DC1596A - Demo Manual

DEMO MANUAL DC1596A
LTC3607EUD
Dual 600mA 15V Monolithic
Synchronous Step-Down Regulator
DESCRIPTION
Demonstration circuit DC1596 is a dual output regulator
consisting of two constant-frequency step-down converters, based on the LTC®3607 monolithic dual channel
synchronous buck regulator. The DC1596 has an input
voltage range of 4.5V to 15V, with each regulator capable of
delivering up to 600mA of output current. The DC1596 can
operate in either Burst Mode® operation or pulse-skipping
mode. In shutdown, the DC1596 quiescent current is less
than 1µA. The DC1596 is a very efficient circuit attaining
up to 90%. The DC1596 uses the LTC3607’s16-lead QFN
PERFORMANCE SUMMARY
PARAMETER
package, which has an exposed pad on the bottom side
of the IC for better thermal performance. These features,
plus a set operating frequency range of 2.25MHz, make
the DC1596 demo board an ideal circuit for industrial or
distributed power applications.
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
Minimum Input Voltage
4.5V
Maximum Input Voltage
15V
Run
RUN Pin = GND
RUN Pin = VIN
Shutdown
Operating
Output Voltage VOUT1 Regulation
VIN1 = 4.5V to 15V, IOUT1 = 0A to 600mA
1.2V ±4% (1.152V-1.148V)
1.5V ±4% (1.44V-1.56V)
1.8V ±4% (1.728V-1.872V)
Typical Output Ripple VOUT1
VIN1 = 12V, IOUT1 = 600mA (20MHz BW)
<20mVP-P
Output Voltage VOUT2 Regulation
VIN2 = 4.5V to 15V, IOUT2 = 0A to 600mA
2.5V ±4% (2.425V-2.6V)
3.3V ±4% (3.168V-3.432V)
5V ±4% (4.8V-5.2V)
Typical Output Ripple VOUT2
VIN2 = 12V, IOUT2 = 600mA (20MHz BW)
<20mVP-P
Mode Setting
Mode Pin Floating
Mode Pin Grounded
Burst Mode Operation
Pulse-Skipping
Burst Mode Operation Output Current Thresholds
Channel 1: PVIN1 = 12V, VOUT1 = 1.8V
Channel 2: PVIN2 = 12V, VOUT2 = 3.3V
IOUT1 < 480mA
IOUT2 < 360mA
Pulse-Skipping Operation Output Current
Thresholds
Channel 1: PVIN1 = 12V, VOUT1 = 1.8V
Channel 2: PVIN2 = 12V, VOUT2 = 3.3V
IOUT1 < 330mA
IOUT2 < 240mA
Switching Frequency
2.25MHz ±20%
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DEMO MANUAL DC1596A
QUICK START PROCEDURE
The DC1596 is easy to set up to evaluate the performance
of the LTC3607. For a proper measurement equipment
configuration, set up the circuit according to the diagram
in Figure 1.
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 VIN
or VOUT and GND terminals. See the proper scope probe
technique in Figure 2.
5.Set the load current of both outputs to 600mA and the
input voltages to 12V, and then measure each output
ripple voltage (refer to Figure 2 for proper measurement technique); they should each measure less than
20mVAC. Also, observe the voltage waveform at either
switch node (Pin 5 for reg.1 and Pin 8 for reg.2) of each
regulator. The switching frequencies should be about
2.25MHz ±20% (T = 555ns and 370ns). Both switch
node waveforms should be rectangular in shape, and
180° out-of-phase with each other.
Please follow the procedure outlined below for proper
operation.
6.To operate the ckt.s in Burst Mode operation, change
the shunt position of header JP3 to BURST MODE.
1.Connect the input power supply to the PVIN1/PVIN2 and
GND terminals (VIN1 and VIN2 are separate nodes but
are connected). Connect the loads between the VOUT
and GND terminals. Refer to Figure 1 for the proper
measurement equipment setup.
7.Regulators 1 (PVIN1) and 2 (PVIN2) are completely
separated from each other; thus, they can be powered
from different individual input supplies (if R11 is removed), as can the signal input supply, SVIN. However,
SVIN must powered for either regulator to function
(SVIN is connected to PVIN1 through a filter on the
demo board.).
Before proceeding to operation, insert jumper shunts
XJP1 and XJP2 into the OFF positions of headers JP1
and JP2, shunt XJP3 into the pulse-skip position of
MODE header JP3, and shunt XJP4 into the VOUT1
voltage options of choice of header JP4: 1.2V, 1.5V, or
1.8V, and shunt XJP5 into the VOUT2 voltage options
of choice of header JP5: 2.5V, 3.3V, or 5V.
2.Apply 5.5V at PVINs 1, 2. Measure both VOUTs; they
should read 0V. If desired, one can measure the shutdown supply current at this point. The supply current
will be less than 1µA in shutdown.
3.Turn on VOUT1 and VOUT2 by shifting shunts XJP1
and XJP2 from the OFF positions to the ON positions.
Both output voltages should be within a tolerance of
±2%.
8.When finished, insert shunts XJP1 and XJP2 to the OFF
position(s) and disconnect the power.
Warning: If the power for the demo board is carried in
long leads, the input voltage at the part could “ring”, which
could affect the operation of the circuit or even exceed the
maximum voltage rating of the IC. To eliminate the ringing, a small tantalum capacitor (for instance, AVX part #
TPSY226M035R0200) is inserted on the pads between
the input power and return terminals on the bottom of the
demo board. The (greater) ESR of the tantalum capacitor
will dampen the (possible) ringing voltage caused by the
long input leads. On a normal, typical PCB, with short
traces, this capacitor is not needed.
4.Vary the input voltages from 5.8V (the minimum VIN is
dependent on VOUT) to 15V, and the load currents from
0A to 600mA. Both output voltages should be within
±4% tolerance.
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DEMO MANUAL DC1596A
QUICK START PROCEDURE
Figure 1. Proper Measurement Equipment Setup
VIN
GND
Figure 2. Measuring Input or Output Ripple
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DEMO MANUAL DC1596A
QUICK START PROCEDURE
VSW1
10V/DIV
VOUT
100mV/DIV
AC-COUPLED
VOUT1
20mV/DIV
AC VOLTAGE
IOUT
200mA/DIV
VSW2
10V/DIV
VOUT2
20mV/DIV
AC VOLTAGE
200ns/DIV
PVIN1,2 = 12V
VOUT1 = 1.8V AT IOUT1 = 600mA
VOUT2 = 3.3V AT IOUT2 = 600mA
PULSE-SKIPPING MODE
DC1596A F03
20µs/DIV
VIN = 12V
VOUT1 = 1.2V
400mA LOAD STEP (200mA TO 600mA)
PULSE-SKIPPING MODE, fSW = 2.25MHz
Figure 3. Switch Operation
Figure 4. Load Step Response
VOUT
100mV/DIV
AC-COUPLED
VOUT
100mV/DIV
AC-COUPLED
IOUT
200mA/DIV
IOUT
200mA/DIV
20µs/DIV
VIN = 12V
VOUT1 = 1.5V
400mA LOAD STEP (200mA TO 600mA)
PULSE-SKIPPING MODE, fSW = 2.25MHz
DC1596A F04
DC1596A F05
Figure 5. Load Step Response
20µs/DIV
VIN = 12V
VOUT1 = 1.8V
400mA LOAD STEP (200mA TO 600mA)
PULSE-SKIPPING MODE, fSW = 2.25MHz
DC1596A F06
Figure 6. Load Step Response
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DEMO MANUAL DC1596A
QUICK START PROCEDURE
VOUT
100mV/DIV
AC-COUPLED
VOUT
100mV/DIV
AC-COUPLED
IOUT
200mA/DIV
IOUT
200mA/DIV
20µs/DIV
VIN = 12V
VOUT2 = 2.5V
400mA LOAD STEP (200mA TO 600mA)
PULSE-SKIPPING MODE, fSW = 2.25MHz
20µs/DIV
VIN = 12V
VOUT2 = 3.3V
400mA LOAD STEP (200mA TO 600mA)
PULSE-SKIPPING MODE, fSW = 2.25MHz
DC1596A F07
Figure 7. Load Step Response
DC1596A F08
Figure 8. Load Step Response
100
VOUT
100mV/DIV
AC-COUPLED
90
EFFICIENCY (%)
80
IOUT
200mA/DIV
20µs/DIV
VIN = 12V
VOUT2 = 5V
400mA LOAD STEP (200mA TO 600mA)
PULSE-SKIPPING MODE, fSW = 2.25MHz
DC1596A F09
Figure 9. Load Step Response
70
60
50
40
30
20
0000.1
L1: 2.2µH 1616BZ VISHAY
L2: 4.7µH 1616BZ VISHAY
Burst Mode OPERATION
fSW = 2.25MHz
VIN = 5V, VO1 = 1.8V
VIN = 12V, VO1 = 1.8V
VIN = 5V, VO2 = 3.3V
VIN = 12V, VO2 = 3.3V
00.1
000.1
0.1
LOAD CURRENT (A)
1
DC1596A F10
Figure 10. Efficiency
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DEMO MANUAL DC1596A
PARTS LIST
ITEM
QTY
REFERENCE
PART DESCRIPTION
MANUFACTURER/PART NUMBER
Required Circuit Components
1
2
CFFW1, CFFW2
CAP., NPO, 22pF, 25V, 5%, 0402
AVX, 04025A220JAT2A
2
2
CIN1BYP, CIN2BYP
CAP., X7R, 0.1µF, 16V, 10%, 0603
AVX, 0603YC104KAT2A
3
2
COUT1, COUT2
CAP., X5R, 10µF, 6.3V, 10%, 0805
AVX, 08056D106KAT2A
4
2
CIN1, CIN2
CAP., X5R, 10µF, 16V, 10%, 1206
AVX, 1206YD106KAT2A
5
1
L1
Inductor, 2.2µH
VISHAY, IHLP1616BZER2R2M11
6
1
L2
Inductor, 4.7µH
VISHAY, IHLP1616BZER4R7M11
7
1
R1
RES., CHIP, 210k, 1%, 0402
VISHAY, CRCW0402210KFKED
8
1
R2
RES., CHIP, 887k, 1%, 0402
VISHAY, CRCW0402887KFKED
9
1
R6
RES., CHIP, 196k, 1%, 0402
VISHAY, CRCW0402196KFKED
10
1
R7
RES., CHIP, 105k, 1%, 0402
VISHAY, CRCW0402105KFKED
11
1
U1
IC., LTC3607EUD, 16-PIN QFN 3X3
LINEAR TECH., LTC3607EUD
Additional Demo Board Circuit Components
1
3
COUT3, COUT4, CF
CAP., X7R, 0.1µF, 16V, 10%, 0603
AVX, 0603YC104KAT2A
2
2
CIN3, CIN4
CAP., TANT, 22µF, 35V, 20%, CASE Y
AVX, TPSY226M035R0200
3
0
COUT5, COUT6 (OPT.)
CAP., X5R, 47µF, 6.3V, 10%, 1210
AVX, 12106D476KAQ2A
4
0
CIN5, CIN6 (OPT.)
CAP., X5R, 47µF, 20V, 10%, 1812
5
1
RF
RES., CHIP, 100Ω, 1/16W, 5%, 0402
VISHAY, CRCW0402100RJNED
6
1
R3
RES., CHIP, 210k, 1%, 0402
VISHAY, CRCW0402210KFKED
7
1
R4
RES., CHIP, 280k, 1%, 0402
VISHAY, CRCW0402280KFKED
8
1
R5
RES., CHIP, 140k, 1%, 0402
VISHAY, CRCW0402140KFKED
VISHAY, CRCW0402105KFKED
9
1
R8
RES., CHIP, 121k, 1%, 0402
10
0
R9, R10 (OPT.)
RES., 0402
11
1
R11
RES., CHIP, 0Ω, 1%, 0805
VISHAY, CRCW08050000Z0ED
12
2
RSD1, RSD2
RES., CHIP, 5.1M, 5%, 0402
VISHAY, CRCW04025M10JNED
13
2
RPG1, RPG2
RES., CHIP, 100k, 1%, 0402
VISHAY, CRCW0402100KFKED
1
12
E1-E12
Testpoint, TURRET, 0.094"
MILL-MAX-2501-2-00-80-00-00-07-0
2
2
JP1,JP2
0.079 SINGLE ROW HEADER, 3-PIN
SAMTEC, TMM103-02-L-S
3
2
JP4,JP5
0.079, 2X4 HEADER
SAMTEC, TMM104-02-L-D
4
1
JP3
0.079, 2X3 HEADER
SAMTEC, TMM103-02-L-D
5
5
JP1-JP5
SHUNT, FOR JP1-JP5
SAMTEC, 2SN-BK-G
Hardware
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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.
1
2
3
E11
E9
E7
E4
E6
E3
1
3
5
7
JP4
VFB1
COUT3
0.1uF
16V
2
4
6
8
CIN1
10uF
16V
A
2
1
RSD1
5.1M
SW1
PGOOD1
MODE/SYNC
LTC3607EUD
U1
CF
0.1uF
SW2
PGOOD2
APPROVALS
TITLE: SCHEMATIC
R2
887k
1%
C
THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND
SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.
TG
APP ENG.
SCALE = NONE
HZ
1
3
5
7
CFFW2
22pF
*
E8
E5
E2
2.5V
3.3V
5V
USER SELECT
E12
E10
COUT4
0.1uF
16V
+ CIN4
22uF
35V
TOM G.
DATE
3-15-13
GND
GND
VOUT2
600mA
PGOOD2
PVIN2
4.5V - 15V
APPROVED
E
DATE:
N/A
SIZE
D
LTC3607EUD
DEMO CIRCUIT 1596A
Thursday, May 16, 2013
IC NO.
E
SHEET 1
2
OF 1
REV.
DUAL 600mA MONOLITHIC, SYNCHRONOUS STEP-DOWN REGULATOR
1630 McCarthy Blvd.
Milpitas, CA 95035
Phone: (408)432-1900 www.linear.com
Fax: (408)434-0507
LTC Confidential-For Customer Use Only
2
4
6
8
COUT6
47uF
6.3V
OPT
+ CIN6
47uF
20V
OPT
JP5
VFB2
RPG2
100k
CIN2
10uF
16V
TECHNOLOGY
R10
OPT
R9
OPT
PCB DES.
R8
121k
1%
CUSTOMER NOTICE
COUT2
10uF
6.3V
CIN2BYP
0.1uF
16V
R7
105k
1%
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.
L2
4.7uH
OFF
ON
Vishay
IHLP-1616BZER4R7M11
8
11
RSD2
5.1M
1
2
3
JP2
RUN2
R6
196k
1%
5
Vishay
IHLP-1616BZER2R2M11
L1
2.2uH
2
4
6
1
2
3
RF
100
DESCRIPTION
REVISION HISTORY
PRODUCTION
R5
140k
1%
B
1
3
5
JP1
RUN1
2
REV
R4
280k
1%
R1
210k
1%
ON
OFF
JP3
MODE/SYNC
COUT1
10uF
6.3V
BURST MODE
PULSE-SKIP
EXT SYNC
CIN1BYP
0.1uF
16V
__
ECO
D
R3
210k
1%
CFFW1
22pF
RPG1
100k
COUT5
47uF
6.3V
OPT
+ CIN5
47uF
20V
OPT
[*] CIN3 AND CIN4 ARE INSERTED ON DC1596A TO DAMPEN THE (POSSIBLE)
RINGING VOLTAGE DUETO THE USE OF LONG INPUT LEADS. ON A NORMAL,
TYPICAL PCB, WITH SHORT TRACES, CIN3 AND CIN4 ARE NOT NEEDED.
1.2V
1.5V
1.8V
USER SELECT
GND
GND
VOUT1
600mA
PGOOD1
SYNC
GND
+ CIN3
22uF
35V
VFB1
15
*
PGND1
4
E1
GND
17
PVIN1
SGND
SGND
10
12
4.5V - 15V
R11
0 Ohm
0805
9
4
16
RUN1
3
SVIN
6
PVIN1
C
7
PGND2
B
13
RUN2
PVIN2
VFB2
14
A
1
2
3
4
DEMO MANUAL DC1596A
SCHEMATIC DIAGRAM
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DEMO MANUAL DC1596A
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
dc1596afa
8
Linear Technology Corporation
LT 0114 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