NOTES
(1) All parameters measured at Tc=25°C, nominal input voltage and full rated load unless otherwise
noted.
(2) Measurement bandwidth is 0-20 MHz for peak-peak measurements, 10 kHz to 1 MHz for RMS
measurements. Output noise is measured with a 0.01µF/100V ceramic capacitor in parallel with a
1µF/35V Tantalum capacitor, 1 inch from the output pins to simulate standard PCB decoupling
capacitance.
(3) Short term stability is specified after a 30 minute warm-up at full load, constant line and recording
he drift over a 24 hour period.
(4) Per ETSI-300-132
(5) Recovery to within 1% in less than 1 millisecond after transient has been applied.
DFC25 SERIES APPLICATION NOTES:
External Capacitance Requirements
A low ESR external capacitance is required for operation of the DFC25 Series. For maximum
performance, it is recommended that the DFC25 Series use a capacitor of sufficient ripple current
capacity connected across the input pins, especially if a capacitive input source is farther than 1"
from the converter. To meet the reflected ripple requirements of the converter, an input impedance
of less than 0.09 Ohms at 200 kHz is required. External output capacitance is not required for
operation, however it is recommended that 1µF to 10µF of Tantalum and 0.001 to 0.1µF ceramic
capacitance be selected for each output to reduce system noise. Additional output capacitance may
be added for increased filtering, but should not exceed 400µF.
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 TTL compatible circuitry. When the ON/OFF pin is pulled low with respect to the
-INPUT, the converter is placed in a low power drain state. The input capacitors are kept fully
charged in the OFF mode. For proper operation, this input may be driven from a logic gate directly.
The ON/OFF pin should never be pulled more than 0.3 volts below -INPUT or have a voltage
greater than +6 volts applied.
DFC25 SERIES – SINGLE OUTPUT
Input Parameters (1)
Model DFC25E12S3.3 DFC25E24S5 DFC25E48S5 DFC25E48S12 Units
Reflected Ripple (2) TYP 330 230 150 150 mAPP
Input Current
Full Load TYP 2870 1563 781 762
mA
No Load TYP 100 10 10 10
Inrush Current (4) MAX 50 50 50 50 A
PK
Efficiency TYP 72 80 80 82 %
Switching Frequency TYP 150 150 150 150 kHz
Maximum Input
Overvoltage, MAX 24 45 85 85 VDC
100ms Maximum
Turn-on Time,
1% Output Error
TYP 10 10 10 10 ms
Output Parameters (1)
Model DFC25E12S3.3 DFC25E24S5 DFC25E48S5 DFC25E48S12 Units
Output Voltage 3.3 5 5 12 VDC
MIN 3.26 5.05 5.05 11.90
Output Voltage Accuracy TYP 3.30 5.10 5.10 12.00 VDC
MAX 3.33 5.15 5.15 12.10
Rated Load Range
MIN 0.75 0.60 0.60 0.25 A
MAX 7.50 6.00 6.00 2.50
Load Regulation
10% Load - Max Load
TYP 1 1 1 1 %
Line Regulation
Vin = Min-Max VDC
TYP 0.2 0.2 0.2 0.2 %
Transient Response
25% Load Step (5)
TYP 2 2 2 2 %
Short Term Stability (3) TYP <0.05 <0.05 <0.05 <0.05 %/24Hrs
Long Term Stability TYP <0.1 <0.1 <0.1 <0.1 %/kHrs
Input Ripple Rejection TYP >40 >40 >40 >40 dB
Noise, Peak - Peak (2) TYP 75 75 75 75 mVPP
Temperature Coefficient TYP 100 100 100 100 ppm/°C
Short Circuit Protection
Continuous, Current Limit Protection
from +OUT to -OUT
2
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.
