MOR283R3SWSLASH883 datasheet(4/21 Pages) CRANE

4 / 21 page

MOR Single and Dual DC/DC Converters

Crane Aerospace & Electronics Power Solutions

Page 4 of 21

Rev G - 20060418

www.craneae.com

28 VOLT INPUT – 120 WATT

HOW TO USE FUNCTIONS

POSITIVE INPUT AND INPUT COMMON

Steady state voltage range is 16 to 40 VDC. Transient range is 40

to 50 V for a maximum of 120 msec. Low voltage lockout prevents

the units from operating below approximately 15.5 VDC input

voltage to keep system current levels smooth, especially during

initialization or re-start operations. All models include a soft-start

function to prevent large current draw and minimize overshhoot.

CASE AND EXTERNAL INPUT FILTERS

Internal 500 V capacitors are connected between the case and

input common and between the case and output common. See

Figure 3.

Interpoint’s FME filters are recommended to meet CE03 require-

ments for reflected input line current. When using an external input

filter it is important that the case of the filter and the case of the

converter be connected through as low as an impedance as

possible. Direct connection of the baseplates to chassis ground is

the best connection. If connected by a single trace, the trace should

be as wide as it is long.

TRIM

Both single and dual output models include a trim function. Output

voltage can be trimmed from 60% up to 110% of nominal V out .

When trimming up, do not exceed the maximum output power.

When trimming down, do not exceed the maximum output current.

See Figure 4.

On dual models the positive output is regulated and the negative

output is transformer coupled (cross-regulated) to the positive

output. When trimming the duals, both output voltages will be

adjusted equally. See Figure 5.

INHIBIT 1 AND 2

Two inhibit terminals disable switching, resulting in no output and

very low quiescent

input

current.

The

two inhibit pins allow

access to an inhibit

function

either

side of the isolation

barrier to help main-

tain isolation.

An open collector is

required

for

inter-

facing with both of

the inhibit pins. Applying an open-collector TTL logic low to either

inhibit pin will inhibit the

converter. Applying an

open collector TTL logic

high or leaving the pins

open

will

enable

the

converter. Inhibit 1 is

referenced

Input

Common, while Inhibit 2

is referenced to Sense

Return on the output side.

The open circuit voltage

for Inhibit 1 is 13 V and for

Inhibit 2 it is 8 V. Float the inhibit pin(s) if not used. The required

logic low voltage level is 0.2 V maximum.

See Figures 6 and 7.

Positive

Input

Inhibit 1

Input

Common

MOR Input Side

FIGURE 6: INHIBIT – INPUT SIDE

Current

Limit

Feedback

Voltage

E/A

Inhibit 2

Sense

Return

MOR Output Side

FIGURE 7: INHIBIT – OUTPUT SIDE

Positive Input

2 Input Common

MOR

Single or Dual

Output

10, 11, 12

7, 8, 9

Case

Chassis Ground

Positive Input

1, 2, 3

4, 5, 6

28V

Input Common

FME28-461

EMI Filter

Positive Output

Output Common

FIGURE 3: EXTERNAL FILTER CONNECTION

Trim

Positive Output

Positive Sense

Sense Return

Output Common

MOR

Single

Output

TRIM UP

TRIM

DOWN

FIGURE 4: TRIM – SINGLE

10 Trim

TRIM UP

TRIM DOWN

MOR

Dual

Output

Positive Output

Output Common

Negative Output

FIGURE 5: TRIM – DUAL

Vo nominal

50 •

α – 30

1 –

Trim Up:

, 1.0

≤ α ≤ 1.1

RT (kΩ) =

– 50

Example:

Vo nominal = 5.0, Vo = 5.25, α = 1.05, RT = 390 kΩ

Trim Down:

, 0.6

≤ α ≤ 1.0

RT (kΩ) =

Example: Vo nominal = 5.0,Vo = 4.5, α = 0.9, RT = 150 kΩ

Vo nominal

(

– 1

) • 20

(

α -1)

2.5

TRIM FORMULAS

MOR283R3SW/883 Datasheet(PDF) 4 Page - Crane Aerospace & Electronics.

MOR283R3SW/883 Datasheet(HTML) 4 Page - Crane Aerospace & Electronics.

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21

Datasheet Descarga

Enlace URL