1

Size (max.): Non flanged, case E2, 1.460 x 1.130 x 0.330 inches (37.08 x 28.70 x 8.38 mm)

Flanged , case G2, 2.005 x 1.130 x 0.330 inches (50.93 x 28.70 x 8.38 mm)

See Figures 13 - 16 for dimensions.

Weight:

32 grams maximum.

Screening:

Standard, ES, or 883 (Class H). See Table 1 for screening options.

DESCRIPTION

Interpoint’s MHF+ Series™ Triple DC/DC converters provide a wide

input voltage range of 16 to 48 VDC delivering 15 watts of total

output power with output voltages of +5 and ±12 or +5 and ±15

VDC. The main output, +5 VDC, will supply up to 7.5 watts and the

auxiliaries will supply up to 7.5 watts of combined power. Full power

operation at -55° C to +125°C plus the ability to withstand transients

of up to 80 V for up to 120 milliseconds make these converters an

ideal choice for your high reliability systems.

MHF+ Triple Series of DC/DC converters incorporate dual-phase,

phase-shifted technology with a continuous flyback topology. This

design eliminates a minimum load requirement on the main output

and eliminates cross regulation effects between the main output

voltage and the auxiliary output voltages. The phase-shifted design

offers a further benefit in reduced input and output ripple.

An open collector, TTL compatible, inhibit terminal (pin 1) provides

shut-down and start-up control. Applying a logic level low (<0.8 V),

referenced to input common, will disable the output of the converter.

When inhibited input current is reduced to 5 mA or less and there is

no generation of switching noise. The inhibit terminal typically sinks

3 mA when the converter is inhibited.

Leaving the terminal open or pulling it high will enable the converter.

Use an open collector interface for logic high voltages of up to 11

volts. (Refer to Figure 2 for a connection diagram.) An open collector

interface is not required if the logic high is in excess of the open

circuit voltage of the inhibit terminal, 11 volts, but less than 40 volts.

The soft-start feature provides a controlled 20 milliseconds turn-on

to minimize inrush current and reduce overshoot at initial start-up or

when inhibit is released.

To synchronize the converter’s switching frequency to a system

clock apply the clock signal to the sync terminal (pin 7). When

multiple converters are powered from a single power source, asyn-

chronous (free run) operation will result in lower peak noise for

common spectral peaks, but synchronous operation will eliminate

any possibility of interference frequencies in the low audio band.

Source impedance of the signal should be less than 100 ohms and

the transition time should be less than 100 nanoseconds. The

capacitively coupled sync input will synchronize on a differential

signal of as low as 4 volts to as high as 10 volts. If the sync function

is not used, the terminal should be left open.

Internal current limiting circuitry protects all three outputs against

short circuits. When output power exceeds approximately 130% of

maximum output power, the output currents are limited. In addition,

separate current limiting circuitry protects each output individually

resulting in normal operation of either the main or the auxiliaries,

whichever is not in a shorted condition.

MHF+ Triple converters are packaged in hermetically sealed metal

cases. MHF+ Triple converters can be purchased in a flanged or

non-flanged case. The flanged option provides increased heat dissi-

pation and also provides greater stability when mechanically

secured.

MHF+ SERIES TRIPLE

15 WATT

• –55° to +125°C operation

• 16 to 48 VDC input

• Fully Isolated

• Optocoupler feedback

• Fixed frequency 450 kHz

• Topology – Current Mode Flyback

• Transient protection 80 V/120 ms

• Inhibit and sync functions

• Indefinite short circuit protection

• Undervoltage lockout

• Up to 76% efficiency

MODELS

TRIPLE OUTPUT

+5 and ±12

+5 and ±15