Data Sheet
August 2000
JAHW050F, JAHW075F, and JAHW100F Power Modules:
dc-dc Converters; 36 to 75 Vdc Input, 3.3 Output; 33 W to 66 W
Test Configurations
TO OSCILLOSCOPE
CURRENT
PROBE
V
I
(+)
Design Considerations
Input Source Impedance
L
TEST
12
µ
H
C
S
220
µ
F
ESR < 0.1
Ω
@ 20
°
C, 100 kHz
BATTERY
33
µ
F
ESR < 0.7
Ω
@ 100 kHz
V
I
(–)
8-203 (F).l
The power module should be connected to a low
ac-impedance input source. Highly inductive source
impedances can affect the stability of the power mod-
ule. For the test configuration in Figure 16, a 33 µF
electrolytic capacitor (ESR < 0.7
Ω
at 100 kHz)
mounted close to the power module helps ensure sta-
bility of the unit. For other highly inductive source
impedances, consult the factory for further application
guidelines.
Note: Measure input reflected-ripple current with a simulated source
inductance (L
TEST
) of 12 µH. Capacitor C
S
offsets possible bat-
tery impedance. Measure current as shown above.
Safety Considerations
For safety-agency approval of the system in which the
power module is used, the power module must be
installed in compliance with the spacing and separation
requirements of the end-use safety agency standard,
i.e.,
UL1950, CSA
C22.2 No. 950-95, and
VDE
0805
(EN60950, IEC950).
If the input source is non-SELV (ELV or a hazardous
voltage greater than 60 Vdc and less than or equal to
75 Vdc), for the module’s output to be considered
meeting the requirements of safety extra-low voltage
(SELV), all of the following must be true:
s
Figure 16. Input Reflected-Ripple Test Setup
COPPER STRIP
V
O
(+)
1.0
µF
V
O
(–)
10
µF
SCOPE
RESISTIVE
LOAD
8-513 (F).d
Note: Use a 1.0 µF ceramic capacitor and a 10 µF aluminum or tan-
talum capacitor. Scope measurement should be made using a
BNC socket. Position the load between 51 mm and 76 mm
(2 in. and 3 in.) from the module.
The input source is to be provided with reinforced
insulation from any hazardous voltages, including the
ac mains.
One V
I
pin and one V
O
pin are to be grounded, or
both the input and output pins are to be kept floating.
The input pins of the module are not operator acces-
sible.
Another SELV reliability test is conducted on the
whole system, as required by the safety agencies, on
the combination of supply source and the subject
module to verify that under a single fault, hazardous
voltages do not appear at the module’s output.
s
Figure 17. Peak-to-Peak Output Noise
Measurement Test Setup
s
s
SENSE(+)
V
I
(+)
I
I
SUPPLY
V
I
(–)
CONTACT
RESISTANCE
SENSE(–)
V
O
(–)
V
O
(+)
CONTACT AND
DISTRIBUTION LOSSES
I
O
LOAD
Note:
Do not ground either of the input pins of the
module without grounding one of the output pins.
This may allow a non-SELV voltage to appear
between the output pin and ground.
8-749 (F)
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.
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 maxi-
mum 6 A normal-blow fuse in the ungrounded lead.
[
V
O
(+) – V
O
(–)
]
I
O
η
=
------------------------------------------------
x 100
[
V
I
(+) – V
I
(–)
]
I
I
%
Figure 18. Output Voltage and Efficiency
Measurement Test Setup
Lucent Technologies Inc.
9
ETC [ ETC ]
