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BCD.00002 Rev AJ, 28-May-2018

Page 11 of 17

IMX70 / IMY70 Series

70 to 90 Watt DC-DC Converters

© 2018 Bel Power Solutions & Protection

Sense Lines

The sense inputs of single-output models allow for compensating a voltage drop up to 1 V (0.6 V for models withV

Synchronization (W)

Double-output models can be synchronized to an external TTL signal (220 ±10 kHz, duty cycle 10 – 15%). Due to the higher

switching frequency, the efficiency will slightly drop.

Note: If this feature is not used, W (pin 6) can be connected to Vi– (pin 2) or left open-circuit.

Shutdown (S

_

D

_

)

The outputs of the converters may be enabled or disabled by a logic signal (TTL, CMOS, etc.) applied between the shutdown pin

8 and Vi–. If the shutdown function is not required, pin 8 should be left open-circuit. Voltage on pin 8:

Converter operating:

2.0 to 20 V

Converter disabled:

–0.7 to +0.7 V

Progr. Input Voltage Lockout PUL

A special feature of these converters is the adjustable undervoltage lockout function, protecting the converter (and system) from

high currents caused by operation at too low input voltage. This ensures easierstart-up in distributed power systems.

The undervoltage lockout level can be programmed by an external resistor R

levels, as indicated in the table below (with hysteresis). The overvoltage lockout (OVL) cannot be varied.

Table 8: Turn-on and shutdown voltage (pin 1 left open)

Model

Turn-on level

Hysteresis

OVL

Unit

24IMX70

3.5 – 14.5

typ. 2.5

41 – 43

V

110IMY70

44.5 – 47.5

typ. 6

160 – 175

Table 9: Typical values for R

24IMX70

R

110IMY70

R

V

single-output double-output

V

single-output double-output

14

∞

∞

46

∞

∞

16

40.5

120

50

68

270

18

60

62

57

25.5

110

20

65

41

61

18

82