IMX15, IMY15 , IMS15 Series Data Sheet

15 Watt DC-DC Converters

BCD20008-G Rev AE, 25-Aug-2017

Page 13 of 19

MELCHER

The Power Partners.

[V]

Ω

Ω

Ω

Ω

Ω] V

Ω

Ω

Ω

Ω

Ω]

3.3

90

0.47

100

∞

95

2.7

105

15

100

∞

110

6.8

5.1

90

3.3

100

∞

95

8.2

105

9.1

100

∞

110

3.9

Auxiliary Functions

Shutdown Function

The outputs of the converters may be enabled or disabled by

means of a logic signal (TTL, CMOS, etc.) applied to the shut-

down pin. If this function is not required, the shut-down pin

should be left open-circuit.

• Converter operating:

2.0 to 20 V

• Converter disabled:

–10 to +0.7 V

Adjustable Output Voltage

• R input for single-output models and -0503-models

• Trim input for double-output models

As a standard feature, the single- and double-output models

offer adjustable output voltage(s) by using the control input R or

Trim. If the control input is left open-circuit, the output voltage is

voltage

(see

Electrical

Input

Data)

increases

Single-output models with synchronous rectifier (G):

The R input is referenced to the secondary side of the

converter. Adjustment of the output voltage is possible by

means of an external resistor connected between the R pin and

either Vo+ or Vo–.

adjustment differs from other models with R input.

Double-output models with Trim input:

The Trim input is referenced to the primary side. The figure

below shows the topology. Adjustment is possible trough either

Fig. 16

Output voltage control for double-output models (with Trim

input) by means of the Trim input.

Fig. 15

Output voltage control for single-output models, -0503-models,

and double-output models by means of the R input.

All other models fitted with R-input:

The R input is referenced to the secondary side of the

converter. Adjustment of the output voltage is possible by

means of either an external resistor or a voltage source.

Fig. 14

Output voltage control for single-output models with

synchronous rectifier.

Depending upon the value of the required output voltage,

the resistor shall be connected:

either: Between the R pin and Vo– to achieve an output

or: Between the R pin and Vo+ to achieve an output voltage

≈ 100 to 105% of V

≈ 4 kΩ • ––––––––––––––––––

between Vo– and R pin.

The control voltage range is 1.96 to 2.62 V and allows for

Attempting to adjust the output below this range will cause

the converter to shut down (hiccup mode).

Note: Applying an external control voltage >2.75 V may damage

the converter.

R

Vo+

Vo–

Vi+

Vi–

R

ext2

R

ext1

06131

Trim

Vo1+

Vo2–

+

V

ext

–

Vi+

Vi–

R

ext

Vo1–

Vo2+

06089a

Control

circuit

V

R

Vo+

Vo–

+

V

ext

–

4 k

Ω

V

Control

logic

R

ext1

R

ext 2

06029e

Vi–

Vi+

+