Page 1
DESCRIPTION
DEMO MANUAL DC1596A
LTC3607EUD
Dual 600mA 15V Monolithic
Synchronous Step-Down Regulator
Demonstration circuit DC1596 is a dual output regulator
consisting of two constant-frequency step-down convert-
®
ers, 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 CONDITIONS VALUE
Minimum Input Voltage 4.5V
Maximum Input Voltage 15V
Run RUN Pin = GND
Output V
Typical Output Ripple V
Output Voltage V
Typical Output Ripple V
Mode Setting Mode Pin Floating
Burst Mode Operation Output Current Thresholds
Pulse-Skipping Operation Output Current
Thresholds
Switching Frequency 2.25MHz ±20%
oltage V
Regulation V
OUT1
OUT1
Regulation V
OUT2
OUT2
RUN Pin = V
IN1
V
IN1
IN2
V
IN2
Mode Pin Grounded
Channel 1: PV
Channel 2: PV
Channel 1: PV
Channel 2: PV
Specifications are at TA = 25°C
IN
= 4.5V to 15V, I
= 12V, I
= 4.5V to 15V, I
= 12V, I
= 600mA (20MHz BW) <20mV
OUT1
= 600mA (20MHz BW) <20mV
OUT2
= 12V, V
IN1
= 12V, V
IN2
= 12V, V
IN1
= 12V, V
IN2
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.
Shutdown
Operating
= 0A to 600mA 1.2V ±4% (1.152V-1.148V)
OUT1
= 0A to 600mA 2.5V ±4% (2.425V-2.6V)
OUT2
= 1.8V
OUT1
= 3.3V
OUT2
= 1.8V
OUT1
= 3.3V
OUT2
1.5V ±4% (1.44V-1.56V)
1.8V ±4% (1.728V-1.872V)
P-P
3.3V ±4% (3.168V-3.432V)
5V ±4% (4.8V-5.2V)
P-P
Burst Mode Operation
Pulse-Skipping
< 480mA
I
OUT1
I
< 360mA
OUT2
< 330mA
I
OUT1
I
< 240mA
OUT2
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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 V
or V
technique in Figure 2.
Please follow the procedure outlined below for proper
operation.
1. Connect the input power supply to the PVIN1/PVIN2 and
Before proceeding to operation, insert jumper shunts
2.
3. Turn on VOUT1 and VOUT2 by shifting shunts XJP1
and GND terminals. See the proper scope probe
OUT
GND terminals (V
are connected). Connect the loads between the VOUT
and GND terminals. Refer to Figure 1 for the proper
measurement equipment setup.
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
Apply 5.5V at PVINs 1, 2. Measure both VOUTs; they
should read 0V. If desired, one can measure the shut
down supply current at this point. The supply current
will be less than 1µA in shutdown.
and XJP2 from the OFF positions to the ON positions.
Both output voltages should be within a tolerance of
±2%.
IN1
and V
are separate nodes but
IN2
, or 5V.
IN
-
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 measure
ment technique);
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.
6. To operate the ckt.s in Burst Mode operation, change
the shunt position of header JP3
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 re
moved), as can the signal input supply, SVIN. However,
must powered for either regulator to function
SVIN
(SVIN is connected to PVIN1 through a filter on the
demo board.).
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 ring
ing, a small tantalum capacitor (for instance, AV
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.
they should each measure less than
to BURST MODE.
-
-
-
X part #
4. Vary the input voltages from 5.8V (the minimum V
dependent on V
0A to 600mA. Both output voltages should be within
±4% tolerance.
) to 15V, and the load currents from
OUT
2
IN
is
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QUICK START PROCEDURE
DEMO MANUAL DC1596A
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
V
SW1
10V/DIV
V
OUT1
20mV/DIV
AC VOLTAGE
V
SW2
10V/DIV
V
OUT2
20mV/DIV
AC VOLTAGE
OUT1
OUT2
200ns/DIV
= 600mA
= 600mA
= 12V
PV
IN1,2
= 1.8V AT I
V
OUT1
OUT2 = 3.3V AT I
V
PULSE-SKIPPING MODE
Figure 3. Switch Operation Figure 4. Load Step Response
DC1596A F03
V
OUT
100mV/DIV
AC-COUPLED
I
OUT
200mA/DIV
= 12V
V
IN
= 1.2V
V
OUT1
400mA LOAD STEP (200mA TO 600mA)
PULSE-SKIPPING MODE, f
20µs/DIV
= 2.25MHz
SW
DC1596A F04
V
OUT
100mV/DIV
AC-COUPLED
I
OUT
200mA/DIV
= 12V
V
IN
= 1.5V
V
OUT1
400mA LOAD STEP (200mA TO 600mA)
PULSE-SKIPPING MODE, f
20µs/DIV
= 2.25MHz
SW
DC1596A F05
V
OUT
100mV/DIV
AC-COUPLED
I
OUT
200mA/DIV
= 12V
V
IN
= 1.8V
V
OUT1
400mA LOAD STEP (200mA TO 600mA)
PULSE-SKIPPING MODE, f
20µs/DIV
= 2.25MHz
SW
Figure 6. Load Step ResponseFigure 5. Load Step Response
DC1596A F06
4
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QUICK START PROCEDURE
V
OUT
100mV/DIV
AC-COUPLED
I
OUT
200mA/DIV
DEMO MANUAL DC1596A
V
OUT
100mV/DIV
AC-COUPLED
I
OUT
200mA/DIV
V
OUT
100mV/DIV
AC-COUPLED
I
OUT
200mA/DIV
= 12V
V
IN
= 2.5V
V
OUT2
400mA LOAD STEP (200mA TO 600mA)
PULSE-SKIPPING MODE, f
20µs/DIV
= 2.25MHz
SW
DC1596A F07
= 12V
V
IN
= 3.3V
V
OUT2
400mA LOAD STEP (200mA TO 600mA)
PULSE-SKIPPING MODE, f
20µs/DIV
= 2.25MHz
SW
Figure 7. Load Step Response Figure 8. Load Step Response
100
90
80
70
L1: 2.2µH 1616BZ VISHAY
L2: 4.7µH 1616BZ VISHAY
Burst Mode OPERATION
f
SW
000.1
00.1
LOAD CURRENT (A)
= 2.25MHz
VIN = 5V, VO1 = 1.8V
V
IN
V
IN
V
IN
= 12V
V
IN
= 5V
V
OUT2
400mA LOAD STEP (200mA TO 600mA)
PULSE-SKIPPING MODE, f
20µs/DIV
= 2.25MHz
SW
DC1596A F09
60
50
EFFICIENCY (%)
40
30
20
0000.1
Figure 9. Load Step Response
Figure 10. Efficiency
DC1596A F08
= 12V, VO1 = 1.8V
= 5V, VO2 = 3.3V
= 12V, VO2 = 3.3V
0.1
DC1596A F10
1
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Page 6
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, 04025A220J AT2A
2 2 CIN1BYP, CIN2BYP CAP., X7R, 0.1µF, 16V, 10%, 0603 AVX, 0603YC104K AT2A
3 2 COUT1, COUT2 CAP., X5R, 10µF, 6.3V, 10%, 0805 AVX, 08056D106K AT2A
4 2 CIN1, CIN2 CAP., X5R, 10µF, 16V, 10%, 1206 AVX, 1206YD106K AT2A
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, 0603YC104K AT2A
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
9 1 R8 RES., CHIP, 121k, 1%, 0402 VISHAY
10 0 R9, R10 (
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
Hardware
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
OPT.) RES., 0402
, CRCW0402105KFKED
6
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DEMO MANUAL DC1596A
A
B
C
D
E
11
SCHEMATIC DIAGRAM
2
GND
0.1uF
COUT4
COUT6
47uF
CFFW2
22pF
R2
16V
6.3V
887k
OPT
1%
E10
GND
www.linear.com
SHEET OF
E12
2.5V5V3.3V
USER SELECT
87
VFB2
JP5
1 2
3 4
5 6
R6
R4
280k
1%
196k
R8
1%
121k
1%
R10
OPT
Fax: (408)434-0507
Milpitas, CA 95035
Phone: (408)432-1900
1630 McCarthy Blvd.
LTC Confidential-For Custom er Use Only
E
LTC3607EUD
DEMO CIRCUIT 1596A
TECHNOLOGY
4.5V - 15V
PVIN2
TOM G.PRODUCTION2 3-15-13
REVISION HISTORY
DESCRIPTION DATEAPPROVEDECO REV
E2
22uF
CIN4
35V
+
*
47uF
CIN6
20V
+
CIN2
10uF
16V
CIN2BYP
0.1uF
16V
OPT
PGOOD2
E5
RPG2
VOUT2
E8
100k
COUT2
10uF
__
6.3V
SCHEMATIC
DUAL 600mA MONOLITHIC, SYNCHRONOUS STEP-DOWN REGULATOR
TITLE:
ON
OFF
RUN2
JP2
R11
0 Ohm
123
13
7
3
6
JP3
11
RUN2
PVIN2
SVIN
PVIN1
1
1 2
3 4
5 6
MODE/SYNC
EXT SYNC
BURST MODE
PGOOD2
MODE/SYNC
PULSE-SKIP
5.1M
RSD2
CF
100
123
ON
16V
OFF
RSD1
0.1uF
5.1M
0805
RF
RUN1
JP1
CIN1BYP
0.1uF
U1
LTC3607EUD
PGOOD1
2
L2
4.7uH
Vishay
85
SW2SW1
L1
2.2uH
Vishay
IHLP-1616BZER4R7M11
VFB2
14
PGND2
9
SGND
12
SGND
10
GND
17
PGND1
4
VFB1 RUN1
15 16
IHLP-1616BZER2R2M11
COUT1
10uF
6.3V
R1
210k
1%
HZ
APPROVALS
PCB DES.
APP ENG.
CUSTOMER NOTICE
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
TG
APPLICATION. COMPONENT SUBSTITUTION AND PRINTED
CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT
Thursday, May 16, 2013
D
IC NO. REV.
N/A
SIZE
DATE:
SCALE = NONE
C
PERFORMANCE OR RELIABILITY. CONTACT LINEAR
TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE.
THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND
SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.
B
CIN1
10uF
CIN5
+
CIN3
+
47uF
22uF
16V
20V
35V
OPT
*
E3
E1
GND
PVIN1
4.5V - 15V
4 4
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.
E6
SYNC
CFFW1
100k
RPG1
E4
PGOOD1
3 3
22pF
COUT5
47uF
6.3V
OPT
COUT3
0.1uF
16V
E7
E9
GND
600mA 600mA
VOUT1
R3
E11
210k
GND
R5
1%
140k
1%
JP4
2 2
VFB1
R7
1 2
3 4
1.2V
1.5V
105k
1%
87
5 6
1.8V
USER SELECT
R9
OPT
A
[*] 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 1
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DEMO MANUAL DC1596A
DEMONSTRATION BOARD IMPORTANT NOTICE
Linear Technology Corporation (LT C) 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 LT C 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 LT C 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. LT C assumes no liability for applications assistance,
customer product design, software performance, or infringement of patents or any other intellectual property rights of any kind.
LT C 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 LT C application engineer.
Mailing Address:
Linear Technology
1630 McCarthy Blvd.
Milpitas, CA 95035
Copyright © 2004, Linear Technology Corporation
Linear Technology Corporation
8
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com
dc1596afa
LT 0114 REV A • PRINTED IN USA
LINEAR TECHNOLOGY CORPORATION 2013
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