Data Sheet
July 1999
JW050A, JW075A, JW100A, JW150A Power Modules:
dc-dc Converters; 36 to 75 Vdc Input, 5 Vdc Output; 50 W to 150 W
Test Configurations
SENSE(+)
TO OSCILLOSCOPE
L
TEST
12 µH
C
S
220 µF
ESR < 0.1
Ω
33 µF
@ 20
°C,
100 kHz ESR < 0.7
Ω
@ 100 kHz
V
I
(–)
CURRENT
PROBE
V
I
(+)
CONTACT AND
DISTRIBUTION LOSSES
V
I
(+)
I
I
SUPPLY
V
I
(–)
CONTACT
RESISTANCE
V
O
(+)
I
O
LOAD
V
O
(–)
BATTERY
SENSE(–)
8-749 (C)
8-203 (C).l
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.
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.
[
V
O
(+) – V
O
(–)
]
I
O
η
=
-----------------------------------------------
x 100
[
V
I
(+) – V
I
(–)
]
I
I
-
%
Figure 17. Input Reflected-Ripple Test Setup
Figure 19. Output Voltage and Efficiency
Measurement Test Setup
COPPER STRIP
V
O
(+)
1.0 µF
V
O
(–)
10 µF
SCOPE
RESISTIVE
LOAD
Design Considerations
Input Source Impedance
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 17, 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.
8-513 (C).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.
Figure 18. Peak-to-Peak Output Noise
Measurement Test Setup
Tyco Electronics Corp
9
MA-COM [ M/A-COM TECHNOLOGY SOLUTIONS, INC. ]
