Linear Technology DC1733A Quick setup guide

1
dc1733af
DEMO MANUAL DC1733A
DESCRIPTION
LT3669
Industrial Transceiver with Integrated
Step-Down Regulator and LDO
Demonstration circuit 1733A is an industrial transceiver
with integrated step-down regulator and LDO featuring the
LT
®
3669.Theboardoperatesfrom7.5Vto40VwhenJP7is
set to L+. When the JP7 is set to RES, the minimum input
voltage is 16.5V. The board withstands transients up to
60V.Thestep-downregulatoroutput
is5V.TheLDOoutput
is 3.3V. There are two assembly versions. DC1733A-A is
for the LT3669 and DC1733A-B is for the LT3669-2. The
difference is the LT3669 has an integrated catch diode.
The LT3669-2 requires an external catch diode. Table 1
shows the differences between the two versions. L, LTC, LTM, LT, Burst Mode are registered trademarks of Linear Technology Corporation.
Other product names may be trademarks of the companies that manufacture the products..
PERFORMANCE SUMMARY
The board also provides various interfaces for line drivers
and receivers. JP8 to JP11 set the signal sources or levels
for TXEN1, TXEN2, TXD1 and TXD2.
The LT3669 data sheet gives complete descriptions of the
part, operation and application information. The data sheet
must be read in conjunction with this quick start guide for
working on or modifying the demo circuit 1733A.
Design files for this circuit board are available.
Call the LT C Factory.
Specifications are at TA= 25°C
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
L+Input Supply 7.5 40 V
VBUCK Output Voltage Step-Down Regulator 4.75 5 5.25 V
VLDO Output Voltage LDO 3.135 3.3 3.465 V
IBUCK Maximum Buck Output Current LT3669, Step-Down Regulator VBUCK = 5V 100 mA
LT3669-2, Step-Down Regulator VBUCK = 5V 300 mA
ILDO Maximum LDO Output Current LT3669, VLDO = 3.3V 100 mA
LT3669-2, VLDO = 3.3V 150 mA
FSW Switching Frequency 600 kHz
EFF Efficiency LT3669, L+= 12V, VBUCK = 5V, IBUCK = 100mA 65 %
LT3669-2, L+= 12V, VBUCK = 5V, IBUCK = 300mA 76 %
TRST Reset Timeout Period C5=100nF 12.5 ms
Table 1. Version Table
ASSY TYPE U1 ILDO IBUCK C8 C9 D6 L1
DC1733A-A LT3669EUFD 0.1A 0.1A 10µF 0.1µF OPEN 82µH, CDRH4D22HPNP-820MC
DC1733A-B LT3669EUFD-2 0.15A 0.3A 22µF 0.22µF DFLS160 33µH, CDRH50D28RNP-330MC

2
dc1733af
DEMO MANUAL DC1733A
QUICK START PROCEDURE
Demonstration circuit 1733A is easy to set up to evaluate
the performance of the LT3669 or the LT3669-2. Refer to
Figure 1 for proper measurement equipment setup and
follow the procedure below:
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
ripplebytouchingtheprobetipdirectly across theterminals
of the input or output capacitors. See Figure 2 for proper
scope probe technique.
1. Place jumpers in the proper positions.
2. With power off, connect an input power supply to
L+ and L–/GND. The input supply can be a bench
power supply or can be from the respective output
from a master controller.
3. With power off, connect the load to VBUCK and GND.
4. With power off, connect another load to VLDO and GND.
5. Turn on the power at the input.
6. Check for the proper output voltages.
NOTE. If there is no output, temporarily disconnect
the load to make sure that the load is not set too high
or is shorted.
7. Once the proper output voltage is established, adjust
the loads within the operating range and observe the
output voltage regulation, ripple voltage, efficiency and
other parameters.
8. To test driver and receiver functions, use JP8 to JP11
to set up the proper signal sources or levels for TXEN1,
TXEN2, TXD1, and TXD2.
9. Set up or monitor other signals as needed.
10. Once the above signals are set up, observe driver’s
outputs and receiver’s inputs and outputs.

3
dc1733af
DEMO MANUAL DC1733A
QUICK START PROCEDURE
Figure1. Proper Measurement Equipment Setup
Figure2. Measuring Input or Output Ripple

4
dc1733af
DEMO MANUAL DC1733A
PARTS LIST
ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER
Required Circuit Components
1 1 C1 CAP., C0G, 10pF, 25V, 5% 0402 AVX, 04023A100JAT2A
2 1 C5 CAP., X7R, 100nF, 25V, 10% 0402 AVX, 04023C104KAT2A
3 2 C6, C11 CAP., C0G, 470pF, 50V, 5% 0402 AVX, 04025A471JAT2A
4 1 C7 CAP., X7R, 1µF, 6.3V, 10% 0603 AVX, 06036C105KAT2A
5 1 C12 CAP., X7R, 4.7µF, 50V, 10% 1206 MURATA, GRM31CR71H475KA88L
6 3 C13, C15, C16 CAP., X5R, 0.1µF, 25V, 10% 0603 AVX, 06033D104KAT2A
7 4 D1, D2, D3, D4 TVS, SMCJ36A SMC Diodes Inc., SMCJ36A
8 2 R9, R21 RES., CHIP, 10K, 1/16W, 1% 0402 VISHAY, CRCW040210K0FKED
9 5 R10, R11, R14, R18, R25 RES., CHIP, 100K, 1/16W, 1% 0402 VISHAY, CRCW0402100KFKED
10 1 R12 RES., CHIP, 42.2K, 1/16W, 1% 0402 VISHAY, CRCW040242K2FKED
11 1 R13 RES., CHIP, 0Ω, 1/16W, 0402 VISHAY, CRCW04020000Z0ED
12 5 R15, R16, R26, R27, R28 RES., CHIP, 1K, 1/16W, 5% 0402 VISHAY, CRCW04021K00JKED
13 1 R17 RES., CHIP, 1M, 1/16W, 1% 0402 VISHAY, CRCW04021M00FKED
14 1 R19 RES., CHIP, 14K, 1/16W, 1% 0402 VISHAY, CRCW040214K0FKED
15 1 R20 RES., CHIP, 4.42K, 1/16W, 1% 0402 VISHAY, CRCW04024K42FKED
16 1 R22 RES., CHIP, 53.6K, 1/16W, 1% 0402 VISHAY, CRCW040253K6FKED
17 1 R23 RES., CHIP, 10.2K, 1/16W, 1% 0402 VISHAY, CRCW040210K2FKED
18 1 R24 RES., CHIP, 38.3K, 1/16W, 1% 0402 VISHAY, CRCW040238K3FKED
DC1733A-A Version Specific Components
1 1 C8 CAP., X5R, 10µF, 6.3V, 10% 0805 MURATA, GRM219R60J106KE19D
2 1 C9 CAP., X7R, 0.1µF, 10V, 10% 0402 TDK, C1005X7R1A104K
3 0 D6(OPEN) DIODE, POWER-DI-123
4 1 L1 INDUCTOR, 82µH SUMIDA, CDRH4D22HPNP-820MC
5 1 U1 IC., LT3669EUFD QFN 4X5, 29 PIN LINEAR TECH., LT3669EUFD#PBF
DC1733A-B Version Specific Components
1 1 C8 CAP., X5R, 22µF, 6.3V, 10% 0805 MURATA, GRM21BR60J226M
2 1 C9 CAP., X7R, 0.22µF, 10V, 10% 0402 TDK, C1005X7R1A224K
3 1 D6 DIODE, POWER-DI-123 Diodes Inc., DFLS160-7
4 1 L1 INDUCTOR, 33µH SUMIDA, CDRH50D28RNP-330MC
5 1 U1 IC., LT3669EUFD-2 QFN 4X5, 29 PIN LINEAR TECHNOLOGY CORPORATION, LT3669EUFD-2#PBF
Additional Demo Board Circuit Components
1 0 C10(OPT) CAP., 1206
2 0 C14(OPT) CAP., 0402
3 0 D5(OPT) DIODE, POWER-DI-123
Hardware: For Demo Board Only
1 21 E1-E21 TESTPOINT, TURRET, .094" pbf MILL-MAX, 2501-2-00-80-00-00-07-0
2 7 JP1-JP7 3 PIN 0.079 SINGLE ROW HEADER SULLINS, NRPN031PAEN-RC
3 4 JP8-JP11 2X4, 0.079 DOUBLE ROW HEADER SULLINS, NRPN042PAEN-RC
4 11 xJP1-xJP11 SHUNT, 0.079" CENTER SAMTEC, 2SN-BK-G
5 1 J1 M12 CONNECTOR, 5 PIN BINDER, 09 3441 500 05
6 1 J2 CONNECTOR, OSTTV041150 On shore tech., OSTTV041150
7 1 J3 2X8, 0.079 DOUBLE ROW HEADER SULLINS, NRPN082PAEN-RC
8 4 (STAND-OFF) STAND-OFF, NYLON 0.25" KEYSTONE, 8831(SNAP ON)

5
dc1733af
DEMO MANUAL DC1733A
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 representa-
tion that the interconnection of its circuits as described herein will not infringe on existing patent rights.
Figure3. DC1733A Demo Circuit Schematic
SCHEMATIC DIAGRAM
5 5
4 4
3 3
2 2
1 1
D
D
C
C
B
B
A
A
SC1
RXD1
SC2
RST
SYNC
1. ALL RESISTORS ARE 0402 ALL CAPACITORS ARE 0402. NOTE: UNLESS OTHERWISE SPECIFIED
ILIM
SR
5V
GND
CQ1-2
PAR OPEN
GND RES
PAR OPEN PAR OPEN LDOIN
VOUT
DIO
TXEN1
TXEN2
TXD1
TXD2
TXEN1-2
TXD1-2
7.5V - 40V
EN/UVLO
L+
RES
L+
Q2
L-/GND CQ1
ASSY TYPE
VERSION TABEL
*
DC1733A-A DC1733A-B
U1
LT3669EUFD LT3669EUFD-2
C8
0.1uF
C9
10uF 22uF 0.22uF
D6
DFLS160
OPEN
L1
33uH, CDRH50D28RNP-330MC
82uH, CDRH4D22HPNP-820MC
II
LDO BUCK
0.1A 0.1A
0.15A 0.3A
*
*
RXD1
SC1 SYNC SC2
WAKE
WAKE
SC1
SYNC
RST
TXEN2-J
TXD2-J TXD1-J
RXD1
TXEN1-J
5V 5V
GND GND
TXEN1-J
5V 5V
GND GND
TXEN2-J TXD1-J TXD2-J
SC2
RST
5V
5V
5V
5V
5V
5V
5V
3.3V
5V
3.3V
5V
EXPOSED
PAD
U1
*
EXPOSED
PAD
U1
*
SC1
1
SC2
2
WAKE 3
RXD1
4
TXEN1
5
TXD1
6TXEN2 7
TXD2
8
Q2 9
L+ 11
EN/UVLO 12
DIO 13
DA 14
SW 15
BST 16
BD 17
LDO_IN 18
LDO 19
FB_LDO 20
FB_OUT 21
RT 22
AGND
23
SYNC
24
SR
25
ILIM
26
CPOR
27
RST
28
GND
29
CQ1 10
C8
*
6.3V
0805
C8
*
6.3V
0805
E13E13
JP9JP9
1 2 3 5 7
4 6 8
C6
470pF
50V
C6
470pF
50V
J2
CON-OSTTV041150
J2
CON-OSTTV041150
1 2 3 4
R27 1K R27 1K
C5
100nF
C5
100nF
E14
GND
E14
GND
R15 1K R15 1K
E11
Q2
E11
Q2
E9
L+
E9
L+
JP2JP2
1
2
3
R20
4.42K
R20
4.42K
D2D2
E7
WAKE
E7
WAKE
R16 1K R16 1K
E21
GND
E21
GND
C10 OPT
1206
C10 OPT
1206
JP8JP8
1 2 3 5 7
4 6 8
R14
100K
R14
100K
D3D3
R17
1M
R17
1M
E17
TXEN1
E17
TXEN1
C1
10pF
C1
10pF
E15
GND
E15
GND
C14
OPT
C14
OPT
E5 3.3V / I
V
LDO
LDO
E5 3.3V / I
V
LDO
LDO
JP1JP1
1
2
3
R22
53.6K
R22
53.6K
E4E4
JP10JP10
1 2 3 5 7
4 6 8
E10
CQ1
E10
CQ1
C9
*
C9
*
C12
4.7uF
50V
1206
C12
4.7uF
50V
1206
JP7JP7
1
2
3
R11 100K R11 100K
R18
100K
R18
100K
C7
1uF
6.3V
0603 C7
1uF
6.3V
0603
JP3JP3
1
2
3
R23
10.2K
R23
10.2K
JP4JP4
1
2
3
C13
0.1uF
6.3V
0603
C13
0.1uF
6.3V
0603
R26 1K R26 1K
R9
10K
R9
10K
E2E2
E16
EN/UVLO
E16
EN/UVLO
E6 5V / I
V
BUCK
BUCK
E6 5V / I
V
BUCK
BUCK
R24
38.3K
R24
38.3K
E18
TXEN2
E18
TXEN2
D6
*
D6
*
JP6JP6
1
2
3
E19
TXD1
E19
TXD1
L1
*
L1
*
R21
10K
R21
10K
E8
GND
E8
GND
J3
HEADER 2X8 2MM
J3
HEADER 2X8 2MM
1 2 3 4 5 6 7 8 9
10 11 12 13 14 15 16
E12
L-/GND
E12
L-/GND
C11
470pF
50V C11
470pF
50V
C16
0.1uF
6.3V
0603
C16
0.1uF
6.3V
0603
D1
SMCJ36A
D1
SMCJ36A
JP5JP5
1
2
3
JP11JP11
1 2 3 5 7
4 6 8
R10
100K
R10
100K
R25
100K
R25
100K
R28
1K
R28
1K
E1E1
C15
0.1uF
6.3V
0603
C15
0.1uF
6.3V
0603
E20
TXD2
E20
TXD2
E3E3
D5 OPT D5 OPT
R12
42.2K
R12
42.2K
D4 SMCJ36A D4 SMCJ36A
R19
14K
R19
14K
R13
0
R13
0
J1
M12-MALE-5PIN
J1
M12-MALE-5PIN
1 2 3 4 5 S2
S1

6
dc1733af
DEMO MANUAL DC1733A
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
[phone] ●FAX: [phone] ●www.linear.com
 LINEAR TECHNOLOGY CORPORATION 2014
LT 0614 • PRINTED IN USA
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 applica-
tion engineer.
Mailing Address:
Linear Technology
1630 McCarthy Blvd.
Milpitas, CA 95035
Copyright © 2004, Linear Technology Corporation

Mouser Electronics
Authorized Distributor
Click to View Pricing, Inventory, Delivery & Lifecycle Information:
Analog Devices Inc.:
DC1733A-B DC1733A-A