DC2004A - Demo Manual

DEMO MANUAL DC2004A
LTC3622EMSE
17V, Dual 1A Synchronous
Step-Down Regulator with
Ultralow Quiescent Current
DESCRIPTION
Demonstration circuit 2004A is a synchronous stepdown regulator using the power-saving LTC®3622EMSE
monolithic buck regulator in a 16-lead MSE package. The
DC2004A operates from an input voltage range of 2.7V to
17V and provides dual 1A outputs with adjustable output
voltage range from 1.2V to 5V. The LTC3622 IC quiescent
current can be as low as 5µA in Burst Mode® operation
with both channels enabled and less than 0.1µA in shutdown mode. The switching frequency is fixed to 1MHz or
2.25MHz with a ±50% synchronization range to an external
clock. A user-selectable mode input is provided to allow
the user to trade off ripple noise for light load efficiency.
PERFORMANCE SUMMARY
PARAMETER
Burst Mode operation provides the highest efficiency at
light loads, while pulse-skipping mode provides the lowest ripple noise.
It is recommended to read the data sheet LTC3622 with
this demo manual prior to working on or making any
changes to DC2004A.
Design files for this circuit board are available at
http://www.linear.com/demo
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
VALUE
Default IC
LTC3622EMSE
Default Switching Frequency
1MHz
Default Operation Mode
Burst Mode Operation
Input Voltage Range
Onboard User Selectable Output Voltages
2.7V to 17V
VIN = 2.7V to 17V, IOUT1 = IOUT2 = 0A to 1A
(VOUT ≤ VIN)
VOUT1: 1.2V, 1.8V, 2.5V
VOUT2: 3.3V, 5.0V
Default Output Voltage
VOUT1 = 2.5V
VOUT2 = 3.3V
Per Channel Maximum Continuous Output Current VIN = 2.7V to 17V
IOUT1 = IOUT2 = 1A
Efficiency, VOUT1
VIN = 12V, VOUT1 = 2.5V, IOUT1 = 1A
85.7% (See Figure 3)
Efficiency, VOUT2
VIN = 12V, VOUT2 = 3.3V, IOUT2 = 1A
87.9% (See Figure 4)
Output Voltage Ripple, VOUT1
VIN = 12V, VOUT1 = 2.5V, IOUT1 = 1A
<4.7mVP-P (See Figure 5)
Output Voltage Ripple, VOUT2
VIN = 12V, VOUT2 = 3.3V, IOUT2 = 1A
<5.3mVP-P (See Figure 6)
Load Transient Response, VOUT1
VIN = 12V, VOUT1 = 2.5V, IOUT1 = 100mA to 1A
See Figure 7
Load Transient Response, VOUT2
VIN = 12V, VOUT2 = 3.3V, IOUT2 = 100mA to 1A
See Figure 8
Thermal Image
VIN = 12V, VOUT1 = 2.5V, VOUT2 = 3.3V,
IOUT1 = IOUT2 = 1A, TA = 25°C
See Figure 9
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DEMO MANUAL DC2004A
QUICK START PROCEDURE
Demonstration circuit 2004A is easy to set up to evaluate
the performance of the LTC3622. Please refer to Figure 1
for proper measurement equipment setup and follow the
procedure below:
1.Place jumpers in the following positions:
Table 1. Jumper Selection
JP1
JP2
JP3
JP4
JP5
RUN1
RUN2
MODE/SYNC
PHASE
ILIM
ON
ON
BURST
180°
1A
2.Place VO1 SELECT jumper in 2.5V position (JP8) and
VO2 SELECT jumper in 3.3V position (JP10).
3.With power off, connect the input power supply at VIN1
and GND.
4.Connect the Loads between VOUT1 and GND, VOUT2
and GND. Preset the loads to 0A.
5.Connect the DMMs to the input and output to monitor
the input voltage and output voltages.
6.Turn on the power supply at the input. The RUN1 and
RUN2 pin jumpers should be at ON position. Measure
and make sure the input supply voltage is 12V. The
output voltage VOUT1 should be 2.5V ±1%, and VOUT2
should be 3.3V ±1%.
7.Once the input and output voltages are properly established adjust the loads within the operating range (0A
to 1A max) and observe the output voltage regulations,
output ripple voltages, switch node waveforms and other
parameters. Refer to Figure 2 for proper input/output
voltage ripple measurement.
8.To select other output voltages, use the onboard user
selectable output voltage jumpers. Shutting down
LTC3622 by placing RUN1 and RUN2 pin jumpers to
the OFF position or turn off the input power supply.
Refer to the following tables (Table 2 and Table 3) for
the output voltage selections and repeat steps 3 to 6.
Table 2. VOUT1 Jumper Selection
JP6
JP7
JP8
JP9
1.2V
1.8V
2.5V
*USER SELECT
Table 3. VOUT2 Jumper Selection
JP10
JP11
JP12
3.3V
5V
*USER SELECT
*Note: If JP9 or JP12 is selected, R5 or R15 needs to be calculated and
inserted to obtain the desired 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.
Note 2: DC2004A can also be used to evaluate
LTC3622EMSE-2 (2.25MHz) by simply changing U1 to
LTC3622EMSE-2, L1 to 1.0µH (Coilcraft XFL4020-102ME)
and L2 to 2.2µH (Coilcraft XFL4020-222ME).
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DEMO MANUAL DC2004A
QUICK START PROCEDURE
Figure 1. Proper Equipment Measurement Setup
+
VOUT
COUT
–
GND
Figure 2. Scope Probe Placements for Measuring Input or Output Ripple
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DEMO MANUAL DC2004A
QUICK START PROCEDURE
100
100
Burst Mode
OPERATION
90
80
EFFICIENCY (%)
EFFICIENCY (%)
80
70
PULSE-SKIPPING
MODE
60
50
70
60
50
40
40
30
30
20
0.0001
Burst Mode
OPERATION
90
0.01
0.001
0.1
LOAD CURRENT (A)
20
0.0001
1
Figure 3. VOUT1 Measured Efficiency at VIN = 12V, VOUT1 = 2.5V,
L1 = 3.3µH, fSW = 1MHz (with VOUT2 OFF)
VOUT1
10mV/DIV
PULSE-SKIPPING
MODE
0.01
0.001
0.1
LOAD CURRENT (A)
1
Figure 4. VOUT2 Measured Efficiency at VIN = 12V, VOUT2 = 3.3V,
L1 = 4.7µH, fSW = 1MHz (with VOUT1 OFF)
VOUT2
10mV/DIV
20MHz BW LIMIT
2µs/DIV
Figure 5. VOUT1 Measured Output Voltage Ripple at VIN = 12V,
VOUT1 = 2.5V, IOUT1 = 1A, fSW = 1MHz
20MHz BW LIMIT
2µs/DIV
Figure 6. VOUT2 Measured Output Voltage Ripple at VIN = 12V,
VOUT2 = 3.3V, IOUT2 = 1A, fSW = 1MHz
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DEMO MANUAL DC2004A
QUICK START PROCEDURE
VOUT1
200mV/DIV
IOUT1
0.5A/DIV
IOUT1: 100mA TO 1A
100µs/DIV
Figure 7. Load Transient Response at VIN = 12V, VOUT1 = 2.5V,
IOUT1 = 100mA to 1A, fSW = 1MHz, Burst Mode Operation
VOUT2
200mV/DIV
IOUT2
0.5A/DIV
IOUT2: 100mA TO 1A
100µs/DIV
Figure 8. Load Transient Response at VIN = 12V, VOUT2 = 3.3V,
IOUT2 = 100mA to 1A, fSW = 1MHz, Burst Mode Operation
Figure 9. Thermal Performance at VIN = 12V, VOUT1 = 2.5V,
IOUT1 = 1A, VOUT2 = 3.3V, IOUT2 = 1A, fSW = 1MHz, No Airflow, TA = 25°C
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DEMO MANUAL DC2004A
PARTS LIST
ITEM
QTY
REFERENCE
PART DESCRIPTION
MANUFACTURER/PART NUMBER
Required Circuit Components
1
2
CFF1, CFF2
CAP, 0402 22pF 5% 50V NPO
AVX 04025A220JAT2A
2
2
CIN1, CIN2
CAP, 7343 22µF 20% 35V TANT
AVX TPSY226M035R0200
3
2
C1, C2
CAP, 1206 47µF 20% 16V X5R
TDK C3216X5R1C476M160AB
4
2
C5, C6
CAP, 1206 10µF 20% 25V X5R
TDK C3216X5R1E106M
5
1
C7
CAP, 1206 1.0µF 20% 10V X5R
TDK C3216X5R1A105M
6
1
C8
CAP, 0402 1.0µF 20% 10V X5R
TDK C1005X5R1A105M
7
1
L1
IND, 3.3µH 20%
COILCRAFT XFL4020-332MEC
8
1
L2
IND, 4.7µH 20%
COILCRAFT XFL4020-472MEC
9
2
RPG1, RPG2
RES, 0402 100k 1% 1/16W
VISHAY CRCW0402100KFKED
10
3
RSET1, R1, RSET2
RES, 0402 619k 1% 1/16W
VISHAY CRCW0402619KFKED
11
1
R2
RES, 0402 309k 1% 1/16W
VISHAY CRCW0402309KFKED
12
1
R3
RES, 0402 196k 1% 1/16W
VISHAY CRCW0402196KFKED
13
1
R13
RES, 0402 137k 1% 1/16W
VISHAY CRCW0402137KFKED
14
1
R6
RES, 0805 0Ω JUMPER
VISHAY CRCW08050000Z0EA
15
1
R7
RES, 0603 0Ω JUMPER
VISHAY CRCW06030000Z0EA
16
2
R8, R9
RES, 0402 0Ω 1%
VISHAY, CRCW04020000Z0ED
17
1
R14
RES, 0402 84.5k 1% 1/16W
VISHAY CRCW040284K5FKED
18
1
U1
IC, DUAL SYNCHRONOUS STEP-DOWN CONVERTER
LINEAR TECH LTC3622EMSE
Additional Demo Board Circuit Components
1
0
C3, C4
CAP, 0402 OPTION
OPTION
2
0
R5, R15
RES, 0402 OPTION
OPTION
1
13
E1, E2, E3, E4, E5, E6, E7, E8,
TURRET
MILL-MAX 2501-2-00-80-00-00-07-0
2
2
JP1, JP2
HEADER, 3PIN, 2mm
SULLINS NRPN031PAEN-RC
3
2
JP3, JP5
HEADER, 3PIN, DBL ROW 2mm
SULLINS NRPN032PAEN-RC
4
1
JP4
HEADER, 2mm DBL ROW (2X2) 4PIN
SULLINS, NRPN022PAEN-RC
5
7
JP6, JP7, JP8, JP9, JP10,
JP11, JP12
HEADER, 2PIN, 2mm
SULLINS NRPN021PAEN-RC
6
7
XJP1, XJP2, XJP3, XJP4, XJP5, SHUNT, 2mm
XJP6, XJP10
SAMTEC 2SN-BK-G
7
4
MH1, MH2, MH3, MH4
KEYSTONE_8831
Hardware
E9, E10, E11, E12, E13
STANDOFF, SNAP ON
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6
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
E1
E12
INTVCC
SYNC
3.6V
E3
E2
2.7V - 17V
VIN2
GND
E13
2.7V - 17V
VIN1
GND
E8
2.7V - 17V
SVIN
E11
5
INTVCC
CIN2
15uF
35V
7343
CIN1
15uF
35V
7343
5
1A
5
3
500mA CHAN 2 ONLY
ILIM
JP5
6
4
2
JP4
4
PHASE
3
1
0
6
JP3
2
5
PULSE-SKIP
4
2
1
3
BURST
180
1
SYNC
MODE/SYNC
3
OFF
1
3
2
JP2
RUN2
JP1
2
1
ON
OFF
500mA
C6
10uF
25V
1206
R6
0
0805
ON
RUN1
C8
1uF
0
4
1. ALL RESISTORS ARE IN OHMS, 0402.
ALL CAPACITORS ARE IN MICROFARADS, 0402.
NOTE: UNLESS OTHERWISE SPECIFIED
+
+
C5
10uF
25V
1206
R7
4
12
7
5
4
10
8
14
1
2
INTVCC
ILIM
PHASE
17
GND
FB2
SW2
PGOOD2
NC
FB1
SW1
PGOOD1
JP7
1.8V
R2
309k
1%
0
4.7uH
CUSTOMER NOTICE
R9
RPG2
100k
1%
INTVCC
JP6
1.2V
R1
619k
1%
R8 0
L2
VOUT1
3.3uH
L1
RPG1
100k
1%
INTVCC
JP10
3.3V
R13
137k
1%
RSET2
619k
1%
JP8
2.5V
R3
196k
1%
3
THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND
SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.
2
REV
SCALE = NONE
2
C2
47uF
1206
C1
47uF
1206
DATE:
N/A
SIZE
E10
E7
E6
E9
1
DATE
2-4-14
IC NO.
1
SHEET 1
LTC3622EMSE
DEMO CIRCUIT 2004A
Thursday, February 13, 2014
PCB NO.
HAORAN W.
APPROVED
2
OF 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
GND
1A
VOUT2
PGOOD2
GND
VOUT1
1A
PGOOD1
TECHNOLOGY
C4
OPT
C3
OPT
E5
E4
PROD.
DESCRIPTION
REVISION HISTORY
DUAL WIDE VIN SYNCHRONOUS BUCK REGULATOR
WITH ULTRA-LOW QUIESCENT CURRENT
TITLE: SCHEMATIC
JP12
USER SELECT
APPROVALS
JP11
5V
R15
OPT
CFF2
22pF
JP9
USER SELECT
R5
OPT
CFF1
22pF
R14
84.5K
1%
RSET1
619k
1%
2
ECO
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. HZ
VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL
APP ENG. HAORAN W.
APPLICATION. COMPONENT SUBSTITUTION AND PRINTED
CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT
PERFORMANCE OR RELIABILITY. CONTACT LINEAR
TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE.
11
9
6
15
13
16
3
LTC3622EMSE
MODE/SYNC
RUN2
VIN2
RUN1
VIN1
SVIN
U1
C7
1uF
25V
1206
3
A
B
C
D
DEMO MANUAL DC2004A
SCHEMATIC DIAGRAM
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7
DEMO MANUAL DC2004A
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
dc2004af
8
Linear Technology Corporation
LT 0714 • PRINTED IN USA
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900
●
FAX: (408) 434-0507 ● www.linear.com
 LINEAR TECHNOLOGY CORPORATION 2014
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