PD-97309A
HTA-SERIES
HIGH RELIABILITY
DC/DC CONVERTER
Description
The HTA Series of DC/DC converters is a family of 20W,
single and dual output, high reliability devices designed to
operate in extremely high temperature environments such as
those encountered in oil exploration applications. Features
include small size, low weight and high tolerance to
environmental stresses such as wide temperature extremes,
severe shock and vibration. All internal components are
derated to meet the intended operating environment.
Documentation including electrical stress and thermal analysis
are available.
The converters incorporate a fixed frequency single forward
topology with magnetic feedback and internal EMI filter. All
models include an external inhibit port and have an adjustable
output voltage. They are enclosed in a hermetic 1.5" x 4.0" x
0.430" AlSi package and weigh less than 70grams. The
package utilizes rugged ceramic feed-thru copper core pins
and is sealed using parallel seam welding.
Full environmental screening includes temperature cycling,
constant acceleration, fine and gross leak, and burn-in. Non-
screened versions of the HTA converters are available for
system development purposes. Variations in electrical
specifications and screening to meet custom requirements
can be accommodated.
200V Input, Single/Dual Output
Features
n
150 to 250V DC Input Range
n
Up to 20W Output Power
n
Single and Dual Output Models Include
3.3, 5, 12, 15,
±5, ±12
and
±15V
n
Internal EMI Filter
n
Magnetically Coupled Feedback
n
High Efficiency - to 76%
n
-35°C to +185°C Operating Case Temperature Range
n
10MΩ @ 500VDC Isolation
n
Under-Voltage Lockout
n
Short Circuit and Overload Protection
n
Output Over Voltage Limiter
n
Adjustable Output Voltage
n
Synchronization Input and Output
n
External Inhibit
n
Low Weight, < 70grams
Applications
n
Down Hole Exploration Tools
The current limit point exhibits a slightly negative
temperature coefficient to reduce the possibility of
thermal runaway.
An external Inhibit port is provided to control converter
operation. The converter’s operation is inhibited when
this pin is pulled low. It is designed to be driven by an
open collector logic device. The pin may be left open
for normal operation and has a nominal open circuit
voltage of 4.0V with respect to the Input Return (pin 2).
The output voltage of all models can be adjusted using
a single external resistor.
Circuit Description
The HTA series of converters utilize a single-ended forward
topology with resonant reset. The nominal switching frequency
is 500KHz. Electrical isolation and tight output regulation are
achieved through the use of a magnetically coupled feedback.
Voltage feed-forward with duty factor limiting provides high
line rejection and protection against output over voltage in the
event of an internal control loop failure. This mechanism
limits the maximum output voltage to approximately 20% over
the nominal regardless of the line voltage.
Output current is limited under any load fault condition to
approximately 125% of rated load at maximum operating case
temperature. An overload condition causes the converter
output to behave like a constant current source with the output
voltage dropping below nominal. The converter will resume
normal operation when the load current is reduced below the
current limit point. This protects the converter from both
overload and short circuit conditions.
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03/03/09
HTA-SERIES
Absolute Maximum Ratings
Input voltage range
Output power
Lead temperature
Operating case temperature
Storage temperature
-0.5Vdc to +300Vdc
Internally limited
-35°C to +185°C
-55°C to +185°C
Maximum Operating Conditions
Input voltage range
Output power
150Vdc to 250Vdc
0 to Max. Rated
-35°C to +185°C
+300°C for 10 seconds Operating temperature
Electrical Performance Characteristics
Parameter
Input Voltage
Output voltage ( Vout )
HTA2003R3S
HTA20005S
HTA20012S
HTA20015S
HTA20005D
HTA20012D
HTA20015D
HTA20003R3S
HTA20005S
HTA20012S
HTA20015S
HTA20005D
HTA20012D
HTA20015D
Output power ( P
OUT
)
Output current ( I
OUT
)
HTA20003R3S
HTA20005S
HTA20012S
HTA20015S
HTA20005D
HTA20012D
HTA20015D
Line regulation ( VR
LINE
)
Load regulation ( VR
LOAD
)
Cross regulation ( VR
CROSS
)
HTA20005D
HTA20012D
HTA20015D
1
1
1
1
1
1
1
2,3
2,3
2,3
2,3
2,3
2,3
2,3
1,2,3
Group A
Subgroup
Conditions
-35°C
≤
T
C
≤
+185°C
V
IN
= 200V DC ± 5%, C
L
= 0
unless otherwise specified
Limits
Min
150
3.25
4.95
11.88
14.85
±4.95
±11.88
±14.85
3.20
4.85
11.64
14.55
±4.85
±11.64
±14.55
0
Nom
200
3.30
5.00
12.00
15.00
±5.00
±12.00
±15.00
Max
250
3.35
5.05
12.12
15.15
±5.05
±12.12
±15.15
V
I
OUT
= 100% rated load
Note 4
3.40
5.15
12.36
15.45
±5.15
±12.36
±15.45
20
W
Unit
V
I
OUT
= 100% rated load
Note 4
V
IN
= 150, 200, 250 Volts, Note 2
1,2,3
V
IN
= 150, 200, 250 Volts, Note 2
Either Output, Note 3
Either Output, Note 3
Either Output, Note 3
1,2,3
1,2,3
V
IN
= 150, 200, 250 Volts
I
OUT
= 0, 50%, 100% rated, Note 4
I
OUT
= 0, 50%, 100% rated, Note 4
V
IN
= 150, 200, 250 Volts
V
IN
= 150, 200, 250 Volts
Duals only, Note 5
0
0
0
0
0
0
0
-0.5
-1.0
-5.0
-3.0
-3.0
6.10
4.00
1.67
1.33
3.20
1.34
1.06
+0.5
+1.0
5.0
3.0
3.0
A
%
%
1,2,3
%
For Notes to Electrical Performance Characteristics, refer to page 5
2
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HTA-SERIES
Electrical Performance Characteristics
Group A
Subgroup
1,2,3
1,2,3
1,2,3
1,2,3
1,2,3
( continued )
Limits
Min
Nom
Max
146
V
119
Unit
Parameter
Under Voltage Lockout
Turn-on
( input voltage rising )
Turn-off
( input voltage decreasing )
Synchronization
Frequency Range
Pulse Amplitude, High
Pulse Amplitude, Low
Pulse Rise Time
Pulse Duty Cycle
Transient Recovery Specification
Transient Load Response
Half to Full Load
Transient Load Response
Full to Half Load
Transient Load Response
10% to Half Load
Transient Load Response
Half to 10% Load
Enable Input ( Inhibit Function )
open circuit voltage
drive current ( sink )
voltage range
Current Limit Point
Expressed as a percentage
of full rated load current
Power dissipation, load fault ( P
D
)
Turn-on Response
Overshoot ( V
OS
)
Turn-on Delay (T
DLY
)
Capacitive Load ( C
L
)
HTA20003R3S
HTA20005S
HTA20012S
HTA20015S
HTA20005D
HTA20012D
HTA20015D
Line Rejection
Isolation
Device Weight
Conditions
-35°C
≤
T
C
≤
+185°C
V
IN
= 200V DC ± 5%, C
L
= 0
unless otherwise specified
No load, Full load
Notes 1, 4
Note 1
500
2.0
-0.5
20
650
10
0.8
100
80
KHz
V
V
ns
%
Notes 4, 10, 11, 12
4,5,6
4,5,6
4,5,6
4,5,6
Overshoot
Recovery Time
Overshoot
Recovery Time
Overshoot
Recovery Time
Overshoot
Recovery Time
Note 1
3.0
-0.5
1
2
3
1,2,3
115
105
130
10
300
10
450
15
300
15
450
5.0
100
50
175
150
220
30
10
200
2200
1000
180
120
500
90
60
40
100
70
50
%
µs
%
µs
%
µs
%
µs
V
µA
V
1,2,3
V
OUT
= 90% of Nominal, Note 4
%
Short Circuit, Overload, Note 8
No Load, Full Load
Notes 4, 9
I
OUT
= 100% rated load
No effect on DC performance
Notes 1, 4, 7
Each output on duals
W
%
ms
4,5,6
1
2.0
µF
1
1
MIL-STD-461, CS101
30Hz to 50KHz, Notes 1, 4
Input to Output or Any Pin to Case
except pin 3, test @ 500VDC
dB
MΩ
g
For Notes to Electrical Performance Characteristics, refer to page 5
4
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HTA-SERIES
Notes for Electrical Performance Characteristics
Table
1.
2.
3.
4.
5.
6.
7.
Parameter is tested as part of design characterization or after design changes. Thereafter, parameter shall be
guaranteed to the limits specified.
Parameter verified during line and load regulation tests.
Output load current must be distributed such that at least 20% of the total load current is being provided by one
of the outputs.
Load current split equally between outputs on dual output models.
Cross regulation is measured with 20% rated load on output under test while changing the load on the other
output from 20% to 80% of rated.
Guaranteed for a D.C. to 20MHz bandwidth. Tested using a 20KHz to 10MHz bandwidth using the circuit on
page 6.
Capacitive load may be any value from 0 to the maximum limit without compromising dc performance. A
capacitive load in excess of the maximum limit may interfere with the proper operation of the converter’s
overload protection, causing erratic behavior during turn-on.
Overload power dissipation is defined as the device power dissipation with the load set such that V
OUT
= 90% of
nominal.
Turn-on delay time from either a step application of input power or a logic low to a logic high transition on the
inhibit pin (pin 4) to the point where V
OUT
= 90% of nominal.
Transient recovery time is from the change in load condition until the output is within 3% of the nominal output
voltage.
Recovery time is measured from initiation of the transient to where V
OUT
has returned to within
±1%
of V
OUT
at
50% load.
Load transient time
≥
10µs.
8.
9.
10.
11.
12.
Fig I. Circuit for Measuring Output Ripple Voltage
50
Ω
50
Ω
Coax
1 µF
Oscilliscope or Equivalent
with 10 MHz Bandwidth.
Multiply readings by 2.
50
Ω
Termination
0.1 µF
+ Vout
DUT
Return
R
L
for I
RATED
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