Typical start up times for this series, with a typical input voltage rise time of 2.2s and output capacitance of 10F, are swn in the table below. The product
series will start into a capacitance of 47F with an increased start time, however, the maximum recommended output capacitanceis 10F
The voltage tolerance envelope shows typical load regulation characteristics for this
product series. The tolerance envelope is the maximum output voltage variation due
to changes in output
OUTPUT RIPPLE REDUCTION
Output ripple reduction
By using the values of inductance and capacitance stated, the output ripple at the rated load is lowered to 5mV p-p max.
Component selection
Capacitor: Ceramic chip capacitors are recommended. It is required that the ESR(Equivalent Series Resistance)should be as low as possible.X7R types are recommended.
The voltage rating should be at least twice(except for 15V output),the rated output voltage of the DC/DC converter.
Inductor: The rated current of the inductor should not be less than of the output of the DC/DC converter. At the rated current, the DC resistance of the inductor should be
such that the voltage drop across the inductor is <2% of the rated voltage of the DC/DC converter. The SRF(Self Resonant Frequency) should be >20MHz.
CHARACTERISATION TEST METHODS
Ripple & Noise Characterisation Method
All measurement to be taken with the following components connected to the UUT as detailed below. 50 Ohm coax cable, solder
connections one end, BNC plug at the other end.
Ripple and noise measurements are performed with the following test configuration.
C1
C2
C3
R1
R2
T1
RLOAD
1μF X7R multilayer ceramic capacitor, voltage rating to be a minimum of 3 times the output voltage of the DC/DC converter
10μF tantalum capacitor, voltage rating to be a minimum of 1.5 times the output voltage of the DC/DC converter with an ESR of less than 100mΩ at 100 KHz
100nF multilayer ceramic capacitor, general purpose
450Ω resistor, carbon fi lm,
±1%
tolerance
50Ω BNC termination
3T of the coax cable through a ferrite toroid
Resistive load to the maximum power rating of the DC/DC converter. Connections should be made via twisted wires
Measured values are multiplied by 10 to obtain the specified values.
"Hi Pot Test","Flash Tested","Withstand Voltage","Dielectric Withstand Voltage"&”Isolation Test Voltage" are all terms that relate to the same thing, a test voltage.
Applied for a specified time, across a component designed to provide electrical isolation, to verify the integrity of that isolation.
Professional Power Module B series of DC/DC converters are all 100% production tested at their stated isolation voltage. This is 1KVDC for 1 second.
A question commonly asked is,"What is the continuous voltage that can be applied across the part in normal operation?"
The B_X(S)D-2W series has been recognized by Underwriters Laboratory for functional insulation. Both input and output should normally be maintained within SELV limits i.e. less than
42.4V peak, or 60VDC.The isolation test voltage represents a measure of immunity to transient voltages and the part should never be used as an element of a safety isolation system.
The part could be expected to function correctly with several hundred volts offset applied continuously across the isolation barrier, but then the circuitry on both sides of the barrier must
be regarded as operating at an unsafe voltage and further isolation/insulation systems must form a barrier between these circuits and any user-acssible circuitry according to
safety standard requirements.
REPEATED HIGH-VOLTAGE ISOLATION TESTING
It is well known that repeated high-voltage isolation testing of a barrier component can actually degrade isolation capability, to a lesser or greater degree depending on materials.
Construction and environment. The B series has toroidal isolation transformers, with no additional insulation between primary and secondary windings of enameled wire. While
parts can be expected to withstand several times the stated test voltage, the isolation capability does depend on the wire insulation. Any material, including this enamel (typically
polyurethane) is susceptible to eventual chemical degradation when subject to very high applied voltages thus implying that the number of tests should be strictly limited. We
therefore strongly advise against repeated high voltage isolation testing. but if it is absolutely required, that the voltage be reduced by 20% from specified test voltage.
This consideration equally applies to agency recognized parts for better than functional isolation where the wire enamel insulation is always supplemented by a further
insulation system of physical spacing or barriers.
PACKAGE SPECIFICATIONS
MECHANICAL DIMENSIONS
SIP Package
DIP Package
PIN
1
2
4
6
FOOTPRINT
SIP7
SIP7
Function
PIN
1
7
8
9
11
NC No connection
FOOTPRINT
DIP14
Function
+Vin
-Vin
-Vout
+Vout
14
GND
NC
0V
+V0
No Pin
Vin
Specifcations can be changed any time without notice.
No parallel connection or plug and play.
All dimensions in inches
±
0.01(mm±0.25mm).
0.01(mm
±
All pins on a 0.1(2.54) pitch and within
±
0.01(0.25)of true position.
Weight: 2.8g
Note:
1. The load shouldn't be less than 10%, otherwise ripple will increase dramatically.
2. Operation under 10% load will not damage the converter; However, they may not meet all specification listed.
3. All specifications measured at Ta=25°C, humidity<75%, nominal input voltage and rated output load unless
otherwise specified.
4. In this datasheet, all the test methods of indications are based on corporate standards.
RECOMMENDED FOOTPRINT DETAILS
4 Pin SIP Package
14 Pin DIP Package
Unless otherwise stated all dimensions in inches (mm) 0.5mm
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