OHD2805S
OHD2812S
OHD2815S
LOW PROFILE DC/DC CONVERTER IN A
HERMETIC METAL PACKAGE
Low Profile Hermetic DC/DC Converter
+5, +12, And +15 Volt In A Metal Package
FEATURES
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Up To 20 Watts Output Power
5, 12, 15 Vdc Outputs
MIL-STD-704D Compatible
NAVMAT P-4855-1A Component Derating
Ultra-Low Profile: 0.385" Height
Constant Frequency PWM Design
Seam Welded Case For Enhanced Reliability
Low Voltage Lockout
16 to 40 Vdc Input Range
-55° to +125°C Full Power Operation
Up to 81% Efficiency
Industry Standard Pin-Outs
Magnetic Feedback
Short Circuit Current Limiting Protection
Cascaded Dual Loop Control Scheme For Superior Load Transient Characteristics
Available Hi-Rel Screened
2.1
DESCRIPTION
Omnirel’s OHD2800S series of DC/DC Converters are rated up to 20 watts of output power
over the full military temperature range. These converters are supplied in a fully hermetic,
ultra-low profile package to produce a power density of up to 22 watts per cubic inch.
MAXIMUM RATINGS
(T = 25°C, V
IN
= 28 Vdc unless otherwise specified)
Operating Temperature Range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -55°C to +125°C (T
case
)
Storage Temperature Range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -65°C to +150°C
Isolation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . >100 M @ 500 Vdc
Conversion Frequency: Free Run Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 400 KHz
Conversion Frequency
Sync. Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 425 KHz - 525 KHz
4 11 R0
2.1 - 1
OHD2805S OHD2812S OHD2815S
Topology
The OHD2800S series is a single ended forward
converter operating at a nominal oscillator
frequency of 400 KHz. These fixed frequency
converters use a resonant transformer reset
circuit which allows for a maximum duty cycle of
67% without increasing the voltage stress on the
primary MOSFET or output rectifiers. Tight line
and load regulation are achieved through wide
bandwidth magnetic feedback circuit. This
magnetic feedback circuit, in conjunction with
bipolar control ICs, offers greater long term
reliability and radiation tolerance when compared
to converters using an optocoupler feedback
circuit and/or CMOS control ICs.
Flexible Synchronization
The OHD2800S series offers two different
synchronization options. The standard
OHD2800S can be synchronized to an external
system clock for any rate between 425 KHz and
525 KHz. A second option allows the system
designer to synchronize multiple “slave”
converters to one “master” converter. The
appropriate parts must be ordered to utilize this
master/slave configuration. A suffix of “-MST” is
added for the master part number and “-SLV”
suffix for the slave part number.
Example:
Part No.:
Description:
OHD2805S-MST
Master Synch. Config.
High Reliability Design
Omnirel’s OHD2800S series of DC/DC
converters are designed to achieve the high
reliability demanded by military programs. The
case is resistance seam welded for superior long
term hermeticity. The converters use only
ceramic input capacitors to provide high product
reliability over the military temperature range of -
55°C to +125°C. All semiconductor devices are
of the highest level of performance and reliability.
Omnirel’s converters are designed in accordance
with the NAVMAT P-4855-1A component
derating guidelines when operating over the MIL-
STD-704D input voltage range. The converters
meet the conducted emissions (CE03) noise
limits of MIL-STD-461C when operated with
Omnirel’s OFC461 EMI filter module.
Inhibit Feature
The OHD2800S series of converters provide an
active low (<0.8 V) inhibit pin that can be used to
disable the converter, resulting in a zero output
voltage and very low quiescent current.
2.1
Low Voltage Lockout
Omnirel’s OHS2800S series of converters are
designed to operate from an input voltage of 16
to 40 Vdc. The converter will not start until the
input voltage reaches approximately 15 Vdc.
Once operating, the unit will shut down when the
input voltage drops below approximately 14 Vdc.
2.1 - 3
FPGA/CPLD
京公网安备 11010802033920号
Copyright © 2005-2026 EEWORLD.com.cn, Inc. All rights reserved
电子工程世界
