HW/HC 4A – 6A Series Power Modules; dc-dc Converters
18
36 Vdc & 36
75 Vdc In
ut; 1.0Vdc to 5Vdc Out
ut
Data Sheet
Se
tember 29, 2003
16 Tyco Electronics Power Systems
Test Configurations
TO OSCILLOSCOPE CURRENT PROBE
LTEST
12µH
BATTERY
CS 220µF
E.S.R.<0.1Ω
@ 20°C 100kHz
33µF
VIN(+)
VIN(-)
NOTE: Measure input reflected ripple current with a simulated
source inductance (LTEST) of 12µH. Capacitor CS offsets
possible battery impedance. Measure current as shown
above.
Figure 61. Input Reflected Ripple Current Test Setup
VO
COM
RLOAD
SCOPE
COPPER STRIPS
1
F10
F
NOTE: Use a 1µF ceramic capacitor and a 10µF aluminium or
tantalum capacitor. The scope measurement should be
made using a BNC socket. Position the load 50mm to
75mm (2" to 3") from the module.
Figure 62. Output Ripple and Noise Test Setup
VO
COM
VIN
+
VIN
-
RLOAD
Rcontact Rdistribution
Rcontact Rdistribution
Rcontact
Rcontact
Rdistribution
Rdistribution
VIN VO
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 63. Output Voltage and Efficiency Test Setup
η =
VO. IO
VIN. IIN
x 100 %
Efficiency
Design Considerations
Input Source Impedance
The power module should be connected to a low
ac-impedance source. A highly inductive source
impedance can affect the stability of the power module.
For the test configuration in Figure 61, a 33µF
electrolytic capacitor (ESR<0.7Ω at 100kHz), mounted
close to the power module helps ensure the stability of
the unit. Consult the factory for further application
guidelines.
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., UL 1950, CSA C22.2 No. 60950-00, and VDE
0805:2001-12 (IEC60950 3rd Ed).
If the input source is non-SELV (ELV or a hazardous
voltage greater than 60 Vdc and less than or equal to
75Vdc), for the module’s output to be considered as
meeting the requirements for safety extra-low voltage
(SELV), all of the following must be true:
The input source is to be provided with reinforced
insulation from any other hazardous voltages, including the
ac mains.
One VIN pin and one VOUT 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 accessible.
Another SELV reliability test is conducted on the whole
system (combination of supply source and subject
module), as required by the safety agencies, to verify that
under a single fault, hazardous voltages do not appear at
the module’s output.
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 pins and ground.
The power module has extra-low voltage (ELV) outputs
when all inputs are ELV.
For input voltages exceeding –60 Vdc but less than or
equal to –75 Vdc, these converters have been evaluated
to the applicable requirements of BASIC INSULATION
between secondary DC MAINS DISTRIBUTION input
(classified as TNV-2 in Europe) and unearthed SELV
outputs (-B option only).
"All flammable materials used in the manufacturing of
these modules are rated 94V-0 and UL60950 A.2 for
reduced thicknesses. The input to these units is to be
provided with a maximum 3A fast-acting fuse in the
unearthed lead."