鈥?/div>
NO DERATING 鈥?鈥?5擄 C to +125擄 C
SUPPLY RANGE 鈥?16V to 40V
HIGH ISOLATION 鈥?500V
HIGH POWER DENSITY 鈥?21W/IN
3
OUTPUT VOLTAGE ADJUSTMENT STANDARD
REMOTE SHUTDOWN
OPERATES 11 TO 50V
IN
AT 5W
Package Dimensions
1" W x 1" L x .35" H
TYPICAL APPLICATION WITH OPTIONS
10nF
8
DHW2805S
5
SET UV
LOCKOUT
SHUTDOWN
OPTO
7
3
1
2
6
50K
+V
鈥揤
Control
System
DESCRIPTION
The DHW2805S DC-DC converter is a high performance
version of our standard DHC2805S converter. This converter
provides the ruggedness, reliability, and features required to
meet the advanced design challenges of today鈥檚 hi-rel market.
This is accomplished while retaining a power density of 21 W/
in
3
and 525 mW/gram of power/package performance. The
use of advanced substrate and reflow soldering techniques
during construction results in a rugged, cost-effective, and
completely solderable package.
DHW2805S hybrid converter utilizes all ceramic capacitors
and surface mount magnetics to provide reliable operation at
all operating temperatures while surviving very high G forces.
DHW2805S standard features include output fault monitor-
ing and/or turn on voltage point programming via the shutdown
pin. All three functions may be implemented simultaneously
with a minimum of external components. An output voltage
adjustment / load compensation pin is also standard however
DHW2805S may be ordered without this feature (/F option).
Fault tolerant design protects these converters from most
external circuit faults. The output and output adjust pins will
withstand +35 V while the shutdown pin will withstand +50 V
protecting the converters from a variety of system or board
faults i.e. solder bridges etc. Unique load fault protection
circuitry allows this converter to pull up loads having difficult
static load line characteristics and allows short term load
excursions significantly beyond ratings in most applications.
A transformer isolated forward converter topology operating
at a switching frequency of 400 kHZ allows operation over a
wide input voltage range. Internal filtering of both input and
output eliminates the need for external capacitors in many
applications.
The 8-pin DIP package (see Package Outlines) is hermeti-
cally sealed and isolated from the internal circuits. Heat sinking
is recommended for full power operation at elevated ambient
temperatures.
V
TRIM
R
SP
200K
+5V
5K
J174
V
IN
OPERATION
NORMAL
(TTL)
BLOCK DIAGRAM
6
1
2
5
PWM
FEED FORWARD
CONTROLLER
7
ERROR AMPLIFIER
REFERENCE AND
ISOLATION
3
EXTERNAL CONNECTIONS
+ OUTPUT
鈥?OUTPUT
ADJUST/COMP*
NO CONNECTION
SHUTDOWN PLUS
1
2
3
4
5
6
+ INPUT
TOP
VIEW
7
鈥?INPUT
8
CASE
* Optional N/C on DHW2805S/F
APEX MICROTECHNOLOGY CORPORATION
鈥?TELEPHONE (520) 690-8600 鈥?FAX (520) 888-3329 鈥?ORDERS (520) 690-8601 鈥?EMAIL prodlit@apexmicrotech.com
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