DC2359A - Demo Manual

DEMO MANUAL DC2359A
LTC3624
High Efficiency Synchronous
Step-Down Regulator with
Ultralow Quiescent Current
Description
Demonstration circuit 2359A is a synchronous step-down
regulator using LTC®3624HMSE monolithic buck regulator.
The DC2359A operates from an input voltage range of 2.7V
to 17V and provides and adjustable output voltage range
from 1.2V to 5V (VOUT < VIN) at 2A of continuous output
current. A user-selectable mode input is provided with
the following options: Burst Mode® operation provides
the highest efficiency at light loads, while Pulse-Skipping
mode (PS) provides the lowest output voltage ripples.
Forced Continuous mode (FC) is also available for low
EMI and noise interference.
The MODE/SYNC pin can also be used to synchronize
the switching frequency to an external clock signal. The
switching frequency is fixed at 1MHz with a ±40% sync
capture range.
The regulator features ultralow quiescent current and high
efficiencies over a wide VIN and VOUT range. DC2359A
Performance Summary
PARAMETER
uses very low profile surface mount components and all
ceramic output capacitor solutions. The compact 12-lead
MSE (5mm × 4mm × 1mm) thermally enhanced package
makes LTC3624HMSE an excellent choice for battery
powered equipment, emergency radio and general purpose step-down power supplies. The H-Grade version is
specified over an operating junction temperature range
of –40°C to 150°C, typically required for automotive, industrial and military applications that are subject to high
ambient temperatures.
It is recommended to read the data sheet and demo manual
of LTC3624 prior using or making any changes to DC2359A.
Design files for this circuit board are available at
http://www.linear.com/demo/DC2359A
L, LT, LTC, LTM, Linear Technology, the Linear logo and Burst Mode are registered trademarks
of Linear Technology Corporation. All other trademarks are the property of their respective
owners.
Specifications are at TA = 25°C
CONDITIONS
Input Voltage Range
VALUE
2.7V to 17V
On Board User Selectable Output Voltages
VIN = 2.7V to 17V, IOUT = 2A
(VOUT < VIN)
1.2V, 1.8V, 2.5V, 3.3V and 5V
Default Mode Setting
JP2
Burst Mode (“BM” on Circuit Board)
Fixed Switching Frequency
Internally Programmed Frequency
1MHz ±20%
Default Output Voltage VOUT
VIN = 12V, VOUT = 5V, IOUT = 0A to 2A
5V ±2%
2A
Maximum Continuous Output Current IOUT
Output Voltage Ripples (Peak to Peak)
VIN = 12V, VOUT = 5V, IOUT = 2A
8.8mV (Figure 7)
Load Transient Response
VIN = 12V, VOUT = 5V, IOUT_STEP = 1A to 2A,
COUT = 1 × 47µF
219mV (Figure 8)
Thermal Performance
VIN = 12V, VOUT = 5V, IOUT = 2A,
fSW = 1MHz, TA = 25°C
Figure 9
Efficiency
VIN = 12V, VOUT = 5V, IOUT = 2A, BM,
fSW = 1MHz, TA = 25°C
89.7% (Figure 3)
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DEMO MANUAL DC2359A
Quick Start Procedure
Demonstration circuit 2359A is easy to set up to evaluate
the performance of the LTC3624HMSE. 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
5V output application:
Table 1. Typical 5V Output Voltage Jumper Selection
JP1
JP2
JP7
RUN
MODE/SYNC
VOUT
ON
BM
5.0V
7.To select other output voltages, use the on board user
selectable output voltage jumpers. Shutting down
LTC3624HMSE by placing RUN pin jumper (JP1) to the
OFF position or turn off the input power supply. Refer
to the following table (Table 2) for the output voltage
selection and repeat step 2 to 6.
Table 2. Output Voltage Jumper Selection
JP3
JP4
JP5
JP6
JP7
JP8*
1.2V
1.8V
2.5V
3.3V
5V
User Select
*If JP8 is selected, R6 needs to be calculated and inserted to obtain the
desired output voltage.
4.Connect the DMMs to the input and output to monitor
the input voltage and output voltage.
NOTE 1: To measure the input/output voltage ripple properly, do not use the long ground lead on the oscilloscope
probe. See Figure 2 for the proper scope probe technique.
Short, stiff leads need to be soldered to the (+) and (–)
terminals of an output capacitor. The probe’s ground ring
needs to touch the (–) lead and the probe tip needs to
touch the (+) lead.
5.Turn on the power supply at the input. The RUN pin
jumper should be at “ON” position. Measure and make
sure the input supply voltage is 12V. The output voltage
should be 5V ±2%.
NOTE 2: The DC2359A can also be used to evaluate the
LTC3624HMSE-2 (2.25MHz) by simply replacing U1 with
the LTC3624HMSE-2 and changing inductor L1 to 1.5µH
(Coilcraft XAL4020-152ME).
2.With power off, connect the input power supply at
VIN (E1) and GND (E2)
3.Connect the Load between VOUT (E8) and GND (E9).
Preset the load to 0A.
6.Once the input and output voltages are properly established, adjust the loads within the operating range
(0A to 2A Max) and observe the output voltage regulation, output voltage ripple, switch node waveform and
other parameters. Refer to Figure 2 for proper output
voltage ripple measurement.
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2
DEMO MANUAL DC2359A
Quick Start Procedure
Figure 1. Proper Measurement Equipment Setup
+
VOUT
–
COUT
GND
Figure 2. Scope Probe Placement for Measuring Output Voltage Ripple
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DEMO MANUAL DC2359A
100
100
95
95
90
90
85
85
80
75
70
65
1.2VOUT
1.8VOUT
2.5VOUT
3.3VOUT
5.0VOUT
60
55
50
0.01
0.10
LOAD CURRENT (A)
EFFICIENCY (%)
EFFICIENCY (%)
Quick Start Procedure
80
75
70
1.2VOUT
1.8VOUT
2.5VOUT
3.3VOUT
5.0VOUT
65
60
55
50
0.0
1.00 1.10
0.5
DC2359a F04
DC2359a F03
Figure 4. Forced Continuous Mode –
Efficiency vs Load Current at 12VIN
100
100
95
95
90
90
85
85
EFFICIENCY (%)
EFFICIENCY (%)
Figure 3. Burst Mode – Efficiency vs Load Current at 12VIN
80
75
70
65
1.2VOUT
1.8VOUT
2.5VOUT
3.3VOUT
60
55
50
0.01
0.10
LOAD CURRENT (A)
1.00 1.10
DC2359a F05
Figure 5. Burst Mode – Efficiency vs Load Current at 5VIN
2.0
1.0
1.5
LOAD CURRENT (A)
80
75
70
65
1.2VOUT
1.8VOUT
2.5VOUT
3.3VOUT
60
55
50
0.0
0.5
1.0
1.5
LOAD CURRENT (A)
2.0
DC2359a F06
Figure 6. Forced Continuous Mode –
Efficiency vs Load Current at 5VIN
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4
DEMO MANUAL DC2359A
Quick Start Procedure
20MHz BW LIMIT
VP-P = 8.8mV
VOUT
20mV/DIV
VSW
10V/DIV
t(1µs/DIV)
DC2359a F07
fSW = 1MHz
VIN = 12V
VOUT = 5V
ILOAD = 2A
L = 3.3µH
COUT = 1x 47µF/6.3V/X5R/1206
Figure 7. Measured Output Voltage Ripple
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5
DEMO MANUAL DC2359A
Quick Start Procedure
20MHz BW LIMIT
VP-P = 219mV
VOUT
200mV/DIV
1A TO 2A
IOUT
1A/DIV
t(50µs/DIV)
DC2359a F08
fSW = 1MHz
VIN = 12V
VOUT = 5V
ILOAD = 1A TO 2A
L = 3.3µH
COUT = 1x 47µF/6.3V/X5R/1206
CFF = 15pF
Figure 8. Load Transient Response
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6
DEMO MANUAL DC2359A
Quick Start Procedure
DC2359a F09
VIN = 12V
VOUT = 5V
ILOAD = 2A
L = 3.3µH
fSW = 1MHz
NO FORCED AIRFLOW
TA = 25°C
Figure 9. Thermal Performance
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7
DEMO MANUAL DC2359A
Parts List
ITEM
QTY
REFERENCE
PART DESCRIPTION
MANUFACTURER/PART NUMBER
Required Circuit Components
1
1
CFF
CAP, 0402 15pF 1% 50V NPO
AVX 04025U150FAT2A
2
1
CIN
CAP, 47μF 20% 20V 33mΩ
PANASONIC OSCON 20SVPA47M
3
2
C2, C3
CAP, 1206 22μF 10% 25V X5R
MURATA GRM31CR61E226KE15L
4
1
C4
CAP, 1206 47μF 20% 6.3V X5R
TAIYO YUDEN JMK316BJ476ML-T
5
1
C8
CAP, 0603 2.2μF 10% 10V X5R
AVX 0603ZD225KAT2A
6
1
L1
IND, 3.3μH
XAL4030-332ME
7
2
R1, RSET
RES, 0402 619kΩ 1% 1/16W
VISHAY CRCW0402619KFKED
8
1
R2
RES, 0402 309kΩ 1% 1/16W
VISHAY CRCW0402309KFKED
9
1
R3
RES, 0402 196kΩ 1% 1/16W
VISHAY CRCW0402196KFKEA
10
1
R4
RES, 0402 137kΩ 1% 1/16W
VISHAY CRCW0402137KFKED
11
1
R5
RES, 0402 84.5kΩ 1% 1/16W
VISHAY CRCW040284K5FKED
12
2
R7, R12
RES, 0402 0Ω JUMPER
VISHAY CRCW04020000Z0ED
13
1
R11
RES, 0402 1MΩ 5% 1/16W
VISHAY CRCW04021M00JNED
14
1
U1
IC, MONOLITHIC SYNCHRONOUS BUCK
REGULATOR
LINEAR TECH LTC3624HMSE#PBF
Additional Demo Board Circuit Components
1
0
C5
CAP, 1206 22μF 20% 6.3V X5R OPTION
TAIYO YUDEN EMK316BJ226ML-T OPTION
2
0
C6
CAP, 1210 OPTION
OPTION
3
0
C7
CAP, 0402 OPTION
OPTION
4
0
R6, R8, R9, R10
RES, 0402 OPTION
OPTION
1
10
E1, E2, E3, E4, E5, E6, E7, E8,
E9, E10
TURRET
MILL-MAX 2501-2-00-80-00-00-07-0
2
1
JP1
HEADER, 3-PIN, 2mm
SAMTEC TMM-103-02-L-S
3
1
JP2
HEADER, 4-PIN, 2mm
SAMTEC TMM-104-02-L-S
Hardware
4
6
JP3, JP4, JP5, JP6, JP7, JP8
HEADER, 2-PIN, 2mm
SAMTEC TMM 102-02-L-S
5
4
MH1, MH2, MH3, MH4
STANDOFF, SNAP ON
KEYSTONE 8833
6
3
XJP1, XJP2, XJP7
SHUNT, 2mm
SAMTEC 2SN-BK-G
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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
E6
E5
E4
E3
E7
9
10
C8
2.2uF
10V
0603
C7
OPT
5
4
MODE/SYNC
INTVCC
RUN
VIN
VIN
7
6
8
2
1
JP4
1.8V
3
`\
SCALE = NONE
Z_
JP6
3.3V
R3
196k
1%
R4
137k
1%
2
C4
47uF
6.3V
1206
C5
OPT
1206
E10
E9
C6
OPT
1210
E8
GND
GND
IC NO.
2
1
SHEET 1
LTC3624HMSE
DEMO CIRCUIT 2359A
DATE: Wednesday, August 12, 2015
N/A
SIZE
2A
VOUT
ADJ
OF 1
1
REV.
1630 McCarthy Blvd.
Milpitas, CA 95035
Phone: (408)432-1900 www.linear.com
Fax: (408)434-0507
LTC Confidential-For Customer Use Only
JP8
USER SELECT
R6
OPT
CFF
15pF
TECHNOLOGY
JP7
5.0V
R5
84.5K
1%
RSET
619k
1%
R12
0
1
MONOLITHIC SYNCHRONOUS BUCK REGULATOR
WITH ULTRA-LOW QUIESCENT CURRENT
TITLE: SCHEMATIC
JP5
2.5V
R2
309k
1%
APPROVALS
JP3
1.2V
R1
619k
1%
3.3uH
L1
Coilcraft XAL4030-332ME
VOUT
THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND
SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.
CUSTOMER NOTICE
NC
PGOOD
FB
SW
SW
3
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.
FOR FCM OPERATION, STUFF R9 AND
R10 WITH 1MEG OHM RESISTOR.
R11
1Meg
INTVCC
[2]
R10
OPT
[2]
R9
OPT
R8
OPT
5
4
[2]
4
3
2
1
JP1
3
2
1
C3
22uF
25V
1206
CIN IS AN OPTIONAL CAPACITOR. IT IS INSERTED
ON THE DC2359A TO DAMPEN THE (POSSIBLE)
RINGING VOLTAGE DUE TO THE LONG INPUT LEADS.
ON A NORMAL, TYPICAL PCB, WITH SHORT TRACES,
THE CAPACITOR IS NOT NEEDED.
PS
JP2
MODE
BM
[2]
FCM / SYNC
INTVCC
OFF
ON
RUN
R7
0
C2
22uF
25V
1206
[1]
NOTES:
PGOOD
GND
SYNC
INTVCC
RUN
GND
E2
47uF
20V
+ CIN [1]
3
U1
LTC3624HMSE (1MHz)
GND
11
E1
VIN
2.7V - 17V
4
GND
12
5
A
B
C
D
DEMO MANUAL DC2359A
Schematic Diagram
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9
DEMO MANUAL DC2359A
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
dc2359afb
10 Linear Technology Corporation
LT 1015 REV B • PRINTED IN USA
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900
●
FAX: (408) 434-0507 ● www.linear.com
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