Test configurations, Typical application circuit, Design considerations – GE Industrial Solutions NaOS NXA025 SIP User Manual

Page 9: Safety considerations, Naos, Input source impedance, Lineage power 9, Figure 22. output ripple and noise test setup, Figure 24. application schematic

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Data Sheet
October 5, 2009

Naos

TM

NXA025 SIP Non-isolated Power Modules:

10 – 14Vdc Input; 0.8Vdc to 5.5Vdc Output; 25A output current


LINEAGE

POWER

9

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 21. 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 22. 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 23. Output Voltage and Efficiency Test Setup.

η =

V

O

. I

O

V

IN

. I

IN

x

100

%

Efficiency

Typical Application Circuit

Vout

Qx

Rx

4.99k

Dx

Share

SEN+

SEQ/ENA

SEN-

GND

GND

GND

Vin Vin

Vout

Vout

V

IN

C

IN

Cout

Share

1uF

R

trim

Figure 24. Application Schematic


Design Considerations

Input Source Impedance

The power module should be connected to a low
ac-impedance source. Highly inductive source impedance
can affect the stability of the power module. The input
capacitor C

IN

should be located equal distance from the

two input pins of the module. C

IN

is recommended to be

150μF minimum. The ripple voltage is 50mV RMS at
1MHz and the capacitor should be chosen with an ESR
and an RMS Current Rating for this amount of ripple
voltage. When using multiple modules in parallel, a small
inductor (0.2 –0.5μH) is recommended at the input of
each module to prevent interaction between modules.
Consult the factory for further application guidelines.

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 60950-1, CSA C22.2 No. 60950-1-03, and VDE
0850:2001-12 (EN60950-1) 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.
The input to these units is to be provided with a maximum
of 30 A fast-acting fuse in the ungrounded lead.

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