DC1963A - Demo Manual

DEMO MANUAL DC1963A
LT8310
48VIN to 12V/6A
Isolated Forward Converter
Description
Demonstration circuit 1963A is a resonant reset forward
converter featuring the LT®8310 controller.
This circuit was designed to demonstrate the high level
of performance, and small solution size attainable using
the LT8310. It operates at a 250kHz switching frequency,
and regulates a 12V, 6A output from a 36V to 72V input
source, making it well suited for telecom, industrial, and
other applications. Table 1 summarizes the performance
of the DC1963A.
The LT8310 is a constant-frequency forward converter
controller with a low side N-channel MOSFET gate driver.
Output regulation is handled on the secondary side by the
LT1431, which is an adjustable shunt voltage regulator
providing feedback to the primary side via an opto-coupler.
The DC1963A takes advantage of the LT8310’s input
undervoltage and overvoltage protection to shutdown the
system when the input voltage is outside of the set limits.
The DC1963A also has precise overcurrent protection
that allows for continuous operation under short circuit
conditions. The low power dissipation under a short circuit
condition ensures high reliability even during a prolonged
output voltage short circuit.
The LT8310 data sheet gives a complete description of
the part, operation and application information. The data
sheet must be read in conjunction with this quick start
guide for demo circuit 1963A.
Design files for this circuit board are available at
http://www.linear.com/demo/DC1963A
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
PARAMETER
Specifications are at TA = 25°C
CONDITIONS
Input Voltage
Output Voltage
VIN = 36V – 72V
Maximum Output Current
MIN
TYP
MAX
36
48
72
V
11.76
12
12.24
V
6
Switching (Clock) Frequency
Output Voltage Ripple (Peak-to-Peak)
VIN = 36V – 72V, IOUT = 6A (20MHz BW)
Output Regulation
Line and Load (36V to 72VIN, 0A to 6AOUT)
Efficiency (See Figure 3)
UNITS
A
250
kHz
50
mV
±0.1
%
VIN = 36V, IOUT = 6A
91
%
VIN = 48V, IOUT = 6A
91.5
%
VIN = 72V, IOUT = 6A
90.5
%
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DEMO MANUAL DC1963A
Quick Start Procedure
Demonstration circuit 1963A is easy to set up to evaluate the performance of the LT8310. Refer to Figure 1 for
proper measurement equipment setup and follow the
procedure below:
1. With power off, connect the input power supply to the
board through +VIN and –VIN terminals. Connect the
load to the terminals +VOUT and –VOUT on the board.
2. Turn on the power at the input.
NOTE: Make sure that the input voltage does not exceed
72V. Input voltages lower than 36V can keep the converter
from turning on due to the undervoltage lockout feature
of the LT8310.
NOTE: If there is no output, temporarily disconnect the
load to make sure that the load is not set too high.
4. Once the proper output voltage is established, adjust
the input voltage and load current within the operating
range and observe the output voltage regulation, ripple
voltage, efficiency and other parameters.
NOTE: When measuring the input or output voltage ripples,
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
and –VIN, or +VOUT and –VOUT terminals. See Figure 2 for
proper scope probe technique.
3. Check for the proper output voltages. The output should
be regulated at 12V (±2%).
2
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DEMO MANUAL DC1963A
Quick Start Procedure
POWER SUPPLY
–
–
+
VIN
+
+
–
LOAD
–
IIN
–
VOUT
+
+
–
+
IOUT
Figure 1. Proper Measurement Equipment Setup
INPUT OR OUTPUT CAPACITOR
Figure 2. Proper Scope Probe Placement for Measuring Input/Output Ripple
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DEMO MANUAL DC1963A
performance
93
91
EFFICIENCY (%)
89
87
85
83
81
79
VIN = 36V
VIN = 48V
VIN = 72V
77
75
0
1
2
3
4
LOAD CURRENT (A)
5
6
Figure 3. Typical Efficiency Curve
GATE VOLTAGE
10V/DIV
GATE VOLTAGE
10V/DIV
SWITCH NODE
VOLTAGE
50V/DIV
SWITCH NODE
VOLTAGE
50V/DIV
1µs/DIV
1µs/DIV
(4a) 36VIN to 6AOUT
(4b) 48VIN to 6AOUT
GATE VOLTAGE
10V/DIV
SWITCH NODE
VOLTAGE
50V/DIV
1µs/DIV
(4c) 72VIN to 6AOUT
Figure 4. Steady State Waveforms
4
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DEMO MANUAL DC1963A
performance
SWITCH NODE VOLTAGE OF
SECONDARY DIODE
50V/DIV
SWITCH NODE VOLTAGE OF
PRIMARY MOSFET
50V/DIV
50ms/DIV
Figure 5. Output Short-Circuit Waveforms at 72VIN
Parts List
ITEM
QTY
REFERENCE
PART DESCRIPTION
MANUFACTURER/PART NUMBER
Required Circuit Components
1
1
C1
Cap., Alum. Elect. 47µF, 80V, ±20%
United Chemi-Con EMZA800ADA470MJA0G
2
2
C2, C3
Cap., X7S 4.7µF, 100V, 10%, 1210
TDK C3225X7S2A475K
3
2
C5, C6
Cap., X5R 47µF, 16V, 20%, 1210
Murata GRM32ER61C476ME15L
4
2
C7, C8
Cap., POSCAP 150µF, 16V, 10%, 7343
SANYO 16TQC150MYF
5
1
C9
Cap., X7S 1µF, 100V, 10%, 0805
TDK C2012X7S2A105K
6
1
C10
Cap., COG 5.6nF, 25V, 5%, 0603
TDK C1608C0G1E562J080AA
7
1
C11
Cap., X5R 4.7µF, 25V, 10%, 0805
AVX 08053D475KAT2A
8
1
C12
CAP CER 180pF, 450V, 5%, NP0 0805
TDK C2012C0G2W181J
9
2
C13, C24
Cap., X5R 1µF, 25V, 20%, 0603
AVX 06033D105MAT2A
10
1
C16
Cap., X7R 4700pF, 250V, 20%, 1812
MurataErie GA343DR7GD472KW01L
11
1
C18
Cap., X7R 3.3nF, 50V, 10%, 0603
AVX 06035C332KAT2A (to FT223A)
12
1
C21
Cap., X7R 1.2nF, 25V, 10%, 0603
AVX 06033C122KAT1A
13
1
C22
Cap., X5R 10µF, 16V, 20%, 0805
AVX 0805YD106MAT2A (from FT182/189A)
14
1
C26
Cap., NPO 100pF, 25V, 5%, 0603
AVX 06033A101JAT2A
15
1
C27
Cap., U2J 2.2nF, 250V, 5%, 0805
Murata GRM21A7U2D222JW31
16
2
D2, D3
Schottky Diode, 30A/80V, TO-263AB
Vishay Semi. VBT3080S-E3
17
1
D4
Zener Diode, 11V SOD-123
Central Semi. CMHZ5241BTR
18
1
D5
Diode, 1A/200V SOD-123
Central Semi. CMMR1U-02TR
19
1
ISO1
Opto Iso., NEPOC Series
NEC PS2801C-1-A
20
1
L1
Inductor, 22µH
Würth Electronik 74435572200
21
1
L2
Inductor, 6.8µH
Coilcraft XAL6060-682MEC
22
1
Q1
Mosfet-N Channel, 200V/36A SuperSO8
Infineon BSC320N20NS3G
23
1
R1
Res., Chip 86.6k, 0.06W, 1%, 0603
Vishay CRCW060386K6FKEA
24
1
R2
Res., Chip 1.74k, 0.10W, 1%, 0603
Vishay CRCW06031K74FKEA
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DEMO MANUAL DC1963A
Parts List
ITEM
QTY
REFERENCE
PART DESCRIPTION
MANUFACTURER/PART NUMBER
25
26
1
R5
Res., Chip 1.43k, 0.10W, 1%, 0603
Vishay CRCW06031K43FKEA
1
R6
Res., Chip 118k, 0.06W, 1%, 0603
Vishay CRCW0603118KFKEA
27
1
R7
Res., Chip 40.2k, 0.06W, 1%, 0603
Vishay CRCW060340K2FKEA
28
2
R8, R9
Res/Jumper, Chip 0Ω, 1/16W, 1 AMP 0603
Vishay CRCW06030000Z0EA
29
1
R10
Res., RL Vert. 0.025, 1W, 1%, 0815
SSM Thin Film Tech. RL3720WT-R025-F
30
2
R13, R25
Res., Chip 10k, 0.06W, 5%, 0603
Vishay CRCW060310K0JNEA
31
1
R14
Res., Chip 3k, 0.06W, 5%, 0603
Vishay CRCW06033K00JNEA
32
1
R15
Res., Chip 3.3k, 0.06W, 5%, 0603
Vishay CRCW06033K30JNEA
33
2
R16, R23
Res., Chip 100k, 0.06W, 5%, 0603
Vishay CRCW0603100KJNEA
34
1
R17
Res., Chip 95.3k, 0.06W, 1%, 0603
Vishay CRCW060395K3FKEA
35
1
R20
Res., Chip 24.9k, 0.06W, 1%, 0603
Vishay CRCW060324K9FKEA
36
1
R21
Res., Chip 200, 0.125W, 1%, 0805
Vishay CRCW0805200RFKEA
37
1
R22
Res., Chip 499, 0.06W, 1%, 0603
Vishay CRCW0603499RFKEA
38
1
R24
Res., Chip 61.9k, 0.06W, 1%, 0603
Vishay CRCW060361K9FKEA
39
1
R26
Res., Chip 20.0k, 0.06W, 1%, 0603
Vishay CRCW060320K0FKEA
40
1
R27
Res., Chip 59.0k, 0.25W, 1%, 1206
Vishay CRCW120659K0FKEA
41
1
T1
XFMR., PULSE-PA4078NL
PULSE PA4078NL
42
1
U1
I.C., Converter Controller TSSOP20-FE20
Linear Tech. Corp. LT8310EFE#PBF
43
1
U2
I.C., Prog. Reference SO8NB
Linear Tech. Corp. LT1431CS8#PBF
Optional Circuit Components
1
1
C14
Cap., 0603
5
E1, E2, E3, E4, E5
Turret, Testpoint
Hardware
1
6
Mill Max 2501-2-00-80-00-00-07-0
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DEMO MANUAL DC1963A
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 DC1963A
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
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ANY INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES.
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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.
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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
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