LTM8023 - Linear Technology

LTM8023
2A, 36V DC/DC
Step-Down µModule
Regulator
DESCRIPTION
FEATURES
Complete Step-Down Switch Mode Power Supply
Wide Input Voltage Range: 3.6V to 36V
2A Output Current
0.8V to 10V Output Voltage
Selectable Switching Frequency: 200kHz to 2.4MHz
Current Mode Control
Programmable Soft-Start
SnPb (BGA) or RoHS Compliant (LGA and BGA)
Finish
n Tiny, Low Profile, Surface Mount LGA (9mm ×
11.25mm × 2.82mm) and BGA (9mm × 11.25mm ×
3.42mm) Packages
n
n
n
n
n
n
n
n
APPLICATIONS
n
n
n
n
n
Automotive Battery Regulation
Power for Portable Products
Distributed Supply Regulation
Industrial Supplies
Wall Transformer Regulation
The LTM®8023 is a complete 2A, DC/DC step-down power
supply. Included in the package are the switching controller,
power switches, inductor, and all support components.
Operating over an input voltage range of 3.6V to 36V, the
LTM8023 supports an output voltage range of 0.8V to 10V,
and a switching frequency range of 200kHz to 2.4MHz,
each set by a single resistor. Only the bulk input and output
filter capacitors are needed to finish the design.
The low profile package enables utilization of unused
space on the bottom of PC boards for high density point
of load regulation.
The LTM8023 is packaged in a thermally enhanced, compact and low profile over-molded land grid array (LGA)
and ball grid array (BGA) packages suitable for automated
assembly by standard surface mount equipment. The
LTM8023 is available with SnPb (BGA) or RoHS compliant terminal finish.
L, LT, LTC, LTM, Linear Technology, the Linear logo, Burst Mode and µModule are registered
trademarks of Linear Technology Corporation. All other trademarks are the property of their
respective owners.
TYPICAL APPLICATION
5.5VIN to 36VIN, 3.3V/2A DC/DC µModule® Converter
VIN*
5.5V TO 36V
VIN
VOUT
AUX
22µF
BIAS
SHARE
LTM8023
PGOOD
RT
1.6
1.4
80
1.2
75
1.0
70
0.8
65
0.6
0.4
VIN = 12V
VOUT = 3.3V
f = 650 kHz
55
GND SYNC
8023 TA01
49.9k
85
60
ADJ
SELECTABLE
OPERATING
FREQUENCY
1.8
154k
50
*RUNNING VOLTAGE RANGE. PLEASE
REFER TO APPLICATIONS INFORMATION
FOR START-UP DETAILS
POWER LOSS (W)
RUN/SS
VOUT
3.3V
2A
EFFICIENCY (%)
2.2µF
Efficiency and Power Loss
90
0.01
0.1
1
LOAD CURRENT (A)
0.2
0
10
8023 TA01b
8023fj
For more information www.linear.com/LTM8023
1
LTM8023
ABSOLUTE MAXIMUM RATINGS
(Note 1)
VIN + BIAS..................................................................56V
Internal Operating Temperature
(Note 2)................................................... –40°C to 125°C
Storage Temperature.............................. –55°C to 125°C
Solder Temperature................................................ 250°C
VIN, RUN/SS Voltage..................................................40V
ADJ, RT, SHARE Voltage..............................................5V
VOUT, AUX..................................................................10V
PGOOD, SYNC...........................................................30V
BIAS...........................................................................16V
PIN CONFIGURATION
GND (BANK 3)
SHARE RT
ADJ
SHARE RT
GND (BANK 3)
7
ADJ
7
6
SYNC
PGOOD
6
SYNC
PGOOD
5
RUN/SS
5
RUN/SS
BIAS
4
3
VOUT
(BANK 2) 2
VIN
(BANK 1)
BIAS
4
AUX
AUX
3
VOUT
(BANK 2) 2
1
VIN
(BANK 1)
1
A
B
C
D
E
F
G
H
A
LGA PACKAGE
50-LEAD (11.25mm × 9mm × 2.82mm)
B
C
E
D
F
G
H
BGA PACKAGE
50-LEAD (11.25mm × 9mm × 3.42mm)
TJMAX = 125°C, θJA = 30.4°C/W, θJCbottom = 12.2°C/W,
θJCtop = 23.9°C/W, θJB = 12.1°C/W, WEIGHT = 0.9g
θ VALUES DETERMINED PER JEDEC 51-9, 51-12
TJMAX = 125°C, θJA = 32.1°C/W, θJCbottom = 14.8°C/W,
θJCtop = 23.7°C/W, θJB = 14.6°C/W, WEIGHT = 0.9g
θ VALUES DETERMINED PER JEDEC 51-9, 51-12
ORDER INFORMATION
PART NUMBER
PAD OR BALL FINISH
LTM8023EV#PBF
Au (RoHS)
PART MARKING*
DEVICE
FINISH CODE
PACKAGE
TYPE
LTM8023V
e4
LGA
MSL
RATING
3
TEMPERATURE RANGE
(Note 2)
–40°C to 85°C
LTM8023IV#PBF
Au (RoHS)
LTM8023V
e4
LGA
3
–40°C to 85°C
LTM8023MPV#PBF
Au (RoHS)
LTM8023MPV
e4
LGA
3
–55°C to 125°C
LTM8023EY#PBF
SAC305 (RoHS)
LTM8023Y
e1
BGA
3
–40°C to 85°C
LTM8023IY#PBF
SAC305 (RoHS)
LTM8023Y
e1
BGA
3
–40°C to 85°C
LTM8023IY
SnPb (63/37)
LTM8023Y
e0
BGA
3
–40°C to 85°C
LTM8023MPY#PBF
SAC305 (RoHS)
LTM8023Y
e1
BGA
3
–55°C to 125°C
LTM8023MPY
SnPb (63/37)
LTM8023Y
e0
BGA
3
–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
• Terminal Finish Part Marking:
www.linear.com/leadfree
• LGA and BGA Package and Tray Drawings:
www.linear.com/packaging
2
8023fj
For more information www.linear.com/LTM8023
LTM8023
ELECTRICAL
CHARACTERISTICS
The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C. VIN = 10V, VRUN/SS = 10V, VBIAS = 3V, RT = 60.4k, COUT = 4.7µF unless
otherwise specified.
SYMBOL
PARAMETER
VIN
Input DC Voltage
VOUT
Output DC Voltage
RADJ(MIN)
Minimum Allowable RADJ
(Note 4)
IOUT
Continuous Output DC Current
4 ≤ VIN ≤ 36, COUT = 51µF
IQVIN
VIN Quiescent Current
VRUN/SS = 0.2V, RT = 174k
VBIAS = 3V, Not Switching, RT = 174k (E, I)
VBIAS = 3V, Not Switching, RT = 174k (MP)
VBIAS = 0V, Not Switching, RT = 174k
l
l
VRUN/SS = 0.2V, RT = 174k
VBIAS = 3V, Not Switching, RT = 174k (E, I)
VBIAS = 3V, Not Switching, RT = 174k (MP)
VBIAS = 0V, Not Switching, RT = 174k
l
l
IQBIAS
BIAS Quiescent Current
CONDITIONS
MIN
l
TYP
3.6
0A < IOUT ≤ 2A, RADJ Open, COUT = 51µF (Note 3)
0A < IOUT ≤ 2A, RADJ = 43.2k, COUT = 51µF (Note 3)
MAX
36
0.8
10
UNITS
V
V
V
42.2
kΩ
0
2
A
0.1
25
25
85
0.5
60
350
120
µA
µA
µA
µA
0.03
50
50
1
0.5
120
200
5
µA
µA
µA
µA
ΔVOUT/VOUT
Line Regulation
5 ≤ VIN ≤ 36, IOUT = 1A, VOUT = 3.3V, COUT = 51µF
0.1
ΔVOUT/VOUT
Load Regulation
VIN = 24V, 0 ≤ IOUT ≤ 2A, VOUT = 3.3V, COUT = 51µF
0.4
%
VIN = 24V, IOUT = 2A, VOUT = 3.3V, COUT = 51µF
10
mV
325
kHz
VOUT(AC_RMS) Output Ripple (RMS)
fSW
Switching Frequency
RT = 113k, COUT = 51µF
ISC(OUT)
Output Short Circuit Current
VIN = 36V, VOUT = 0V (Note 5)
VADJ
Voltage at ADJ Pin
COUT = 51µF
VBIAS(MIN)
Minimum BIAS Voltage for Proper
Operation
IADJ
Current Out of ADJ Pin
ADJ = 1V, COUT = 51µF
IRUN/SS
RUN/SS Pin Current
VRUN/SS = 2.5V
VIH(RUN/SS)
RUN/SS Input High Voltage
COUT = 51µF
2.9
l
765
A
790
805
mV
2.3
2.8
V
2
5
µA
10
2.5
VIL(RUN/SS)
RUN/SS Input Low Voltage
COUT = 51µF
PGOOD Threshold
VOUT Rising
730
0.2
IPGOOD(O)
PGOOD Leakage
VPGOOD = 30V
0.1
IPGOOD(SINK)
PGOOD Sink Current
VPGOOD = 0.4V
VSYNCIL
SYNC Input Low Threshold
fSYNC = 550kHz, COUT = 51µF
VSYNCIH
SYNC Input High Threshold
fSYNC = 550kHz, COUT = 51µF
ISYNCBIAS
SYNC Pin Bias Current
VSYNC = 0V
200
µA
V
VPGOOD(TH)
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 LTM8023E is guaranteed to meet performance specifications
from 0°C to 85°C ambient. Specifications over the full –40°C to
85°C ambient operating temperature range are assured by design,
characterization and correlation with statistical process controls. The
LTM8023I is guaranteed to meet specifications over the full –40°C to 85°C
ambient operating temperature range. The LTM8023MP is guaranteed to
%
1
800
µA
µA
0.5
0.7
V
mV
V
V
0.1
µA
meet specifications over the full –55°C to 125°C 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.
Note 3: COUT = 51µF is composed of a 4.7µF ceramic capacitor in parallel
with a 47µF electrolytic.
Note 4: Guaranteed by design.
Note 5: Short circuit current at VIN = 36V is guaranteed by characterization
and correlation. 100% tested at VIN = 10V
8023fj
For more information www.linear.com/LTM8023
3
LTM8023
TYPICAL PERFORMANCE CHARACTERISTICS
Efficiency (8VOUT)
90
VOUT = 8V
90
70
60
50
40
30
20
0.01
0.1
OUTPUT CURRENT (A)
75
70
65
50
0.01
20
0.1
OUTPUT CURRENT (A)
8023 G01
Minimum Required Input Voltage
vs Output Voltage
75
70
65
60
12VIN
24VIN
36VIN
55
1
VOUT = 3.3V
80
60
12VIN
24VIN
36VIN
Efficiency (3.3VOUT)
85
80
EFFICIENCY (%)
EFFICIENCY (%)
90
VOUT = 5V
85
80
5VIN
12VIN
24VIN
36VIN
55
50
0.01
1
0.1
OUTPUT CURRENT (A)
8023 G02
36VIN Start-Up Waveforms
(5VOUT)
1
8023 G03
36VIN Start-Up Waveforms
(3.3VOUT)
IOUT = 2A
18
16
INPUT VOLTAGE (V)
Efficiency (5VOUT)
EFFICIENCY (%)
100
TA = 25°C unless otherwise noted
14
OPERATING FREQUENCY
AS RECOMMENDED
IN TABLE 1
12
10
VOUT
2V/DIV
IIN
0.2A/DIV
VOUT
2V/DIV
IIN
0.2A/DIV
RUN/SS
5V/DIV
RUN/SS
5V/DIV
VIN = 36V
IOUT = 2A
VBIAS = 3V
8
6
50µs/DIV
8023 G05
VIN = 36V
IOUT = 2A
VBIAS = 3V
50µs/DIV
8023 G06
4
2
0
2
4
6
OUTPUT VOLTAGE (V)
8
10
8023 G04
Input Current vs Output Current
1600
VOUT = 8V
1400
800
600
400
12VIN
24VIN
36VIN
200
4
VOUT = 5V
0
500
1000
1500
OUTPUT CURRENT (mA)
2000
8023 G07
VOUT = 3.3V
1800
1600
INPUT CURRENT (mA)
1000
0
Input Current vs Output Current
2000
1000
1200
INPUT CURRENT (mA)
INPUT CURRENT (mA)
Input Current vs Output Current
1200
800
12VIN
24VIN
36VIN
600
400
1400
1200
5VIN
12VIN
24VIN
36VIN
1000
800
600
400
200
200
0
0
500
1000
1500
OUTPUT CURRENT (mA)
2000
8023 G08
0
0
500
1000
1500
OUTPUT CURRENT (mA)
2000
8023 G09
8023fj
For more information www.linear.com/LTM8023
LTM8023
TYPICAL PERFORMANCE CHARACTERISTICS
Output Short-Circuit Current
vs Input Voltage
BIAS Current vs Load Current
30
3200
2500
25
2600
2400
2200
2000
20
3.3VOUT
5VOUT
8VOUT
15
10
1500
1000
500
5
1800
0
10
20
30
INPUT VOLTAGE (V)
2500
0
40
0
500
1000
1500
LOAD CURRENT (mA)
Load Current
vs Input Voltage (5VOUT, LGA)
1500
1000
0
10
20
30
INPUT VOLTAGE (V)
40
8023 G13
1500
1000
0
40
25°C
40°C
85°C
0
10
8023 G14
20
30
INPUT VOLTAGE (V)
80
60
70
TEMPERATURE RISE (°C)
35
30
25
20
15
10
12VIN
24VIN
36VIN
5
1000
1500
CURRENT (mA)
2000
2500
8023 G16
TEMPERATURE RISE (°C)
50
40
40
30
20
12VIN
24VIN
36VIN
10
0
40
8023 G15
8VOUT Junction Temperature
vs Load (LGA)
45
TEMPERATURE RISE (°C)
20
30
INPUT VOLTAGE (V)
Load Current
vs Input Voltage (3.3VOUT, LGA)
5VOUT Junction Temperature
vs Load (LGA)
50
500
10
500
25°C
40°C
85°C
3.3VOUT Junction Temperature
vs Load (LGA)
0
0
2000
500
0
25°C
40°C
85°C
8023 G11
2500
LOAD CURRENT (mA)
LOAD CURRENT (mA)
0
2000
8023 G10
2000
0
Maximum Load Current
vs Input Voltage (8VOUT, LGA)
2000
LOAD CURRENT (mA)
2800
BIAS CURRENT (mA)
OUTPUT CURRENT (mA)
3000
1600
TA = 25°C unless otherwise noted
0
500
1000
1500
CURRENT (mA)
2000
2500
8023 G17
60
50
40
30
20
16VIN
24VIN
36VIN
10
0
0
500
1000
1500
CURRENT (mA)
2000
2500
8023 G18
8023fj
For more information www.linear.com/LTM8023
5
LTM8023
TYPICAL PERFORMANCE CHARACTERISTICS
5VOUT Temperature Rise vs
Load Current (BGA)
60
50
50
40
30
20
12VIN
24VIN
36VIN
0
0
6
500
1000
1500
2000
LOAD CURRENT (mA)
2500
8023 G19
8VOUT Temperature Rise vs
Load Current (BGA)
90
80
TEMPERATURE RISE (°C)
60
TEMPERATURE RISE (°C)
TEMPERATURE RISE (°C)
3.3VOUT Temperature Rise vs
Load Current (BGA)
10
TA = 25°C unless otherwise noted
40
30
20
12VIN
24VIN
36VIN
10
0
0
500
1000
1500
2000
LOAD CURRENT (mA)
2500
8023 G20
70
60
50
40
30
20
18VIN
24VIN
36VIN
10
0
0
500
1000
1500
2000
LOAD CURRENT (mA)
2500
8023 G21
8023fj
For more information www.linear.com/LTM8023
LTM8023
PIN FUNCTIONS
VIN (Bank 1): The VIN pin supplies current to the LTM8023’s
internal regulator and to the internal power switch. This
pin must be locally bypassed with an external, low ESR
capacitor of at least 2.2µF.
VOUT (Bank 2): Power Output Pins. Apply the output filter
capacitor and the output load between these pins and
GND pins.
AUX (Pin F5): Low Current Voltage Source for BIAS. The
VAUX pin is internally connected to VOUT and is placed
adjacent to the BIAS pin to ease printed circuit board
routing. Although this pin is internally connected to VOUT,
do NOT connect this pin to the load. If this pin is not tied
to BIAS, leave it floating.
large impact on the thermal performance of the part. See
the PCB Layout and Thermal Consideration sections for
more details. Return the feedback divider (RADJ) to this net.
RT (Pin G7): The RT pin is used to program the switching
frequency of the LTM8023 by connecting a resistor from
this pin to ground. The Applications Information section of
the data sheet includes a table to determine the resistance
value based on the desired switching frequency. Minimize
capacitance at this pin.
SHARE (Pin F7): Tie this to the SHARE pin of another
LTM8023 when paralleling the outputs. Otherwise, do not
connect (leave floating).
BIAS (Pin G5): The BIAS pin connects to the internal power
bus. Connect to a power source greater than 2.8V. If the
output is greater than 2.8V, connect this pin there. If the
output voltage is less, connect this to a voltage source
between 2.8V and 16V. Also, make sure that BIAS + VIN
is less than 56V.
SYNC (Pin G6): This is the external clock synchronization
input. Ground this pin for low ripple Burst Mode® operation
at low output loads. Tie to a stable voltage source greater
than 0.7V to disable Burst Mode operation. Do not leave
this pin floating. Tie to a clock source for synchronization.
Clock edges should have rise and fall times faster than 1µs.
See synchronizing section in Applications Information.
RUN/SS (Pin H5): Tie RUN/SS pin to ground to shut down
the LTM8023. Tie to 2.5V or more for normal operation.
If the shutdown feature is not used, tie this pin to the VIN
pin. RUN/SS also provides a soft-start function; see the
Applications Information section.
PGOOD (Pin H6): The PGOOD pin is the open-collector
output of an internal comparator. PG remains low until
the ADJ pin is within 10% of the final regulation voltage.
PG output is valid when VIN is above 3.6V and RUN/SS is
high. If this function is not used, leave this pin floating.
GND (Bank 3): Tie these GND pins to a local ground plane
below the LTM8023 and the circuit components. In most
applications, the bulk of the heat flow out of the LTM8023
is through these pads, so the printed circuit design has a
ADJ (Pin H7): The LTM8023 regulates its ADJ pin to 0.79V.
Connect the adjust resistor from this pin to ground. The
value of RADJ is given by the equation RADJ = 394.21/
(VOUT – 0.79), where RADJ is in kΩ.
8023fj
For more information www.linear.com/LTM8023
7
LTM8023
BLOCK DIAGRAM
VIN
VOUT
4.7µH
0.1µF
4.7pF
499k
10µF
AUX
BIAS
SHARE
RUN/SS
PGOOD
CURRENT MODE
CONTROLLER
SYNC
GND
RT
ADJ
8023 BD
8
8023fj
For more information www.linear.com/LTM8023
LTM8023
OPERATION
The LTM8023 is a standalone nonisolated step-down
switching DC/DC power supply. It can deliver up to 2A of
DC output current with only bulk external input and output
capacitors. This module provides a precisely regulated
output voltage programmable via one external resistor
from 0.8VDC to 10VDC. The input voltage range is 3.6V to
36V. Given that the LTM8023 is a step-down converter,
make sure that the input voltage is high enough to support
the desired output voltage and load current. A simplified
Block Diagram is given on the previous page.
The LTM8023 contains a current mode controller, power
switching element, power inductor, power Schottky diode
and a modest amount of input and output capacitance.
The LTM8023 is a fixed frequency PWM regulator. The
switching frequency is set by simply connecting the
appropriate resistor value from the RT pin to GND.
An internal regulator provides power to the control circuitry. The bias regulator normally draws power from the
VIN pin, but if the BIAS pin is connected to an external
voltage higher than 2.8V, bias power will be drawn from
the external source (typically the regulated output voltage). This improves efficiency. The RUN/SS pin is used
to place the LTM8023 in shutdown, disconnecting the
output and reducing the input current to less than 1µA.
To further optimize efficiency, the LTM8023 automatically
switches to Burst Mode operation in light load situations.
Between bursts, all circuitry associated with controlling
the output switch is shut down reducing the input supply
current to 50µA in a typical application. The oscillator
reduces the LTM8023’s operating frequency when the
voltage at the ADJ pin is low. This frequency foldback helps
to control the output current during start-up and overload.
The LTM8023 contains a power good comparator which
trips when the ADJ pin is at 92% of its regulated value.
The PGOOD output is an open-collector transistor that is
off when the output is in regulation, allowing an external
resistor to pull the PGOOD pin high. Power good is valid
when the LTM8023 is enabled and VIN is above 3.6V.
APPLICATIONS INFORMATION
For most applications, the design process is straight
forward, summarized as follows:
1.Look at Table 1 and find the row that has the desired
input range and output voltage.
2.Apply the recommended CIN, COUT, RADJ and RT values.
3.Connect BIAS as indicated.
While these component combinations have been tested
for proper operation, it is incumbent upon the user to
verify proper operation over the intended system’s line,
load and environmental conditions.
Capacitor Selection Considerations
The CIN and COUT capacitor values in Table 1 are the
minimum recommended values for the associated operating conditions. Applying capacitor values below those
indicated in Table 1 is not recommended, and may result
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.
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 applied voltage and give dependable service. Other types,
including Y5V and Z5U have very large temperature and
voltage coefficients of capacitance. In an application circuit they may have only a small fraction of their nominal
capacitance resulting in much higher output voltage ripple
than expected.
8023fj
For more information www.linear.com/LTM8023
9
LTM8023
APPLICATIONS INFORMATION
Table 1. Recommended Component Values and Configuration (TA = 25°C)
VIN
VOUT
CIN
COUT
RADJ
BIAS
fOPTIMAL (kHz)
RT(OPTIMAL)
fMAX (kHz)
RT(MIN)
3.6V to 36V
0.82V
10µF
200µF 1206
13M
≥2.8V, <16V
250
150k
250
150k
3.6V to 36V
1.00V
10µF
147µF 1206
1.87M
≥2.8V, <16V
300
124k
300
124k
3.6V to 36V
1.20V
10µF
100µF 1206
953k
≥2.8V, <16V
350
105k
350
105k
88.7k
3.6V to 36V
1.50V
10µF
100µF 1206
549k
≥2.8V, <16V
400
88.7k
400
3.6V to 36V
1.80V
4.7µF
100µF 1206
383k
≥2.8V, <16V
450
79k
450
79k
3.6V to 36V
2.00V
2.2µF
68µF 1206
324k
≥2.8V, <16V
450
79k
500
69.8k
3.6V to 36V
2.20V
2.2µF
47µF 1206
274k
≥2.8V, <16V
500
69.8k
550
61.9k
4.1V to 36V
2.50V
2.2µF
47µF 1206
226k
≥2.8V, <16V
550
61.9k
615
54.9k
5.5V to 36V
3.30V
2.2µF
22µF 1206
154k
AUX
650
49.9k
750
42.2k
7.5V to 36V
5.00V
2.2µF
10µF 0805
93.1k
AUX
650
49.9k
890
34.8k
3.6V to 15V
0.82V
10µF
200µF 1206
13M
VIN
350
105k
650
49.9k
3.6V to 15V
1.00V
10µF
147µF 1206
1.87M
VIN
400
88.7k
725
43.2k
3.6V to 15V
1.20V
10µF
100µF 1206
953k
VIN
450
79k
800
39.2k
3.6V to 15V
1.50V
10µF
100µF 1206
549k
VIN
450
79k
1000
29.4k
3.6V to 15V
1.80V
4.7µF
100µF 1206
383k
VIN
450
79k
1100
26.7k
3.6V to 15V
2.00V
2.2µF
68µF 1206
324k
VIN
450
79k
1200
23.7k
3.6V to 15V
2.20V
2.2µF
47µF 1206
274k
VIN
500
69.8k
1300
21.0k
3.6V to 15V
2.50V
2.2µF
47µF 1206
226k
VIN
550
61.9k
1450
18.2k
5.5V to 15V
3.30V
2.2µF
22µF 1206
154k
AUX
650
49.9k
1400
19.6k
7.5V to 15V
5.00V
2.2µF
10µF 0805
93.1k
AUX
650
49.9k
1200
23.7k
9V to 24V
0.82V
10µF
200µF 1206
13M
≥2.8V, <16V
250
150k
250
150k
9V to 24V
1.00V
10µF
147µF 1206
1.87M
≥2.8V, <16V
300
124k
450
79k
9V to 24V
1.20V
2.2µF
100µF 1206
953k
≥2.8V, <16V
450
79k
500
69.8k
9V to 24V
1.50V
2.2µF
100µF 1206
549k
≥2.8V, <16V
450
79k
615
54.9k
9V to 24V
1.80V
2.2µF
100µF 1206
383k
≥2.8V, <16V
450
79k
700
44.2k
9V to 24V
2.00V
2.2µF
68µF 1206
324k
≥2.8V, <16V
450
79k
750
42.2k
9V to 24V
2.20V
2.2µF
47µF 1206
274k
≥2.8V, <16V
500
69.8k
800
39.2k
9V to 24V
2.50V
2.2µF
47µF 1206
226k
≥2.8V, <16V
550
61.9k
890
34.8k
9V to 24V
3.30V
2.2µF
22µF 1206
154k
AUX
650
49.9k
1150
25.5k
9V to 24V
5.00V
2.2µF
10µF 0805
93.1k
AUX
650
49.9k
1000
29.4k
14.5V to 24V
8.00V
2.2µF
10µF 0805
53.6k
AUX
650
49.9k
800
39.2k
18V to 36V
0.82V
10µF
200µF 1206
13M
≥2.8V, <16V
250
150k
250
150k
18V to 36V
1.00V
10µF
147µF 1206
1.87M
≥2.8V, <16V
300
124k
300
124k
18V to 36V
1.20V
2.2µF
100µF 1206
953k
≥2.8V, <16V
350
105k
350
105k
18V to 36V
1.50V
2.2µF
100µF 1206
549k
≥2.8V, <16V
400
88.7k
400
88.7k
18V to 36V
1.80V
2.2µF
100µF 1206
383k
≥2.8V, <16V
450
79k
450
79k
18V to 36V
2.00V
2.2µF
68µF 1206
324k
≥2.8V, <16V
450
79k
500
69.8k
18V to 36V
2.20V
2.2µF
47µF 1206
274k
≥2.8V, <16V
450
79k
550
61.9k
18V to 36V
2.50V
2.2µF
47µF 1206
226k
≥2.8V, <16V
500
69.8k
615
54.9k
18V to 36V
3.30V
2.2µF
22µF 1206
154k
AUX
650
49.9k
750
42.2k
18V to 36V
5.00V
2.2µF
10µF 0805
93.1k
AUX
800
39.2k
890
34.8k
18V to 36V
8.00V
2.2µF
10µF 0805
53.6k
AUX
650
49.9k
800
39.2k
20V to 36V
10.00V
2.2µF
10µF 0805
42.2k
AUX
615
54.9k
750
42.2k
4.75V to 32V
–3.30V
2.2µF
22µF 1206
154k
AUX
550
61.9k
800
39.2k
7V to 31V
–5.00V
2.2µF
10µF 0805
93.1k
AUX
800
39.2k
1100
26.7k
15V to 28V
–8.00V
2.2µF
10µF 0805
53.6k
AUX
800
39.2k
1600
15.8k
A bulk input capacitor is required.
10
8023fj
For more information www.linear.com/LTM8023
LTM8023
APPLICATIONS INFORMATION
Ceramic capacitors are also piezoelectric. In Burst Mode
operation, the LTM8023’s switching frequency depends
on the load current, and can excite a ceramic capacitor
at audio frequencies, generating audible noise. Since the
LTM8023 operates at a lower current limit during Burst
Mode operation, the noise is typically very quiet to a
casual ear.
If this audible noise is unacceptable, use a high performance
electrolytic capacitor at the output. The input capacitor can
be a parallel combination of a 2.2µF ceramic capacitor and
a low cost electrolytic capacitor.
A final precaution regarding ceramic capacitors concerns
the maximum input voltage rating of the LTM8023. A
ceramic input capacitor combined with trace or cable
inductance forms a high Q (under damped) tank circuit.
If the LTM8023 circuit is plugged into a live supply, the
input voltage can ring to twice its nominal value, possibly exceeding the device’s rating. This situation is easily
avoided; see the Hot-Plugging Safely section.
Frequency Selection
The LTM8023 uses a constant frequency PWM architecture
that can be programmed to switch from 200kHz to 2.4MHz
by using a resistor tied from the RT pin to ground. Table 2
provides a list of RT resistor values and their resultant
frequencies.
Table 2. Switching Frequency vs RT Value
SWITCHING FREQUENCY (MHz)
RT VALUE (kΩ)
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
1.2
1.4
1.6
1.8
2.0
2.2
2.4
187
124
88.7
69.8
56.2
46.4
39.2
34.6
29.4
23.7
19.6
15.8
13.3
11.5
9.76
8.66
Operating Frequency Trade-Offs
It is recommended that the user apply the optimal RT
value given in Table 1 for the input and output operating
condition. System level or other considerations, however,
may necessitate another operating frequency. While the
LTM8023 is flexible enough to accommodate a wide range
of operating frequencies, a haphazardly chosen one may
result in undesirable operation under certain operating or
fault conditions. A frequency that is too high can reduce
efficiency, generate excessive heat or even damage the
LTM8023 if the output is overloaded or short circuited. A
frequency that is too low can result in a final design that has
too much output ripple or too large of an output capacitor.
The maximum frequency (and attendant RT value) at which
the LTM8023 should be allowed to switch is given in Table 1
in the f(MAX) column, while the recommended frequency
(and RT value) for optimal efficiency over the given input
condition is given in the fOPTIMAL column.
There are additional conditions that must be satisfied if
the synchronization function is used. Please refer to the
Synchronization section for details.
BIAS Pin Considerations
The BIAS pin is used to provide drive power for the internal
power switching stage and operate internal circuitry. For
proper operation, it must be powered by at least 2.8V. If
the output voltage is programmed to be 2.8V or higher,
simply tie BIAS to VOUT. If VOUT is less than 2.8V, BIAS
can be tied to VIN or some other voltage source. In all
cases, ensure that the maximum voltage at the BIAS pin
is both less than 16V and the sum of VIN and BIAS is less
than 56V. If BIAS power is applied from a remote or noisy
voltage source, it may be necessary to apply a decoupling
capacitor locally to the LTM8023.
8023fj
For more information www.linear.com/LTM8023
11
LTM8023
APPLICATIONS INFORMATION
Load Sharing
Minimum Input Voltage
Two or more LTM8023’s may be paralleled to produce
higher currents. To do this, tie the VIN, ADJ, VOUT and
SHARE pins of all the paralleled LTM8023’s together. To
ensure that paralleled modules start up together, the RUN/
SS pins may be tied together, as well. If the RUN/SS pins
are not tied together, make sure that the same valued softstart capacitors are used for each module. An example
of two LTM8023 modules configured for load sharing is
given in the Typical Applications section.
The LTM8023 is a step-down converter, so a minimum
amount of headroom is required to keep the output in
regulation. In addition, the input voltage required to turn
on is higher than that required to run, and depends upon
whether the RUN/SS is used. As shown in Figure 2, it
takes only about 3.5VIN for the LTM8023 to run a 3.3V
output at light load. If RUN/SS is tied to VIN, a 5.5V input
voltage is required to start. If VIN is allowed to settle in
the operating region first then the RUN/SS pin is enabled,
the minimum input voltage to start at light load is lower,
about 4.2V. A similar curve for 5VOUT operation is also
provided in Figure 2.
For current sharing applications using multiple LTM8023s,
the ADJ pins for all regulators may be combined using
one resistor to ground as determined by:
6.0
394.21
N
R ADJ =
V
OUT – 0.79
where N is the number of paralleled modules and RADJ
is in kΩ.
INPUT VOLTAGE (V)
5.5
Burst Mode Operation
4.5
RUN/SS ENABLED
4.0
3.5
Burst Mode operation is enabled by tying SYNC to GND.
To disable Burst Mode operation, tie SYNC to a stable
voltage above 0.7V or synchronize to an external clock.
Do not leave the SYNC pin floating.
VOUT = 3.3V
TA = 25°C
f = 650kHz
TO RUN
3.0
500
1000
1500
LOAD CURRENT (mA)
0
2000
7.5
7.0
INPUT VOLTAGE (V)
To enhance efficiency at light loads, the LTM8023 automatically switches to Burst Mode operation which keeps
the output capacitor charged to the proper voltage while
minimizing the input quiescent current. During Burst Mode
operation, the LTM8023 delivers single cycle bursts of
current to the output capacitor followed by sleep periods
where the output power is delivered to the load by the output
capacitor. In addition, VIN and BIAS quiescent currents are
reduced to typically 25µA and 50µA respectively during
the sleep time. As the load current decreases towards a no
load condition, the percentage of time that the LTM8023
operates in sleep mode increases and the average input
current is greatly reduced, resulting in higher efficiency.
12
TO START
5.0
6.5
TO START
6.0
RUN/SS ENABLED
5.5
5.0
VOUT = 5V
TA = 25°C
f = 650kHz
TO RUN
0
500
1000
1500
2000
LOAD CURRENT (mA)
8023 F02
Figure 2. The LTM8023 Needs More Voltage to Start Than to Run
8023fj
For more information www.linear.com/LTM8023
LTM8023
APPLICATIONS INFORMATION
Soft-Start
Shorted Input Protection
The RUN/SS pin can be used to soft-start the LTM8023,
reducing the maximum input current during start-up.
The RUN/SS pin is driven through an external RC filter
to create a voltage ramp at this pin. Figure 3 shows the
start-up and shutdown waveforms with the soft-start
circuit. By choosing an appropriate RC time constant,
the peak start-up current can be reduced to the current
that is required to regulate the output, with no overshoot.
Choose the value of the resistor so that it can supply at
least 20µA when the RUN/SS pin reaches 2.5V.
Care needs to be taken in systems where the output will be
held high when the input to the LTM8023 is absent. This
may occur in battery charging applications or in battery
backup systems where a battery or some other supply is
diode OR-ed with the LTM8023’s output. If the VIN pin is
allowed to float and the RUN/SS pin is held high (either
by a logic signal or because it is tied to VIN), then the
LTM8023’s internal circuitry will pull its quiescent current through its internal power switch. This is fine if your
system can tolerate a few milliamps in this state. If you
ground the RUN/SS pin, the internal power switch current will drop to essentially zero. However, if the VIN pin
is grounded while the output is held high, then parasitic
diodes inside the LTM8023 can pull large currents from
the output through the VIN pin. Figure 4 shows a circuit
that will run only when the input voltage is present and
that protects against a shorted or reversed input.
IL
1A/DIV
RUN
15k
RUN/SS
0.22µF
VRUN/SS
2V/DIV
GND
VOUT
2V/DIV
VIN
VIN
VOUT
RUN/SS
2ms/DIV
8023 F03
AUX
LTM8023
Figure 3. To Soft-Start the LTM8023, Add a
Resistor and Capacitor to the RUN/SS Pin
VOUT
RT SYNC GND
BIAS
ADJ
8023 F04
Synchronization
The internal oscillator of the LTM8023 can be synchronized
by applying an external 250kHz to 2MHz clock to the SYNC
pin. Do not leave this pin floating. The resistor tied from the
RT pin to ground should be chosen such that the LTM8023
oscillates 20% lower than the intended synchronization
frequency (see the Frequency Selection section).
Figure 4. The Input Diode Prevents a Shorted Input from
Discharging a Backup Battery Tied to the Output. It Also Protects
the Circuit from a Reversed Input. The LTM8023 Runs Only
When the Input is Present.
The LTM8023 will not enter Burst Mode operation while
synchronized to an external clock, but will instead skip
pulses to maintain regulation.
8023fj
For more information www.linear.com/LTM8023
13
LTM8023
APPLICATIONS INFORMATION
PCB Layout
Most of the headaches associated with PCB layout have
been alleviated or even eliminated by the high level of
integration of the LTM8023. The LTM8023 is nevertheless a switching power supply, and care must be taken to
minimize EMI and ensure proper operation. Even with the
high level of integration, you may fail to achieve specified
operation with a haphazard or poor layout. See Figure 5
for a suggested layout.
GND
RT
RADJ
SHARE
RUN/SS
AUX BIAS
COUT
CIN
VIN
8023 F05
Figure 5. Layout Showing Suggested External Components, GND
Plane and Thermal Vias
Ensure that the grounding and heatsinking are acceptable.
A few rules to keep in mind are:
1.Place the RADJ and RT resistors as close as possible to
their respective pins.
2.Place the CIN capacitor as close as possible to the VIN
and GND connection of the LTM8023.
3.Place the COUT capacitor as close as possible to the
VOUT and GND connection of the LTM8023.
14
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 LTM8023.
6.Use vias to connect the GND copper area to the boards
internal ground plane. Liberally distribute these GND vias
to provide both a good ground connection and thermal
path to the internal planes of the printed circuit board.
Hot-Plugging Safely
SYNC
PGOOD
VOUT
4.Place the CIN and COUT capacitors such that their
ground current flow directly adjacent or underneath
the LTM8023.
The small size, robustness and low impedance of ceramic
capacitors make them an attractive option for the input
bypass capacitor of LTM8023. However, these capacitors
can cause problems if the LTM8023 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 voltage at the VIN pin of the LTM8023 can ring to twice the
nominal input voltage, possibly exceeding the LTM8023’s
rating and damaging the part. If the input supply is poorly
controlled or the user will be plugging the LTM8023 into
an energized supply, the input network should be designed
to prevent this overshoot. Figure 6 shows the waveforms
that result when an LTM8023 circuit is connected to a 24V
supply through six feet of 24-gauge twisted pair. The first
plot is the response with a 2.2µF ceramic capacitor at the
input. The input voltage rings as high as 35V and the input
current peaks at 20A. One method of damping the tank
circuit is to add another capacitor with a series resistor to
the circuit. In Figure 6c an aluminum electrolytic capacitor
has been added. This capacitor’s high equivalent series
resistance damps the circuit and eliminates the voltage
overshoot. The extra capacitor improves low frequency
8023fj
For more information www.linear.com/LTM8023
LTM8023
APPLICATIONS INFORMATION
CLOSING SWITCH
SIMULATES HOT PLUG
IIN
VIN
+
LOW
IMPEDANCE
ENERGIZED
24V SUPPLY
DANGER
RINGING VIN MAY EXCEED
ABSOLUTE MAXIMUM RATING
LTM8023
4.7µF
IIN
10A/DIV
STRAY
INDUCTANCE
DUE TO 6 FEET
(2 METERS) OF
TWISTED PAIR
0.7Ω
+
VIN
20V/DIV
0.1µF
20µs/DIV
(6a)
LTM8023
VIN
20V/DIV
4.7µF
IIN
10A/DIV
(6b)
+
22µF
35V
AI.EI.
+
LTM8023
20µs/DIV
VIN
20V/DIV
4.7µF
IIN
10A/DIV
(6c)
20µs/DIV
8023 F06
Figure 6. A Well Chosen Input Network Prevents Input Voltage Overshoot and Ensures Reliable
Operation When the LTM8023 is Connected to a Live Supply
ripple filtering and can slightly improve the efficiency of the
circuit, though it is likely to be the largest component in the
circuit. An alternative solution is shown in Figure 6b. A 0.7Ω
resistor is added in series with the input to eliminate the
voltage overshoot (it also reduces the peak input current).
A 0.1µF capacitor improves high frequency filtering. This
solution is smaller and less expensive than the electrolytic
capacitor. For high input voltages its impact on efficiency
is minor, reducing efficiency less than one-half percent
for a 5V output at full load operating from 24V.
8023fj
For more information www.linear.com/LTM8023
15
LTM8023
APPLICATIONS INFORMATION
Thermal Considerations
The LTM8023 output current may need to be derated if
it is required to operate in a high ambient temperature or
deliver a large amount of continuous power. The amount
of current derating is dependent upon the input voltage,
output power and ambient temperature. The temperature
rise curves given in the Typical Performance Characteristics section can be used as a guide. These curves were
generated by an LTM8023 mounted to a 33cm2 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.
The thermal resistance numbers listed in the Pin Configuration are based on modeling the µModule package
mounted on a test board specified per JESD51-9 “Test
Boards for Area Array Surface Mount Package Thermal
Measurements.” The thermal coefficients provided in this
page are based on JESD 51-12 “Guidelines for Reporting
and Using Electronic Package Thermal Information.”
For increased accuracy and fidelity to the actual application,
many designers use FEA to predict thermal performance.
To that end, the Pin Configuration typically gives four
thermal coefficients:
• θJA – Thermal resistance from junction to ambient.
• θJCbottom – Thermal resistance from junction to the
bottom of the product case.
• θJCtop – Thermal resistance from junction to top of
the product case.
• θJB – Thermal resistance from junction to the printed
circuit board.
While the meaning of each of these coefficients may seem
to be intuitive, JEDEC has defined each to avoid confusion and inconsistency. These definitions are given in
JESD 51-12, and are quoted or paraphrased in the following:
• θJA is the natural convection junction-to-ambient air
thermal resistance measured in a one cubic foot sealed
enclosure. This environment is sometimes referred to as
16
“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.
• θJCbottom is the junction-to-board thermal resistance
with all of the component power dissipation flowing
through the bottom of the package. In the typical
µModule regulator, the bulk of the heat flows out the
bottom of the package, but there is always heat flow out
into the ambient environment. 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.
• θJCtop is determined with nearly all of the component
power dissipation flowing through the top of the package. As the electrical connections of the typical µModule
regulator are on the bottom of the package, it is rare
for an application to operate such that most of the heat
flows from the junction to the top of the part. As in the
case of θJCbottom, this value may be useful for comparing
packages but the test conditions don’t generally match
the user’s application.
• θJB is the junction-to-board thermal resistance where
almost all of the heat flows through the bottom of the
µModule regulator and into the board, and is really the
sum of the θJCbottom and the thermal resistance of the
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 most appropriate way to use the coefficients is when
running a detailed thermal analysis, such as FEA, which
considers all of the thermal resistances simultaneously.
None of them can be individually used to accurately predict the thermal performance of the product, so it would
be inappropriate to attempt to use any one coefficient to
correlate to the junction temperature versus load graphs
given in the LTM8023 data sheet.
8023fj
For more information www.linear.com/LTM8023
LTM8023
APPLICATIONS INFORMATION
A graphical representation of these thermal resistances
is given in Figure 7.
The blue resistances are contained within the µModule
regulator, and the green are outside.
The die temperature of the LTM8023 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 LTM8023. The bulk of the heat flow out of the
LTM8023 is through the bottom of the module and the LGA
pads into the printed circuit board. Consequently a poor
printed circuit board design can cause excessive heating,
resulting in impaired performance or reliability. Please
refer to the PCB Layout section for printed circuit board
design suggestions.
Finally, be aware that at high ambient temperatures the
internal Schottky diode will have significant leakage current
increasing the quiescent current of the LTM8023.
JUNCTION-TO-AMBIENT RESISTANCE (JESD 51-9 DEFINED BOARD)
JUNCTION-TO-CASE (TOP)
RESISTANCE
JUNCTION
CASE (TOP)-TO-AMBIENT
RESISTANCE
JUNCTION-TO-BOARD RESISTANCE
JUNCTION-TO-CASE
CASE (BOTTOM)-TO-BOARD
(BOTTOM) RESISTANCE
RESISTANCE
At
BOARD-TO-AMBIENT
RESISTANCE
8023 F07
µMODULE REGULATOR
Figure 7
8023fj
For more information www.linear.com/LTM8023
17
LTM8023
TYPICAL APPLICATIONS
0.82V Step-Down Converter
VIN*
3.6V TO 15V
VIN
1.8V Step-Down Converter
VOUT
BIAS
10µF
200µF
RUN/SS
VOUT
0.82V
2A
VIN*
3.6V TO 15V
VIN
VOUT
BIAS
4.7µF
100µF
RUN/SS
AUX
AUX
LTM8023
LTM8023
SHARE
PGOOD
SHARE
PGOOD
ADJ
ADJ
RT GND SYNC
RT GND SYNC
8023 TA02
105k
8023 TA03
13M
79k
*RUNNING VOLTAGE RANGE. PLEASE
REFER TO APPLICATIONS INFORMATION
FOR START-UP DETAILS
VIN
2.2µF
5V Step-Down Converter
VOUT
47µF
RUN/SS
SHARE
VOUT
2.5V
2A
VIN*
7.5V TO 36VDC
BIAS
VOUT
RUN/SS
BIAS
10µF
VOUT
5V
2A
AUX
LTM8023
PGOOD
SHARE
ADJ
PGOOD
ADJ
RT GND SYNC
RT GND SYNC
8023 TA04
61.9k
VIN
AUX
2.2µF
LTM8023
3.3V
383k
*RUNNING VOLTAGE RANGE. PLEASE
REFER TO APPLICATIONS INFORMATION
FOR START-UP DETAILS
2.5V Step-Down Converter
VIN*
4.5V TO 36VDC
VOUT
1.8V
2A
8023 TA05
226k
49.9k
*RUNNING VOLTAGE RANGE. PLEASE
REFER TO APPLICATIONS INFORMATION
FOR START-UP DETAILS
93.1k
*RUNNING VOLTAGE RANGE. PLEASE
REFER TO APPLICATIONS INFORMATION
FOR START-UP DETAILS
VIN*
5.5V TO 36V
VIN
VOUT
RUN/SS
BIAS
VOUT
3.3V
2A
AUX
LTM8023
2.2µF
22µF
SHARE
PGOOD
ADJ
RT
GND SYNC
8023 TA07
49.9k
154k
*RUNNING VOLTAGE RANGE. PLEASE
REFER TO APPLICATIONS INFORMATION
FOR START-UP DETAILS
18
8023fj
For more information www.linear.com/LTM8023
LTM8023
TYPICAL APPLICATIONS
–5V Positive to Negative Converter
VIN*
7V TO 31V
VIN
–5V Positive to Negative Converter
Load Current vs Input Voltage
VOUT
2500
AUX
RUN/SS
BIAS
LOAD CURRENT (mA)
2000
LTM8023
SHARE
2.2µF
PGOOD
10µF
ADJ
RT
1500
1000
500
GND SYNC
8023 TA06
39.2k
93.1k
0
–5V
*RUNNING VOLTAGE RANGE. PLEASE
REFER TO APPLICATIONS INFORMATION
FOR START-UP DETAILS
0
10
20
30
INPUT VOLTAGE (V)
40
8023 TA06b
Two LTM8023’s in Parallel, 3.3V at 4A
VIN*
6.5V TO 36V
VIN
VOUT
RUN/SS
BIAS
AUX
VOUT
3.3V
4A
LTM8023
SHARE
PGOOD
ADJ
2.2µF
RT SYNC GND
49.9k
76.8k
VIN
VOUT
RUN/SS
BIAS
AUX
2.2k
47µF
LTM8023
SHARE
2.2µF
PGOOD
ADJ
0.22µF
RT SYNC GND
8023 TA08
49.9k
*RUNNING VOLTAGE RANGE. PLEASE
REFER TO APPLICATIONS INFORMATION
FOR START-UP DETAILS
8023fj
For more information www.linear.com/LTM8023
19
For more information www.linear.com/LTM8023
0.000
3.810
2.540
1.270
0.3175
0.3175
1.270
2.540
0.000
SUGGESTED PCB LAYOUT
TOP VIEW
1.905
PACKAGE TOP VIEW
0.635
3.175
aaa Z
3.810
4
0.635
0.9525
0.635
0.3175
PAD 1
CORNER
11.25
BSC
1.905
X
9.00
BSC
Y
DETAIL A
PACKAGE SIDE VIEW
2.45 – 2.55
DETAIL A
MOLD
CAP
0.27 – 0.37
SUBSTRATE
DETAILS OF PAD #1 IDENTIFIER ARE OPTIONAL,
BUT MUST BE LOCATED WITHIN THE ZONE INDICATED.
THE PAD #1 IDENTIFIER MAY BE EITHER A MOLD OR A
MARKED FEATURE
7
PACKAGE ROW AND COLUMN LABELING MAY VARY
AMONG µModule PRODUCTS. REVIEW EACH PACKAGE
LAYOUT CAREFULLY
SYMBOL TOLERANCE
aaa
0.15
bbb
0.10
!
6. THE TOTAL NUMBER OF PADS: 50
5. PRIMARY DATUM -Z- IS SEATING PLANE
LAND DESIGNATION PER JESD MO-222, SPP-010 AND SPP-020
4
3
TRAY PIN 1
BEVEL
PADS
SEE NOTES
1.27
BSC
0.605 – 0.665
7.62
BSC
3
2. ALL DIMENSIONS ARE IN MILLIMETERS
NOTES:
1. DIMENSIONING AND TOLERANCING PER ASME Y14.5M-1994
aaa Z
2.72 – 2.92
(Reference LTC DWG # 05-08-1804 Rev C)
bbb Z
20
Z
LGA Package
50-Lead (11.25mm × 9.00mm × 2.82mm)
H
G
E
D
C
B
A
LGA 50 0113 REV C
PACKAGE IN TRAY LOADING ORIENTATION
LTMXXXXXX
µModule
PACKAGE BOTTOM VIEW
F
8.89
BSC
0.605 – 0.665
1
2
3
4
5
6
7
C(0.30)
PAD 1
7
SEE NOTES
LTM8023
PACKAGE DESCRIPTION
Please refer to http://www.linear.com/designtools/packaging/ for the most recent package drawings.
8023fj
4.445
3.175
4.445
0.630 ±0.025 Ø 50x
SUGGESTED PCB LAYOUT
TOP VIEW
2.540
PACKAGE TOP VIEW
1.270
4
0.3175
0.000
0.3175
PIN “A1”
CORNER
E
1.270
aaa Z
2.540
Y
For more information www.linear.com/LTM8023
4.445
3.175
1.905
0.635
0.000
0.635
1.905
3.175
4.445
D
X
4.76
4.13
aaa Z
NOM
3.42
0.60
2.82
0.78
0.63
11.25
9.0
1.27
8.89
7.62
0.32
2.50
DIMENSIONS
b1
A
A2
MAX
3.62
0.70
2.92
0.85
0.66
NOTES
DETAIL B
PACKAGE SIDE VIEW
0.37
2.55
0.15
0.10
0.20
0.30
0.15
TOTAL NUMBER OF BALLS: 50
0.27
2.45
MIN
3.22
0.50
2.72
0.71
0.60
DETAIL A
SYMBOL
A
A1
A2
b
b1
D
E
e
F
G
H1
H2
aaa
bbb
ccc
ddd
eee
H1
SUBSTRATE
A1
ddd M Z X Y
eee M Z
DETAIL B
H2
MOLD
CAP
ccc Z
Z
3.810
3.810
Z
(Reference LTC DWG # 05-08-1883 Rev A)
Øb (50 PLACES)
// bbb Z
BGA Package
50-Lead (11.25mm × 9.00mm × 3.42mm)
F
e
7
5
4
3
2
PACKAGE BOTTOM VIEW
6
1
DETAIL A
H
G
F
E
D
C
B
A
PIN 1
DETAILS OF PIN #1 IDENTIFIER ARE OPTIONAL,
BUT MUST BE LOCATED WITHIN THE ZONE INDICATED.
THE PIN #1 IDENTIFIER MAY BE EITHER A MOLD OR
MARKED FEATURE
4
TRAY PIN 1
BEVEL
COMPONENT
PIN “A1”
7
!
BGA 50 1212 REV A
PACKAGE IN TRAY LOADING ORIENTATION
LTMXXXXXX
µModule
PACKAGE ROW AND COLUMN LABELING MAY VARY
AMONG µModule PRODUCTS. REVIEW EACH PACKAGE
LAYOUT CAREFULLY
6. SOLDER BALL COMPOSITION CAN BE 96.5% Sn/3.0% Ag/0.5% Cu
OR Sn Pb EUTECTIC
5. PRIMARY DATUM -Z- IS SEATING PLANE
BALL DESIGNATION PER JESD MS-028 AND JEP95
3
2. ALL DIMENSIONS ARE IN MILLIMETERS
7
SEE NOTES
NOTES:
1. DIMENSIONING AND TOLERANCING PER ASME Y14.5M-1994
b
3
SEE NOTES
G
LTM8023
PACKAGE DESCRIPTION
Please refer to http://www.linear.com/designtools/packaging/ for the most recent package drawings.
8023fj
21
LTM8023
PACKAGE DESCRIPTION
Table 3. Pin Assignment (Sorted by Pin Number)
PIN
22
SIGNAL DESCRIPTION
PIN
SIGNAL DESCRIPTION
A1
VOUT
D5
GND
A2
VOUT
D6
GND
A3
VOUT
D7
GND
A4
VOUT
E1
GND
A5
GND
E2
GND
A6
GND
E3
GND
A7
GND
E4
GND
B1
VOUT
E5
GND
B2
VOUT
E6
GND
B3
VOUT
E7
GND
B4
VOUT
F5
AUX
B5
GND
F6
GND
B6
GND
F7
SHARE
B7
GND
G1
VIN
C1
VOUT
G2
VIN
C2
VOUT
G3
VIN
C3
VOUT
G5
BIAS
C4
VOUT
G6
SYNC
C5
GND
G7
RT
C6
GND
H1
VIN
C7
GND
H2
VIN
D1
GND
H3
VIN
D2
GND
H5
RUN/SS
D3
GND
H6
PGOOD
D4
GND
H7
ADJ
8023fj
For more information www.linear.com/LTM8023
LTM8023
REVISION HISTORY
(Revision history begins at Rev F)
REV
DATE
DESCRIPTION
PAGE NUMBER
F
8/10
Added Note 5
3
G
8/11
Added BGA package. Changes reflected throughout the data sheet.
H
8/13
Changed output capacitor from 2.2µF to 22µF
I
2/14
Added SnPb BGA package option
J
8/15
Updated thermal impedance values
1 to 24
1
1, 2
2
8023fj
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 representation that the interconnection
of its
circuits as described
herein will not infringe on existing patent rights.
For more
information
www.linear.com/LTM8023
23
LTM8023
PACKAGE PHOTOGRAPHS
LGA
BGA
RELATED PARTS
PART NUMBER
DESCRIPTION
COMMENTS
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0.8V ≤ VOUT ≤ 24V, Synchronizable, 9mm × 15mm × 4.3mm LGA
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3.3V ≤ VOUT ≤ 15V, Synchronizable, 15mm × 15mm × 2.8mm LGA
LTM4613
EN55022B Certified 36V, 8A Step-Down
µModule Regulator
3.3V ≤ VOUT ≤ 15V, Synchronizable, 15mm × 15mm × 4.3mm LGA
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32V, 2A Li-Ion/Li-Polymer µModule Battery
Charger
C/10 or Timer Termination, Auto-Recharge, Programmable Charge Current,
9mm × 15mm × 4.3mm LGA
24 Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
For more information www.linear.com/LTM8023
(408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com/LTM8023
8023fj
LT 0815 REV J • PRINTED IN USA
 LINEAR TECHNOLOGY CORPORATION 2007