DC2270A - Demo Manual

DEMO MANUAL DC2270A
LT3095
Dual-Channel Low Noise Bias
Generators
DESCRIPTION
Demonstration circuit 2270A is a dual-channel low noise
bias generator featuring LT3095. The LT3095 generates two
low noise bias supplies from a common input voltage range
from 3V to 20V. Each channel includes a fixed frequency,
peak current mode step-up switching regulator and a low
noise, single resistor programmable linear regulator. The
maximum load current is 50mA for each channel.
2MHz. The SYNC pin on the demo board is grounded by
default. To synchronize to an external clock, move JP1
to SYNC and apply the external clock to the SYNC turret.
The RT resistor (R2) should be chosen to set the LT3095
internal switching frequency to the SYNC frequency.
Each boost regulator adjusts its output voltage to 2V above
the corresponding linear regulator’s output voltage, optimizing power dissipation, PSRR and transient response.
The integrated boost regulator, frequency compensation
and Schottky diodes minimize the external component
count and simplify system design.
The LT3095 data sheet gives a complete description of
the device, operation and application information. The
data sheet must be read in conjunction with this quick
start guide for demo circuit 2270.
The switching frequency can be programmed either via
oscillator resistor or an external clock from 450kHz to
PERFORMANCE SUMMARY
The LT3095 is available in a thermally enhanced 24-Lead
3mm × 5mm QFN package.
Design files for this circuit board are available at
http://www.linear.com/demo/DC2270A
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.
Specifications are at TA = 25°C
SYMBOL
PARAMETER
VIN
Input Voltage Range
CONDITIONS
MIN
VOUT1
Channel1 Output Voltage
4.9
VOUT2
Channel2 Output Voltage
14.7
IOUT1
Channel1 Max Output Current
IOUT2
Channel2 Max Output Current
fSW
Switching Frequency
RT = 100kΩ
VOUT,P-P
Output Voltage Peak-to-Peak Noise
VIN = 5V, VOUT = 15V, IOUT = 50mA, fSW = 1MHz
20MHz BW
TYP
3
MAX
V
5
5.1
V
15
15.3
50
V
mA
50
0.95
UNITS
20
mA
1
65
1.05
MHz
µV
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DEMO MANUAL DC2270A
QUICK START PROCEDURE
Demonstration circuit 2270 is easy to set up to evaluate
the performance of the LT3095. Refer to Figure 2 for
proper measurement equipment setup and follow the
procedure below:
1. Place JP1 on RT position.
2. With power off, connect the input power supply to VIN
and GND. Make sure that the input voltage does not
exceed 20V.
3. With power off, connect loads from VOUT1 to GND, and
VOUT2 to GND.
6. Once the proper output voltage is established, adjust
the load within the operating range and observe the
output voltage regulation and other parameters.
7. An external clock can be added to the SYNC terminal
when SYNC function is used (JP1 on the SYNC position).
The set switching frequency should be programmed
to the SYNC frequency. See the data sheet section
Programming the Switching Frequency for details.
8. The output noise can be measured by J1 and J2. Please
refer to Application Notes 70 for details.
4. Turn on the power at the input.
5. Check for the proper output voltages (5V and 15V).
NOTE: If there is no output, temporarily disconnect the
load to make sure that the load is not set too high or
is shorted.
VBSTOUT
20mV/DIV
VOUT
50µV/DIV
VIN = 5V
VOUT = 15V
ILOAD = 50mA
fOSC = 1MHz
20MHz BW
1µs/DIV
dc2270a F01
Figure 1. Transient Output Ripple
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DEMO MANUAL DC2270A
QUICK START PROCEDURE
*J1 AND J2 ARE THE BNC CONNECTORS TO COAXIAL CABLE FOR NOISE MEASUREMENT.
PLEASE REFER TO AN70 APPENDIX B FOR DETIALS
Figure 2. Proper Measurement Equipment Setup
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DEMO MANUAL DC2270A
PARTS LIST
ITEM
QTY
REFERENCE
PART DESCRIPTION
MANUFACTURER/PART NUMBER
CAP., 2.2µF, X7R, 25V, 10%, 0805
MURATA, GRM21BR71E225KA73L
Required Circuit Components
1
2
C1, C2
2
2
C3, C4
CAP., 10µF, X7R, 25V, 10%, 1210
MURATA, GRM32DR71E106KA12L
3
2
C5, C6
CAP., 2.2µF, X7R, 25V, 10%, 1210
AVX, 12103C225KAT2A
4
2
C7, C8
CAP., 1µF, X7R, 25V, 10%, 0603
MURATA, GRM188R71E105KA12D
5
1
C9
CAP., 0.1µF, X7R, 6.3V, 10%, 0603
AVX, 06036D104KAT2A
6
1
L1
INDUCTOR, 6.8µH
COILCRAFT LPS4012-682MR
7
1
L2
INDUCTOR, 10µH
COILCRAFT LPS4012-103MR
8
4
R1, R2, R4, R5
RES., CHIP, 100k, 1/10W, 1%, 0603
VISHAY, CRCW0603100KFKEA
9
1
R3
RES., CHIP, 300k, 1/10W, 1%, 0603
VISHAY, CRCW0603300KFKEA
10
1
U1
I.C., REGULATOR, QFN24-3X5-UDD
LINEAR TECH., LT3095EUDD#PBF
Additional Demo Board Circuit Components
1
0
C10, C11 (OPT)
CAP., 0805
2
0
C12, C13 (OPT)
CAP., 0603
3
0
R6, R7 (OPT)
RES., 0603
4
0
C14 (OPT)
CAP, TANT., 10µF, 25V, 20%, 2312
AVX, TAJW106M025RNJ
TESTPOINT, TURRET, 0.094" pbf
MILL-MAX, 2501-2-00-80-00-00-07-0
Hardware: For Demo Board Only
1
10
E1-E10
2
1
JP1
HEADER 3 PIN 0.079 SINGLE ROW
WURTH, 620 003 111 21
3
1
XJP1
SHUNT, 0.079" CENTER
WURTH, 608 002 134 21
4
2
J1-J2
CONN, BNC, 5 PINS
CONNEX, 112404
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DEMO MANUAL DC2270A
SCHEMATIC DIAGRAM
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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.
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DEMO MANUAL DC2270A
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
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Linear Technology Corporation
LT 1015 REV A • PRINTED IN USA
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900
●
FAX: (408) 434-0507 ● www.linear.com
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