ISO-9001 CERTIFIED BY DSCC
M.S.KENNEDY CORP.
7.5W
DC-DC
CONVERTER
4707 Dey Road Liverpool, N.Y. 13088
DHD2805S
(315) 701-6751
MIL-PRF-38534 CERTIFIED
FEATURES:
Typical Efficiency 70%
All Ceramic Capacitors
Surface Mount Magnetics
80 Volt Input Transient Tolerant
Operates to 12V Input at 5W
Wide Supply Range - 16V to 40V
High Isolation - 500V
Output Voltage Adjustment - Standard
Remote Shutdown
5V Output (See DHC Series for Other Voltages)
Replaces IR ASA2805S
Replaces Interpoint MSA2805S
DESCRIPTION:
The DHD2805S DC-DC converter provides the ruggedness, reliability and features required to meet the
advanced design challenges of today's hi-rel market. The use of advanced substrate and reflow soldering
techniques during construction results in a rugged, cost-effective and completely solderable package.
DHD2805S hybrid converter utilizes all ceramic capacitors and surface mount magnetics to provide
reliable operation at all operating temperatures while surviving very high G forces.
DHD2805S standard features include output fault monitoring 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.
Fault tolerant design protects these converters from most external circuit faults. The output and output
adjust pins will withstand +35V while the shutdown pin will withstand +50V 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 400kHz 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 is hermetically sealed and isolated from the internal circuits. Heat sinking is
recommended for full power operation at elevated ambient temperatures.
1
Rev. C 3/05
EQUIVALENT SCHEMATIC
PIN-OUT INFORMATION
TYPICAL APPLICATIONS
1
2
3
4
5
Isolated Step Down Power Supply
Microprocessor Power Source
Low Voltage Subsystem Power Source
+50V
VIN Input Voltage (pin 7 to pin 6)
Input
Transient
(pin
7
to
pin
6
@
50mS)
80V
VINT
Output
Current
IOUT
DHD2805S
1.5A
Case
Temperature
Range
TC
DHD2805S H/E
-55°C to +125°C
DHD2805S
-40°C to +85°C
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8 Case
7 -Input
6 +Input
1
ABSOLUTE MAXIMUM RATINGS
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+Output
-Output
Adjust/Comp
NC
Shutdown Plus
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TST Storage Temperature Range
TLD Lead Temperature Range
(10 Seconds)
PD Power Dissipation
TJ Junction Temperature
θJC Thermal Resistance
(Switches)
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-65°C to +150°C
300°C
See Efficiency Curve
150°C
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6.5°C/W
NOTE:
1 Continuous operation at or above absolute maximum ratings may adversely effect
the performance and/or life cycle.
2
Rev. C 3/05
ELECTRICAL SPECIFICATIONS
Group A
Subgroup
Test Conditions 1
Parameter
2
Output Voltage Ripple
Input Current Ripple 2
Line Regulation
Load Regulation
Step Load Recovery
Step Line Response 2
Step Line Recovery 2
Start Up Overshoot
Start Up Delay
Min.
Typ.
Max.
5.00
5.05
4.90
5.00
5.10
VDC
-
5.20
-
-
-
VDC
1
120
-
1500
120
-
1500
mA
2,3
120
-
1500
-
-
-
mA
1
-
75
190
-
75
190
mVp-p
2,3
-
-
475
-
-
-
mVp-p
1
-
100
200
-
100
225
mAp-p
2,3
-
-
200
-
-
-
mAp-p
1
-
±9
±25
-
±9
±30
mV
2,3
-
-
±50
-
-
-
mV
VIN=28V
1
-
±15
±35
-
±15
±40
mV
IOUT=120mA to/from 1500mA
2,3
-
-
±50
-
-
-
mV
1
65
70
-
63
70
-
%
2,3
60
-
-
-
-
-
%
IOUT=500mA to/from 1000mA
4
-
±300
±500
-
±300
±500
mV
16V≤VIN≤40V
BW=10KHz to 2MHz
BW=10KHz to 2MHz
VIN=16V to 40V
Transition TIme=30µS
5,6
-
-
±750
-
-
-
mV
IOUT=500mA to/from 1000mA
4
-
90
300
-
90
300
µS
Transition TIme=30µS
5,6
-
-
300
-
-
-
µS
VIN=16V to/from 40V
4
-
±160
±500
-
±160
±500
mV
Transition Time=30µS, IOUT=1A
5,6
-
-
±500
-
-
-
mV
VIN=16V to/from 40V
4
-
140
500
-
140
500
µS
Transition Time=30µS, IOUT=1A
5,6
-
-
500
-
-
-
µS
4
-
0
200
-
0
200
mV
5,6
-
0
200
-
-
-
mV
4
-
30
50
-
30
50
mS
5,6
-
-
50
-
-
-
mS
4
-
220
500
-
220
500
µS
5,6
-
-
500
-
-
-
µS
-
-
60
-
-
60
-
mS
POUT=7.5W MAX.
1,2,3
16
-
40
16
-
40
V
POUT=5W MAX.
1,2,3
12
-
50
12
-
50
V
POUT=2.5W MAX.
1,2,3
10
-
50
10
-
50
V
1
-
35
40
-
35
45
mA
2,3
-
-
40
-
-
-
mA
1
-
2
5
-
2
5
mA
2,3
-
-
5
-
-
-
mA
No Effect on DC Performance
1,2,3
-
-
300
-
-
300
µF
Input to output or any pin to case @ 500V
1
100
-
-
100
-
-
MΩ
IOUT=1A
IOUT=0A and 1A
Enabled, IOUT=0mA
Quiescent Current
Disabled, IOUT=0mA
Isolation
Max.
4.80
Shutdown Recovery 2
Capacitive Load 2
Typ.
4.95
Shutdown Delay 2
Input Voltage Range 2
Units
Min.
1
Efficiency
Step Load Response
DHD2805S
2,3
Output Voltage
Output Current
DHD2805S H/E
Short Circuit Current Limit 7
1
1.6
1.9
2.2
1.5
1.9
2.3
A
Switching Frequency
4
375
400
425
350
400
450
KHz
1
±10
-
-
±10
-
-
%
VOUT Adjustment Range
RPOT=50KΩ
NOTES:
1
2
3
4
5
6
+VIN = 28V, IOUT = 1.5A, TA=TC=25°C unless otherwise specified.
Guaranteed by design but not tested. Typical parameters are representative of actual device performance but are for reference only.
Industrial grade and "E" suffix devices shall be tested to subgroups 1 and 4 unless otherwise specified.
Military grade devices ("H" suffix) shall be 100% tested to subgroups 1, 2, 3 and 4.
Subgroups 5 and 6 testing available upon request.
Subgroup 1, 4 TA=TC=+25°C
2, 5 TA=TC=+125°C
3, 6 TA=TC= -55°C
7 Device has internal shutdown feature that pulses the output with a low duty cycle during faults.
3
Rev. C 3/05
APPLICATION NOTES
POWER SUPPLIES
LOAD FAULT RESPONSE
The output voltage of the DHD2805S may be adjusted from
90% to 110% of nominal value by the use of a 50KΩ potentiometer as shown. Adjustment beyond this range is possible
however certain characteristics of the converter such as but
not limited to input voltage range, efficiency, ripple and temperature performance will change. Characterization by the user
is recommended in such applications.
Load fault conditions include short-circuit and severe overload conditions. The DHD2805S converter responds to load
faults by turning off all power conversion circuits for 250mS
and then attempting to restart for 10mS (typical). The net "on"
duty factor during a fault is very low resulting in low converter
dissipation and immunity from overheating at 125°C. Current
beyond rated can flow into the load at startup time. This allows the converter to bring up capacitive and other difficult
load types more reliably than competing converters.
Adjust/comp (pin 3) may be driven by external circuitry referenced to pin 2 (-output) if desired. Grounding pin 3 causes
voltage to increase (25% typically) while driving pin 3 above
1.3V causes output voltage to decrease. Pin 3 may be driven
through 10KΩ or more if connection of the comp function is
also required.
The comp function of pin 3 allows capacitive loads as large
as 1000µF to be accommodated on the DHD2805S without
loss of stability. This feature may be utilized by connecting a
10nF capacitor between pins 3 and 1. This is generally recommended when low ESR load capacitances of 100µF or greater
are used.
SHUTDOWN PLUS
Pin 5 is used for remote shutdown, output fault detection,
and/or setting the input voltage point at which the converter
will turn on as shown in the typical application diagram. No
connection to pin 5 is necessary for normal operation of the
converter. Pin 5 is referenced to the -input (pin 7).
Shutdown may be implemented by simply connecting pin 5
to an open collector logic output or switch rated at 2.5mA,
25Vdc or higher.
Input voltage turn on point is programmed with a single resistor from pin 5 to 7. An input turn on/off hysteresis (typically
3.5% of Vin) will be observed. This should be considered when
making or verifying set point adjustment. The value of the
setpoint resistor may be determined by the following:
R= 210·10³
ETO-9.5
(±10% accuracy at 25°C)
Set point temperature coefficient is typically +400ppm/°C.
Output fault monitoring is accomplished by observing pin 5
with a high impedance monitoring circuit. Pin 5 voltage drops
from over 10V to below 1V when a load fault causes the converters fault protection circuitry to activate. It will remain low
for at least 100mS and return high. If the load fault is still
present pin 5 will return low and the cycle will repeat. A resistor >400KΩ from pin 5 to 7 provides pull down for pin 5 if
there is no input setpoint programming resistor already in place.
4
Rev. C 3/05
TYPICAL APPLICATION CIRCUIT
5
Rev. C 3/05
TYPICAL PERFORMANCE CURVES
EFFICIENCY CONTOURS
EFFICIENCY CONTOURS
30%
TEMP = 25°C
40%
50%
55%
40
60%
30
65%
68%
70%
71%
20
TEMP = –55°C
40%
40
50%
55%
30
60%
63%
66%
20
68%
69%
TEMP =
125°C
50%
55%
40
60%
63%
30
66%
20
68%
69%
70%
70%
LOAD TRANSIENT RESPONSE 100µF
1.2
1.5
1.6
2.0
LOAD TRANSIENT RESPONSE 1000µF
LINE TRANSIENT RESPONSE
VOUT
500mA
1.2A
IOUT
600mA
INCLUDES 1000µF ON OUTPUT BUS
OUTPUT RESPONSE, V
XOUT
(UNITS/DIV)
(50mV/DIV)
10V
50mV
TIME, t (100µsec/DIV)
1V
OUTPUT CURRENT, IOUT (A)
LOAD = 1.2A
VOUT
40V
16V
VIN
INCLUDES 100µF ON OUTPUT BUS
TIME, t (200µsec/DIV)
TURN ON THRESHOLD
TURN ON RESPONSE
16
12
10K
20K 30K 40K 60K 90K
SET POINT RESISTOR, RSP (Ω)
RESPONSE, XV(UNITS/DIV)
OUT(2V/DIV)
10 V
2V
20
INCLUDES 100µF ON OUTPUT BUS
VOUT
28V
0V VIN
INCLUDES 100µF ON OUTPUT BUS
6
LOAD = 1.2A
VIN
11V
TIME, t (200µsec/DIV)
5.0V
TIME, t (5msec/DIV)
VOUT
80V
LOAD = 1.2A
0V
INCLUDES 100µF ON OUTPUT BUS
LINE TRANSIENT RESPONSE
0
28
600mA
IOUT
TIME, t (200µsec/DIV)
TIME, t (500µsec/DIV)
24
500mA
NO OUTPUT BUS CAPCITANCE
100mV
0.8
1.0
VOUT
1.2A
20V
0.4
0.5
600mA
IOUT
OUTPUT RESPONSE, V
XOUT
(UNITS/DIV)
(100mV/DIV)
10
0.0
1.2A
AUDIO REJECTION, A V (dB)
12
500mA
OUTPUT DC
CURRENT RATING
14
VOUT
1V
LOAD TRANSIENT RESPONSE
OUT(1V/DIV)
OUTPUT RESPONSE, XV(UNITS/DIV)
LOW LINE DROP OUT
1V
11
.12 .24
.48
.78
.96
1.2
OUTPUT CURRENT, IOUT (A)
OUTPUT RESPONSE, X
(UNITS/DIV)
VOUT
(1V/DIV)
11
.12 .24
.48
.78
.96
1.2
OUTPUT CURRENT, IOUT (A)
TEMP = 25°C
OUTPUT RESPONSE, V
X OUT
(UNITS/DIV)
(1V/DIV)
30%
40%
11
.12 .24
.48
.78
.96
1.2
OUTPUT CURRENT, IOUT (A)
16
INPUT VOLTAGE, VIN (V)
INPUT VOLTAGE, VIN (V)
30%
50
72%
TURN ON VOLTAGE, ETO (V)
EFFICIENCY CONTOURS
50
INPUT VOLTAGE, VIN (V)
INPUT VOLTAGE, VIN (V)
50
–20
AUDIO REJECTION
VIN = 28V
IOUT = 1.2A
–40
–60
–80
–100
100 200 400 1K 2K
10K 20K
FREQUENCY, f (Hz)
100K
Rev. C 3/05
MECHANICAL SPECIFICATIONS
WEIGHT=14.5 GRAMS TYPICAL
CONTAINS INTERNAL BeO (BERYLLIUM OXIDE)
ESD TRIANGLE INDICATES PIN 1
ALL DIMENSIONS ARE ±0.010 INCHES UNLESS OTHERWISE LABELED
ORDERING INFORMATION
Part
Number
DHD2805S
DHD2805SE
DHD2805SH
Screening Level
Output
Voltage
Industrial
Extended Reliability
Mil-PRF-38534 Class H
5.0V
M.S. Kennedy Corp.
4707 Dey Road, Liverpool, New York 13088
Phone (315) 701-6751
FAX (315) 701-6572
www.mskennedy.com
The information contained herein is believed to be accurate at the time of printing. MSK reserves the right to make
changes to its products or specifications without notice, however, and assumes no liability for the use of its products.
Please visit our website for the most recent revision of this datasheet.
7
Rev. C 3/05