MODELS

B4-47

SINGLE

5

12

15

DUAL

±12

±15

DESCRIPTION

The HR120 Series™ of DC/DC converters offers up to 12 watts of

power from single or dual outputs in a single package over a –40°C

to +85°C temperature range. Thick film hybrid manufacturing tech-

nology produces high levels of miniaturization, giving the HR120

Series converters a low profile (0.330 inch), small board area (1.65

The parts are packaged in sealed steel enclosures, making them

ideal for use in high reliability applications. Each unit is guaranteed

to pass a hermeticity test with a maximum leak rate of 0.001 atm-

cc/sec.

The HR120 converters are switching regulators which use a quasi-

square wave, single ended forward converter design with a nominal

switching frequency of 600 kHz. Isolation between input and output

circuits is provided with a transformer in the forward power loop and

a temperature insensitive optical link in the feedback control loop.

Output regulation is accomplished with constant frequency pulse

width modulation. Both line and load regulation are typically within

10 mV.

On dual output models, the positive output is independently regu-

lated and the negative output is cross-regulated. Figures 7 and 8

illustrate what effects load changes have on the negative output.

Indefinite short circuit protection and overload protection are

provided by sensing output load current and restricting the output

current to approximately 125% of full load output current. Since the

output current is sensed in the secondary stage, the result is a

predictable, constant output current control with no foldback char-

acteristics. HR120 converters are provided with internal filtering

elements on both the input and output to help reduce the need for

external components.

The 5 and 12 volt output models provide full power operation over

the input voltage range of 16 to 40 volts (19 to 40 volts for 15 volt

output models). Operation below 16 volts (or below 19 volts for the

15 volt output models), including operation in MIL-STD-704E emer-

gency power conditions, is possible with derated output power.

Please refer to the low voltage drop-out graphs, Figures 9 and 10.

The HR120 Series provides full power operation at case tempera-

tures from –40°C up to +85°C. Depending on operating levels, air

flow, and ambient temperature, heat sinking may be required.

An inhibit terminal is provided that can be used to disable internal

switching, resulting in a very low quiescent input current. An open

collector TTL compatible low (

≤0.8 V) is required to control the

inhibit function. This level may be supplied by an open collector gate

since the inhibit pin is provided with an internal pull-up resistor.

HR120 SERIES

12 WATT

• –40°C to +85°C operation

• 16 to 40 VDC input

(19 to 40 VDC input for

15 volt output models)

• Fully Isolated

• Optocoupler feedback

• 600 kHz typical operating frequency

• Topology – Single Ended Forward

• 50 V for up to 50 ms transient protection

• Inhibit function

• Indefinite short circuit protection

• Up to 83% efficiency

Size (max.): 1.460 x 1.130 x 0.330 inches (37.08 x 28.70 x 8.38 mm)

See Section B8, case E1 for dimensions.

Weight:

21 grams typical.

Screening:

Standard only. See Section C2 for screening description.