Linear Technology DC2049A Quick setup guide

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DEMO MANUAL DC2049A
DESCRIPTION
LT3999EMSE
Low Noise Isolated
Power Supply
The DC2049Ademonstrates how apower supply regulates
two output voltage by using the LT
®
3999 and low dropout
(LDO) regulators.
The LT3999 is a monolithic push-pull DC/DC driver which
features wide input range and small external passive
components.
The LT3999 has duty circle control for ΔVIN compensa-
tion, which allows for a wide input voltage range and low
LDO losses.
TheDC2049Aemploysapush-pulltopologythatinherently
provides a low-noise solution. The design is well suited
to noise sensitive systems such as medical instruments,
industrial sensing and control, data conversion and wide
band communications. The post regulator LDOs reduce
output noise further. For more details about the LDOs,
please check the LT3065 and LT3090 data sheets. L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear
Technology Corporation. All other trademarks are the property of their respective owners.
PERFORMANCE SUMMARY
TheDC2049A produces an isolated 12VOUT and–12VOUT at
up to 200mA each from a 10V~ 15.5V input voltage range.
This board can be modified, by changing the transformer
(and duty cycle), to produce other output voltages.
TheDC2049A featuresa small transformer,small inductors
and capacitors that work at a 1MHz switching frequency.
The LT3999 data sheet gives a complete description of the
part,operation and applicationsinformation. The datasheet
must be read in conjunction with this demo manual. The
LT3999EMSE is assembled in a 10-lead plastic MSE pack-
age with a thermally enhanced ground pad. Proper board
layout is essential for maximum thermal performance. See
the data sheet section Layout Consideration Check List.
Design files for this circuit board are available at
http://www.linear.com/demo/DC2049A
Specifications are at TA= 25°C
PARAMETERS MIN TYP MAX UNITS
Input Voltage Range 10.0 15.5 VDC
Output Voltage 1 (VOUT1) 11.64 12.0 12.3 VDC
Output Voltage 2 (VOUT2) –12.36 –12.0 –11.64 VDC
Output Current 1 0 200 mA
Output Current 2 0 200 mA
Switching Frequency 1.0 MHz
Isolation 1000 VDC

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DEMO MANUAL DC2049A
QUICK START PROCEDURE
DC2049A is easy to set up to evaluate the performance of
the LT3999EMSE. Refer to Figure 1 for proper measure-
ment equipment setup and follow the procedure below:
1. Connect Load 1 (positive) between the VOUT1 and GND
terminals and another Load 2 (negative) between the
VOUT2 and GND terminals.
2. With power off, connect the input power supply to the
+VIN and –VIN terminals.
3. Turn the input power supply on and make sure the
voltage is between 10V and 15.5V.
4. To measure the output noise, connect one end of a BNC
connector J1. Connect the other end of the BNC cable
to an oscilloscope with a 50Ω input impedance. Refer
to Application Note 70 for more precise techniques for
measuring the output noise.
Figure 1. Test Procedure Setup Drawing for DC2049A
*J1 is the BNC connector to coaxial
cable for noise measurement, please
refer to AN70 Appendix B for details.

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DEMO MANUAL DC2049A
QUICK START PROCEDURE
Figure 3. Switch Node Voltage, VIN = 10V
Figure 5. Thermal Image, VIN = 10V, IOUT1 = IOUT2 = 200mA
Figure 4. Switch Node Voltage, VIN = 15V
Figure 6. Thermal Image, VIN = 15V, IOUT1 = IOUT2 = 200mA
Figure 2. Efficiency and Power Loss vs Input Voltage with LT3999 and LDOs
VIN (V)
10
EFFICIENCY (%)
70
50
60
40
30
POWER LOSS (W)
4
2
3
1
0
12 14
dc2049a F02
1611 13 15
IOUT1 = 200mA
IOUT2 = 200mA
POWER LOSS
EFFICIENCY

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DEMO MANUAL DC2049A
ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER
Required Circuit Components
1 1 U1 I.C., Push-Pull DC/DC Driver Linear Tech. Corp. LT3999EMSE#PBF
2 1 U2 I.C., Low Noise Linear Reg. Linear Tech. Corp. LT3065EDD#PBF
3 1 U3 I.C., Negative Linear Reg. Linear Tech. Corp. LT3090EDD#PBF
4 4 D1, D2, D3, D4 Schottky Diode 200V/1AMP Central Semi. CMSH1-200HE
5 1 T1 Xfmr. Würth Elektronik 750314781
6 2 L1, L2 Inductor, 39µH Coilcraft XFL3012-393MEC
7 1 C1 Cap., Alum 10µF 50V 10% Sun Elect., 50CE10BSS
8 1 C2 Cap., X5R 4.7µF 25V 20% 0805 Taiyo Yuden TMK212BJ475MG-T
9 2 C3 Cap., X7R 0.1µF 25V 10% 0603 AVX 06033C104KAT2A
10 1 C4 Cap., NPO 180pF 50V 10% 0805 AVX 08055A181KAT2A
11 1 C5 Cap., X7R 4.7µF 25V 20% 1206 TDK C3216X7R1E475M
12 2 C7, C14 Cap., X5R 10µF 50V 20% 1206 TDK C3216X5R1H106M
13 1 C9 Cap., X7R 0.01µF 50V 10% 0603 AVX 06035C103KAT2A
14 2 C10, C16 Cap., X7R 10µF 25V 20% 1206 TDK C3216X7R1E106MT
15 1 C17 Cap., X7R 2200pF 1KV 20% 1206 AVX 1206AC222MAT2A
16 3 R1, R2, R13 Res., Chip 1.00M 0.10W 1% 0603 Vishay CRCW06031M00FKEA
17 1 R4 Res., Chip 143k 0.10W 1% 0603 Vishay CRCW0603143KFKEA
18 1 R5 Res., Chip 86.6k 0.10W 1% 0603 Vishay CRCW060386K6FKEA
19 1 R7 Res., Chip 12.1k 0.10W 1% 0603 Vishay CRCW060312K1FKEA
20 1 R8 Res., Chip 13.3k 0.10W 1% 0603 Vishay CRCW060313K3FKEA
21 1 R9 Res., Chip 49.9k 0.10W 1% 0603 Vishay CRCW060349K9FKEA
22 1 R10 Res., Chip 39Ω 0.125W 5% 0805 Vishay CRCW080539R0JNEA
23 1 R12 Res., Chip 10k 0.50W 5% 1210 Vishay CRCW121010K0JNEA
24 1 R14 Res., Chip 52.3k 0.10W 1% 0603 Vishay CRCW060352K3FKEA
25 1 R16 Res., Chip 10k 0.25W 5% 1206 Vishay CRCW120610K0JNEA
26 1 R17 Res., Chip 243k 0.10W 1% 0603 Vishay CRCW0603243KFKEA
Additional Demo Board Circuit Components
1 1 R11 Res/Jumper, Chip 0Ω 0.10W 0603 Vishay CRCW06030000Z0EA
2 2 C12 Cap., X7R 0.1µF 25V 10% 0603 AVX 06033C104KAT2A
3 1 C11 Cap., X5R 1µF 25V 20% 0603 AVX 06033D105MAT2A
4 0 C6, C8, C13, C15 (Opt) Cap., 1206
5 0 R3, R6 (Opt) Res., 0603
6 0 R15 (Opt) Res., 1206
Hardware: For Demo Board Only
1 1 J1 BNC Connector Connex 112404
2 7 E1, E2, E3, E4, E5, E6, E7 Turret, Testpoint Mill Max 2501-2-00-80-00-00-07-0
PARTS LIST

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DEMO MANUAL DC2049A
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.
SCHEMATIC DIAGRAM

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DEMO MANUAL DC2049A
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
[phone] ●FAX: [phone] ●www.linear.com
 LINEAR TECHNOLOGY CORPORATION 2014
LT 1014 • PRINTED IN USA
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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
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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
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