DEMO MANUAL DC1696
LTM8026
36V, 5A, CVCC Step-Down µModule Regulator
DESCRIPTION
Demonstration circuit 1696 is a 36V, 5A, CVCC step-down
μModule regulator featuring the LTM8026. The demo
circuit is designed for a 3.3V output from an input volt-
age range of 6V to 36V. The output can source 5A. The
circuit can be operated in either constant voltage mode
or constant current mode.
The LTM8026 data sheet gives a complete description of
the part, operation and application information. The data
sheet must be read in conjunction with this quick start
guide prior to working on or modifying demo circuit 1696.
Design files for this circuit board are available at
http://www.linear.com/demo
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 Supply Voltage Range
Output Voltage
Switching Frequency
Maximum Output Current
Efficiency
I
OUT
= 5A
CONDITIONS
(T
A
= 25°C)
MIN
6
3.135
5
3.3
550
TYP
MAX
36
3.465
UNITS
V
V
kHz
A
86
%
V
IN
= 12V, I
OUT
= 5A
BOARD PHOTO
dc1696f
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DEMO MANUAL DC1696
QUICK START PROCEDURE
Demonstration circuit 1696 is an easy way to evaluate
the performance of the LTM8026. Refer to Figure 1 for
proper measurement equipment setup and follow the
procedure below:
NOTE. When measuring the input or output voltage ripple,
care must be taken to avoid a long ground lead on the
oscilloscope probe. Measure the input or output voltage
ripple by touching the probe tip directly across the V
IN
and GND or V
OUT
and GND terminals.
1. With power off, connect the input power supply to V
IN
and GND.
2. Connect a load to V
OUT
and GND.
3. Turn on the power at the input.
4. Check for the proper output voltage and current.
NOTE. If there is no output, temporarily disconnect the
load to make sure that the load is not set too high.
5. Once the proper output voltage is established, adjust the
load and input within the operating ranges and observe
the output voltage regulation, output current regulation,
ripple voltage, efficiency and other parameters.
I
IN
I
OUT
POWER SUPPLY
V
IN
V
OUT
Figure 1. Proper Measurement Equipment Setup
dc1696f
2
DEMO MANUAL DC1696
QUICK START PROCEDURE
0
–20
INTENSITY (dBm)
–40
–60
–80
–100
–120
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5
FREQUENCY (MHZ)
1696 F01
Figure 2. DC1696A Output Noise Spectrum. (V
IN
= 12V, V
OUT
= 3.3V, I
OUT
= 5A)
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DEMO MANUAL DC1696
PARTS LIST
ITEM
1
2
3
4
5
6
7
8
9
10
11
12
13
QTY
1
1
1
1
1
1
1
2
1
1
1
1
1
REFERENCE
CIN1
CIN2
COUT1
COUT3
C1
C2
R1
R2, R3
R4
R5
R6
R7
U1
PART DESCRIPTION
Cap., Ceramic 10μF 50V, 10%, 1210
,
Cap., Alum 22μF 50V, 10%, OSCON-CE-6.3
,
Cap., X5R 100μF 6.3V, 20%, 1210
,
Cap., OSCON 330μF 4V, 20%, OSCON-C6
,
Cap., NPO 1000pF 50V, 20%, 0603
,
Cap., X7R 1500pF 25V, 10%, 0603
,
Res., Chip 10k, 0.06W, 5%, 0603
Res., Chip 100k, 0.06W, 5%, 0603
Res., Chip 301k, 0.06W, 1%, 0603
Res., Chip 75.0k, 0.06W, 1%, 0603
Res., Chip 5.62k, 0.06W, 1%, 0603
Res., Chip 510k, 0.06W, 5%, 0603
I.C.,Step-Down Converter.
LGA(81)15mm
×
11.25mm
×
2.82mm
Cap., 1210
Cap., 1206
Cap., 1210
Cap.
Ferrite Bead, 1206
Inductor
Res., 0603
MILL-MAX 2501-2-00-80-00-00-07-0
MILL-MAX 2308-2-00-80-00-00-07-0
SAMTEC TMM-103-02-L-S
KEYSTONE 575-4
SAMTEC 2SN-BK-G
MANUFACTURER/PART NUMBER
Murata GRM32ER71H106K
SUNCON 50CE22BSS
TDK C3225X5R0J107M
SANYO 4SVPC330M
AVX 06035A102MAT1A
AVX 06033C152KAT1A
Vishay CRCW060310K0JNEA
Vishay CRCW0603100KJNEA
Vishay CRCW0603301KFKEA
Vishay CRCW060375K0FKEA
Vishay CRCW060335K62FKEA
Vishay CRCW0603510KJNEA
Linear Tech. Corp. LTM8026EV
Required Circuit Components
Additional Demo Board Circuit Components
1
2
3
4
5
6
7
1
2
3
4
5
0
0
0
0
0
0
0
5
4
2
4
2
COUT2 (OPT)
C3 (OPT)
C4 (OPT)
C5 (OPT)
FB1 (OPT)
L1 (OPT)
R8 (OPT)
Hardware For Demo Board Only
E1, E2, E3, E8, E9 Turret, Testpoint
E4, E5, E6, E7
JP1, JP2
J1, J2, J3, J4
XJP1, XJP2
Turret, Testpoint
Headers, Single Row 3 Pins 2mm Ctrs.
Connector, Banana Jack
Shunt, 2mm Ctrs.
dc1696f
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5
4
3
2
1
REVISION HISTORY
ECO
DESCRIPTION
REV
APPROVED
DATE
D
D
VOUT
+
SCHEMATIC DIAGRAM
VREF
CTL_I
COMP
+
C
CTL_T
VOUT
VOUT
VOUT
VOUT
VOUT
VOUT
VOUT
VOUT
VIN
VIN
VIN
VIN
VIN
VIN
VIN
VIN
VIN
VIN
VOUT
VOUT
VOUT
VOUT
VOUT
VOUT
VOUT
VOUT
SYNC
C
RUN
RT
SS
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
ADJ
VIN
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.
VIN
B
B
EVIN
CUSTOMER NOTICE
+
APPROVALS
TECHNOLOGY
TITLE: SCHEMATIC
www.linear.com
A
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 PCB DES.
VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL
APP ENG.
APPLICATION. COMPONENT SUBSTITUTION AND PRINTED
CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT
PERFORMANCE OR RELIABILITY. CONTACT LINEAR
TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE.
μ
SIZE
THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND
SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.
IC NO.
SCALE = NONE
3
2
REV.
DATE:
1
SHEET 1
OF
1
5
4
DEMO MANUAL DC1696
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