DATEL, Inc., Mansfield, MA 02048 (USA)
Tel: (508)339-3000, (800)233-2765 Fax: (508)339-6356
Email: sales@datel.com
Internet: www.datel.com
Single Output
UNS Series
Features
Figure 1. Simplified Schematic
+V
IN
+V
OUT
PWM
CONTROLLER
REFERENCE &
ERROR AMP
ON/OFF
CONTROL
TRIM
+V
IN
V
IN
V
IN
+V
OUT
OUTPUT
RETURN
OUTPUT
RETURN
Non-Isolated, 3.3V and 5V
3 Amp, DC/DC Converters
Low cost, high efficiency, wide input voltage range and low output noise define
DATEL's new UNS Series of non-isolated, step-down, switching DC/DC converters.
The 3.3V- and 5V-output devices are, respectively, 90% and 92% efficient. All
models are fully line and load regulated and maintain specified accuracy over the
impressively wide input voltage ranges of 4.75 to 13.6 Volts for 3.3V outputs and 6
to 16.5 Volts for 5V outputs. Output ripple and noise are typically 50mVp-p.
UNS devices are fabricated using proven SMT-on-pcb construction techniques.
The 3.3V and 5V devices are both available in either lightweight SIP (2" x 0.4" x
0.8") or DIP (2" x 0.8" x 0.4", 600 mil spacing between rows) package configura-
tions. The DIP option is designated by a "D" suffix added to the part number. All
models are conformally coated for protection against moisture and dust.
The high efficiency of the UNS Series' fixed-frequency (190kHz) switching
design eliminates the need for thermally conductive potting compound. Devices are
specified for full-power operation up to ambient temperatures of +50C. With
derating, they operate up to +70C. Calculated MTBF (MIL-HDBK-217F) is more
than 1.6 million hours.
These simple-to-use power converters have no minimum load requirements.
They draw 1mA when unloaded and a mere 100A in the standby mode (On/Off
Control turned off). 3.3V models have an output voltage adjustment range of 2.7 to
3.3 Volts. 5V models are adjustable down to 3.0V.
INNOVATION and EX C ELL E N C E
s
n
n
n
n
n
n
n
n
n
n
n
Low cost
SIP or DIP packaging
3.3V (10W) or 5V (15W) outputs
Wide range inputs:
4.75-13.6V for 3.3V models
6-16.5V for 5V models
High efficiencies, typically 90-92%
Low output noise, 50mVp-p
Remote on/off control
100A "standby" input current
Output current limiting
EMC compliant
Highly reliable, 100% SMT construction
Conformally coated for harsh
environments
UNS Series
N O N - I S O L A T E D , 1 0 a n d 1 5 W , S I N G L E O U T P U T D C / D C C O N V E R T E R S
2
Case B1 (SIP)
P A R T N U M B E R S T R U C T U R E
M E C H A N I C A L S P E C I F I C A T I O N S
0.900
(22.86)
1.97
(50.00)
0.400
(10.16)
0.81
(20.50)
0.03
(0.8)
0.1
(2.5)
0.28
(7.0)
0.07
(1.85)
1 2 3 4 5
6 7 8 9 10
4 EQ. SP. @
0.100 (2.54)
0.400
(10.16)
4 EQ. SP. @
0.100 (2.54)
0.13
(3.41)
0.30
(7.62)
0.025
(0.64)
Case B2 (DIP)
0.900
(22.86)
1.97
(50.00)
0.400
(10.16)
0.81
(20.50)
0.03
(0.8)
0.14
(3.5)
0.28
(7.0)
1 2 3 4 5
6 7 8 9 10
4 EQ. SP. @
0.100 (2.54)
0.400
(10.16)
4 EQ. SP. @
0.100 (2.54)
0.13
(3.41)
0.40
(10.16)
0.025
(0.64)
0.60
(15.24)
0.10
(2.63)
*
*
* NO CONNECTION. FOR MECHANICAL STABILITY ONLY.
STANDOFF
Input Voltage Range:
D5 = 4.75-13.6 Volts (7.5V nominal)
D12 = 6-16.5 Volts (12V nominal)
Nominal Output Voltage:
3.3 or 5 Volts
Maximum Output Current
in Amps
Non-Isolated
SIP packaging
Output Configuration:
U = Unipolar
Add "D" suffix for optional
DIP package configuration
3.3
U NS
3 D5 D
-
/
-
I/O Connections
Pin
6
7
8
9
10
Function P18
Trim
Output Rtn.
Output Rtn.
+Output
+Output
Function P18
+Input
+Input
Input
Input
On/Off Control
Pin
1
2
3
4
5
T E M P E R A T U R E D E R A T I N G
O
u
tp
u
t
P
o
w
e
r (W
a
t
ts
)
Ambient Temperature (C)
20
18
16
14
12
10
8
6
4
2
0
10 0 10 20 30 40 50 60 70 80 90 100
UNS-3.3/3-D5
UNS-5/3-D12
Note: Derating curves apply to both SIP and DIP package configurations
Performance Specifications and Ordering Guide
I
OUT
(Amps)
R/N (mVp-p)
Load
V
OUT
(Volts)
Package
(Case,
Pinout)
Efficiency
Regulation (Max.)
Line
V
IN
Nom.
(Volts)
Range
(Volts)
Model
I
IN
(mA)
Max.
Typ.
Typ.
Min.
Output
Input
UNS-3.3/3-D5
3.3
3
50
100
1.0%
3.0%
7.5
4.75-13.6
1/1400
--
90%
B1, P18
UNS-3.3/3-D5D
3.3
3
50
100
1.0%
3.0%
7.5
4.75-13.6
1/1400
--
90%
B2, P18
UNS-5/3-D12
5
3
50
100
1.0%
3.0%
12
6-16.5
1/1330
--
92%
B1, P18
UNS-5/3-D12D
5
3
50
100
1.0%
3.0%
12
6-16.5
1/1330
--
92%
B2, P18
Typical at T
A
= +25C under nominal line voltage and full-load conditions, unless otherwise noted.
"D" suffix indicates DIP package.
Ripple/Noise (R/N) measured over a 20MHz bandwidth with a 100F external input capacitor and a
220F external output capacitor. Additional ouput capacitors will lower R/N. See Technical Notes.
Listed output regulation specifications describe the total change in output voltage as the input (line)
voltage or output (load) current is varied over its full specified range. Typically, line regulation is
better than 0.5% and load regulation is better than 1.0%. Load regulation applies for 0 to 100% load conditions.
Nominal line voltage, no-load/full-load conditions.
N O N - I S O L A T E D , 1 0 a n d 1 5 W , S I N G L E O U T P U T D C / D C C O N V E R T E R S
UNS Series
3
T E C H N I C A L N O T E S
Input Voltage:
"D5" Models
15 Volts
"D12" Models
18 Volts
Input Reverse-Polarity Protection
None. See Technical Notes.
Output Overvoltage Protection
None
Output Current
Current limited. Devices can
withstand an output short circuit
for brief durations only.
Storage Temperature
25 to +85C
Lead Temperature (soldering, 10 sec.)
+300C
These are stress ratings. Exposure of devices to any of these conditions may adversely
affect long-term reliability. Proper operation under conditions other than those listed in the
Performance/Functional Specifications Table is not implied.
Absolute Maximum Ratings
Input and Output Capacitors
Though UNS Series, non-isolated, DC/DC converters have on-board input
and output capacitors (C
IN
= 6.8F, C
OUT
= 6.8F), the majority of applica-
tions will require the installation of additional external I/O capacitance.
The total input capacitance functions as a true energy-storage element, and
its optimal value will vary as a function of line voltage. The selected external
input capacitor should have both low ESR and low ESL because, as the
power converter's input FET switch cycles on and off, the input capacitance
must have the ability to instantaneously supply pulses of relatively high
current.
Rather than install a large, expensive, on-board capacitor that addresses all
possible input-voltage and output-load conditions, DATEL has chosen to
leave out the bulk of the input capacitance so that users may select a cost-
effective component appropriate to their own application. We use a low-ESR
100F external input capacitor during production testing and have found
330F to be a conservative value that works well in the majority of applica-
tions.
In addition to their on-board output capacitor, UNS Series devices require the
installation of additional output capacitors to achieve rated ripple/noise
specifications. External output capacitors should be low-ESR tantalum or
electrolytic types, and they should be located as close to the converters as
possible. A minimum of 220F is required to achieve rated ripple/noise
specs. Increased capacitance will lower output noise. There are no limitations
on output capacitance; however, we have found minimal noise improvements
beyond 4700F.
Typical @ T
A
= +25C under nominal line voltage and full-load conditions, unless noted.
UNS Series devices require external input/output capacitors to achieve rated performance.
Listed specifications assume C
IN
= 100F and C
OUT
= 220F.
See Technical Notes.
Output Ripple/Noise can be reduced with external capacitors. See Technical Notes.
UNS Series converters have no minimum-load requirements.
Current limiting initiates at approximately 5% above rated load.
DIP models have a standoff which makes their total above-board height 0.44 inches.
Input
Input Voltage Range:
"D5" and "D5D" Models
4.75-13.6 Volts (7.5V nominal)
"D12" and "D12D" Models
6-16.5 Volts (12V nominal)
Input Current
See Ordering Guide
Input Filter Type
Capacitive
Overvoltage Protection
None
Reverse-Polarity Protection
None
On/Off Control (Pin 5)
TTL high (or open) = on, low = off
Output
V
OUT
Accuracy
5%, maximum
Temperature Coefficient
0.01% per C
Ripple/Noise (20MHz bandwidth)
See Ordering Guide
Line/Load Regulation
See Ordering Guide
Efficiency
See Ordering Guide
Current Limiting
Auto-recovery
Dynamic Characteristics
Transient Response (50% load step)
200sec max. to 2% of final value
Switching Frequency
190kHz
Environmental
Operating Temperature:
Without Derating
10 to +50C
With Derating
to +70C (See Derating Curve)
Storage Temperature
25 to +85C
Physical
Dimensions: SIP Models
2 x 0.41 x 0.8" (50 x 10.3 x 21mm)
DIP Models
2 x 0.8 x 0.44" (50 x 21 x 11.3mm)
Shielding
None
Case Connection
None
Pin Material
Gold-plated phosphor bronze
Weight
0.35 ounces (10 grams)
UNS Series
N O N - I S O L A T E D , 1 0 a n d 1 5 W , S I N G L E O U T P U T D C / D C C O N V E R T E R S
Output Trimming
5V devices can be trimmed down to 3.0V, and 3.3V devices can be trimmed
down to 2.7V using a single external trimpot or fixed resistor. The trimpot
should be connected between +V
OUT
(pins 9 and 10) and Trim (pin 6) as
shown in the figure below. The trimpot can be used to determine the value of
a single fixed resistor which can then be connected between pins 9 and 10
and 6. Fixed resistors should be metal-film types with relatively low absolute
TCR's to ensure stability.
In order to maximize their efficiency, UNS devices employ high-value
resistors in their voltage feedback loop. Consequently, the external trimpots
must also be high-resistance devices (1-2 megohms). If the trimpots are
accidentally turned to their 0
W
stops, it will not damage the converters;
however, the output voltage will be pulled down to an unstable level. Use care
not to trim the output voltage below the levels indicated in the accompanying
table.
100
98
96
94
92
90
88
86
84
Ef
f
i
ci
ency (
%
)
3.3V Output Current (Amps)
V
IN
= 13.6V
V
IN
= 7.5V
V
IN
= 4.75V
0 0.5 1.0 1.5 2.0 2.5 3.0
100
98
96
94
92
90
88
86
84
Ef
f
i
ci
ency (
%
)
5V Output Current (Amps)
V
IN
= 16.5V
V
IN
= 12V
V
IN
= 6V
0 0.5 1.0 1.5 2.0 2.5 3.0
OUTPUT
RETURN
+OUTPUT
R
LOAD
TRIM
ERROR
AMP
1.195V
R1
R3
R2
R
TRIM
6
7, 8
9, 10
Figure 2. Output Voltage Trimming
Product
UNS-3.3/3
UNS-5/3
Output Voltage
Adjustment Range
2.7 to 3.3V
3.0 to 5.0V
R1
68.68k
W
124.7k
W
R2
38k
W
39k
W
R3
10k
W
10k
W
R
TRIM
160k
W
100k
W
Table 1. Output Voltage Trim Values
Efficiency vs. Output Current and Input Voltage (Model UNS-5/3)
T Y P I C A L P E R F O R M A N C E C U R V E S
Efficiency vs. Output Current and Input Voltage (Model UNS-3.3/3)
The On/Off Control Pin
For normal operation, pin 5 should be left open. This pin has an internal
250k
W
pull-up resistor to +5V (or to +V
IN
if +V
IN
< 5V). For dynamic control of
the converters' on/off functionality, a TTL logic high (+2.4V minimum, +5V
maximum or +V
IN
maximum if +V
IN
< 5V, 100A max.) applied to pin 5
enables the converter, and a quasi-TTL logic low (0 to +0.5V, 100A max.)
disables the converter. Control voltages should be referenced to pins 3 and 4
(Input). For best results, use a mechanical relay or open-collector logic.
When the converter is turned off, its input "standby" current will be approxi-
mately 100A. Applying a voltage that is greater than V
IN
to the On/Off
Control pin, or applying any voltage to this pin when no input power is
applied to the converter, may cause permanent damage to the converter.
DS-0406 9/98
DATEL makes no representation that the use of its products in the circuits described herein, or the use of other technical information contained herein, will not infringe upon existing or future patent rights. The descriptions contained herein
do not imply the granting of licenses to make, use, or sell equipment constructed in accordance therewith. Specifications are subject to change without notice. The DATEL logo is a registered DATEL, Inc. trademark.
DATEL (UK) LTD. Tadley, England Tel: (01256)-880444
DATEL S.A.R.L. Montigny Le Bretonneux, France Tel: 01-34-60-01-01
DATEL GmbH Mnchen, Germany Tel: 89-544334-0
DATEL KK Tokyo, Japan Tel: 3-3779-1031, Osaka Tel: 6-354-2025
DATEL, Inc. 11 Cabot Boulevard, Mansfield, MA 02048-1151
Tel: (508) 339-3000 (800) 233-2765 Fax: (508) 339-6356
Internet: www.datel.com Email: sales@datel.com
Data Sheet Fax Back: (508) 261-2857
INNOVATION and EX C ELL E N C E
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