DEMO MANUAL DC1245A
LTM4616
Dual 2.7V
IN(MIN)
, 8A Step-Down
µModule Regulator
Description
Demonstration circuit 1245A features the
LTM
®
4616,
the
high efficiency, high density, dual output switch mode
power module. The rated load current is 8A for each chan-
nel, while derating is necessary for certain V
IN
, V
OUT
, and
thermal conditions. By applying a clock signal to the CLKIN
pin, the module’s switching frequency may be synchronized
from 0.75MHz to 2.25MHz. The same clock frequency is
available at the CLKOUT pin with the phase relationship
between CLKIN and CLKOUT determined by the PHMODE
pin. This feature can be used not only to reduce undesirable
frequency harmonics but also to parallel the two channels
of LTM4616 or even multiple LTM4616s and LTM4608s to
provide higher output currents. The LTM4616 data sheet
must be read in conjunction with this demo manual prior
to working on or modifying demo circuit DC1245A.
Design files for this circuit board are available at
http://www.linear.com/demo/DC1245A
L,
LT, LTC, LTM, µModule, Linear Technology and the Linear logo are registered trademarks of
Linear Technology Corporation. All other trademarks are the property of their respective owners.
perForMAnce sUMMArY
PARAMETER
Input Voltage Range
Output Voltage V
OUT1
V
OUT2
Maximum Continuous Output Current
Default Operating Frequency
Efficiency
Load Transient
CONDITIONS
(T
A
= 25°C)
VALUE
2.7V to 5.5V
1.8 ±2%
1.2 ±2%
8A
DC
Each Channel
1.5MHz
V
IN
= 3.3V, I
OUT1
= 8A
I
OUT2
= 8A
Derating Is Necessary for Certain V
IN
, V
OUT
, and Thermal
Conditions, See Data Sheet for Details
V
IN
= 5V, V
OUT1
= 1.8V, V
OUT2
= 1.2V, 8A Per Channel
V
IN
= 3.3V, V
OUT1
=1.8V; V
OUT2
= 1.2V
77.5%, See Figure 3 for More Information
See Figures 4 and 5 for Details
BoArD photo
dc1245afa
1
DEMO MANUAL DC1245A
qUick stArt proceDUre
Demonstration circuit 1245A is an easy way to evaluate
the performance of the LTM4616. Please refer to Figure 1
for proper measurement equipment setup and follow the
procedure below:
1. Place jumpers in the following positions for a typical
1.8V
OUT
and 1.2V
OUT
application:
PHMODE2
2PH
TRACK1
DISABLED
MARGINING2
NO
PHMODE1
2PH
RUN2
ON
MODE
BURST
MARGINING1
NO
RUN1
ON
4. Once the proper output voltage is established, adjust
the load within the operating range and observe the
output voltage regulation, ripple voltage, efficiency and
other parameters. To measure input and output ripple,
please refer to Figure 2 for proper setup.
5. To synchronize channel 1 to an external clock, please
apply the desired clock signal to CLKIN and SGND1.
The external clock signal should have amplitude of at
least 2V but less than V
IN
.
6. V
OUT1
can track another supply connected at TP20 as
determined by resistors R6 and R17. V
OUT2
is set up
to track V
OUT1
in a manner determined by resistors
R15 and R16. By default both resistor pairs have been
selected to support coincident tracking. Please refer to
Figure 6 for reference.
2. With power off, connect the input power supply, load
and meters as shown in Figure 1. Preset the load to 0A
and V
IN
supply within the 2.7V to 5.5V operating range.
3. Turn on the power at the input. The output voltage at
VO1
+
and VO1
–
should be 1.8V ±2% and the voltage
at VO2
+
and VO2
–
should be 1.2V ±2%.
INPUT OR OUTPUT CAPACITOR
Figure 2. Proper Scope Probe Placement
for Measuring Input or Output Ripple
Overall Efficiency vs Load Current
95
90
85
80
EFFICIENCY (%)
75
70
65
60
55
50
45
40
35
0
2
6
4
8
10
LOAD CURRENT FOR EACH CHANNEL (A)
dc1245a F03
V
IN
= 3.3V, V
O1
= 1.8V, V
O2
= 1.2V
V
IN
= 5V, V
O1
= 1.8V, V
O2
= 1.2V
Figure 3. Measured Overall Supply Efficiency with Different V
IN
Figure 1. Test Setup of DC1245A
dc1245afa
2
DEMO MANUAL DC1245A
qUick stArt proceDUre
7. Channel 2 is set up to synchronize to the CLKOUT sig-
nal of channel 1. The default phase difference is 180°.
Please refer to data sheet for how to set up PHMODE1
and PHMODE2 for paralleling more than 2 channels.
dc1245a F05
V
IN
= 3.3V
V
OUT
=1.2V
CONTINUOUS CURRENT MODE (CCM)
2A TO 6A LOAD STEP
C
OUT
=
×2
100µF CERAMIC (1210, X5R, 6.3V) +
22µF CERAMIC (0805, X5R, 6.3V)
C
FF2
= 0pF
V
OUT
OVERSHOOT AND UNDERSHOOT = 128mV
dc1245a F04
V
IN
= 3.3V
V
OUT
=1.8V
CONTINUOUS CURRENT MODE (CCM)
2A TO 6A LOAD STEP
C
OUT
=
×2
100µF CERAMIC (1210, X5R, 6.3V) +
22µF CERAMIC (0805, X5R, 6.3V)
C
FF1
= 47pF
V
OUT
OVERSHOOT AND UNDERSHOOT = 172mV
Figure 5. Measured Load Transient Response for 1.2V
OUT
(4A Step, 25% to 75%)
Figure 4. Measured Load Transient Response for 1.8V
OUT
(4A Step, 25% to 75%)
Figure 6. Measured Tracking Performance of V
OUT1
and V
OUT2
(with 2A Load Current)
dc1245afa
3
DEMO MANUAL DC1245A
pArts list
ITEM
1
2
3
4
5
6
1
2
3
4
5
6
7
8
1
2
3
4
5
6
7
8
9
10
11
QTY
4
1
4
1
1
1
0
2
0
0
1
1
3
1
0
5
3
8
15
2
4
2
2
4
4
REFERENCE
CIN1, CIN2, CO13, CO23
CIN4
CO11, CO12, CO21, CO22
RSET1
RSET2
U1
CO14, CO15, CO24, CO25 (OPT)
R7, R5
R9, R11, R19 (OPT)
CTHP1, CTHP2, C1, CFF2, CSP (OPT)
CFF1
R17
R15, R16, R6
R18
CIN3(OPT)
JP1, JP2, JP3-JP5
JP6, JP7, JP9
JP1-JP7, JP9
TP1, TP2, TP7-TP10, TP12, TP14-TP18,
TP20-TP22
TP6, TP3
TP6, TP3
TP6, TP3
TP6, TP3
TP4, TP5, TP11, TP13
(STAND-OFF)
PART DESCRIPTION
Capacitor, X5R, 22µF 6.3V, 20%, 1206
,
Capacitor, OS-CON, 150µF 10V, E7 Size
,
Capacitor, X5R, 100µF 6.3V, 20%, 1210
,
Resistor, Chip, 4.99k, 1/16W, 1%, 0402
Resistor, Chip, 10k, 1/16W, 1%, 0402
IC LTM4616EV 144-Pin LGA
Capacitor, 1210-3743
Resistor, Chip, 100k, 1/16W, 5%, 0402
Resistor, Chip, 0402
Capacitor, 0402
Capacitor, C0G, 47pF 50V, 10%, 0402
,
Resistor, Chip, 4.99k, 1/16W, 1%, 0402
Resistor, Chip, 10k, 1/16W, 1%, 0402
Resistor, Chip, 0, 1/16W, 0402
Capacitor, 1210-3743
2
×
3, 0.079 Double Row Header
Header 3-Pin 0.079 Single Row
Shunt, 0.079" Center
Testpoint, Turret, 0.094" Pbf
Stud, Test Pin
Nut, Brass Nuts #10-32
Ring, Lug Ring #10
Washer, Tin Plated Brass
Jack Banana
Stand-Off, Nylon 0.50"
Samtec, TMM103-02-L-D
Samtec, TMM103-02-L-S
Samtec, 2SN-BK-G
Mill-Max, 2501-2-00-80-00-00-07-0
PEM KFH-032-10
Any #10-32
Keystone #10
Any #10
Keystone, 575-4
Keystone, 8833(SNAP ON)
AVX, 04025A470KAT2A
Vishay, CRCW04024K99FKED
Vishay, CRCW040210K0FKED
Vishay, CRCW04020000Z0ED
Vishay, CRCW0402100KJNED
MANUFACTURER/PART NUMBER
AVX, 12066D226MAT2A
Sanyo, 10SVPA150MAA
AVX, 12106D107MAT2A
Vishay, CRCW04024K99FKED
Vishay, CRCW040210K0FKED
Linear Technology, LTM4616EV
Required Circuit Components
Additional Demo Board Circuit Components
Hardware/Components (For Demo Board Only)
dc1245afa
4
VIN+
VOUT1
TP4
TP2
VO1+
VOUT1
TP1
VIN
CIN2
22uF
6.3V
SVIN1
U1
LTM4616EV
F1
F2
F3
F4
E1
E2
E3
E4
D1
D2
C1
C2
B6
E5
J1
J2
K1
K2
L1
L2
L3
L4
M1
M2
M3
M4
H6
TP3
SVIN2
L5
VIN
CO11
100uF
6.3V
CO12
100uF
6.3V
TP5
TP7
VOUT2
CO21
100uF
6.3V
CO22
100uF
6.3V
CO23
22uF
6.3V
CO24
opt
6.3V
CO25
opt
6.3V
TP9
CO13
22uF
6.3V
CO14
opt
6.3V
CO15
opt
6.3V
2.5V - 5.5V
R5
100K
SW1
VIN1
VIN1
VIN1
VIN1
VIN1
VIN1
VIN1
VIN1
VIN1
VIN1
VIN1
VIN1
SVIN1
VIN2
VIN2
VIN2
VIN2
VIN2
VIN2
VIN2
VIN2
VIN2
VIN2
VIN2
VIN2
SW2
SVIN2
+
CIN4
150uF
10V
R7
100K
CIN3
100uF
opt
CIN1
22uF
6.3V
1.8V @ 8A MAX
GND1
VO1-
VO2+
GND
TP6
VIN-
A11
PGOOD1
PGOOD2
G11
TP8
PGOOD1
scheMAtic DiAgrAM
PGOOD2
A6
BSEL1
MGN1
MODE1
A10
TP10
TP12
VOUT1
VOUT1
VOUT1
VOUT1
VOUT1
VOUT1
VOUT1
VOUT1
VOUT1
VOUT1
VOUT1
VOUT1
D9
D10
D11
D12
E9
E10
E11
E12
F9
F10
F11
F12
VOUT2
TP11
1.2V @ 8A MAX
TP13
TP14
GND2
VO2-
PBS1
MODE
A8
VOUT1
ITH2
ITHM2
E7
BSEL2
MGN2
MODE2
ITH2
ITHM2
CLKOUT2
A9
PHMODE1
PHMODE2
TRACK2
RUN2
RUN1
PLLFLTR2
PLLFLTR1
CLKIN1
CLKIN2
SGND2
GND2
GND2
GND2
GND2
GND2
GND2
GND2
GND2
GND2
GND2
GND2
GND2
GND2
GND2
GND2
GND2
GND2
GND2
GND2
GND2
GND2
GND2
GND2
GND2
GND2
GND2
GND2
GND2
GND2
GND2
GND2
GND2
M5
G7
SGND1
GND1
GND1
GND1
GND1
GND1
GND1
GND1
GND1
GND1
GND1
GND1
GND1
GND1
GND1
GND1
GND1
GND1
GND1
GND1
GND1
GND1
GND1
GND1
GND1
GND1
GND1
GND1
GND1
GND1
GND1
GND1
GND1
E6
L6
M6
L8
G9
TRACK1
E8
FB2
K8
M7
L7
M8
G8
G10
G6
ITHM1
SVIN1
R9
R11 opt
CLK
F7
CLKOUT1
FB1
D8
LOW
5
JP1
*
MARGINING1
HI
1
2
NO
3
4
opt
CTHP1
F8
ITH1
opt.
ITH2
6
ITHM2
TP15
VOUT2
VOUT2
VOUT2
VOUT2
VOUT2
VOUT2
VOUT2
VOUT2
VOUT2
VOUT2
VOUT2
VOUT2
K9
K10
K11
K12
L9
L10
L11
L12
M9
M10
M11
M12
PBS2
JP2
*
MARGINING2
2
4
6
TP16
MODE
ITH2
ITHM2
CTHP2
opt.
R18 0
SVIN2 VOUT2
1
SVIN1
CFF1
VFB
47pF
(PULSE SKIPPING) PS
BURST
1
JP3
MODE
RSET1
4.99K
HI
2
VOUT1
NO
3
5
LOW
RSET2
CFF2
10.0K 1%
opt
VOUT2
SVIN2
R19
PFB2
PFB1
VFB
opt
TP17
TP18
VOUT1
SVIN2
JP5
PHMODE2
2
1
3
4
(CONTINUOUS) CON
5
6
SVIN1
C1
opt
F6
A7
JP4
PHMODE1
CLK
3PH (PHASE)
F5
4PH (PHASE)
2PH (PHASE)
1
2
3
4
5
6
CLKOUT
VFB
A1
A2
A3
A4
A5
A12
B1
B2
B3
B4
B5
B7
B8
B9
B10
B11
B12
C3
C4
C5
C6
C7
C8
C9
C10
C11
C12
D3
D4
D5
D6
D7
SVIN1
SVIN1
1
G1
G2
G3
G4
G5
G12
H1
H2
H3
H4
H5
H7
H8
H9
H10
H11
H12
J3
J4
J5
J6
J7
J8
J9
J10
J11
J12
K3
K4
K5
K6
K7
2PH (PHASE)
4
6
3
5
JP6
TRACK1
2
1
DISABLED
RUN1
JP7
ENABLED
3
2
ON
OFF
R15
10.0K
1%
4PH (PHASE)
3PH (PHASE)
TRACK
3
R6
TP20
10K
CSP
opt
R16
10.0K
1%
SVIN2
1
2
R17
4.99K
CLKIN
IN LAYOUT, MANUALLY TIED ALL GND TOGETHER ON LAYER 2.
3
OFF
ON
JP9
RUN2
Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no representa-
tion that the interconnection of its circuits as described herein will not infringe on existing patent rights.
CUSTOMER NOTICE
CONTRACT NO.
APPROVALS
DRAWN
ENGINEER
CHECKED
APPROVED
Friday, February 15, 2008
TP21
SGND1
TP22
1630 McCarthy Blvd.
Milpitas, CA 95035
Phone: (408)432-1900
Fax: (408)434-0507
*DC1245A STILL USES THE OLD METHOD TO DISABLE MARGINING.
AN IMPROVED METHOD OF TYING THE MGN PIN TO A VOLTAGE DIVIDER
WITH 50k RESISTORS FROM V
IN
TO GROUND IS RECOMMENDED NOW.
DATE
J. Wu
M. Xie
3/7/07
3/7/07
TITLE
TECHNOLOGY
LTM4616EV
Dual 8A High Density Step-Down Power Module
SIZE
CAGE CODE
SCALE:
FILENAME:
DWG NO
DC1245A
SHEET
1
OF
REV
A
LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A
CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS;
HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO
VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL
APPLICATION. COMPONENT SUBSTITUTION AND PRINTED
CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT
PERFORMANCE OR RELIABILITY. CONTACT LINEAR
TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE.
THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND
SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.
1
DEMO MANUAL DC1245A
dc1245afa
5
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