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dc1988af
DEMO MANUAL DC1988A
Description
LTM8058
Isolated μModule DC/DC Converter
with LDO Post Regulator
Demonstration circuit 1988A is a 2kV AC (3kVDC) isolated
flyback μModule
®
DC/DC converter with LDO post regulator
featuring the LTM
®
8058. The demo circuit is designed for
a 6V flyback output and a 5V post regulator output from
a 4.5V to 30V input. The current capability of the 6V fly-
back output varies with input voltage from about 100mA
at 4.5VIN to about 320mA at 30VIN. Figure 1 shows the
typical maximum output current on VOUT1 when VOUT2 is
not loaded. VOUT2 is the LDO post regulator from VOUT1.
The current capability of VOUT2 is limited by either the cur-
rent capability of VOUT1 minus VOUT1 loading or the 300mA
current limit on the LDO post regulator itself. R1 provides
the necessary minimum load current to keep the VOUT1
in regulation throughout the entire input voltage range.
Please see the typical performance characteristic curves L, LT, LTC, LTM, µModule, 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
BoarD photo
in the LTM8058 data sheet to determine the minimum load
current for other input/output configurations.
The two-stage converter provides an isolated flyback output
as well as a low noise LDO output. Figure 2 shows the
output noise spectrum on VOUT1 and Figure 3 shows the
output noise spectrum on VOUT2.
The LTM8058 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 1988A.
Design files for this circuit board are available at
http://www.linear.com/demo/DC1988A
Specifications are at TA = 25°C
PARAMETER CONDITIONS VALUE
Minimum Input Voltage 4.5V
Maximum Input Voltage 30V
Output Voltage VOUT1 VIN = 7V to 30V 6V ±5%
Output Voltage VOUT2 VIN = 7V to 30V 5.0V ±3%
Voltage Ripple VOUT1 VIN = 12V, IOUT2 = 0mA, IOUT2 = 100mA 10mV
Voltage Ripple VOUT2 VIN = 12V, IOUT2 = 0mA, IOUT2 = 100mA 5mV
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dc1988af
DEMO MANUAL DC1988A
Quick start proceDure
Demo circuit 1988A is easy to set up to evaluate the per-
formance of the LTM8058. Refer to Figure 4 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
ripple by touching the probe tip directly across the VIN or
VOUT and GND terminals. See Figure 5 for proper scope
probe technique.
1. With power off, connect the input power supply to VIN
and GND.
2. Turn on the power at the input.
NOTE. Make sure that the input voltage does not exceed 30V.
3. Check for the proper output voltages. (For VOUT1, check
the voltage between VOUT1 and VOUT–. For VOUT2, check
the voltage between VOUT2 and VOUT–.)
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 voltages are established, adjust
the load within the operating range and observe the
output voltage regulation, ripple voltage, efficiency and
other parameters.
Figure 1. VOUT1 Typical Maximum Output
Current vs VIN with VOUT2 Unloaded
Figure 2. VOUT1 Output Noise Spectrum with IOUT1
at 100mA and VIN at 12V (VOUT2 Has No Extra Load)
Figure 3. VOUT2 Output Noise Spectrum with IOUT2
at 100mA and VIN at 12V (VOUT1 Has No Extra Load)
VIN (V)
4
0
OUTPUT CURRENT (mA)
300
250
200
150
100
50
400
350
6 22 24 26 28 308 10 12 181614
dc1988a F01
20
FREQUENCY (MHz)
0
–90
INTENSITY (dBm)
–20
–30
–40
–50
–60
–70
–80
0
–10
3.5 4 4.5 50.5 1 2.521.5
dc1988a F02
3
FREQUENCY (MHz)
0
–90
INTENSITY (dBm)
–20
–30
–40
–50
–60
–70
–80
0
–10
3.5 4 4.5 50.5 1 2.521.5
dc1988a F03
3
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dc1988af
DEMO MANUAL DC1988A
parts List
ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER
Required Circuit Components
1 1 C1 CAP., CHIP, X5R, 10μF, 50V, 10% 1210 MÜRATA, GRM32ER71H106KA12L
2 1 C2 CAP., CHIP, X5R, 22μF, 16V, 10% 1206 AVX, 1206YD226KAT2A
3 1 C3 CAP., CHIP, X5R, 10μF, 16V, 10% 1206 AVX, 1206YD106KAT2A
4 1 C4 CAP., CHIP, X5R, 4.7μF, 50V, 20% 0805 TDK, C2012X5R1H475M
5 1 C5 CAP., CHIP, X7R, 0.01μF, 25V, 10% 0603 AVX, 06033C103kAT2A
6 1 C6 CAP., CHIP, X7R, 0.1μF, 25V, 10% 0603 AVX, 06033C104KAT2A
7 1 R1 RES., CHIP, 200k, 1/4W, 1% 1210 VISHAY, CRCW1210200RFKEA
8 1 R2 RES., CHIP, 200k, 1/10W, 1% 0603 VISHAY, CRCW0603200KFKEA
9 1 R3 RES., CHIP, 90.9k, 1/10W, 1% 0603 VISHAY, CRCW060390K9FKEA
10 1 R4 RES., CHIP, 162k, 1/10W, 1% 0603 VISHAY, CRCW0603162KFKEA
11 1 R5 RES., CHIP, 5.9k, 1/10W, 1% 0603 VISHAY, CRCW06035k90FKEA
12 1 U1 IC., LINEAR TECH., LTM8058EY#PBF LINEAR TECH., LTM8058EY#PBF
Additional Demo Board Circuit Components
1 0 C7 (OPT) CAP., 1808
2 0 C8, C9 (OPT) Cap., 1210
3 2 C10, C11 CAP., CHIP, X7R, 1μF, 16V, 10% 0603 AVX, 0603YC105KAT2A
4 0 C12 (OPT) CAP., 0603
5 1 CIN1 CAP., TANT., 10μF, 35V CASE-C AVX, TAJC106K035RNJ
6 0 L1 OPT.
7 0 R6 OPT. 0603
Hardware: For Demo Board Only
1 6 E1-E4, E6, E7 Testpoint, Turret, .094" Mill-Max, 2501-2-00-80-00-00-07-0
22 E5, E8 Testpoint, Turret, .064" Mill-Max, 2308-2-00-80-00-00-07-0
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dc1988af
DEMO MANUAL DC1988A
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
VIN VIN
4.5V - 30V
FOR INPUT VOLTAGE DAMPING PURPOSE ONLY.
0805
1206
OPT
1%
1206
5V
6V
*
1%
1%
1%
1. ALL RESISTORS ARE 0603.
2. ALL CAPACITORS ARE 0603.
NOTE: UNLESS OTHERWISE SPECIFIED
*
**
SEE QUICK START GUIDE FOR OUTPUT CURRENT RANGE.
**
**
R6
OPT
R6
OPT
R3
90.9k
R3
90.9k
C6
0.1uF
25V
C6
0.1uF
25V
C3
10uF
16V
C3
10uF
16V
R4
162k
R4
162k
C9
OPT
1210
C9
OPT
1210
C11
1uF
16V
C11
1uF
16V
U1
LTM8058EY
U1
LTM8058EY
RUN
F3
GND
E4
BIAS
H5
VOUT1 A6
SS
H6
VIN
G1
GND
F7
ADJ2 A2
VOUT- A3
VIN
H1
GND
E5
GND
E6
GND
E7
GND
F4
GND
F5
GND
F6
GND
G4
GND
G5
GND
E3
VOUT- A4
VOUT- A5
VOUT- B3
VOUT- B4
VOUT- B5
VOUT1 A7
VOUT1 B6
VOUT1 B7
VIN
G2
VIN
H2
BYP B2
VOUT2 B1
VOUT2 A1
ADJ1
G7
GND
G6
GND
H4
GND
E2 GND
E1
GND
H7
E4 VOUT-
E4 VOUT-
C8
OPT
1210
C8
OPT
1210
E5
RUN E5
RUN
R5
5.9k
R5
5.9k
E8
BIAS E8
BIAS
L1
10uH
CDRH4D22/HP
L1
10uH
CDRH4D22/HP
C12
OPT
C12
OPT
R1
200
1210
R1
200
1210
C5
0.01uF
25V
C5
0.01uF
25V
C4
4.7uF
50V
C4
4.7uF
50V
C7
470pF
OPT
GA342QR7GD471KW01L
1808
C7
470pF
OPT
GA342QR7GD471KW01L
1808
+
10uF
35V
CIN1
+
10uF
35V
CIN1 C1
10uF
1210
50V
C1
10uF
1210
50V
R2
200k
R2
200k
E6
VOUT2
E6
VOUT2
E3
VOUT1
E3
VOUT1
C2
22uF
16V
C2
22uF
16V
E2
GND E2
GND
E1
VIN
E1
VIN
E7 VOUT-
E7 VOUT-
C10
1uF
16V
C10
1uF
16V
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dc1988af
DEMO MANUAL DC1988A
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900 ● FAX: (408) 434-0507 ● 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.
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 applica-
tion engineer.
Mailing Address:
Linear Technology
1630 McCarthy Blvd.
Milpitas, CA 95035
Copyright © 2004, Linear Technology Corporation
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