TEST CONFIGURATIONS
DESIGN CONSIDERATIONS
Input Source Impedance
To maintain low noise and ripple at the input voltage, it is
critical to use low ESR capacitors at the input to the
module. A highly inductive source can affect the stability
of the module. An input capacitance must be placed close
to the modules input pins to filter ripple current and ensure
module stability in the presence of inductive traces that
supply the input voltage to the module.
Safety Considerations
Figure 25: Input reflected-ripple test setup
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.
COPPER STRIP
Vo
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.
Resistive
Load
0.1uF
10uF
SCOPE
ceramic ceramic
GND
The input to these units is to be provided with a
maximum 20A fuse in the ungrounded lead.
Note: Use a 10μF tantalum and 1μF capacitor. Scope
measurement should be made using a BNC connector.
Figure 26: Peak-peak output noise and startup transient
Input Under voltage Lockout
measurement test setup.
At input voltages below the input under voltage lockout
limit, the module operation is disabled. The module will
begin to operate at an input voltage above the under
voltage lockout turn-on threshold.
CONTACT AND
DISTRIBUTION LOSSES
VI
Vo
II
Io
LOAD
SUPPLY
GND
Over-Current Protection
CONTACT RESISTANCE
To provide protection in an output over load fault
condition, the unit is equipped with internal over-current
protection. When the over-current protection is triggered,
the unit enters hiccup mode. The units operate normally
once the fault condition is removed.
Figure 27: Output voltage and efficiency measurement test
setup
Note: All measurements are taken at the module terminals. When
the module is not soldered (via socket), place Kelvin
connections at module terminals to avoid measurement
errors due to contact resistance.
Vo Io
Vi Ii
(
)100 %
DS_ DCM04S0A0S12PFA_10022013
E-mail: DCDC@delta.com.tw
http://www.deltaww.com/dcdc
P7
DELTA [ DELTA ELECTRONICS, INC. ]
