DC1847A - Demo Manual

DEMO MANUAL DC1847A
LTC3607EMSE
Dual 600mA 15V Monolithic
Synchronous Step-Down Regulator Board
Description
Demonstration circuit 1847 is a dual output regulator based
on the LTC®3607 monolithic dual channel synchronous
buck regulator. The DC1847 has an input voltage range of
4.5V to 15V, with each regulator capable of delivering up
to 600mA of output current. The DC1847 can operate in
either Burst Mode® or pulse-skipping mode. In shutdown,
the DC1847 can run off of less than 1µA total. The DC1847
is a very efficient circuit: up to 90%. The DC1847 uses the
16 Pin MSOP LTC3607 package, which has an exposed pad
Performance Summary
PARAMETER
on the bottom-side of the IC for good thermal performance.
These features, plus a set operating frequency of 2.25MHz,
make the DC1847 demo board an ideal circuit for use in
industrial, automotive, or distributed power applications.
Design files for this circuit board are available at
http://www.linear.com/demo
L, LT, LTC, LTM, Burst Mode, Linear Technology 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
CONDITIONS
VALUE
Minimum Input Voltages
4.5V
Maximum Input Voltages
15V
Run
Output Voltage VOUT1 Regulation
RUN Pin = GND
Shutdown
RUN Pin = VIN
Operating
VIN1 = 4.5V to 15V, IOUT1 = 0A to 600mA
1.2V ±4% (1.152V to 1.148V)
1.5V ±4% (1.44V to 1.56V)
1.8V ±4% (1.728V to 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 to 2.6V)
3.3V ±4% (3.168V to 3.432V)
5V ±4% (4.8V to 5.2V)
Typical Output Ripple VOUT2
VIN2 = 12V, IOUT2 = 600mA (20MHz BW)
< 20mVP-P
Mode Setting
Mode Pin Floating
Burst Mode
Mode Pin Grounded
Pulse-Skipping
Channel 1: PVIN1 = 12V, VOUT1 = 1.8V
IOUT1 < 480mA
Channel 2: PVIN2 = 12V, VOUT2 = 3.3V
IOUT2 < 360mA
Channel 1: PVIN1 = 12V, VOUT1 = 1.8V
IOUT1 < 330mA
Channel 2: PVIN2 = 12V, VOUT2 = 3.3V
IOUT2 < 240mA
Burst Mode Operation
Output Current Thresholds
Pulse-Skipping Operation
Output Current Thresholds
Switching Frequency
2.25MHz ±20%
dc1847af
1
DEMO MANUAL DC1847A
Quick Start Procedure
Demonstration circuit 1847A The DC1847 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.
Please follow the procedure outlined below for proper
operation.
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.
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 PVIN1 or PVIN2 turret. 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%.
4.Vary the input voltages from 5.8V (the min. VIN is dependent on VOUT) to 15V, and the load currents from
0 to 600 mA. Both output voltages should be within
±4% tolerance.
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 20
mVAC. 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 frequency should be about
2.25MHz ±20% (period between 370ns and 555ns).
Both switch node waveforms should be rectangular in
shape, and 180° out-of-phase with each other.
6.For Burst Mode operation, change the shunt position
of header JP3 to Burst Mode.
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.).
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.
2
dc1847af
DEMO MANUAL DC1847A
Quick Start Procedure
IOUT2
IOUT1
–
+
VO1 LOAD1
–
+
+
+
+
–
–
–
–
+
LOAD2 VO2
–
dc1847 F01
+
+
–
–
VS
+
Figure 1. Proper Measurement Equipment Setup
GND
VIN
Figure 2. Measuring Input or Output Ripple
dc1847af
3
DEMO MANUAL DC1847A
Quick Start Procedure
VSW1
10V/DIV
VOUT1
AC VOLTAGE
20mV/DIV AC
VSW2
10V/DIV
VOUT2
AC VOLTAGE
20mV/DIV AC
dc1847 F03
VIN = 12V, VOUT = 1.8V AT IOUT1 = 600mA, VOUT2 = 3.3V AT IOUT2 = 600mA
Figure 3. Switch Operation
OUTPUT VOLTAGE
AC COUPLED
100mV/DIV
OUTPUT CURRENT
200mA/DIV
dc1847 F04
VIN = 10V, VOUT1 = 1.2V, 400mA Load Step (200mA <-> 600mA)
Pulse-Skipping Mode, fSW = 2.25MHz
Figure 4. Load Step Response
4
dc1847af
DEMO MANUAL DC1847A
Quick Start Procedure
OUTPUT VOLTAGE
AC COUPLED
100mV/DIV
OUTPUT CURRENT
200mA/DIV
dc1847 F05
VIN = 12V, VOUT1 = 1.5V, 400mA Load Step (200mA <-> 600mA)
Pulse-Skipping Mode, fSW = 2.25MHz
Figure 5. Load Step Response
OUTPUT VOLTAGE
AC COUPLED
100mV/DIV
OUTPUT CURRENT
200mA/DIV
dc1847 F06
VIN = 12V, VOUT1 = 1.8V, 400mA Load Step (200mA <-> 600mA)
Pulse-Skipping Mode, fSW = 2.25MHz
Figure 6. Load Step Response
dc1847af
5
DEMO MANUAL DC1847A
Quick Start Procedure
OUTPUT VOLTAGE
AC COUPLED
100mV/DIV
OUTPUT CURRENT
200mA/DIV
dc1847 F07
VIN = 12V, VOUT2 = 2.5V, 400mA Load Step (200mA <-> 600mA)
Pulse-Skipping Mode, fSW = 2.25MHz
Figure 7. Load Step Response
OUTPUT VOLTAGE
AC COUPLED
100mV/DIV
OUTPUT CURRENT
200mA/DIV
dc1847 F08
VIN = 12V, VOUT2 = 3.3V, 400mA Load Step (200mA <-> 600mA)
Pulse-Skipping Mode, fSW = 2.25MHz
Figure 8. Load Step Response
6
dc1847af
DEMO MANUAL DC1847A
Quick Start Procedure
OUTPUT VOLTAGE
AC COUPLED
100mV/DIV
OUTPUT CURRENT
200mA/DIV
dc1847 F09
VIN = 12V, VOUT2 = 5V, 400mA Load Step (200mA <-> 600mA)
Pulse-Skipping Mode, fSW = 2.25MHz
Figure 9. Load Step Response
100
90
80
EFFICIENCY (%)
70
VIN = 5V, VO1 = 1.8V
60
VIN = 5V, VO2 = 3.3V
50
VIN = 12V, VO1 = 1.8V
VIN = 12V, VO2 = 3.3V
40
L1 - 2.2µH 1616BZ VISHAY
L2 - 4.7µH 1616BZ VISHAY
BURST MODE
fSW = 2.25MHz
30
20
1.00E-04
dc1847 F10
1.00E-03
1.00E-02
1.00E-01
1.00E+00
LOAD CURRENT (A)
Figure 10. DC1847 Efficiency
dc1847af
7
DEMO MANUAL DC1847A
Parts List
ITEM
QTY
REFERENCE
PART DESCRIPTION
MANUFACTURER/PART NUMBER
CAP., NPO, 22pF, 25V, 5%, 0402
AVX, 04025A220JAT2A
Required Circuit Components
1
2
CFFW1, CFFW2
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., LTC3607EMSE, 16 Pin QFM 3 × 3
Linear Tech., LTC3607EMSE
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, 100, 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, 0, 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: For Demo Board Only
1
12
E1-E12
Testpoint, TURRET, .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, 2 × 4 HEADER
SAMTEC, TMM104-02-L-D
4
1
JP3
0.079, 2 × 3 HEADER
SAMTEC, TMM103-02-L-D
5
5
JP1-JP5
SHUNT, FOR JP1-JP5
SAMTEC, 2SN-BK-G
8
dc1847af
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
E1
1
3
5
7
JP4
VFB1
COUT3
0.1uF
16V
+ CIN3
22uF
35V
2
4
6
8
CIN1
10uF
16V
A
SW1
PGOOD1
MODE/SYNC
CF
0.1uF
SW2
PGOOD2
L2
4.7uH
OFF
ON
APPROVALS
U1
LTC3607EMSE
COUT2
10uF
6.3V
TITLE: SCHEMATIC
Vishay
IHLP1616BZER4R7M11
6
9
5.1M
RSD2
1
2
3
R2
887k
1%
R6
196k
1%
R4
280k
1%
CIN2BY
0.1uF
16V
C
THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND
SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.
HZ
TOM G.
SCALE = NONE
LINEAR
TOM G.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
APP ENG.
APPLICATION. COMPONENT SUBSTITUTION AND PRINTED
CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT
PERFORMANCE OR RELIABILITY. CONTACT LINEAR
TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE.
DESCRIPTION
2
4
6
8
*
E2
E12
E10
E8
2.5V
3.3V
5V
USER SELECT
COUT4
0.1uF
16V
E5
+ CIN4
22uF
35V
DATE
GND
GND
VOUT2
600mA
PGOOD2
PVIN2
4.5V - 15V
3-29-13
DATE:
N/A
SIZE
D
LTC3607EMSE
DEMO CIRCUIT 1847A
Tuesday, May 14, 2013
IC NO.
E
SHEET 1
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
JP5
VFB2
COUT6
47uF
6.3V
OPT.
+ CIN6
47uF
20V
OPT.
TOM G.
DUAL 600mA MONOLITHIC, SYNCHRONOUS STEP-DOWN REGULATOR
TECHNOLOGY
1
3
5
7
CFFW2
22pF
RPG2
100k
CIN2
10uF
16V
E
APPROVED
REVISION HISTORY
PRODUCTION
R10
OPT.
CUSTOMER NOTICE
3
16
15
RSD1
5.1M
RF
100
JP2
RUN2
1
REV
R9
OPT.
B
1
2
3
Vishay
IHLP1616BZER2R2M11
L1
2.2uH
JP1
RUN1
__
ECO
D
R8
121k
1%
R1
210k
1%
OFF
ON
JP3
MODE/SYNC
1
2
3
4
5
6
COUT1
10uF
6.3V
BURST MODE
PULSE-SKIP
EXT SYNC
CIN1BY
0.1uF
16V
R11
0 Ohm
0805
11
R7
105k
1%
R5
140k
1%
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
PVIN1
4.5V - 15V
14
RUN1
VFB1
13
4
2
1
SVIN
4
PVIN1
PGND1
C
GND
17
5
7
B
SGND
SGND
8
10
PVIN2
PGND2
RUN2
VFB2
12
A
1
2
3
4
DEMO MANUAL DC1847A
Schematic Diagram
dc1847af
9
DEMO MANUAL DC1847A
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
10 Linear Technology Corporation
dc1847af
LT 0314 • 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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