Test configurations, Design considerations, Safety considerations – GE Industrial Solutions Austin Lynx 24V User Manual

Page 10: Austin lynx, Input filtering, Output filtering, Lineage power 10, Figure 26. output ripple and noise test setup, The austin lynx

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Data Sheet
September 10, 2013

Austin Lynx

TM

24V: Non-isolated Power Modules:

18/20– 30/32Vdc input; 3 – 6Vdc & 5 – 15Vdc Output; 30/50W

LINEAGE

POWER

10

Test Configurations

TO OSCILLOSCOPE

CURRENT PROBE

L

TEST

1μH

B

A

TTE

R

Y

C

S

220μF

E.S.R.<0.1

Ω

@ 20°C 100kHz

Min

150μF

V

IN

(+)

COM

NOTE: Measure input reflected ripple current with a simulated

source inductance (L

TEST

) of 1μH. Capacitor C

S

offsets

possible battery impedance. Measure current as shown
above.

C

IN

Figure 25. Input Reflected Ripple Current Test
Setup.

NOTE: All voltage measurements to be taken at the module

terminals, as shown above. If sockets are used then
Kelvin connections are required at the module terminals
to avoid measurement errors due to socket contact
resistance.

V

O

(+)

COM

1uF

.

RESISTIVE

LOAD

SCOPE

COPPER STRIP

GROUND PLANE

10uF

Figure 26. Output Ripple and Noise Test Setup.

V

O

COM

V

IN

(+)

COM

R

LOAD

R

contact

R

distribution

R

contact

R

distribution

R

contact

R

contact

R

distribution

R

distribution

V

IN

V

O

NOTE: All voltage measurements to be taken at the module

terminals, as shown above. If sockets are used then
Kelvin connections are required at the module terminals
to avoid measurement errors due to socket contact
resistance.

Figure 27. Output Voltage and Efficiency Test Setup.

η =

V

O

. I

O

V

IN

. I

IN

x

100

%

Efficiency

Design Considerations

Input Filtering

The Austin Lynx

TM

24V SMT module should be

connected to a low-impedance source. A highly
inductive source can affect the stability of the module.
An input capacitance must be placed directly adjacent
to the input pin of the module, to minimize input ripple
voltage and ensure module stability.

Output Filtering

The Austin Lynx

TM

24V SMT module is designed for low

output ripple voltage and will meet the maximum output
ripple specification with 1 µF ceramic and 10 µF
tantalum capacitors at the output of the module.
However, additional output filtering may be required by
the system designer for a number of reasons. First,
there may be a need to further reduce the output ripple
and noise of the module. Second, the dynamic
response characteristics may need to be customized to
a particular load step change.

To reduce the output ripple and improve the dynamic
response to a step load change, additional capacitance
at the output can be used. Low ESR polymer and
ceramic capacitors are recommended to improve the
dynamic response of the module. For stable operation
of the module, limit the capacitance to less than the
maximum output capacitance as specified in the
electrical specification table.


Safety Considerations

For safety agency approval the power module must be
installed in compliance with the spacing and separation
requirements of the end-use safety agency standards,
i.e., UL 60950, CSA C22.2 No. 60950-00, EN60950
(VDE 0850) (IEC60950, 3

rd

edition) Licensed.

For the converter output to be considered meeting the
requirements of safety extra-low voltage (SELV), the
input must meet SELV requirements. The power
module has extra-low voltage (ELV) outputs when all
inputs are ELV.

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