®
®
INNOVATION and EXCELLENCE
Single Output
UNR Series
Non-Isolated, 1.2/1.5/1.8/2.5/3.3V
OUT
8 and 10 Amp DC/DC Converters
Features
Input ranges of 4.75-5.5V or 10.8-13.6V
Output voltages of 1.2/1.5/1.8/2.5/3.3V
8 and 10 Amp output current models
V
OUT
user-trimmable from 1.28V to 3.6V
Non-isolated, full synchronous topology
1" x 2" through-hole or SMT package
Gull-wing leads/standard reflow for SMT
High efficiency to 91%; Low noise
340kHz switching; Planar magnetics
–40 to +40/50/60°C ambient operation with
no derating
Remote on/off control; Output overcurrent
detection
IEC950/EN60950/UL1950 approval
As supply voltages trend lower and load currents increase, centralized power
becomes more impractical. The tight accuracy, low noise and quick transient
response demanded by today's low voltage CPU's, ASIC's and DSP's make power
processing at the point of use the only viable solution. The UNR 12-33W series
provides a complete line of non-isolated DC/DC converters to satisfy this require-
ment. With input voltages of 5V (-D5 models) and 12V (-D12 models) these convert-
ers offer standard output voltages of 1.2, 1.5, 1.8, 2.5 and 3.3 Volts and up to
10 Amps of output current in both through-hole and surface-mount 1" x 2" metal
cases.
With on/off control and output voltage trim capability as standard features, these
non-isolated converters exploit full synchronous rectification, planar magnetics, and
100% automated assembly to deliver high efficiencies (to 91%) and low noise at
low cost.
These versatile DC/DC’s are fully line and load regulated. They feature quick
transient response (50µsec), user-optional on/off control (for power sequencing),
and output overcurrent detection and shutdown ("hiccup" technique with auto-
recovery). Their impressive guaranteed efficiencies enable them to deliver fully rated
output power from –40 to +50/55°C (ambient) without supplemental cooling.
If your high current requirements have made the use of inefficient linear regula-
tors impractical, take a look at one of DATEL’s new switching buck regulators. Their
high efficiency, ease-of-use, long-term reliability, and overall cost effectiveness will
impress you. Safety agency approvals and EMC characterizations are currently in
progress.
+V
IN
+V
OUT
INPUT
RETURN
OUTPUT
RETURN
➀
LOGIC
GROUND
VOLTAGE
BOOST
+V
CC
ON/OFF
CONTROL
PWM
CONTROLLER
OVERCURRENT
DETECTION
REFERENCE &
ERROR AMP
V
OUT
TRIM
➀
-D5 models only.
Figure 1. Simplified Schematic
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
UNR Series
N O N - I S O L AT E D , 1 2 - 3 3 W, 5 & 1 2 V- I N P U T D C / D C C O N V E R T E R S
Performance Specifications and Ordering Guide
➀
Output
Model
UNR-1.2/10-D5T
UNR-1.2/10-D5SM
UNR-1.5/10-D5T
UNR-1.5/10-D5SM
UNR-1.8/10-D5T
UNR-1.8/10-D5SM
UNR-2.5/10-D5T
UNR-2.5/10-D5SM
UNR-3.3/8-D5T
UNR-3.3/8-D5SM
UNR-3.3/8-D12T
UNR-3.3/8-D12SM
UNR-3.3/10-D5T
UNR-3.3/10-D5SM
UNR-3.3/10-D12T
UNR-3.3/10-D12SM
Input
Regulation (Max.)
Line
±0.1%
±0.1%
±0.1%
±0.1%
±0.1%
±0.1%
±0.1%
±0.1%
±0.1%
±0.1%
±0.25%
±0.25%
±0.1%
±0.1%
±0.25%
±0.25%
PRELIMINARY
V
OUT
(Volts)
1.2
1.2
1.5
1.5
1.8
1.8
2.5
2.5
3.3
3.3
3.3
3.3
3.3
3.3
3.3
3.3
I
OUT
(Amps)
10
10
10
10
10
10
10
10
8
8
8
8
10
10
10
10
R/N (mVp-p)
➁
Typ.
TBD
TBD
TBD
TBD
70
40
75
75
40
40
40
40
40
50
70
70
Max.
TBD
TBD
TBD
TBD
10
80
10
10
80
80
10
10
80
10
120
120
Load
➂
±0.5%
±0.5%
±0.5%
±0.5%
±0.5%
±0.5%
±0.5%
±0.5%
±0.5%
±0.5%
±0.875%
±0.875%
±0.5%
±0.5%
±0.875%
±0.875%
V
IN
Nom.
(Volts)
5
5
5
5
5
5
5
5
5
5
12
12
5
5
12
12
Range
(Volts)
4.75-5.5
4.75-5.5
4.75-5.5
4.75-5.5
4.75-5.5
4.75-5.5
4.75-5.5
4.75-5.5
4.75-5.5
4.75-5.5
10.8-13.6
10.8-13.6
4.75-5.5
4.75-5.5
10.8-13.6
10.8-13.6
I
IN
➃
(mA/A)
TBD
TBD
TBD
TBD
150/4190
150/4190
150/5620
150/5620
100/5470
100/5470
50/2420
50/2420
150/7250
150/7250
90/500
90/500
Efficiency
Min.
TBD
TBD
TBD
TBD
82%
82%
85%
85%
88%
88%
86%
86%
86%
86%
86%
86%
Typ.
TBD
TBD
TBD
TBD
86%
86%
89%
89%
92%
92%
91%
91%
91%
91%
89%
89%
Package
(Case,
Pinout)
C16A2, P23
C18, P25
C16A2, P23
C18, P25
C16A2, P23
C18, P25
C16A2, P23
C18, P25
C16A1, P23
C18, P25
C16A1, P23
C18, P25
C16A2, P23
C18, P25
C16C2, P23
TBD, P25
➀
Typical at T
A
= +25°C under nominal line voltage and full-load conditions, unless
otherwise noted. All models are tested and specified with an external 22µF output capacitor
with a 200mΩ ESR. See I/O Filtering and Noise Reduction for more details.
➁
Ripple/Noise (R/N) is tested/specified over a 20MHz bandwidth. Output noise may be further
reduced by installing additional external output caps. See I/O Filtering and Noise Reduction.
➂
These devices have no minimum-load requirements and will regulate under no-load conditions.
➃
Nominal line voltage, no-load/full-load conditions.
MECHANICAL SPECIFICATIONS
P A R T NUM
E R S T RU C T UR E
2.00
(50.80)
METAL CASE
SEE
NOTES
U NR
-
1.8
/
10
-
D5 SM
Output Configuration:
U
= Unipolar
Non-Isolated
Packaging:
T
= Through-Hole Package
SM
= Surface-Mount Package
Input Voltage Range:
D5
= 4.75 to 5.5 Volts (5V nominal)
D12
= 10.8 to 13.6 Volts (12V nominal)
INSULATED BASE
Case C16A1, A2,C2
0.20 MIN
(5.08)
Nominal Output Voltage:
1.2, 1.5,1.8, 2.5 or 3.3 Volts
1.800
(45.72)
1
2
5
6
7
BOTTOM VIEW
DIMENSIONS IN INCHES (MM)
0.10
0.10 (2.54)
(2.54)
3
4
0.800
(20.32)
4 EQ. SP. @
0.200 (5.08)
0.10
(2.54)
Maximum Rated Output
Current in Amps
0.300
(7.62)
1.00
(25.40)
0.100
(2.54)
4
3
0.500
(12.70) 0.300
(7.62)
2
1
9
8
0.110
(2.79)
CASE C16A1
CASE HEIGHT: 0.39 (9.91)
PIN DIAMETERS:
PINS 1-7:
0.040 ±0.002 (1.016 ±0.051)
Case C18
7
6
5
0.800
(20.32)
4 EQ. SP. @
0.200 (5.08)
1.00
(25.40)
CASE C16A2
CASE HEIGHT: 0.39 (9.91)
PIN DIAMETERS:
PINS 1-2, 4:
0.040 ±0.002 (1.016 ±0.051)
PINS 3, 5-7:
0.062 ±0.002 (1.575 ±0.051)
I/O Connections
TOP VIEW
CASE C16C2
CASE HEIGHT: 0.48 (12.19)
PIN DIAMETERS:
PINS 1-2, 4:
0.040 ±0.002 (1.016 ±0.051)
PINS 3, 5-7:
0.062 ±0.002 (1.575 ±0.051)
Pin
1
2
3
4
5
6
7
8
9
Function P23
Logic Ground
On/Off Control
+Output
Trim
Output Return
Input Return
+Input
No Pin
No Pin
Function P25
Logic Ground
On/Off Control
N.C.
N.C.
+Output
Trim
Output Return
Input Return
+Input
0.10
(2.54)
2.00
(50.80)
0.110
(2.79)
0.060
(1.52)
0.015
(0.38)
0.43
(10.92)
INSULATED BASE
METAL CASE
DIMENSIONS ARE IN INCHES (MM)
0.015
(0.38)
0.055
(1.40)
2
N O N - I S O L AT E D, 1 2 - 3 3 W, 5 & 1 2 V- I N P U T D C / D C C O N V E RT E R S
UNR Models
Performance/Functional Specifications
Typical @ T
A
= +25°C under nominal line voltage and full-load conditions unless noted.
➀
Physical
Shielding
Case Connection
Case Material
5 sided
Input/Output Return
Corrosion-resistant steel with
non-conductive, epoxy-based, black
enamel finish and plastic baseplate
Copper, tin plated
Input
Input Voltage Range
D5 Models
D12 Models
Input Current:
Normal Operating Conditions
Standby/Off Mode
Input Ripple Current:
1.8/2.5V Models
3.3/8 -D5 Models
3.3/10V -D5 Models
3.3/8 -D12 Models
3/3/10 -D12 Models
Input Filter Type
Overvoltage Protection
Reverse-Polarity Protection
On/Off Control:
➂
Functionality
Logic Threshold
V
OUT
Accuracy
(50% load):
1.8V
OUT
Models
2.5/3.3V
OUT
Models
V
OUT
Trim Range
➃
Trim pin tied to +Output:
Trim pin tied to Output Return
Temperature Coefficient
Ripple/Noise
(20MHz BW)
➄
Line/Load Regulation
Efficiency
Overcurrent Protection:
➁
Technique
Overcurrent Detection Point
Average Short Circuit Current:
D5 Models
D12 Models
Transient Response
(50-100% load):
1.8/2.5V
OUT
Models
3.3V
OUT
-D5 Models
3.3/8 -D12 Models
3.3/10 -D12 Models
Start-Up Time:
➅
V
IN
to V
OUT
On/Off to V
OUT
Switching Frequency
Operating Temperature
(Ambient):
➆
Without Derating
With Derating
Storage Temperature
Dimensions:
D5 Through-Hole Models
D5 Surface-Mount Models
D12 Through-Hole Models
D12 Surface-Mount Models
3.0 to 3.6 Volts (3.3V nominal)
4.75-5.5 Volts (5V nominal)
10.8-13.6 Volts (12V nominal)
See Ordering Guide
3.6mA typical
150mAp-p
100mAp-p
150mAp-p
110mAp-p
250mAp-p
Capacitive
None
None
Pin Material
➀
All models are tested and specified with an external 470µF input capacitor with a 20mΩ
ESR and a 6Arms ripple-current rating, as well as a 22µF output capacitor with a 200mΩ ESR.
See I/O Filtering and Noise Reduction for more details. These devices have no minimum-load
requirements and will regulate under no-load conditions. Listed specifications apply for both
"T" and "SM" models as appropriate.
➁
See Output Overcurrent Detection for details.
➂
See On/Off Control for details.
➃
See Output Voltage Trimming for details.
➄
For all models, output noise can be further reduced with the installation of additional
external output capacitors. See I/O Filtering and Noise Reduction for details.
➅
See Start-Up Time for details.
➆
See Temperature Derating for details.
Absolute Maximum Ratings
TTL high (or open) = on, low = off
+0.8-2.0 Volts (1.5V typical)
Input Voltage:
Continuous:
D5 Models
D12 Models
Transient (100msec)
Input Reverse-Polarity Protection
Input/Output Overvoltage Protection
V
OUT
= 1.52 Volts or less
V
OUT
= 3.6 Volts or greater
±0.02% per °C
See Ordering Guide
See Ordering Guide
See Ordering Guide
"Hiccup" with auto-recovery
110-180% of rated current
1 Amp typical, 3 Amps maximum
4 Amp typical, 6 Amps maximum
TECHNICAL NOTES
Output
±2% of V
OUT
maximum
±1% of V
OUT
maximum
7 Volts
15 Volts
15 Volts
None
None
Current limited. Devices can
withstand a sustained output
short circuit without damage.
–40 to +105°C
+300°C
Output Current
Storage Temperature
Lead Temperature
(Soldering, 10 sec.)
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.
Dynamic Characteristics
60µsec to 2.5% of final value
50µsec to 2.5% of final value
50µsec to 1% of final value
50µsec to 2.5% of final value
25/30msec (1.8/2.5V
OUT
models)
25/30msec (1.8/2.5V
OUT
models)
300kHz (±30kHz)
Environmental
See Derating Curves
to +100°C (See Derating Curves)
–40 to +105°C
Return Current Paths
These are non-isolated DC/DC converters. The Input Return, Output Return
and Logic Ground pins are all connected together internally. To the extent
possible, all input and load currents should be returned through the Input
Return and Output Return, respectively (via low-impedance runs). Any con-
trol signals applied to the On/Off Control pin should be referenced to Logic
Ground. The internal trace leading to Logic Ground is not designed to carry
high current. Consequently, devices should never be installed in a manner
that results in high current flow through Logic Ground (i.e., the Input/Output
Return pins should never be left open or connected via high-impedance
paths).
I/O Filtering and Noise Reduction
Physical
2" x 1" x 0.39" (51 x 25 x 9.9mm)
2" x 1" x 0.43" (51 x 25 x 10.9mm)
2" x 1" x 0.48" (51 x 25 x 12.2mm)
2" x 1" x TBD" (51 x 25 x 12.7mm)
All models in the UNR 12-33W Series converters are tested and specified
with external 470µF input capacitors (20mΩ ESR, 6Arms ripple-current
rating) and external 22µF output capacitors (200mΩ ESR). In critical applica-
tions, input/output ripple/noise may be further reduced by installing additional
I/O caps.
3
UNR Series
N O N - I S O L AT E D , 1 2 - 3 3 W, 5 & 1 2 V- I N P U T D C / D C C O N V E R T E R S
External input capacitors serve primarily as energy-storage elements. They
should be selected for bulk capacitance (at appropriate frequencies), low
ESR, and high rms-ripple-current ratings. Input capacitors compensate for
I·R drops on input lines and power sources. Providing a solid input voltage
will greatly reduce the need for capacitors. The switching nature of modern
DC/DC converters requires that dc input voltage sources have low ac imped-
ance, as highly inductive source impedances can affect system stability. Your
specific system configuration may necessitate additional considerations.
Output ripple/noise (also referred to as periodic and random deviations or
PARD) can be reduced below published specifications by using filtering
techniques, the simplest of which is the installation of additional external
output capacitors. Output capacitors function as true filter elements and
should be selected for bulk capacitance, low ESR, and appropriate frequency
response. Any scope measurements of PARD should be made directly at the
DC/DC output pins with scope probe ground less than 0.5" in length.
All external capacitors should have appropriate voltage ratings and be
located as close to the converters as possible. Temperature variations for all
relevant parameters should be taken into consideration.
The most effective combination of external I/O capacitors will be a function
of your line voltage and source impedance, as well as your particular load
and layout conditions. Our Applications Engineers can recommend potential
solutions and discuss the possibility of our modifying a given device’s internal
filtering to meet your specific requirements. Contact our Applications Engi-
neering Group for additional details.
Input Fusing
UNR 12-33W Series converters are not internally fused. Certain applications
and or safety agencies may require the installation of fuses at the inputs of
power conversion components. Fuses should also be used if the possibility
of sustained, non-current-limited, input-voltage polarity reversals exists. For
DATEL UNR 12-33W Series DC/DC converters, you should use either slow-
blow or normal-blow fuses with values no greater than the following.
Output Voltage
1.8V Models
2.5V Models
3.3/8-D5 Models
3.3/10-D5 Models
3.3/8-D12 Models
3.3/10-D12 Models
Fuse Value
9 Amps
12 Amps
12.5 Amps
16 Amps
6 Amps
7 Amps
+INPUT
R
PULL UP
D5 Models 4.99kΩ
D12 Models 12.4kΩ
ON/OFF
CONTROL
LOGIC
GROUND
Figure 2. Driving the On/Off Control Pin
Dynamic control of the on/off function is best accomplished with a mechanical
relay or open-collector/open-drain drive circuit (optically isolated if appropri-
ate). The drive circuit should be able to sink appropriate current when
activated and withstand appropriate voltage when deactivated.
Applying an external voltage to the On/Off Control pin when no input power is
applied to the converter can cause permanent damage to the converter. The
on/off control function, however, is designed such that the converter can
be disabled (control pin pulled low) while input voltage is ramping up and
then "released" once the input has stabilized. The time duration between the
point at which the converter is released and its fully loaded output settles
to within specified accuracy can be found in the Performance/Functional
Specifications Table. See Start-Up Time for more details.
Start-Up Time
The V
IN
to V
OUT
Start-Up Time is the interval between the time at which a
ramping input voltage crosses the lower limit of the specified input voltage
range (4.75V for D5 models, 10.8V for D12 models) and the fully loaded
output voltage enters and remains within it specified accuracy band. Actual
measured times will vary with heavy capacitive loading.
The On/Off to V
OUT
Start-Up Time assumes the converter is turned off via
the Remote On/Off Control with the nominal input voltage already applied
to the converter. The specification defines the interval between the time at
which the converter is turned on and the fully loaded output voltage enters
and remains within its specified accuracy band. See Typical Performance
Curves for details
Output Overvoltage Protection
UNR 12-33W Series DC/DC converters do not incorporate output overvolt-
age protection. In the extremely rare situation in which the device’s feedback
loop is broken, the output voltage may run to excessively high levels. If it is
absolutely imperative that you protect your load against any and all possible
overvoltage situations, voltage limiting circuitry must be provided external to
the power converter.
Output Overcurrent Detection
Overloading the output of a power converter for an extended period of
time will invariably cause internal component temperatures to exceed their
maximum ratings and eventually lead to component failure. High-current-
carrying components such as transformers, FET's and diodes are at the
highest risk. UNR 12-33W Series DC/DC converters incorporate an output
overcurrent detection and shutdown function that serves to protect both the
power converter and its load.
Input Overvoltage and Reverse-Polarity Protection
UNR 12-33W Series DC/DC converters do not incorporate either input over-
voltage or input reverse-polarity protection. Input voltages in excess of the
listed absolute maximum ratings and input polarity reversals of longer than
"instantaneous" duration can cause permanent damage to these devices.
On/Off Control
The On/Off Control pin may be used for remote on/off operation. UNR
12-33W Series DC/DC converters are designed so that they are enabled
when the control pin is pulled high or left open (normal mode) and disabled
when the control pin is pulled low (to less than +0.8V relative to Logic
Ground). As shown in Figure 2, D5 models have internal 4.99kΩ pull-up
resistors to V
IN
(+Input), while D12 models have 12.4kΩ.
4
N O N - I S O L AT E D, 1 2 - 3 3 W, 5 & 1 2 V- I N P U T D C / D C C O N V E RT E R S
UNR Models
When the output current of a thermally stabilized converter exceeds the
maximum rating by 40% (typical) to 80% (maximum), the internal overcurrent
detection circuit shuts down the converter by discharging the soft-start circuit
of the pulse width modulator (PWM). In this off state, which is similar to that
achieved by pulling the On/Off Control low, the output voltage quickly drops
as the output capacitors discharge into the load. Since there is no longer any
output current, the overcurrent detection circuit is released, allowing the soft-
start circuit to recharge and the converter to turn on again. If the faulty load
condition persists, the overcurrent detection circuit will again discharge the
soft-start circuit and shut down the converter. This continuous on/off cycling
of the converter is referred to as “hiccup mode.” Once the overload condition
is removed, the converter remains on, and the output voltage is quickly
restored to its regulated value.
The components used to sense the output current have large temperature
coefficients. Consequently, in a "cold-start" situation, the Overcurrent Detec-
tion Point may temporarily move to 80% to 120% above the rated current
specification. The device quickly heats up, particularly if an overload situation
exists, and restores the normal (40%) Overcurrent Detection Point. The
device will not be damaged by starting up into an output-short-circuit condition.
The overcurrent detection circuitry helps keep internal current levels and
operating temperatures within safe operating limits. Nevertheless, sustained
operation at current levels above the rated output current but below the Over-
current Detection Point may result in permanent damage to the converter.
Output Voltage Trimming
UNR 12-33W devices can be trimmed to any voltage between 1.52V and
3.6V. Trimming is accomplished with either a trimpot or a single fixed resistor.
The trimpot should be connected between +Output and Output Return with
its wiper connected to the Trim pin as shown in Figure 3 below.
+OUTPUT
+INPUT
TRIM
INPUT
RETURN
Trim Up
OUTPUT
RETURN
Trim
Down
LOAD
Note:
Install either a fixed trim-up resistor or a fixed trim-down resistor
depending upon desired output voltage.
Figure 4. Trim Connections Using Fixed Resistors
R
T
DOWN
(kΩ) =
UNR-1.8/10-D5T
UNR-1.8/10-D5SM
R
T
UP
(kΩ) =
2.49(V
O
– 1.26)
1.8 – V
O
3.14
V
O
– 1.8
–1.74
–1.74
UNR-2.5/10-D5T
UNR-2.5/10-D5SM
R
T
DOWN
(kΩ) =
R
T
UP
(kΩ) =
7.5(V
O
– 1.26)
2.5 – V
O
9.47
V
O
– 2.5
–1.74
–1.74
UNR-3.3/8-D5T
UNR-3.3/8-D5SM
UNR-3.3/10-D5T
UNR-3.3/10-D5SM
UNR-3.3/8-D12T
UNR-3.3/8-D12SM
UNR-3.3/10-D12T
UNR-3.3/10-D12SM
R
T
DOWN
(kΩ) =
R
T
UP
(kΩ) =
R
T
DOWN
(kΩ) =
R
T
UP
(kΩ) =
7.5(V
O
– 1.27)
3.3 – V
O
9.5
V
O
– 3.3
–1.0
–1.0
7.5(V
O
– 1.26)
3.3 – V
O
9.41
V
O
– 3.3
–1.0
–1.0
+OUTPUT
+INPUT
TRIM
INPUT
RETURN
20kΩ
5-10
Turns
LOAD
OUTPUT
RETURN
Note: Resistor values are in kΩ. Accuracy of adjustment is subject to
tolerances of resistors and factory-adjusted output accuracy.
V
O
= desired output voltage.
Figure 3. Trim Connections Using a Trimpot
A trimpot can be used to determine the value of a single fixed resistor
which should be connected, as shown in Figure 4, between the Trim pin and
+Output to trim down the output voltage, or between the Trim pin and Output
Return to trim up the output voltage. Fixed resistors should be metal-film
types with absolute TCR’s less than 100ppm/°C to ensure stability.
The equations below can be used as starting points for selecting specific
trim-resistor values. Recall that untrimmed devices are guaranteed to be
between
±1%
and ±2% accurate, depending on model. See Performance
and Functional Specifications.
5
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