DESCRIPTION The compact, dual output DFA20 series provides power densities to 11 watts per cubic inch (0.67 watts per cm3). Ideal for battery operated industrial, medical control and remote data collection systems, this converter has fully filtered inputs and outputs. Complete overload protection with independent pulse-by-pulse current limiting and an overtemperature shutdown ensures reliable system operation. Converters with 48 volt inputs are isolated to 1544 volts. FEATURES Remote ON/OFF and TRIM Water Washable Case Overcurrent Protection and Thermal Shutdown Efficiencies to 85% Low Input to Output Capacitance to 1544Volt Isolation Five-Side Shielded Case Extended Range Input (2:1)
Mechanical tolerances unless otherwise noted: X.XX dimensions: �0.020 inches X.XXX dimensions: �0.005 inches
NOTES (1) All parameters measured = 25�C, nominal input voltage and full rated load unless otherwise noted. Refer to the Technical Reference Section for the definition of terms, measurement circuits and other information.
NOTES (cont) (2) Case is electrically connected to Pin 2, -Input. (3) The functional case operating range is intended to give an additional data point for evaluating this converter. Sustained operation at the higher operating range will reduce expected operational life. The data Sheet specifications are not guaranteed beyond the case operating range. (4) The case thermal impedance is specified as the case temperature rise over ambient per package watt dissipated.Specification notes for this page are located on the next page.
(1) All parameters measured at Tc=25�C, nominal input voltage and full rated load unless otherwise noted. Refer to the Technical Reference Section for the definition of terms, measurement circuits and other information. Noise is measured per Technical Reference Section. Measurement bandwidth is 0-20 MHz for peak-peak measurements, 10 kHz to 1 MHz for RMS measurements. Output noise is measured with a 1�F tantalum located 1" away from the converter to simulate PCB standard decoupling. Input reflected ripple is measured into 1 �H source impedance. Load regulation for the outputs is specified as the voltage change when both outputs are changed from maximum to minimum at the same time. Cross regulation is defined as the change in one output when the other output is changed from full load 25% of full load. The converter can be run at no load on either or both outputs with no damage. Short term stability is specified after a 30 minute warmup at full load, constant line and recording the drift over a 24 hour period. The input ripple rejection is specified for 120 Hz ripple with a modulation amplitude 1% of Vin.
Remote ON/OFF Operation The remote ON/OFF pin may be left floating if this function is not used. It is recommended to drive this pin with an open collector arrangement or a relay contact. When the ON/OFF pin is pulled low with respect to the -INPUT, the converter is placed in a low power drain state. Output TRIM The TRIM pin may be used to adjust the output �5% from the nominal setting. This function allows adjustment for voltage drops in the system wiring. Figure 1 shows the proper connections to use this function. If the TRIM function is not required the pin may be left floating.
+OUT 4 TRIM 7 -OUT 6 USING TRIMPOT 10K LOAD +OUT 4 TRIM DOWN TRIM 7 -OUT 6 USING FIXED RESISTORS LOAD TRIM UP
DFA20 SERIES APPLICATION NOTES: External Capacitance Requirements No external capacitance is required for operation of the DFA20 Series. The use of input capacitors with less than 0.5 ESR may cause peaking in the input filter and degrade filter performance. External output capacitance is not required for operation, however it is recommended that 10F of tantalum and to 0.1F ceramic capacitance be selected for reduced system noise. Additional output capacitance may be added for increased filtering, but should not exceed 400F.
NUCLEAR AND MEDICAL APPLICATIONS Power-One products are not authorized for use as critical components in life support systems, equipment used in hazardous environments, or nuclear control systems without the express written consent of the President of Power-One, Inc. TECHNICAL REVISIONS The appearance of products, including safety agency certifications pictured on labels, may change depending on the date manufactured. Specifications are subject to change without notice.
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