DC2169A - Demo Manual

DEMO MANUAL DC2169A
LT8616
Dual 42V Synchronous Monolithic Step-Down
Regulator with 6.5µA Quiescent Current
Description
Demonstration circuit 2169A is a dual monolithic step-down
DC/DC switching regulator featuring the LT®8616. The
LT8616 is a high efficiency, high speed, dual synchronous
monolithic step-down switching regulator that consumes
only 6.5μA of quiescent current with both channels enabled.
The demo circuit is designed for 5V, 1.5A and 3.3V, 2.5A
outputs. Both channels contain all switches and necessary circuitry to minimize the external components and
solution size. Fast minimum ON time of 35ns enables high
VIN to low VOUT conversion at high switching frequency.
Independent input voltage, feedback, soft-start and power
good pins for each channel simplify complex power supply
tracking/sequencing requirements.
The inputs of the two channels are connected on the demo
board by default. They can also be separated by removing
the 0Ω resistor (R13) from the board. Each output can
be independently disabled using its own EN/UV pin, while
VIN1 must be connected to 3.4V or above even if only
channel 2 is in use. The demo board has an EMI filter
installed between VIN2 and VEMI. To use the EMI filter, the
inputs should be tied to VEMI.
The switching frequency of both channels can be programmed either via an oscillator resistor or a common
external clock up to 3MHz.The SYNC pin on the demo
board is grounded by default for Burst Mode® operation.
Performance Summary
To synchronize to an external clock, move JP1 to SYNC/
MODE and apply the external clock to the SYNC/MODE
turret. The RT resistor (R5) should be chosen to set the
LT8616 internal switching frequency at least 20% below
the lowest synchronization input.
Low ripple Burst Mode operation increases the efficiency
at the light load while keeping the output ripple low.
Figure 1 and Figure 2 show the demo board efficiency for
each channel at 12V input voltage in Burst Mode operation. Figure 3 shows the temperature rising on DC2169A
demo board with different input voltages under full load
conditions on both channels.
The LT8616 data sheet gives a complete description of the
part, operation and application information. The data sheet
must be read in conjunction with this demo manual for
DC2169A. The LT8616 is assembled in a 28-lead plastic
TSSOP package. Proper board layout is essential for both
low EMI operation and maximum thermal performance.
See the data sheet sections for details.
Design files for this circuit board are available at
http://www.linear.com/demo/DC2169A
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
SYMBOL
PARAMETER
CONDITIONS
MIN
VIN1
Channel 1 Input Supply Range
VIN2
Channel 2 Input Supply Range
4.1
VOUT1
Channel 1 Output Voltage
4.88
VOUT2
Channel 2 Output Voltage
fSW
Switching Frequency
IOUT1
Channel 1 Max Output Current
IOUT2
Channel 2 Max Output Current
EFE
Efficiency at DC
TYP
5.8
RT = 14.7kΩ
5.02
UNITS
42
V
42
V
5.15
V
3.21
3.29
3.37
V
1.85
2.05
2.25
MHz
1.5
A
2.5
VIN1 = VIN2 = 12V, IOUT1 = 1.5A, IOUT2 = 2.5A
MAX
A
85.1
%
dc2169af
1
DEMO MANUAL DC2169A
Performance Summary
100
EFFICIENCY (%)
90
80
70
60
50
fSW = 2MHz
VIN1 = 12V
VOUT1 = 5V
0
0.3
0.9
1.2
0.6
LOAD CURRENT (A)
1.5
DC2169A F01
Figure 1. LT8616 Channel 1 Efficiency vs Load Current
100
EFFICIENCY (%)
90
80
70
60
50
fSW = 2MHz
VIN2 = 12V
VOUT2 = 3.3V
0
0.5
1.5
1
LOAD CURRENT (A)
2
2.5
DC2169A F02
Figure 2. LT8616 Channel 2 Efficiency vs Load Current
TEMPERATURE RISING (°C)
100
fSW = 2.05MHz
VOUT1 = 5V, IOUT1 = 1.5A
80
60
40
20
8
16
24
32
INPUT VOLTAGE (V)
40
DC2169A F03
Figure 3. LT8616 Temperature Rising vs Input Voltage
2
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DEMO MANUAL DC2169A
Quick Start Procedure
DC2169A is easy to set up to evaluate the performance
of the LT8616. Refer to Figure 4 for proper measurement
equipment setup and follow the procedure below:
4.Turn on the power at the input.
5.Check for the proper output voltages (5V and 3.3V).
NOTE: If there is no output, temporarily disconnect the
load to make sure that the load is not set too high or
is shorted.
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 Figure 5 for the proper
scope technique.
6.Once the proper output voltages are established, adjust
the load within the operating ranges and observe the
output voltage regulation, ripple voltage, efficiency and
other parameters.
1.Place JP1 on the Burst Mode position.
7.An external clock can be added to the SYNC terminal
when SYNC function is used (JP1 on the SYNC/MODE
position). Please make sure that the SYNC frequency is
at least 20% higher than the set switching frequency.
See the data sheet section Synchronization.
2.With power off, connect the input power supply to VEMI
and GND. Make sure that the input voltage does not
exceed 42V.
3.With power off, connect loads from VOUT1 to GND, and
VOUT2 to GND.
Figure 4. Proper Measurement Equipment Setup
VOUT
GND
Figure 5. Measuring Input or Output Ripple
dc2169af
3
DEMO MANUAL DC2169A
Parts List
ITEM
QTY
REFERENCE
PART DESCRIPTION
MANUFACTURER/PART NUMBER
Required Circuit Components
1
2
C2, C3
CAP., X7R, 0.1µF, 10V, 10% 0402
SAMSUNG, CL05B104KP5NNNC
2
1
C4
CAP., X7R, 22µF, 10V, 10% 1210
MURATA, GRM32ER71A226KE20L
3
1
C5
CAP., X7R, 47µF, 10V, 10% 1210
MURATA, GRM32ER71A476KE15L
4
2
C6, C7
CAP., X7R, 0.01µF, 10V, 10% 0603
AVX, 0603ZC103KAT2A
5
2
C8, C9
CAP., C0G, 4.7pF, 50V, ±0.25pF 0603
AVX, 06035A4R7CAT2A
6
2
C10, C11
CAP., X7R, 2.2µF, 50V, 10% 1206
MURATA, GRM31CR71H225KA88L
7
5
C12, C17, C19, C27, C28
CAP., X7R, 1µF, 10V, 10% 0603
AVX, 0603ZC105KAT2A
8
4
C13, C14, C15, C16
CAP., X7R, 0.1µF, 50V, 10% 0402
TDK, C1005X7R1H104K050BB
9
1
L1
IND., 3.3µH, XAL4030
COILCRAFT, XAL4030-332ME
10
1
L2
IND., 2.2µH, XFL4020
COILCRAFT, XFL4020-222ME
11
6
R1, R3, R6, R8, R10, R11
RES., CHIP, 1M, 0.1W, 1%, 0603
VISHAY, CRCW06031M00FKEA
12
1
R2
RES., CHIP, 187k, 0.1W, 1%, 0603
VISHAY, CRCW0603187KFKEA
13
1
R4
RES., CHIP, 316k, 0.1W, 1%, 0603
VISHAY, CRCW0603316KFKEA
14
1
R5
RES., CHIP, 14.7k, 0.1W, 1%, 0603
VISHAY, CRCW060314K7FKEA
15
2
R7, R13
RES., CHIP, 0Ω, 0.1W, 0603
VISHAY, CRCW06030000Z0EA
16
1
U1
IC., LT8616EFE TSSOP-28/EB
LINEAR TECH., LT8616EFE#PBF
CAP., ALUM., 22µF, 63V,
SUN ELECTRONIC INDUSTRIES CORP., 63CE22BS
Additional Demo Board Circuit Components
1
2
C1, C18
2
1
L3
CHIP BEAD, 30Ω, MPZ2012
TDK, MPZ2012S300AT
3
1
L4
IND., 0.22µH, IHLP1212AB
VISHAY, IHLP1212ABERR22M11
4
1
C23
CAP., X7R, 4.7µF, 50V, 10% 1206
SAMSUNG, CL31B475KBHNNNE
5
1
C24
CAP., X7R, 10µF, 50V, 10% 1210
MURATA, GRM32ER71H106KA12L
6
2
C25, C26
CAP., X7R, 0.1µF, 50V, 10% 0402
TDK, C1005X7R1H104K050BB
7
0
R9, R12 (OPT)
RES., CHIP, 0603
Hardware: For Demo Board Only
1
16
E1-E16
TESTPOINT, TURRET, .094" PBF
MILL-MAX, 2501-2-00-80-00-00-07-0
2
1
JP1
4 PIN 0.079 SINGLE ROW HEADER
SULLINS, NRPN041PAEN-RC
3
1
XJP1
SHUNT, .079" CENTER
SAMTEC, 2SN-BK-G
4
dc2169af
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
VIN1
VEMI
SYNC/MODE
SS2/TR2
SS1/TR1
GND
5V / 1.5A
VOUT1
EN1
GND
4
C6
0.01uF
C24
10uF
50V
1210
L4
0.22uH
IHLP1212ABERR22M11
C7
0.01uF
0402
10V
R5
14.7k
2MHz
SYNC/MODE
TR/SS2
TR/SS1
FB1
FB1
SW1
SW1
BOOST1
EN/UV1
VIN2
17
28
12
13
14
9
10
8
C13
0.1uF
50V
0402
3
C14
0.1uF
50V
0402
C3
R6
1M
10V
L2
2.2uH
R7
R9
OPT
R8
1M
0
1M
R10
1M
R4
316K
R3
C9
VOUT1
VOUT2
4.7pF
XFL4020-222ME
0.1uF
0402
CUSTOMER NOTICE
11
2
26
27
3
4
5
6
22
C11
2.2uF
50V
1206
C5
47uF
10V
1210
VOUT2
VIN2
C27
1uF
+
E6
E4
PG1
PG2
GND
VOUT2
3.3V / 2.5A
EN2
GND
VIN2
4.1V - 42V
1630 McCarthy Blvd.
Milpitas, CA 95035
E14
E12
C19
1uF
E13
E11
E10
C18
22uF
63V
63CE22BS
LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A
Phone: (408)432-1900 www.linear.com
CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS;
TECHNOLOGY Fax: (408)434-0507
HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO
LTC Confidential-For Customer Use Only
VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL
APPLICATION. COMPONENT SUBSTITUTION AND PRINTED
TITLE: SCHEMATIC
CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT
DUAL 42V SYNCHRONOUS MONOLITHIC
PERFORMANCE OR RELIABILITY. CONTACT LINEAR
TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE.
C12
1uF
PG1
PG2
FB2
FB2
SW2
SW2
SW2
BOOST2
BIAS
ENUV2
1
C16
0.1uF
50V
0402
5
THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND
SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.
2
DATE:
SIZE
1
LT8616EFE
DEMO CIRCUIT 2169A
Monday, January 19, 2015
IC NO.
SHEET
1
OF
1
4
REV.
N/A
C23
4.7uF
50V
1206
4
3
JP1
4 Pins 2mm Ctrs.
L3
30 ohm
MPZ2012S300AT
SYNC/MODE
BURST MODE
2
1
R2
187k
3.3uH
XAL4030-332ME
0.1uF
C2
U1
LT8616EFE
16
C15
0.1uF
50V
0402
0
1
STEP-DOWN REGULATOR WITH 6.5µA QUIESCENT CURRENT
C26
0.1uF
50V
0402
C8
1M
4.7pF
PULSE SKIPPING
C4
22uF
10V
1210
R1
L1
R12
OPT
R11
1M
C10
2.2uF
50V
1206
R13
2
1. ALL RESISTORS ARE IN 0603
ALL CAPACITORS ARE IN 0603
C25
0.1uF
50V
0402
SYNC
C17
1uF
C28
1uF
C1
22uF
63V
63CE22BS
VOUT1
+
VIN1
3
NOTE: UNLESS OTHERWISE SPECIFIED
E16
E7
E8
E9
E5
E3
E15
E2
PAD150-094
E1
20
NC
5.8V - 42V
19
VIN1
D
4
18
NC
RT
15
GND
29
23
NC
7
24
VIN2
INTVCC
21
NC
25
NC
5
A
B
C
D
DEMO MANUAL DC2169A
Schematic Diagram
dc2169af
5
DEMO MANUAL DC2169A
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
6
dc2169af
Linear Technology Corporation
LT 0515 • PRINTED IN USA
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900
●
FAX: (408) 434-0507 ● www.linear.com
 LINEAR TECHNOLOGY CORPORATION 2015
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