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7
Lineage Power
Data Sheet
April 2008
36 Vdc to 75 Vdc In; 3.3 Vdc and 5 Vdc Out; 16.5 W and 25 W
LUW025-Series Power Modules: dc-dc Converters:
Characteristics Curves (continued)
8-1263e
Figure 9. LUW025A, F Typical Output Voltage Start-
Up when Signal Is Applied to Remote On/
Off
Test Configurations
8-203p
Note: Input reflected-ripple current is measured with a simulated
source inductance (LTEST) of 12 H. Capacitor Cs offsets
possible battery impedance. Current is measured at the input
of the module.
Figure 10. Input Reflected-Ripple Test Setup
8-513d
Note: Use one external 1 F ceramic capacitor (nearest to the mod-
ule) and one 10 F aluminum or tantalum capacitor (nearest
to the load). Scope measurement should be made using a
BNC socket. Position the load between 50 mm and 75 mm
(2 in. and 3 in.) from the module.
Figure 11. Peak-to-Peak Output Noise
Measurement Test Setup
8-204
Note: All measurements are taken at the module terminals. When
socketing, place Kelvin connections at module terminals to
avoid measurement errors due to socket contact resistance.
Figure 12. Output Voltage and Efficiency
Measurement Test Setup
Design Considerations
Input Source Impedance
The power module should be connected to a low
ac-impedance input source (see Figure
10). Highly
inductive source impedances can affect the stability of
the power module. For the test configuration in Figure
10, a 33 F electrolytic capacitor (ESR < 0.7 at
100 kHz) mounted close to the power module helps
ensure stability of the unit. For other highly inductive
source impedances, consult the factory for further
application guidelines.
TIME, t (1 ms/div)
NORMALIZED
OUTPUT
V
OL
T
A
GE,
V
O
0
5V
0
REMO
TE
ON/OFF
,
V
on/off
(V)
(2
V/div)
TO OSCILLOSCOPE
12 H
CS 220 F
ESR < 0.1
Ω
@ 20 C, 100 kHz
VI(+)
VI(-)
BATTERY
33 F
CURRENT
PROBE
LTEST
1.0
μF
RESISTIVE
SCOPE
COPPER STRIP
10
μF
LOAD
VO(+)
VO(–)
V I(+)
V I(-)
V O (+)
V O (-)
II
IO
SUPPLY
CONTACT RESISTANCE
CONTACT AND
DISTRIBUTION LOSSES
LOAD
η
VO(+) VO(–)
–
[]IO
VI(+) VI(–)
–
[]II
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100
×
=
%