The SMTR Series feed-forward compensation system provides

excellent dynamic response and noise rejection. Audio rejection

is typically 40 dB. The min. to max. step line transient response

is typically less than 4%.

SMTR converters provide an inhibit terminal that can be used to

disable internal switching, resulting in no output voltage and very

low quiescent input current. The converter is inhibited when the

inhibit pin is pulled below 0.8 V and enabled when its inhibit pin

is left floating. An external inhibit interface should be capable of

pulling the converter’s inhibit pin below 0.8 V while sinking the

maximum inhibit current and also allowing the inhibit pin to float

high to enable the converter. A voltage should not be applied to

the inhibit pin. The open circuit voltage present on the inhibit pin

is 9 to 11 V.

TRIM AND REMOTE SENSE (AVAILABLE ON SINGLE OUTPUT MODELS ONLy)

RL

REMOTE SENSE CONNECTION

2 Make connections at load.

SMTR SINGLE OUTPUT CONVERTER

4

3

5

10

1

6

2

2

Output

Common

Positive

Input

Input

Common

Sense

Return

Positive

Sense

Positive

Output

EXTERNAL TRIM CONNECTION

1 Make connections at converter.

RL

Output

Common

SMTR SINGLE OUTPUT CONVERTER

4

3

5

10

1

Positive

Input

Input

Common

6

Sense

Return

Positive

Sense

Positive

Output

1

RT

1

Notes for Remote Sense and Trim

1. When trimming output voltage and/or remote sensing, the

total output voltage increase must be less than 0.6 volts at the

converters pins. Do not exceed maximum power.

2. If neither voltage trim nor remote sense will be used, connect pin 3

to pin 4 and pin 5 to pin 6 or the output voltage will increase by 1.2

volts.

3. CAUTION: The converter will be permanently damaged if the

positive remote sense (pin 6) is shorted to ground. Damage may

also result if the output common or positive output is disconnected

from the load with the remote sense leads connected to the load.

4. When using remote sense for voltage compensation or when using

remote sense for trim, the output will drift over temperature. Contact

Applications Engineering for more information at powerapps@

crane-eg.com

Trim Formulas Vout = desired output voltage;

3.3 V:

1.2475

5 V:

1.2475

12 V:

1.2475

15 V:

1.2475

Crane Aerospace & Electronics Power Solutions

www.craneae.com/interpoint

Page 2 of 14

SMTR Single and Dual DC-DC Converters

28 Volt input – 30 Watt

SMTR Rev AC - 2015.10.14