)
V
V
OUT
IN
8057 G23
8057 G24
8057f
6
For more information www.linear.com/LTM8057
LTM8057
Unless otherwise noted, operating conditions are
TYPICAL PERFORMANCE CHARACTERISTICS
as in Table 1 (TA = 25°C).
Junction Temperature Rise
vs Load Current
Junction Temperature Rise
vs Load Current
9
8
7
6
5
4
3
2
1
0
10
9
8
7
6
5
4
3
2
1
0
V
= 3.3V
V
= 5V
OUT
OUT
3.3V
IN
3.3V
IN
IN
5V
5V
IN
12V
24V
12V
24V
IN
IN
IN
IN
0
50 100 150 200 250 300 350 400
LOAD CURRENT (mA)
0
50 100 150 200 250 300 350
LOAD CURRENT (mA)
V
V
OUT
OUT
8057 G25
8057 G26
Junction Temperature Rise
vs Load Current
Junction Temperature Rise
vs Load Current
12
10
8
12
10
8
V
= 8V
V
= 12V
OUT
OUT
6
6
4
4
3.3V
IN
3.3V
IN
IN
IN
5V
5V
2
2
12V
24V
12V
24V
IN
IN
IN
IN
0
0
0
50
V
100
150
200
250
300
0
50
V
100
150
200
250
LOAD CURRENT (mA)
LOAD CURRENT (mA)
OUT
OUT
8057 G27
8057 G28
8057f
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For more information www.linear.com/LTM8057
LTM8057
PIN FUNCTIONS
PACKAGE ROW AND COLUMN LABELING MAY VARY
RUN (Pin F3): A resistive divider connected to V and this
IN
AMONG µModule PRODUCTS. REVIEW EACH PACKAGE
LAYOUT CAREFULLY.
pin programs the minimum voltage at which the LTM8057
will operate. Below 1.24V, the LTM8057 does not deliver
power to the secondary. Above 1.24V, power will be de-
livered to the secondary and 10µA will be fed into the SS
pin. When RUN is less than 1.24V, the pin draws 2.5µA,
allowing for a programmable hysteresis. Do not allow a
negative voltage (relative to GND) on this pin. Tie this pin
–
V
(Bank 1): V
and V
comprise the isolated
OUT
OUT
OUT
output of the LTM8057 flyback stage. Apply an external
–
–
capacitor between V
exceed V
and V
. Do not allow V
to
OUT
OUT
OUT
.
OUT
–
–
V
(Bank 2): V
is the return for both V
and
OUT1
OUT
V
OUT
and V
to V if it is not used.
IN
–
. V
comprise the isolated output of
OUT2 OUT1
OUT
ADJ (Pins G7): Apply a resistor from this pin to GND to
the LTM8057. In most applications, the bulk of the heat
–
–
set the output voltage V
relative to V
, using the
flow out of the LTM8057 is through the GND and V
OUT1
OUT
OUT
recommended value given in Table 1. If Table 1 does not
pads, so the printed circuit design has a large impact on
list the desired V
value, the equation:
the thermal performance of the part. See the PCB Layout
OUT
and Thermal Considerations sections for more details.
–0.879
RADJ = 28.4 V
kΩ
–
OUT1
Apply an external capacitor between V
and V
.
OUT
OUT
GND (Bank 4): This is the primary side local ground of the
may be used to approximate the value. To the seasoned
designer,thisexponentialequationmayseemunusual.The
equation is exponential due to nonlinear current sources
that are used to temperature compensate the regulation.
LTM8057primary.Inmostapplications,thebulkoftheheat
–
flow out of the LTM8057 is through the GND and V
OUT
pads, so the printed circuit design has a large impact on
the thermal performance of the part. See the PCB Layout
and Thermal Considerations sections for more details.
BIAS (Pin H5): This pin supplies the power necessary to
operate the LTM8057. It must be locally bypassed with a
low ESR capacitor of at least 4.7μF. Do not allow this pin
V (Bank 5): V supplies current to the LTM8057’s inter-
IN
IN
nal regulator and to the integrated power switch. These
pins must be locally bypassed with an external, low ESR
capacitor.
voltage to rise above V .
IN
SS(PinH6):Placeasoft-startcapacitorheretolimitinrush
current and the output voltage ramp rate. Do not allow a
negative voltage (relative to GND) on this pin.
8057f
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For more information www.linear.com/LTM8057
LTM8057
BLOCK DIAGRAM
V
V
OUT
IN
•
0.1µF
•
1µF
RUN
BIAS*
SS
–
V
OUT
CURRENT
MODE
CONTROLLER
ADJ
GND
8057 BD
*DO NOT ALLOW BIAS VOLTAGE TO BE ABOVE V
IN
OPERATION
The LTM8057 is a stand-alone isolated flyback switching
DC/DCpowersupplythatcandeliverupto440mAofoutput
current. This module provides a regulated output voltage
programmable via one external resistor from 2.5V to 12V.
The input voltage range of the LTM8057 is 3.1V to 31V.
Given that the LTM8057 is a flyback converter, the output
current depends upon the input and output voltages, so
make sure that the input voltage is high enough to support
the desired output voltage and load current. The Typical
Performance Characteristics section gives several graphs
the 2kV AC isolation is verified by a 3kV DC test. The peak
voltage of a 2kV AC waveform is 2.83kV DC, so 3kV DC is
applied. For details please refer to the Isolation, Working
Voltage and Safely Compliance section. The LTM8057 is
a UL 60950 recognized component.
An internal regulator provides power to the control cir-
cuitry. The bias regulator normally draws power from the
V
pin, but if the BIAS pin is connected to an external
IN
voltage higher than 3.1V, bias power will be drawn from
the external source, improving efficiency. V
must not
BIAS
ofthemaximumloadversusV forseveraloutputvoltages.
IN
exceed V . The RUN pin is used to turn on or off the
IN
Asimplifiedblockdiagramisgiven.TheLTM8057contains
acurrentmodecontroller,powerswitchingelement,power
transformer, power Schottky diode and a modest amount
of input and output capacitance.
LTM8057,disconnectingtheoutputandreducingtheinput
current to 1μA or less.
The LTM8057 is a variable frequency device. For a fixed
input and output voltage, the frequency increases as the
load increases. For light loads, the current through the
internal transformer may be discontinuous.
The LTM8057 has a galvanic primary to secondary isola-
tion rating of 2kV AC. This is verified by applying 3kV DC
betweentheprimaryandsecondaryfor1second.Notethat
8057f
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For more information www.linear.com/LTM8057
LTM8057
APPLICATIONS INFORMATION
For most applications, the design process is straight
in undesirable operation. Using larger values is generally
acceptable, and can yield improved dynamic response, if
it is necessary. Again, it is incumbent upon the user to
verify proper operation over the intended system’s line,
load and environmental conditions.
forward, summarized as follows:
1. Look at Table 1a and find the row that has the desired
input range and output voltage.
2. ApplytherecommendedC , C
andR ifrequired.
ADJ
IN OUT
Ceramic capacitors are small, robust and have very low
ESR. However, not all ceramic capacitors are suitable.
X5R and X7R types are stable over temperature and ap-
plied voltage and give dependable service. Other types,
including Y5V and Z5U have very large temperature and
voltage coefficients of capacitance. In an application cir-
cuit they may have only a small fraction of their nominal
capacitanceresultinginmuchhigheroutputvoltageripple
than expected.
3. Connect BIAS as indicated, or tie to an external source
up to 15V or V , whichever is less.
IN
Whilethesecomponentcombinationshavebeentestedfor
proper operation, it is incumbent upon the user to verify
proper operation over the intended system’s line, load and
environmentalconditions. Bearinmindthatthemaximum
output current may be limited by junction temperature,
the relationship between the input and output voltage
magnitude and polarity and other factors. Please refer
to the graphs in the Typical Performance Characteristics
section for guidance.
A final precaution regarding ceramic capacitors concerns
the maximum input voltage rating of the LTM8057. A
ceramic input capacitor combined with trace or cable
inductance forms a high-Q (underdamped) tank circuit. If
the LTM8057 circuit is plugged into a live supply, the input
voltage can ring to much higher than its nominal value,
possibly exceeding the device’s rating. This situation is
easily avoided; see the Hot-Plugging Safely section.
Capacitor Selection Considerations
The C and C
capacitor values in Table 1 are the
IN
OUT
minimum recommended values for the associated oper-
ating conditions. Applying capacitor values below those
indicated in Table 1 is not recommended, and may result
LTM8057 Table 1a. Recommended Component Values and Configuration for Specific VOUT Voltages (TA = 25°C)
V
V
V
C
C
R
ADJ
IN
OUT
BIAS
IN
OUT
3.1V to 31V
3.1V to 31V
3.1V to 29V
3.1V to 26V
3.1V to 24V
9V to 15V
2.5V
3.3V
5V
3.1V to 15V or Open
3.1V to 15V or Open
3.1V to 15V or Open
3.1V to 15V or Open
3.1V to 15V or Open
2.2µF, 50V, 1206
2.2µF, 50V, 1206
2.2µF, 50V, 1206
2.2µF, 50V, 1206
2.2µF, 25V, 0805
2.2µF, 50V, 1206
2.2µF, 50V, 1206
2.2µF, 50V, 1206
2.2µF, 50V, 1206
2.2µF, 25V, 0805
2.2µF, 50V, 1206
2.2µF, 50V, 1206
2.2µF, 50V, 1206
2.2µF, 50V, 1206
2.2µF, 50V, 1206
100µF, 6.3V, 1210
100µF, 6.3V, 1210
22µF, 16V, 1210
22µF, 10V, 1206
10µF, 16V, 1210
100µF, 6.3V, 1210
47µF, 6.3V, 1210
22µF, 16V, 1210
22µF, 10V, 1206
10µF, 16V, 1210
100µF, 6.3V, 1210
47µF, 6.3V, 1210
22µF, 16V, 1210
22µF, 10V, 1206
10µF, 16V, 1210
12.4k
10k
6.98k
8V
4.53k
12V
2.5V
3.3V
5V
3.16k/8.2pF*
12.4k
V
V
V
V
V
IN
IN
IN
IN
IN
9V to 15V
10k
9V to 15V
6.98k
9V to 15V
8V
4.53k
9V to 15V
12V
2.5V
3.3V
5V
3.16k
18V to 31V
18V to 31V
18V to 29V
18V to 26V
18V to 24V
3.1V to 15V or Open
3.1V to 15V or Open
3.1V to 15V or Open
3.1V to 15V or Open
3.1V to 15V or Open
12.4k
10k
6.98k
8V
4.53k
12V
3.16k/8.2pF*
Note: Do not allow BIAS to exceed V , a bulk input capacitor is required. If BIAS is open, the minimum V is 4.3V.
IN
IN
*Connect 3.16k in parallel with 8.2pF from ADJ to GND
8057f
10
For more information www.linear.com/LTM8057
LTM8057
APPLICATIONS INFORMATION
BIAS Pin Considerations
The isolation rating of the LTM8057 is not the same as
the working or operational voltage that the application
will experience. This is subject to the application’s power
source, operating conditions, the industry where the end
product is used and other factors that dictate design re-
quirementssuchasthegapbetweencopperplanes,traces
and component pins on the printed circuit board, as well
as the type of connector that may be used. To maximize
the allowable working voltage, the LTM8057 has two
columns of solder balls removed to facilitate the printed
circuit board design. The ball to ball pitch is 1.27mm, and
the typical ball diameter is 0.78mm. Accounting for the
missing columns and the ball diameter, the printed circuit
board may be designed for a metal-to-metal separation of
up to 3.03mm. This may have to be reduced somewhat to
allow for tolerances in solder mask or other printed circuit
board design rules. For those situations where informa-
tion about the spacing of LTM8057 internal circuitry is
required, the minimum metal to metal separation of the
primary and secondary is 0.75mm.
The BIAS pin is the output of an internal linear regulator
that powers the LTM8057’s internal circuitry. It is set to
3V and must be decoupled with a low ESR capacitor of at
least4.7μF.TheLTM8057willrunproperlywithoutapplying
a voltage to this pin, but will operate more efficiently and
dissipate less power if a voltage between 3.1V and V is
IN
applied. At low V , the LTM8057 will be able to deliver
IN
more output current if BIAS is 3.1V or greater. Up to 31V
may be applied to this pin, but a high BIAS voltage will
causeexcessivepowerdissipationintheinternalcircuitry.
For applications with an input voltage less than 15V, the
BIAS pin is typically connected directly to the V pin. For
IN
input voltages greater than 15V, it is preferred to leave the
BIAS pin separate from the V pin, either powered from
IN
a separate voltage source or left running from the internal
regulator. This has the added advantage of keeping the
physical size of the BIAS capacitor small. Do not allow
BIAS to rise above V .
IN
Soft-Start
To reiterate, the manufacturer’s isolation voltage rating
and the required working or operational voltage are often
different numbers. In the case of the LTM8057, the isola-
tion voltage rating is established by 100% hi-pot testing.
The working or operational voltage is a function of the
end product and its system level specifications. The ac-
tual required operational voltage is often smaller than the
manufacturer’s isolation rating.
For many applications, it is necessary to minimize the
inrush current at start-up. The built-in soft-start circuit
significantly reduces the start-up current spike and output
voltageovershootbyapplyingacapacitorfromSStoGND.
When the LTM8057 is enabled, whether from V reaching
IN
a sufficiently high voltage or RUN being pulled high, the
LTM8057 will source approximately 10µA out of the SS
pin. As this current gradually charges the capacitor from
SS to GND, the LTM8057 will correspondingly increase
the power delivered to the output, allowing for a graceful
turn-on ramp.
The LTM8057 is a UL recognized component under
UL 60950, file number 464570. The UL 60950 insula-
tion category of the LTM8057 transformer is Functional.
Considering UL 60950 Table 2N and the gap distances
stated above, 3.03mm external and 0.75mm internal,
the LTM8057 may be operated with up to 250V working
voltage in a pollution degree 2 environment. The actual
workingvoltage, insulationcategory, pollutiondegreeand
other critical parameters for the specific end application
depend upon the actual environmental, application and
safety compliance requirements. It is therefore up to the
user to perform a safety and compliance review to ensure
that the LTM8057 is suitable for the intended application.
Isolation, Working Voltage and Safety Compliance
TheLTM8057isolationis100%hi-pottestedbytyingallof
theprimarypinstogether,allofthesecondarypinstogether
and subjecting the two resultant circuits to a differential
of 3kV DC for one second. This establishes the isolation
voltage rating of the LTM8057 component.
8057f
11
For more information www.linear.com/LTM8057
LTM8057
APPLICATIONS INFORMATION
ADJ and Line Regulation
–
V
OUT
to V
Reverse Voltage
OUT
For V
greater than 8V, parasitics in the transformer
TheLTM8057cannottolerateareversevoltagefromV to
OUT
OUT
–
–
interactingwiththecontrollercausealocalizedincreasein
minimum load. A small capacitor may need to be applied
from ADJ to GND to ensure proper line regulation. Care
must be taken when choosing this capacitor value. Too
small or no capacitor will result in poor line regulation;
V
during operation. If V
raises above V
dur-
OUT
OUT
OUT
ing operation, the LTM8057 may be damaged. To protect
against this condition, a low forward drop power Schottky
diode has been integrated into the LTM8057, anti-parallel
–
to V /V
. This can protect the output against many
OUT OUT
in general, a larger capacitor is needed for higher V
Too large of a capacitance will require excessive minimum
load to maintain regulation.
.
reverse voltage faults. Reverse voltage faults can be both
steady state and transient. An example of a steady-state
voltage reversal is accidentally misconnecting a powered
LTM8057 to a negative voltage source. An example of
transient voltage reversals is a momentary connection to
OUT
The plots in Figure 1 show LTM8057 line regulation at
three different capacitor values applied from ADJ to GND.
a negative voltage. It is also possible to achieve a V
OUT-
The plots in Figure 2 show the minimum load requirement
for the same three capacitors.
reversal if the load is short circuited through a long cable.
The inductance of the long cable forms an LC tank circuit
with the V
capacitance, which drive V
negative.
OUT
OUT
Carefully choose the appropriate capacitor value for the
intended application.
Avoid these conditions.
Safety Rated Capacitors
5
4
Some applications require safety rated capacitors, which
are high voltage capacitors that are specifically designed
and rated for AC operation and high voltage surges. These
capacitorsareoftencertifiedtosafetystandardssuchasUL
60950, IEC 60950 and others. In the case of the LTM8057,
3
2
1
0
–1
–2
a common application of a safety rated capacitor would
–
be to connect it from GND to V
. To provide maximum
–3
OUT
NO CAP
8.2pF CAP
flexibility, the LTM8057 does not include any components
–4
–5
12pF CAP
24
18
–
between GND and V
added externally.
. Any safety capacitors must be
OUT
0
6
12
(V)
V
8057 F01
IN
The specific capacitor and circuit configuration for any
application depends upon the safety requirements of
the system into which the LTM8057 is being designed.
Table 2 provides a list of possible capacitors and their
Figure 1. VOUT Line Regulation vs VIN
25
BIAS = 5V FOR V ≥ 5V
IN
BIAS = V FOR V < 5V
IN
IN
NO CAP
8.2pF CAP
12pF CAP
20
15
10
5
manufacturers. The application of a capacitor from GND
–
to V
may also reduce the high frequency output noise
OUT
on the output.
0
0
6
12
INPUT VOLTAGE (V)
18
24
8057 F02
Figure 2. Minimum Required Load vs Input Voltage
8057f
12
For more information www.linear.com/LTM8057
LTM8057
APPLICATIONS INFORMATION
Table 2. Safety Rated Capacitors
A few rules to keep in mind are:
1. Place the R resistor as close as possible to their
MANUFACTURER PART NUMBER
DESCRIPTION
ADJ
Murata
Electronics
GA343DR7GD472KW01L
4700pF, 250V AC, X7R,
4.5mm × 3.2mm
Capacitor
respective pins.
2. Place the C capacitor as close as possible to the V
IN
IN
Johanson
Dielectrics
302R29W471KV3E-****-SC 470pF, 250V AC, X7R,
and GND connections of the LTM8057.
4.5mm × 2mm
Capacitor
3. Place the C
capacitor as close as possible to V
OUT
OUT1
–
Syfer Technology 1808JA250102JCTSP
100pF, 250V AC, C0G,
1808 Capacitor
and V
.
OUT
4. Place the C and C
capacitors such that their
OUT
IN
PCB Layout
ground current flow directly adjacent or underneath
the LTM8057.
Most of the headaches associated with PCB layout have
been alleviated or even eliminated by the high level of
integration of the LTM8057. The LTM8057 is neverthe-
less a switching power supply, and care must be taken to
minimizeelectricalnoisetoensureproperoperation. Even
with the high level of integration, you may fail to achieve
specified operation with a haphazard or poor layout. See
Figure 3 for a suggested layout. Ensure that the grounding
and heat sinking are acceptable.
5. Connect all of the GND connections to as large a copper
pour or plane area as possible on the top layer. Avoid
breaking the ground connection between the external
components and the LTM8057.
ADJ
V
OUT
LTM8058
SS
C
OUT1
V
BIAS
C
BIAS
–
OUT
RUN
C
IN
V
IN
THERMAL/INTERCONNECT VIAS
8057 F03
Figure 3. Layout Showing Suggested External Components, Planes and Thermal Vias
8057f
13
For more information www.linear.com/LTM8057
LTM8057
APPLICATIONS INFORMATION
voltage, output power and ambient temperature. The
temperature rise curves given in the Typical Performance
Characteristicssectioncanbeusedasaguide.Thesecurves
6. Use vias to connect the GND copper area to the board’s
internal ground planes. Liberally distribute these GND
vias to provide both a good ground connection and
thermal path to the internal planes of the printed circuit
board. Pay attention to the location and density of the
thermal vias in Figure 3. The LTM8057 can benefit from
theheatsinkingaffordedbyviasthatconnecttointernal
GND planes at these locations, due to their proximity
to internal power handling components. The optimum
number of thermal vias depends upon the printed
circuit board design. For example, a board might use
very small via holes. It should employ more thermal
vias than a board that uses larger holes.
2
were generated by the LTM8057 mounted to a 58cm
4-layer FR4 printed circuit board. Boards of other sizes
and layer count can exhibit different thermal behavior, so
it is incumbent upon the user to verify proper operation
over the intended system’s line, load and environmental
operating conditions.
Forincreasedaccuracyandfidelitytotheactualapplication,
many designers use FEA to predict thermal performance.
To that end, the Pin Configuration section of the data sheet
typically gives four thermal coefficients:
ꢀ θ : Thermal resistance from junction to ambient
Hot-Plugging Safely
JA
ꢀ θ
: Thermal resistance from junction to the bot-
The small size, robustness and low impedance of ceramic
capacitors make them an attractive option for the input
bypass capacitor of the LTM8057. However, these capaci-
tors can cause problems if the LTM8057 is plugged into a
live supply (see Linear Technology Application Note 88 for
a complete discussion). The low loss ceramic capacitor
combined with stray inductance in series with the power
source forms an underdamped tank circuit, and the volt-
JCbottom
tom of the product case
ꢀ θ : Thermal resistance from junction to top of the
JCtop
product case
ꢀ θ
:Thermalresistancefromjunctiontotheprinted
JCboard
circuit board.
While the meaning of each of these coefficients may seem
to be intuitive, JEDEC has defined each to avoid confu-
sion and inconsistency. These definitions are given in
JESD 51-12, and are quoted or paraphrased as follows:
age at the V pin of the LTM8057 can ring to more than
IN
twice the nominal input voltage, possibly exceeding the
LTM8057’s rating and damaging the part. If the input
supply is poorly controlled or the user will be plugging
the LTM8057 into an energized supply, the input network
should be designed to prevent this overshoot. This can be
θ
is the natural convection junction-to-ambient air
JA
thermal resistance measured in a one cubic foot sealed
enclosure. This environment is sometimes referred to
as still air although natural convection causes the air to
move. This value is determined with the part mounted to a
JESD 51-9 defined test board, which does not reflect an
actual application or viable operating condition.
accomplishedbyinstallingasmallresistorinseriestoV ,
IN
but the most popular method of controlling input voltage
overshoot is adding an electrolytic bulk capacitor to the
V net. This capacitor’s relatively high equivalent series
IN
resistance damps the circuit and eliminates the voltage
overshoot. The extra capacitor improves low frequency
ripplefilteringandcanslightlyimprovetheefficiencyofthe
circuit, though it can be a large component in the circuit.
θ
is the junction-to-board thermal resistance with
JCbottom
allofthecomponentpowerdissipationflowingthroughthe
bottom of the package. In the typical µModule converter,
the bulk of the heat flows out the bottom of the package,
but there is always heat flow out into the ambient envi-
ronment. As a result, this thermal resistance value may
be useful for comparing packages but the test conditions
don’t generally match the user’s application.
Thermal Considerations
The LTM8057 output current may need to be derated if it
is required to operate in a high ambient temperature. The
amount of current derating is dependent upon the input
8057f
14
For more information www.linear.com/LTM8057
LTM8057
APPLICATIONS INFORMATION
be inappropriate to attempt to use any one coefficient to
correlate to the junction temperature vs load graphs given
in the product’s data sheet. The only appropriate way to
use the coefficients is when running a detailed thermal
analysis, such as FEA, which considers all of the thermal
resistances simultaneously.
θ
isdeterminedwithnearlyallofthecomponentpower
JCtop
dissipation flowing through the top of the package. As the
electricalconnectionsofthetypicalµModuleconverterare
on the bottom of the package, it is rare for an application
to operate such that most of the heat flows from the junc-
tion to the top of the part. As in the case of θ
value may be useful for comparing packages but the test
conditions don’t generally match the user’s application.
, this
JCbottom
A graphical representation of these thermal resistances
is given in Figure 4.
θ
isthejunction-to-boardthermalresistancewhere
JCboard
The blue resistances are contained within the µModule
converter, and the green are outside.
almost all of the heat flows through the bottom of the
µModule converter and into the board, and is really the
sum of the θ
bottom of the part through the solder joints and through a
portion of the board. The board temperature is measured
a specified distance from the package, using a two-sided,
two-layer board. This board is described in JESD 51-9.
The die temperature of the LTM8057 must be lower than
the maximum rating of 125°C, so care should be taken in
the layout of the circuit to ensure good heat sinking of the
LTM8057. The bulk of the heat flow out of the LTM8057
is through the bottom of the module and the BGA pads
into the printed circuit board. Consequently a poor printed
circuit board design can cause excessive heating, result-
ing in impaired performance or reliability. Please refer to
the PCB Layout section for printed circuit board design
suggestions.
and the thermal resistance of the
JCbottom
Giventhesedefinitions,itshouldnowbeapparentthatnone
of these thermal coefficients reflects an actual physical
operating condition of a µModule converter. Thus, none
of them can be individually used to accurately predict the
thermal performance of the product. Likewise, it would
JUNCTION-TO-AMBIENT RESISTANCE (JESD 51-9 DEFINED BOARD)
JUNCTION-TO-CASE (TOP)
RESISTANCE
CASE (TOP)-TO-AMBIENT
RESISTANCE
JUNCTION-TO-BOARD RESISTANCE
JUNCTION
AMBIENT
JUNCTION-TO-CASE
(BOTTOM) RESISTANCE
CASE (BOTTOM)-TO-BOARD
BOARD-TO-AMBIENT
RESISTANCE
RESISTANCE
8057 F04
µMODULE DEVICE
Figure 4
8057f
15
For more information www.linear.com/LTM8057
LTM8057
APPLICATIONS INFORMATION
3.3V Flyback Converter
Maximum Output Current vs VIN
350
300
250
200
V
V
OUT
IN
V
V
OUT
IN
9V TO 15V
3.3V
•
RUN
47µF
•
2.2µF
–
V
OUT
GND
BIAS
4.7µF
10k
SS
ADJ
LTM8057
8057 TA02a
9
11
12
(V)
13
14
15
10
2kV AC ISOLATION
V
IN
8057 TA02b
2.5V Flyback Converter
Maximum Output Current vs VIN
500
400
300
200
100
0
V
V
OUT
IN
V
V
IN
OUT
3.1V TO 31V
2.5V
•
100µF
RUN
•
2.2µF
3.1V
GND
BIAS
–
V
OUT
4.7µF
12.4k
SS
ADJ
LTM8057
8057 TA03a
2kV AC ISOLATION
16
(V)
0
4
8
12
20 24 28 32
V
IN
8057 TA03b
8057f
16
For more information www.linear.com/LTM8057
LTM8057
TYPICAL APPLICATIONS
8V Flyback Converter
V
IN
V
OUT
V
V
IN
OUT
9V TO 15V
8V
•
RUN
22µF
•
2.2µF
–
V
OUT
GND
BIAS
4.7µF
4.53k
SS
ADJ
LTM8057
8057 TA04a
2kV AC ISOLATION
Maximum Output Current vs VIN
250
200
150
100
9
11
12
(V)
13
14
15
10
V
IN
8057 TA04b
8057f
17
For more information www.linear.com/LTM8057
LTM8057
PACKAGE DESCRIPTION
Pin Assignment Table
(Arranged by Pin Number)
PIN FUNCTION PIN FUNCTION PIN FUNCTION PIN FUNCTION PIN FUNCTION PIN FUNCTION PIN FUNCTION PIN FUNCTION
–
–
–
–
–
–
–
–
–
–
A1
A2
A3
A4
A5
A6
A7
V
V
V
V
V
B1
B2
B3
B4
B5
B6
B7
V
V
V
V
V
C1
C2
C3
C4
C5
C6
C7
-
-
-
-
-
-
-
D1
D2
D3
D4
D5
D6
D7
-
-
-
-
-
-
-
E1
E2
E3
E4
E5
E6
E7
GND
GND
GND
GND
GND
GND
GND
F1
F2
F3
F4
F5
F6
F7
-
-
G1
G2
G3
G4
G5
G6
G7
V
V
-
GND
GND
GND
ADJ
H1
H2
H3
H4
H5
H6
H7
V
V
-
GND
BIAS
SS
OUT
OUT
OUT
OUT
OUT
OUT
OUT
OUT
OUT
OUT
IN
IN
IN
IN
RUN
GND
GND
GND
GND
V
V
V
V
OUT
OUT
OUT
OUT
GND
PACKAGE PHOTO
8057f
18
For more information www.linear.com/LTM8057
LTM8057
PACKAGE DESCRIPTION
Please refer to http://www.linear.com/designtools/packaging/ for the most recent package drawings.
/ / b b b
Z
3 . 8 1 0
2 . 5 4 0
1 . 2 7 0
0 . 3 1 7 5
0 . 0 0 0
0 . 3 1 7 5
1 . 2 7 0
2 . 5 4 0
3 . 8 1 0
8057f
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-
19
tion that the interconnection of its circuits as described herein will not infringe on existing patent rights.
LTM8057
TYPICAL APPLICATION
Maximum Output Current vs VIN
12V Flyback Converter with Low Noise Bypass
200
150
100
50
V
V
OUT
IN
V
V
IN
OUT
3.1V TO 24V
12V
•
RUN
10µF
•
2.2µF
3.1V
GND
BIAS
–
V
OUT
4.7µF
6.19k
SS
ADJ
LTM8057
8057 TA05a
0
0
5
10
15
(V)
20
25
2kV AC ISOLATION
V
IN
8057 TA05b
DESIGN RESOURCES
SUBJECT
DESCRIPTION
µModule Design and Manufacturing Resources
Design:
Manufacturing:
• Quick Start Guide
• Selector Guides
• Demo Boards and Gerber Files
• Free Simulation Tools
• PCB Design, Assembly and Manufacturing Guidelines
• Package and Board Level Reliability
µModule Regulator Products Search
1. Sort table of products by parameters and download the result as a spread sheet.
2. Search using the Quick Power Search parametric table.
TechClip Videos
Quick videos detailing how to bench test electrical and thermal performance of µModule products.
Digital Power System Management
Linear Technology’s family of digital power supply management ICs are highly integrated solutions that
offer essential functions, including power supply monitoring, supervision, margining and sequencing,
and feature EEPROM for storing user configurations and fault logging.
RELATED PARTS
PART NUMBER
DESCRIPTION
COMMENTS
LTM8058
2kVAC 1.5W Isolated µModule Converter with 3.1V ≤ V ≤ 31V; 1.2V ≤ V
≤ 12V; 20µV
Output Ripple
RMS
IN
OUT
LDO Post Regulator
LTM8031
LTM8032
LTM8033
LTM4612
LTM8061
LTM4613
LTM8047
Ultralow EMI 1A µModule Regulator
Ultralow EMI 2A µModule Regulator
Ultralow EMI 3A µModule Regulator
Ultralow EMI 5A µModule Regulator
Li-Ion/Polymer µModule Battery Charger
Ultralow EMI 8A µModule Regulator
725V DC Isolated µModule Converter
EN55022 Class B Compliant, 3.6V ≤ V ≤ 36V; 0.8V ≤ V
≤ 10V
≤ 10V
≤ 24V
IN
OUT
OUT
OUT
EN55022 Class B Compliant, 3.6V ≤ V ≤ 36V; 0.8V ≤ V
IN
EN55022 Class B Compliant, 3.6V ≤ V ≤ 36V; 0.8V ≤ V
IN
EN55022 Class B Compliant, 5V ≤ V ≤ 36V; 3.3V ≤ V
≤ 15V
OUT
IN
4.95V ≤ V ≤ 32V, 2A Charge Current, 1-Cell and 2-Cell, 4.1V or 4.2V per Cell
IN
EN55022 Class B Compliant, 5V ≤ V ≤ 36V; 3.3V ≤ V
≤ 15V
OUT
IN
3.1V ≤ V ≤ 32V; 2.5V ≤ V
≤ 12V
OUT
IN
8057f
LT 0514 • PRINTED IN USA
LinearTechnology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
20
(408)432-1900 FAX: (408) 434-0507 www.linear.com/LTM8057
●
●
ꢀLINEAR TECHNOLOGY CORPORATION 2014
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