鈥?Topology 鈥?/div>
Push-Pull DC/DC Converter
鈥?Up to 75% efficiency
鈥?No minimum load
鈥?Output capacitor suggested
DC/DC C
ONVERTERS
5, 12,
OR
28 V
OLT
I
NPUT
DCH SERIES
3 WATT
MODELS
VDC O
UTPUT
SINGLES
5
12
28
DUALS
鹵12
鹵15
鹵28
Size (max.): 0.975 x 0.800 x 0.350 inches (24.77 x 20.32 x 8.89 mm)
See section B8, case A3, for dimensions.
Weight:
20 grams typical
Screening: Standard or ES. See Section C2 for screening options,
see Section A5 for ordering information.
DESCRIPTION
The DCH Series鈩?offers isolated, unregulated DC/DC converters
with up to 3 watts of output power in a low profile (0.350 max.) metal
package. Single and dual output models are available with input
voltages of 5, 12, or 28 VDC. DCH Series converters operate over
a 鈥?5擄C to +100擄C temperature range.
DCH Series converters use a non-saturating core circuit operating
at a frequency of approximately 100 kHz, which reduces reflected
input ripple and minimizes EMI/RFI problems. For applications
requiring MIL-STD-461C, CEO3, reflected input ripple levels, refer
to Section B5 or contact your Interpoint representative for matching
EMI filters.
Figure 1 shows a standard connection scheme for a dual output
model. Users may also elect to use a dual output device to provide
a single output at double the rated output voltage. The double
voltage connection is achieved by leaving the normal output
common pin (Pin 15) unconnected and using either the positive or
negative Vout pin for the output common connection.
On all DCH Series models, a tantalum capacitor with a minimum
value of 22 碌F and an appropriate voltage rating should be
connected between the output common and the output line(s) to
minimize output ripple.
F
IGURE
1:
D
UAL
DCH C
ONVERTER
WITH
E
XTERNAL
C
APACITORS
Positive
Input
28 V
Positive
Output
Output Common
+
+
Load
Load
Input
Common
Negative
Output
Typical Performance Curves: 25擄C Tc ,nominal Vin
Efficiency
DCH2805S
F
IGURE
2
Output Current vs Output Voltage
DCH2805S
F
IGURE
3
Efficiency
DCH1215D
F
IGURE
4
Output Current vs Output Voltage
DCH1215D
F
IGURE
5
B4-31
1
2
3
4
