DC1722A - Demo Manual

DEMO MANUAL DC1722A
LTC3864
55V Low IQ Step-Down
DC/DC Converter with
100% Duty Cycle Capability
DESCRIPTION
Demonstration circuit 1722A is a high voltage, current
mode DC/DC step-down converter featuring the LTC®3864.
for larger MOSFET and diode packages on the back of the
board for higher output current requirements.
The board operates from an input range of 3.5V to 55V,
and provides a 5V, 2A output when the input exceeds 5V.
The PMOSFET architecture allows it to operate seamlessly
up to 100% duty cycle, and function as a saturated switch
below the regulation threshold, down to 3.5VIN. It operates
at 350kHz and may be synchronized to an external clock.
A soft-start feature controls output voltage slew rate at
start-up, reducing current surge and voltage overshoot.
Burst Mode® operation that improves efficiency at light
loads can be enabled with a jumper. A power good output
signal is provided. The demonstration board has options
This board is suitable for a wide range of automotive,
telecom, industrial, and other applications. The LTC3864
is available in small 12-pin thermally enhanced MSOP and
DFN packages. For other output requirements, see the
LTC3864 data sheet or contact the LTC factory.
PERFORMANCE SUMMARY
Design files for this circuit board are available at
http://www.linear.com/demo/DC1722A
L, LT, LTC, LTM, Linear Technology, Burst Mode and the Linear logo are registered trademarks
of Linear Technology Corporation. All other trademarks are the property of their respective
owners.
Specifications are at TA = 25°C
SYMBOL
PARAMETER
CONDITIONS
VIN
Input Supply Range
VOUT
Output Voltage
IOUT
Output Current Range, Continuous
fSW
Switching (Clock) Frequency
VOUT(P-P)
Output Ripple
VIN = 14V, IOUT = 2A (20MHz BW)
VREG
Output Regulation
Line and Load (5.5VIN to 55VIN, 0AOUT to 2AOUT)
POUT/PIN
Efficiency (See Figure 3)
VIN =14V, IOUT = 2A
Approximate Size
Component Area x Top Component Height
MIN
TYP
3.5
MAX
55
5.0
0
UNITS
V
V
2
A
350
kHz
15
mVP–P
0.23
84
0.6 × 0.6 × 0.14
%
%
Inches
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1
DEMO MANUAL DC1722A
QUICK START PROCEDURE
Demonstration circuit 1722 is easy to set up to evaluate
the performance of the LTC3864. Refer to Figure 1 for
proper measurement equipment setup and follow the
procedure below:
NOTE: Make sure that the input voltage never exceeds 55V.
NOTE: When measuring the output voltage ripple, care must
be taken to avoid a long ground lead on the oscilloscope
probe. Measure the output voltage ripple by touching the
probe tip and ground ring directly across the last output
capacitor as shown in Figure 1.
5.Once the proper output voltage is established, connect
a variable load capable of sinking 2A at 5V to the output
terminals VOUT and GND. Set the current for 0A.
1.Set an input power supply that is capable of 3.5V to
55V to 6V. Then turn off the supply.
2.With power off, connect the supply to the input terminals
VIN and GND.
a. Input voltages lower than 3.5V can keep the converter
from turning on due to the undervoltage lockout
feature of the LTC3864.
b.If efficiency measurements are desired, an ammeter
capable of measuring 2ADC or a resistor shunt can
be put in series with the input supply in order to
measure the DC1722A’s input current.
c. A voltmeter with a capability of measuring at least
55V can be placed across the input terminals in order
to get an accurate input voltage measurement.
2
3.Turn on the power at the input.
4.Check for the proper output voltage of 5V. Turn off the
power at the input.
a. If efficiency measurements are desired, an ammeter
or a resistor shunt that is capable of handling 2ADC
can be put in series with the output load in order to
measure the DC1722A’s output current.
b.A voltmeter with a capability of measuring at least 5V
can be placed across the output terminals in order
to get an accurate output voltage measurement.
6.Turn on the power at the input.
NOTE: If there is no output, temporarily disconnect
the load to make sure that the load is not set too high.
7.Once the proper output voltage is again established,
adjust the load and/or input within the operating range
and observe the output voltage regulation, ripple voltage, efficiency and other desired parameters.
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DEMO MANUAL DC1722A
QUICK START PROCEDURE
DC1722a F01
Figure 1. Proper Measurement Equipment Setup
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3
DEMO MANUAL DC1722A
QUICK START PROCEDURE
95
90
EFFICIENCY (%)
85
80
75
70
65
VIN = 6V
VIN = 14V
VIN = 28V
VIN = 55V
60
55
0.01
0.1
1
IOUT (A)
10
DC1722a F02
Figure 2. Efficiency with Burst Mode Operation at Light Loads
10mV/DIV
2µs/DIV
DC1722a F03
Figure 3. Output Ripple at 14VIN and 2AOUT (10mV, 2µs/DIV, 20MHz)
4
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DEMO MANUAL DC1722A
QUICK START PROCEDURE
1A/DIV
50mV/DIV
100µs/DIV
DC1722a F04
Figure 4. Transient Response Waveform at 14VIN and 1A - 2A - 1AOUT (1A, 50mV,100µs/DIV)
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5
DEMO MANUAL DC1722A
PARTS LIST
ITEM
QTY
REFERENCE
PART DESCRIPTION
MANUFACTURER/PART NUMBER
Required Circuit Components
1
1
CIN1
CAP, 10μF 20% 63V ALUM
SUN ELEC. 63HEH10M
2
1
CIN2
CAP, 1210 2.2μF 10% 100V X7R
MURATA GRM32ER72A225KA35L
3
2
COUT1, COUT2
CAP, 1812 100μF 20% 6.3V X5R
TDK C4532X5R0J107M
4
1
COUT3
CAP, 0603 1μF 10% 6.3V X5R
TAIYO YUDEN JMK107BJ105KA-T
5
1
C1
CAP, 0402 100pF 5% 25V NPO
AVX 04023A101JAT2A
6
1
C2
CAP, 0402 2200pF 10% 25V X7R
AVX 04023C222KAT2A
7
1
C4
CAP, 0402 47pF 5% 25V NPO
AVX 04023A470JAT2A
8
1
C5
CAP, 0603 0.47μF 20% 16V X7R
AVX 0603YC474MAT2A
9
1
C6
CAP, 0402 0.1μF 20% 16V X5R
AVX 0402YD104MAT2A
10
1
C7
CAP, 0805 0.1μF 20% 100V X5R
TDK C2012X5R2A104M
11
1
C8
CAP, 0402 220pF 5% 25V NPO
AVX 04023A221JAT2A
12
1
D1
DIODE, SUPER BARRIER RECTIFIER 100V DFN3030-8
DIODES INC./ZETEX SBR3U100LP-7
13
1
L1
IND, 10μH
COILCRAFT XAL5050-103ME
14
1
Q1
XSTR, FET P-CHANNEL 60V
FAIRCHILD SEMI FDMC5614P
15
5
R1, R4, R6, R8, R10
RES, 0402 0Ω JUMPER
VISHAY CRCW04020000Z0ED
16
1
R2
RES, 0402 10k 1% 1/16W
VISHAY CRCW040210K0FKED
17
1
R3
RES, 0402 80.6k 1% 1/16W
VISHAY CRCW040280K6FKED
18
1
R5
RES, 0402 422k 1% 1/16W
VISHAY CRW0402422KFKED
19
1
R7
RES, 2010 0.025Ω 1% 1/2W
VISHAY WSL2010R0250FEA
20
1
R9
RES, 0402 100k 5% 1/16W
VISHAY CRCW0402100KJNED
21
1
U1
IC, VOLTAGE REG. MSOP(12)-MSE
LINEAR TECH. LTC3864EMSE
Additional Demo Board Circuit Components
1
0
CIN3
CAP, 1210 2.2μF 10% 100V X7R OPTION
MURATA GRM32ER72A225KA35L OPTION
2
0
C9
CAP, D CASE OPTION
OPTION
3
0
D2
DIODE, SCHOTTKY, 5A POWERDi5 OPTION
DIODES INC./ZETEXPDS5100-13 OPTION
4
0
L1 – ALTERNATE
IND, 10μH
TOKO B1134AS-100M
5
0
L1 – ALTERNATE
IND, 10μH
WURTH ELECTRONIK 744071100
6
0
Q2
XSTR, MOSFET P-CHANNEL 60V OPTION
VISHAY SILICONIX Si7465DP OPTION
7
0
R11
RES, 0402 OPTION
OPTION
1
4
E1, E2, E8, E9
TURRET
MILL MAX 2501-2-00-80-00-00-07-0
2
5
E3, E4, E5, E6, E7
TURRET
MILL MAX 2308-2-00-80-00-00-07-0
3
1
JP1
HEADER, 3-PIN SINGLE ROW 2mm
SAMTEC TMM-103-02-L-S
4
1
JP2
HEADER, 3-PIN DOUBLE ROW 2mm
SAMTEC TMM-103-02-L-D
5
4
MH1, MH2, MH3, MH4
STANDOFF, SNAP ON
KEYSTONE_8831
6
2
XJP1, XJP2
SHUNT, 2mm
SAMTEC 2SN-BK-G
Hardware
6
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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.
A
B
C
D
TRACK
CLKIN
GND
VIN
5V - 55V
(3.5V Min)
E4
E3
E2
E1
5
5
R3
80.6K
1%
C4
47pF
5%
R4
0 Ohm
JP2
5
6
SKIP
3
1
2
BURST
CLKIN 4
MODE
CIN1
+ 10uF
63V
R5
422K
1%
C2
2200pF
R2
10.0K
1%
0.1uF
C6
0 Ohm
R1
4
ITH
VFB
SS
GND
FREQ
PLL/MODE
C8
220pF
5%
6
5
4
3
2
1
13
GND
LTC3864EMSE
U1
4
R11
(OPT)
R9
100k
VOUT
PGOOD
RUN
CAP
SENSE
VIN
GATE
CIN3
2.2uF
100V
1210
(OPT)
VIN
3
2
JP1
SHDN
1
R10
0 Ohm
0.1uF
100V
0805
C7
OFF
ON
R6
3
THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND
SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.
C:\DESIGN\17\1722A-3.3\1722A-3.3.DSN
2
RB/MI
SCALE = NONE
DAVID B.
2
DATE:
N/A
SIZE
E5
E9
04/19/16
E8
GND
VOUT
5V / 2A
D. B.
D. B.
APPROVED
IC NO.
Tuesday, April 19, 2016
1
LTC3864EMSE
DEMO CIRCUIT 1722A
SHEET
1
OF
1
3.3
REV.
LTC CONFIDENTIAL - FOR CUSTOMER USE ONLY
60V, LOW IQ , STEP-DOWN CONTROLLER
TITLE: SCHEMATIC
DATE
04/17/12
COUT3
1uF
6.3V
0603 E6
VOUT
1
1630 McCarthy Blvd.
Milpitas, CA 95035 www.linear.com
Phone: (408)432-1900
Fax: (408)434-0507
C9
(OPT)
"D" Case
+
TECHNOLOGY
COUT2
100uF
6.3V
1812
CHANGE
3.3
COUT1
100uF
6.3V
1812
PROD
3
REVISION HISTORY
DESCRIPTION
REV
XAL5050-103ME
COILCRAFT
D1
SBR3U100LP-7
L1
10uH
Q2
Si7465DP
(OPT)
ECO
APPROVALS
Q1
FDMC5614P
D2
PDS5100-13
PowerDi5
(OPT)
0 Ohm
CUSTOMER NOTICE
E7
PGOOD
0.47uF
0603
C5
C1
100pF
5%
0 Ohm
R8
R7
0.025
2010
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
APPLICATION. COMPONENT SUBSTITUTION AND PRINTED
APP ENG.
CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT
PERFORMANCE OR RELIABILITY. CONTACT LINEAR
TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE.
7
8
9
10
11
12
CIN2
2.2uF
100V
1210
VIN
3
A
B
C
D
DEMO MANUAL DC1722A
SCHEMATIC DIAGRAM
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7
DEMO MANUAL DC1722A
DEMONSTRATION BOARD IMPORTANT NOTICE
Linear Technology Corporation (LTC) provides the enclosed product(s) under the following AS IS conditions:
This demonstration board (DEMO BOARD) kit being sold or provided by Linear Technology is intended for use for ENGINEERING DEVELOPMENT
OR EVALUATION PURPOSES ONLY and is not provided by LTC for commercial use. As such, the DEMO BOARD herein may not be complete
in terms of required design-, marketing-, and/or manufacturing-related protective considerations, including but not limited to product safety
measures typically found in finished commercial goods. As a prototype, this product does not fall within the scope of the European Union
directive on electromagnetic compatibility and therefore may or may not meet the technical requirements of the directive, or other regulations.
If this evaluation kit does not meet the specifications recited in the DEMO BOARD manual the kit may be returned within 30 days from the date
of delivery for a full refund. THE FOREGOING WARRANTY IS THE EXCLUSIVE WARRANTY MADE BY THE SELLER TO BUYER AND IS IN LIEU
OF ALL OTHER WARRANTIES, EXPRESSED, IMPLIED, OR STATUTORY, INCLUDING ANY WARRANTY OF MERCHANTABILITY OR FITNESS
FOR ANY PARTICULAR PURPOSE. EXCEPT TO THE EXTENT OF THIS INDEMNITY, NEITHER PARTY SHALL BE LIABLE TO THE OTHER FOR
ANY INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES.
The user assumes all responsibility and liability for proper and safe handling of the goods. Further, the user releases LTC from all claims
arising from the handling or use of the goods. Due to the open construction of the product, it is the user’s responsibility to take any and all
appropriate precautions with regard to electrostatic discharge. Also be aware that the products herein may not be regulatory compliant or
agency certified (FCC, UL, CE, etc.).
No License is granted under any patent right or other intellectual property whatsoever. LTC assumes no liability for applications assistance,
customer product design, software performance, or infringement of patents or any other intellectual property rights of any kind.
LTC currently services a variety of customers for products around the world, and therefore this transaction is not exclusive.
Please read the DEMO BOARD manual prior to handling the product. Persons handling this product must have electronics training and
observe good laboratory practice standards. Common sense is encouraged.
This notice contains important safety information about temperatures and voltages. For further safety concerns, please contact a LTC application engineer.
Mailing Address:
Linear Technology
1630 McCarthy Blvd.
Milpitas, CA 95035
Copyright © 2004, Linear Technology Corporation
8
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Linear Technology Corporation
LT 0516 REV A • PRINTED IN USA
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900
●
FAX: (408) 434-0507 ● www.linear.com
 LINEAR TECHNOLOGY CORPORATION 2013
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