DC-DC CONVERTERS

72-165 W High Efficiency DC-DC Converters

1

2 YEAR WARRANTY

EXB250 Series

Single output

(natural convection)

The EXB250 is a new high efficiency, open-frame, isolated 165 Watt converter series in an

industry standard half-brick footprint. The EXB250 delivers very high output current at low

voltages, and excellent useable power density for today’s high end applications. The design takes

advantage of open frame construction to provide a low weight, low thermal impedance baseplate

design. The seven models in the series feature an input voltage range of 33 Vdc to 75 Vdc and

are available in output voltages of 12 V, 5 V, 3.3 V, 2.5 V, 1.8 V, 1.5 V and 1.2 V. The output voltage

on each model is adjustable from 90% to 110% of the nominal value. Typical efficiencies for the

models are 90% for the 3.3 V, 88% for the 2.5 V and 87% for the 1.8 V version. The EXB250

series also has a remote ON/OFF capability. Overcurrent and overvoltage protection features are

included as standard. With full international safety approval including EN60950 (TÜV Rheinland)

and UL/cUL1950, the EXB250 reduces compliance costs and time to market.

All specifications are typical at nominal input, full load at 25 °C unless otherwise stated

OUTPUT SPECIFICATIONS

Voltage adjustability

90% to 110%

Set point accuracy

±1.6% max.

Line regulation

1.2 V model

±0.2% max.

Low line to high line

All other models

±0.1% max.

Load regulation

Full load to min. load

±0.2% max.

Minimum load

0%

Overshoot

At turn-on and turn-off

None

Undershoot

1.2 V, 1.5 V (Z), 1.8 V (Z),

None

2.5 V (Z) and 3.3 V (Z) models

Ripple and noise

5 Hz to 20 MHz

60 mV pk-pk

20 mV rms

Transient response

6% max. deviation

(See Note 1)

150 µs recovery to

within total error band

INPUT SPECIFICATIONS

Input voltage range

48 Vin nominal

33-75 Vdc

Input current

No load

145 mA max.

Remote OFF

35 mA max.

Input current (max.)

5.7 A max. @ Io max.

(See Note 3)

and Vin = 33-75 Vdc

Input reflected ripple

(See Note 5)

350 mA (pk-pk) typ.

Active high remote ON/OFF

Logic compatibility

Open collector ref to -input

ON

Open circuit or >4.0 Vdc

OFF

<1.2 Vdc

Undervoltage lockout

Power up

32.5 V (typ.)

Power down

30.5 V (typ.)

Start-up time

Power up

10 ms (typ.)

(See Note 6)

Remote ON/OFF

3 ms (typ.)

SPECIFICATIONS

File Name: exb250s.pdf Rev (02): 06 Dec 2005

TÜV

EMC CHARACTERISTICS

Conducted emissions

EN55022 (See Note 2)

Level A

EN55022 (See Note 2)

Level B

Immunity:

ESD air

EN61000-4-2

8 kV (NP), 15 kV (NP)

ESD contact

EN61000-4-2

6 kV (NP), 8 kV (NP)

Radiated field enclosure

EN61000-4-3

10 V/m (NP)

Conducted (DC power)

EN61000-4-6

10 V (NP)

Conducted (signal)

EN61000-4-6

10 V (NP)

Input transients

ETS 300 132-2, ETR 283

GENERAL SPECIFICATIONS

Efficiency

See table

Operational

Input/output

1500 Vdc

Input/baseplate

1500 Vdc

Switching frequency

Fixed

400 kHz typ.

Approvals and

EN60950 (TÜV Rheinland)

standards (See Note 4)

UL/cUL1950

Material flammability

UL94V-0

Weight

73 g (2.6 oz)

MTBF

Telcordia SR-332

1,598,243 hours

@ 25 °C, 100% load

ground benign

Demonstrated

>2,000,000 hours

ENVIRONMENTAL SPECIFICATIONS

Thermal performance

Operating baseplate -40 °C to +100 °C

temperature

Non-operating

-40 °C to +125 °C