Single Output UEP Models

Ultra-High Density, 2" x 1", 1.2-6 Amp,15-30 Watt DC/DC’s

MDC_UEP Models.A02 Page 4 of 11

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Accuracy of adjustment is subject to tolerances of resistor values and factory-

20k

Ω

5-22

Turns

+INPUT

+OUTPUT

TRIM

–INPUT

ON/OFF

CONTROL

1

2

3

4

LOAD

–OUTPUT

5

6

Figure 2.Trim Connections Using A Trim Pot

+INPUT

+OUTPUT

–OUTPUT

TRIM

–INPUT

ON/OFF

CONTROL

1

2

3

4

5

LOAD

6

Figure 4.Trim Connections To Increase Output Voltage Using Fixed Resistors

+INPUT

+OUTPUT

TRIM

–INPUT

ON/OFF

CONTROL

1

2

3

4

LOAD

–OUTPUT

5

6

Figure 3.Trim Connections To Decrease Output Voltage Using Fixed Resistors

–

16.9

DOWN

(kΩ) =

UEP-3.3/4500-D12

UEP-3.3/4500-D24

UEP-3.3/4500-D48

UEP-3.3/6000-D48

–

16.9

UP

3.16

–15

DOWN

(kΩ) =

UEP-5/3500-D12

UEP-5/3500-D24

UEP-5/3500-D48

UEP-5/6000-D48

–

15

UP

6.292

–

49.9

DOWN

(kΩ) =

UEP-12/1400-D12

UEP-12/1400-D24

UEP-12/1400-D48

–

49.9

UP

36.23

–

63.4

DOWN

(kΩ) =

UEP-15/1200-D12

UEP-15/1200-D24

UEP-15/1200-D48

–

63.4

UP

56.16

Model

Trim Equation

Floating Outputs

Since these are isolated DC/DC converters, their outputs are “floating.” Design-

ers will usually use the –Output (pin 5) as the ground/return of the load circuit.

You can, however, use the +Output (pin 4) as ground/return to effectively

reverse the output polarity.

Minimum Output Loading Requirements

3.3 and 5V models employ a synchronous-rectifier design topology. All models

regulate within spec and are stable under no-load conditions. 12/15V models

employ a traditional forward, diode-rectification architecture and require 25mA

loading to achieve their listed regulation specs. Operation under 25mA load

conditions will not damage the 12/15V devices; however they may not meet all

listed specifications.

Filtering and Noise Reduction

All UEP Series DC/DC Converters achieve their rated ripple and noise speci-

fications with no external input/output capacitors. In critical applications,

input/output noise may be further reduced by installing external I/O caps.

Input capacitors should be selected for bulk capacitance, low ESR and high

rms-ripple-current ratings. Output capacitors should be selected for low ESR

and appropriate frequency response. All caps should have appropriate voltage

ratings and be mounted as close to the converters as possible.

The most effective combination of external I/O capacitors will be a function

of 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

Engineering Group for additional details.

Input Fusing

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 UEP Series DC/DC Converters, you should use

slow-blow type fuses with values no greater than the following.

VIN Range

Fuse Value

D12 Models

3 Amps

D24 Models

2 Amps

D48 Models (1.2-4.5A)

1 Amp

D48 Models (6A)

2 Amp

Trimming Output Voltages

These converters have a trim capability (pin 6) that allows users to adjust the

output voltage ±5%. Adjustments to the output voltage can be accomplished

via a trim pot, Figure 2, or a single fixed resistor as shown in Figures 3 and 4.

A single fixed resistor can increase or decrease the output voltage depend-

ing on its connection. Fixed resistors should have an absolute TCR less than

100ppm/°C to minimize sensitivity to changes in temperature.

A single resistor connected from the Trim (pin 6) to the +Output (pin 4), see

Figure 3, will decrease the output voltage. A resistor connected from the Trim

(pin 6) to –Output (pin 5) will increase the output voltage.

Trim adjustment greater than 5% can have an adverse effect on the converter's

performance and is not recommended.

TECHNICAL NOTES